FIELD OF THE INVENI ION
The present invention generally relates to a shifter mechanism for controlling transmissions of motor vehicles, and more specifically, to a detent assembly for such a shifter mechanism.
BACKGROUND OF THE INVENTION
In a vehicle equipped with an automatic transmission, a shifter mechanism typically includes a shift Icvcr pivotablc over a series of positions representative of desired transmission gears such ns, for example, park (P), reverse (R), neutral (N), drive (D), and low gears (1. 2). The shifter mechanism is connected lo the motor vehicle transmission by a suitable mechanical andor electronic operating linkage to effect actuation of the transmission to the selected gear when the shift lever is pivoted to the transmission gear's representative position. '1 he shifter mechanism is typically provided with a detent assembly which rcleasablv holds the shift lever in a desired gear position lo prevent inadvertent movement of the shift lever to other positions but to desired movement of the lever lo other positions. The detent

assembly typically includes a mechanical or actuator which is operated to release the detent assembly and permit manual ol'ihe shitl lever lo a new gear position.
Shifter mechanisms also have a secondary detent assembly that creates a centering position for the shifter lever at each position so (hat the shiller lever is precisely located in a desired location for the position and.or a desired "tactile" feel lo the operator a.s the operator moves the shifter Icvci through the year positions so that the operator can feel each position as the shifter lever is moved. One type of secondary detent assembly that is located in a bore. The detent plunger is spring biased so that a profile which the gear positions. When the shift lever is moved from one gear position to another, the free end of the plunger slides along the detent profile, causing the plunger to slide into and of the bore, creating shilling cfTort or dclent feel (also called arlificial feel).
While these prior detent plungers may suitably perform their intended purpose, the operator can get an imprecise shirt feel if free-play or lash hclwccn Ihe plunger and the plunger housing is too excessive due to manufacturing tolerances or wear. Additionally, there is a never ending desire in the motor lo reduce package size, weight and cost. Accordingly, there is a need in the art for an improved detent plunger for a motor vehicle shifter mechanism.
SUMMARY 0I< TIIK INVENTION
The present invention provides a shifter mechanism which overcomes a( least some of the above-noted problems of the related ail. According lo the present invention, a shifter mechanism comprises, in combination, a shift lever movable along a shift path having a plurality of gear positions, a detent profde defining the plurality of gear positions, a bore, a detent plunger located at least partially within the bore, a spring member resilicnlly biasing the detent plunger into engagement with the detent profile, and an expandable bushing located

hcivvccn Ihc detent pkinucr and the bore, Ihc expandable bushing expands to remove free-play fonned between the deleni pluiiger and the boic.
Accordmg to another aspect of the present inveiuion, a shifter mechanism comprises, in conihinatfon, a shifl lever nioxalile along a shift path having a plurality of gear positions, a primary detent assembly thai seleciively locks the shift lever in one of the plurality of gear positions, and a secondary detent assembly, fhe secondary detent assembly comprises a secondary detent protile defining Ihc plurality of gear posilion.s, a bore, a dclcnt plunger located at leasl partially within the bote, a spiing member lesilieiitly biasing the detent plunger into engagement with the detent profite, and an expandable bushing located between the detent plunger and (he bore. The deleni plunger engages the secondary deleni profile and moves along the secondary detent proHle as ihc shift lever moves along the shift path. The expandable bushing expands to remove free-play formed between the deleni plunger and the bore.
According to yet another aspect of the present iitvention, a shifter mechanism comprises, in combination, a shit> lever movable along a shifl path having a plurality of gear positions, a primary detent asscn^bly that seleciively locks the shift lever in one ofthc plurality of gear positions, and a .secondary detent a.s.sembly. The secondary detea!'. assembly comprises a secondary detent profile defining the plurality of gear positions, a bore, a detent plunger located at least partially within the hore, a spring member rcsiiicntly biasing the detent plunger into engagement with the detent profile, a split bushing located between the dclcnt plunger and the bore; and a spacer located bei\s een the spring member and the split bushing. The split bushing is located between the spacer and an abutment of the detent plunger, and the spring member is located between the spacer and an abutment ofthc bore. Contact surfaces between the split bushing and the abutment of llie detent plunger and contact surfaces between the split bushing and the spacer are each angled so thai a force ofthc spring mejTiber expands the split bushing. Ihedetent plunger engages the secondary detent profile and moves along the secondary detent profile as the shiU lever moves along the shift path, fhe split bushing automatically cxpantis io rcnune free-play foniied between the detent plunger and the bore.

