twin grip question

[x-man]

i've since upgraded my open diff to a twin grip unit in my model 20 along with a new ring and pinion set . upon sliding the same stock axles back in and bolting up the backing plates i have alot of axle end play on both sides . what gives ? what am i missing ? thanks for all the help . this is my first post here and i hope to be of help to any one who needs it , x-man

[rollen dean montoya]

can you tell how much end play?

[x-man]

alot ,theres not supposed to be any on the pass side and only a little on the drivers side which is adjusted by shims . same axles same housing , just different carrier .

[rollen dean montoya]

ok. have you measured the carrier? check to see if the old carrier is the same or slightly larger. if the old carrier is larger
then you might have to shim until the play is in the tolerance
according to the tsm.there is also a chance you might not be able to use the new carrier. did you aquire the twingrip from a
junkyard?

[x-man]

the old carrier is gone , i dont think shims are going to help here . my tsm didnt say anything about the size of the carriers

[tufcj]

Since you replaced the carrier, you need to re-set the preload on the axle bearings. There's a slotted block in the center of the diff that the axles seat against. Since you changed carriers, you changed that block, and bearing preload needs to be reset.

My manual calls for .004-.008" end play on the axle shafts, .006" desired. It says to hit the ends of the shafts with a lead hammer to seat the bearing cups against the support plate. Measure end play by pulling the shafts in/out. It also says shims should be installed on the LEFT (driver) side only, NO shims on the right. There should be a shim pack between the end of the axle tube and the brake backing plate.

Don't drive it without getting the end play right, the bearings and seals will wear out quickly.

Bob
tufcj

[x-man]

tuf cj , i read your response . how exactly do you reset axle bearing preload ?? i could sit there all day with a hammer and hit the end of both axles and it wont move . the backing plates push the bearing cup which goes around the bearing which pushes against (seats) the inner seal . backing plates are flush with housing end . i then tap end of axle to seat bearings and still have alot of endplay on both sdes. axle bearings are where there supposed to be on axle . can you please elaborate on this procedure . thanks

[tufcj]

Setting the axle shaft end play sets the bearing preload. Hitting the axle ends just assures that the bearing race is out against the backing plate for an accurate measurement. When I did the rear of my AMX, I had to remove about .020" and all I replaced was the bearings.

Look between the drivers side backing plate and axle housing. There should be a stack of shims that are about the same size and shape as the outer seal. If there are no shims then you could have the wrong races.

Tap the left axle last, then measure end play with a dial indicator (move axle in/out with everything bolted down tight). You'll need to add/remove shims equal to the amount that it is under/over .006". If you have .026" end play, you need to remove .020" of shim.

Bob
tufcj

[x-man]

ok , maybe i'm not explaining this correctly so i'll just start from scratch . swapped open diff for twin grip with new r&p . everything set up fine , good contact pattern . put rear under car , installed pass side axle and tightened down backing plate against housing end , tapped end of axle to seat bearing , pulled on hub and found that axle has about 1/4 inch endplay ( in /out ) . went to drivers side axle followed same procedure , used same shim stack that was there originally ( 4 shims ) . pulled on hub and axle slides out around the same 1/4 in ( endplay ) . from what my tsm says endplay is adjusted on drivers side only with shims . so i would need alot of shims to take up this endplay just on the drivers side, what about the pass side ? . i'm missing something here .

[tufcj]

You need to remove shims to decrease end play. I doubt there is a 1/4" stack of shims though. Removing shims will decrease end play on BOTH sides because of the slotted block in the diff.

Bob
tufcj

[x-man]

i'll be removing the rear this weekend and taking the differential out to see what exactly is going on . i have an identical rear in the garage on stands, only this one has an open differential . i removed the axle and compared it with the one on the other rear then reinstalled . it went in exactly like it was supposed to .