From the foregoing disclosure and iho following more detailed description ofvarious preferred embodmienis ii will be apparent lo lliosc skilled in the art that the present invention provides a sij>nificant advance in the technology and art of motor vehicle shifter mechanisms. Particularly significant in this regard is the potential the invention affords for providing a high quality, reliable, low cost, mechanism ha\ing a lash-free secondary detent plunger. Additional features and advantages ofvarious preferred embodiments will be better understood in view of the detailed description provided below.
BRIEF DESCRIPTION Ol THE DR^VWINGS
Tlicse and further features of the present invention will be apparent with reference to the following description and ilrawings, wherein
I'IG. 1 is a side elevalinnal view of a shifter mechanism according to a preferred embodiment of the present invention;
FIG. 2 is an enlargeti, fragmented clevaiional view, in cross-section, of a secondary detent assembly of the shifter mechanism of FIG. 1, wherein some components arc removed for clarity;
FIG. 3 is a perspective view of a detent plunger stibasscmbly of the secondary detent assembly of FIG. 2;
FIG. 4 is a perspective view of a detent plunger ofthc detent plunger snbiissembly of FIG. .1;
FIG. 5 is perspective view of a s|)lit bushing of the detent plunger subassembly of FIG. 3;
FIG. 6 is perspective view of a back spacer ofthc dclcnt plunger subassembly of FIG. 3; and
FIG. 7 is perspective view of a spring member of tlic dclcnt plunger subassembly of FIG. 3.

It should be understood that (he appended drawmus are not necessarily to scale, presenting a somewhat simplified reprcsenlation oi" various preferred features illustrative ofthe basic principles ofihe mveniion. The spccidc design features ofthe shifter mechanism as disclosed herein, including, for example, specific dimensions, orientations, locations, and shapes of the various componcnls. will be dctcmiincd in pari by ihc particular intended application and use environmenl. Certain features of the illustrated embodiments have been enlarged or distorted relative to others to facilitate visualization and clear understanding. In particular, thin fealuieii may be tiiickened, for example, for clarity or illustralton. All references lo direction and position, unless otherwise indicated, refer to the orienlalion ofthe shifter mechanism illustrated in the drawings. In general, up or upward generally refers to an upward direction within the plane ofthe paper in FKI I and down or downward generally refers to a downward direction within tlie plane ofthe (laper in FIG. 1. Also in general, fore or forward refers to a direction toward the front ofthe motor vehicle, that is, generally toward the left within the plane ofthe paper in l-IG. 1 and aft or rearward refers lo a direction toward the rear ofthe motor vehicle, that is, generally toward the right within the plane ofthe paper in FIG. I.
DETAILED DESCRIPTION OFCKRIAIN PREFERRED EiMBODIMENTS |0015| It will be apparent to those skilled in the art, that is. lo those who have knowledge or experience in this area of technology, that many uses and design variations are possible for the improved shifter mechanism disclosed herein. Ihe following detailed discussion of various alternative and preferred embodiments will illustrate the general principles ofthe invention with reference to an automatic transmission shifter mechanism for a motor vehicle such as, for example an automobile, truck, van. cross over vehicle, sport utility vehicle (SUV), recreational vehicle, trailer, off road vehicle such as a dune buggy, industrial or construction equipment, golf cart, or the like. Other cmbodiinenls suitable for other applications will be apparent to those skilled in the art given the benefit of this disclo.sure.

Referring now to the dra\vinv;s. 1-lG. 1 shows a shifter nieehanism 10 according to a preferred embodiment ofthe prcsctil invention. The illustrated shifter mechanism 10 includes a frame or base 12, a shift lever assembly 14 pivotably mounted to the base 12, a lock or primary detent assembly 16 releasably holding or locking the shirt lever assembly 14 in a desired one of a plurality of gear positions against uiidciired or inadvcrtcni rnovemc it to the other gear positions, and a secondary detcni assembly 18 centering the shift lever assembly 14 at the gear positions and/or providing tactile feci lo the operator when selectively moving the shift lever assembly 14 between the plurality uf gear positioii.s.
The base 12 is adapted to be attached lo the motor vehicle in a fixed position such as a floor or console and can be fonned of any suitable si/c and shape. The illustrated base 12 is shaped to engage the motor vehicle and suppon the various components ofthe shifter mechanism 10 in a desired manner. Ihe illustrated base 12 is provided with openings or holes for receiving mechanical fasteners such as bolts to secure ihe base 12 to the motor vehicle. Olhcr suitable shapes for the base 12 and the attachment means will be apparent to those skilled in the art. The base 12 can be formed of any suitable material such as, for example, plastic aiid can be produced by any desirable method such as molding, Preferably, the base 12 is fonned of unitary or one-piece construct ion hut akcrnatively can bo constructed of multiple components secured together.
'Ihe illustrated shift lever assembly 14 includes a .shificr yoke 20 and a shift poster lever 22 upwardly extending from the shiller yoke 20 for manually moving the shifter yoke 20 to change the gear ofthe transmission. The illustrated shifter yoke 20 is pi votably secured to the base 12 such that it is pivotable about a horizontal and laterally extending pivot axis 24 so thai the shift le\'cr assembly 14 can pivot along a path to move between the gear positions. Tlie shifter yoke 20 is adapted for interacting with the primary detent assembly 16 to selectively release the shift lever assembly 14 from the previous gear position and maintain Ihe shift lever assembly 14 in the desired gear position as described in more detail hereinafter. The shifter yoke 20 is also adapted for interacting with ihe secondary detent assembly 18 for providing a

desired tactile feel while moving lo a desired gear position as described in more detail hereinafter. The shifter yoke 2() can be formed ofady suitable material such as, for example, plastic and can he produced by any desirable method such as molding. Preferably, the shifter yoke 20 is fonned of unitary or one-piece construction but allcniativcly can be constructed of multiple components secured together.
The illustrated shift lever 22 is generally an elongate tube. The lower end of the shift lever 22 is adapted to extend into an opening or bore 26 near a forward end of the shifter yoke 20. A central longitudinal axis of the illustrated bore 26 is substantially perpendicular to and intersects the lateral pivot axis 24. I'he shift lever 22 can be rigidly secured to the shifter yoke 20 in any suitable manner such as. for example, snap-connectors, welding, adhcsivcs, or mechanical fasteners or the shift lever can bo formed unitary, that is as one piece, with the shifter yoke 20. With the shift lever 22 rigidly secured to shifter yoke 20, the shifter yoke 20 cati be selectively pivoted about the lateral pivot axis 24 by manually applying a forward or rearward force to the shift lever 22. The upper end of the shift lever 22 is preferably provided with handle or knob 28 sized and shaped for grasping by the operator.
The illustrated primary dcieni assembly 16 includes a primary detent plate forming a gale or detent proftlc 30. The illustrated detent plate 29 is vertically disposed with the detent profile 30 formed on a lower edge thereof The illustrated gate 30 has a plurality of downward facing discontinuities in the form of grooves or notches 32 fomied therein. The notches 32 correspond with the various gear positions in which the shift lever assembly 14 can he shifted lo provide a desired gear al the transmission of the motor vehicle. The notches 32 can indicate positions such as, for example, park (P). reverse (R), neutral (N), drive (D), and low gears (I, 2). The .shift lever assembly 14 is suitably connected, cither mechanically and/or electrically, lo the transmission of the motor vehicle such thai movement the shift lever assernbly 14 to the various positions cau.scs the transmission to move lo the corresponding gear. The notches 32 are sized and shaped to cooperate with a detent member or gate pin 34 lo limit movement in a known manner, that is, to releasably hold the shift lever assembly 14 in a desired gear position.

The illustrated notches 32 arc each rectangular shaped and arc sized differently in order to control movement of the shift lever jLsscmbly 14 in a desired manner. It is noted that Ihe notches 32 can aliernaiivety have other suitable shapes such as. for example, arcuate and/or can each be si/cd the same.
An actuator 36 is provided for sclcctiveiy nioving the gale pin 34 into and out of engagement with the notches 32 The iiluslraled actuator 36 and gate pin 34 arc secured to the shil\ lever assembly 14 for movement therewith relative lo the stationary notches 32 of the gate 30, but allemativcly the gale 30 and the gale pin 34 can be reversed. The illustrated gate pin 34 is linearly moved by the actuator 36 along a linear path extending toward and away from the notches 32, that is, in a direction substantially pcqicndicular to the notches 32. The illustrated gate pin 34 moves along the central longitudinal axis 38 of the shift lever assembly 14 and intersects the pivot axis 24. The gate pin 34 is si/.ed and shaped to cooperate with the notches 32 of the gate 30 so that the gate pin 34 blocks and limits pivotal movement of the shift lever assembly 14 when the gate pin lU is in one of the notches 32 but pcmiils pivotal movement of the shift lever assembly 14 when the gale pin 34 is removed from the notch 32.
The illustrated actuator 36 includes a manually operated button member 40 and a connecting member or rod extending from the button member 40 to the gate pin 34. The illustrated button member 40 is pivoiably secured to the knob 28 anc is provided with an engagement surface sized and shaped for interacting with tlic comiecting rod. The illustrated connecting rod extends within the interior pas.sagc of the shift lever 22 and is linearly movable along the central axis 38 of the shift lever 22, The lower end of the connecting rod Is secured to the gate pin 34. The upper end of the conitccting rod is sized and shaped to interact with the button member 40 so that manual actuation of the button member 40 in a direction into the knob 28 linearly and downwardly moves the connecting rod and the gale pin 34 connected thereto toward the pivot axis 24 and away from the notches 32. A spring member is preferably provided within the shift lever 22 lo resilicnily bias Ihe connecting rod in an upward direction so that the gate pin 34 is rcsilicntly biased toward the notches 32, It is noted that the actuator

:^6 can ahcrnatively be of any other suitable tyjje such as, for example, an electric linear actuator with a control switch.
The secondary detent assembly 18 includes a secondary detent plate forming a secondary detent profile 4?.. and a secondary detent plunger assembly 44 secured to the shift lever assembly 14 for movement therewith and engaging the secondary detent profile 42. It is noted that alternatively the detent profile 42 can be carried by the shift lever assembly 14 and the plunger assembly 44 can be stationary.
An arcuate lower edge of the secondary detent plate fonns the secondary detent profile 42. The illustrated secondary detent profile 42 is an inward facing contoured surface formed about the pivot axis 24 by a plurality of radially inward facing grooves or notches 46 formed therein. The grooves 46 correspond with the various gear positions in which the shift lever assembly 14 can be shifted as dcfmcd by the gate 30. fhe grooves 46 can itidicate positions such, for example, as park (P). reverse (R). neutral (N), drive (D), and low gears (1, 2). The illustrated secondary detent [)la.e is stationary with the base 12 so that the grooves 46 remain stationary when the shifter yoke 20 is pivoted about the lateral pivot axis 24 relative to the base 12 and are si/cd and shaped lo cooperalc with (lie plunger assembly 44 to provide a desired tactile feel. The illustrated grooves 46 are V-shaped or triangular shaped but is noted that the grooves 46 can alternatively have other suitable shapes such as, for example, arcuate shaped or rectangular or square shaped and can each be sliapcd differently from one another if desired. It is also noted thai ihc contoured surface of the secondary detent profile 42 can alternatively be formed in other manners such as, for example, spaced apart protrusions and/or can alternatively have any desired shape and size.
The illustraied plunger assembly 44 is secured to the shift yoke 20 so that it moves with the shift lever assembly 14 as (he shift lever assembly 14 moves through the gear positions. The illustrated plunger assembly 44 extends into an opening or bore 48 near a rearvvard end of the shifter yoke 20, A cciilrul longitudinal axis 49 of the illustrated bore 48 is
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bubsianiially perpendicular to and inicrsocis the lateral pivot axis 24 of the shift lever assembly 14. The plunger assembly 44 extends from the bore 48 and re.siliently engages the secondary detent profdc 42 as described in more detail hereinafter.
As best shown ni FIGS. 2 to 7, the illustrated plunger assembly 44 includes a detent plunger 50. an expandable bushing 52, a back or rear spacer 54, and a spring member 56. The illustrated detent plunger 50 is generally elongate and cylindrically shaped having a first or inner portion 58 that is sized and shaped to extend within the bore 48 and receive the back spacer 54 and the spring member 56 thereabout, a second or central portion 60 sized and shaped to receive the expandable bushing 52 thereabout, and a third or outer portion 62 sized and shaped to extend into and out of the bore 48. The third portion 62 has an outer diameter larger than an outer diameter of the second portion 60 to fomi an inwardly facing abutment 63. The abutment 63 is fonncd at an acute angle relative to the central axis 64 so that it is concave or frusto-conical-shaped. The abutment 63 is sized and shaped to cooperate with the expandable bushing 52 as described in more detail hereinafter. A free or outer end of the outer portion 62 is sized and shaped closely to cooperate with the grooves 46 of the secondary detent profile 42, 'fhe illustrated free or outer end of the outer portion 62 is provided with a recess 65 sized and shaped for holding a steel ball 66. li is noted that the free end can alternatively have other suitable shapes ajid the ball 66 can be eliminated or the ball 66 can be replaced with a roller or the like. The detent plunger 50 can be formed of any suitable material and can be fomied of unitary or one-piece construction or can be constructed of luultiple components secured together.
The illustrated expandable bushing 52 is generally tubular shaped having a longitudinally extending inner passage or opening 68 extending between first and second ends 70, 72. The passage 68 is sized and shaped for receiving the central portion 60 of the detent plunger 50 therein. A slot 74 extends from the passage 68 to the outer surface 76 of the bushing 52 for the entire length of the bushing 52 so that the bushing 52 is expandable, that is, the size of the outer diameter of the bushing 52 can be increased. While the illustrated
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expandable bushing 52 is a split bushing, it is nolcd thai any oilier suitable t^TJe of expandable bushing 52 can Hllcrnativcly be utilised The illusiralcd outer surface 76 is provided with a plurality of longitudinally extending and circumfcrcntialiy spaced apart grooves 78. The grooves 78 are generally equally spaced apart so that outer diameter of the bushing 52 expands generally evenly. The grooves 7X can also be utilized to contain lubricant if desired. The ilUistralcd grooves 78 are V-shapcd or triangularly-shaped in cross-section but any other suitable shape can aUcrnalively be ulili/,cd. The first and second ends 70, 72 of the illustrated bushing 52 are each foniied at an acute angle relative to the central axis 80 so that they are each concave or frusto-conical-shapcd The fust and second ends 70, 72 arc sized and shaped to cooperate with the back spacer 54 and the detent plunger abutment 6.3 respectively as described in more detail hereinafter. The expandable bushing 52 can be fomied of any suitable material and is preferably formed of unitary or one-piece construction but can alternatively be constructed of multiple components secured togcihcr.
The illustrated back or rear spacer 54 is generally tubular shaped having a longitudinally extending inner passage or opening 82 extending between first and second ends 84,86. The passage 82 is si/.ed and shaped for receiving tiie inner portion 58 of the dclciU plunger 50 therein. The first end 84 of the illustrated back spacer 54 is substantially perpendicular to the central axis 88 so that it is generally flat or planar. The first end 84 is si/.ed and shaped to cooperate with the spring member 56 as described in more detail hereinafter. The second end 86 of the illustrated back spacer 54 is formed at an acute angle relative to the central a.xis 88 so that it is concave oi fruslo-conical-shaped. The second end 86 is sized and shaped to cooperate with the expandable bushiitg 52 as described in more detail hcreinaltcr. The back spacer 54 can be formed of atiy .suitable material and is preferably fonned of unitary or one-piece construction but can alternatively be constructed of multiple components secured together.
The illustrated spring member 56 is a coiled compression spring having a first end 90 engaging an outwardly facing abutment 92 within the bore 48 and a second end 94 engaging
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the f'lrsi end 84 oFthc back spacer 54. Secured in this manner, the spring member 56 resiliently biases the free end of the detent plunger 5(J in an outward direction and into engagement with the secondary detent profile 42. It is noted that any other suitable type or application of the spring member can alternatively be uiiii/ed.
riie Ibrce provided by the spring member 56 squeezes the expandable bushing 52 between the detent plunger abutment 63 and the back spacer second end 86. The outer diameter of the expandable bushing 52 is increased slightly until it engages the bore 48 due to the angular contact surfaces 63, 70, 72, 86 which wedge the expandable bushing in a radially outward direction. Therefore, any free play or lash between the bore 48 and the plunger assembly 44 is automatically eliminated. The expanding force acting on the bushing 52 is deicnnincd by the spring force and the si/.e of angles for the angular contact surfaces 63,70, 72, 86. If the expanding force is too small, the free play or lash will not be eliminated. If the expanding force is loo large, tliere will he an undesirable amount of friction between the bushing 52 and the bore 48 which may result in undesirably quick wear of the plimgcr assembly 44.
As Ihe shifter yoke 20 pivots relaii\e to (he base 12, the spring member 56 resiliently maintains the ball 66 of the detent plunger 50 in sliding contact with the secondary detent profile 42 as the ball 66 moves along the grooves 46. The spring member 56 resiliently flexes so that detent plunger 50 moves in an axial direction within the bore 48 and the ball 66 of the detent plunger 50 follows the .secondary detent profile 42.
It is apparent from the abo\e detailed description of preferred embodiments of the present invention, that the secondary detent assembly 18 automatically eliminates free-play or lash between Ihc plunger assembly 44 and the shifter yoke 20 which is due to manufacturing tolerances or wear. As a result, imprecise shifter lever feel and/or raltic due to excessive free-play or lash is avoided by the shifter mechanism according tot eh present invention.
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Additionally, the secondary dctenl assembly IS provides a relatively small package size, weight and cost.
From the forcyoing disclosure and detailed description ofcertain preferred embodiments, it is also apparent that various modifications, additions and other alternative embodiments are possible without departing from the tnie scope and spirit of the present invention. The embodiments discussed were eliosen and described to f rovide the best illustration of the principles of the present invention and its practical application to thereby enable one of ordinary skill in the art lo ulili/.e the invention in various emboUimcnts and with various modifications as are suited to the particular use contemplated. All such modifications and variations are within the scope of the present invention as determined by the appended claims when interpreted in accordance with the benefit to which they are fairly, legally, and equitably entitled.

We Claim:
1. A shifter comprising, in combination:
a shift lever movable along a shift path having a plvnality of gear positions;
a detent profile dellning the plurality of gear positions;
a bore;
a detent plunger located at least partially within the bore;
a spring member rcsilicntly biasing the detent plunger into engagement with the detent profile;
an expandable located between the plunger and the bore; and
wherein the expandable hushing expands to remove free-play formed between the detent plunger and the bore.
2. The shiller mechanism according lo claim 1, wherein the expandable bushing is a split hushing.
3. The shifter mechanism according to claim 1, wherein the expandable bushing has a slot permitting an outer diameter of the bushing lo be increased.
4. The shifter mechanism acco.ding to claim 1, wherein the spring member provides a force for expanding the expandable hushing.
5. Ihe shifter mechanism according to claim I, wherein the expandable bushing is provided with angled contact surfaces for expanding the bushing.
6. The shifter mechanism according to claim 1, wherein an outer surface of the expandable bushing is provided with a plurality of longitudinally extending and circumfcrcntially spaccd-apart grooves.
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7. The shifter mechanism aceordiag to claim I, wherein the detent plunger engages the detent profile and moves along the deient profile as the lever moves along the shift path.
S. The shifter mcchanisnt according to claim I, wherein the detent profile is a secondary detent profile,
9. The shifter mechanism according to claim 8, further comprising a primary detent assembly that selectively locks shilt lever in one of the plurahty of gear positions.
10 The shifter mechanism according to claim I, wherein the detent profile is stationary and the detent plunger is canied by the shift lever as the shift lever moves along the shift path.
11. A shifter mechanism comprising, in combination: a shift lever movable along a shift path having a plurality of gear positions; a primary detent assembly that selectively loeks the shift lever in one ofthe plurality of gear positions;
a secondary detent assembly comprising:
a secondary detent profile defining the plurality of gear positions;
a bore;
a detent plunger located at least parfially within the bore;
a spring member resiliently biasing the deient plunger into engagement with the detent profile; and
an expandable bushing located between the detent plunger and the bore; wherein the detent plunger engages the secondary detent profile and moves along the secondary detent profile as the shift lever moves along the shift path; and
wherein the expandable bushing expands to remove free-play formed between the detent plunger and the bore.