"new" differential yokes are different lengths
Thread Starter
Instructor
Joined: Dec 2004
Posts: 228
Likes: 3
From: Tampa FL
"new" differential yokes are different lengths
I bought a pair of rebuilt differential yoke for my 60K mile 72. The original ones were worn down slightly past the tapered area, about 1/8 inch. The rest of the differential, including the clutch packs seems to be like new.
The new yokes, when installed have .015 free play on one side and .030 free play on the other side. Turning the center shaft around makes no difference in the measurement. Swapping the yokes from one side to the other moves the exact free play measurement from one side to the other.
This means that the two reman yokes have a difference in length between the clip grove and the hardened end of .015 inch.
Is this an acceptable tolerance or do I have a "bad" yoke?
Should I just shim the clutches differently on each side to make up the .015 difference?
Anyone know where I can get some shims?
FYI. I will have the differential rebuilt/beefed up at a later date, when funds permit and I decide on new engine direction. Stock L48 with 327/350 cam at the moment.
The new yokes, when installed have .015 free play on one side and .030 free play on the other side. Turning the center shaft around makes no difference in the measurement. Swapping the yokes from one side to the other moves the exact free play measurement from one side to the other.
This means that the two reman yokes have a difference in length between the clip grove and the hardened end of .015 inch.
Is this an acceptable tolerance or do I have a "bad" yoke?
Should I just shim the clutches differently on each side to make up the .015 difference?
Anyone know where I can get some shims?
FYI. I will have the differential rebuilt/beefed up at a later date, when funds permit and I decide on new engine direction. Stock L48 with 327/350 cam at the moment.
Racer
Joined: Apr 2005
Posts: 464
Likes: 0
From: Charleston South Carolina
I think you will be okay with the two sides being different. As for the numbers you gave I don't know the limits myself, but I recently got my diff rebuilt by BBC in Linden NJ, they have been around for 40 years and they said mine were very good. I too have a difference in play from one side to the other and I brought that up with them. They said that they were in spec and it's nothing to worry about. On mine, the side with the most play has the most movement at the wheel also. I just got my 6-link from Dragvette and will be installing it this Sunday so I hope to close up the movement with the new setup as the 6-link will better stabilize the trailing arm and prevent any movement at the diff yoke. It just gives me that piece of mind.
Thread Starter
Instructor
Joined: Dec 2004
Posts: 228
Likes: 3
From: Tampa FL
I believe the ideal range of end play is .001 - .008 inch
I will shim the clutches to get down to this range. I am just wondering if the yokes I bought are "good enough" to start with.
As someone mentioned a 6 link is the best solution here, but not the direction I am headed at the moment.
I'm still looking for a source for shims...
I will shim the clutches to get down to this range. I am just wondering if the yokes I bought are "good enough" to start with.
As someone mentioned a 6 link is the best solution here, but not the direction I am headed at the moment.
I'm still looking for a source for shims...
Tech Contributor
Joined: Aug 1999
Posts: 15,188
Likes: 4,010
From: Connecticut, USA
Measure the yoke face to the snap ring - should be .187 +/- .010"
What you have is not unusal if the stock posi is still in there with the springs. I've heard some "rebuilders" say that is ok as that is how they are. This statement,of course is total BS , nothing more then an excuse for a lousy job. You will have to correctly shim the posi to get the endplay down. I do not have a spec or know if there ever was one for the yoke endplay. I custom fit mine to .005-.010" endplay. I just finished one today and I had to grind off .005 per yoke to get them where I wanted them. The yokes were new and I checked brand new and rebuilt yokes in this job and both were within .002 of each other.
What you have is not unusal if the stock posi is still in there with the springs. I've heard some "rebuilders" say that is ok as that is how they are. This statement,of course is total BS , nothing more then an excuse for a lousy job. You will have to correctly shim the posi to get the endplay down. I do not have a spec or know if there ever was one for the yoke endplay. I custom fit mine to .005-.010" endplay. I just finished one today and I had to grind off .005 per yoke to get them where I wanted them. The yokes were new and I checked brand new and rebuilt yokes in this job and both were within .002 of each other.
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Thread Starter
Instructor
Joined: Dec 2004
Posts: 228
Likes: 3
From: Tampa FL
I measured the yoke end to ring grooves on my newly purchase rebuilt diff yokes.
One is .190 -.193
The other is .163 - .173
The ends seem like they are not "flat", especially the second one. I'm not worried about the the first one, but I think I need to get a replacement for the second...
Pretty disappointing quality control here. The ends are visibily different upon inspection. The shorter one has less tappered area than the longer one showing.
Is it normal for the splines to be painted, and to need to grind the paint out of the grooves to get them in the gears?
One is .190 -.193
The other is .163 - .173
The ends seem like they are not "flat", especially the second one. I'm not worried about the the first one, but I think I need to get a replacement for the second...
Pretty disappointing quality control here. The ends are visibily different upon inspection. The shorter one has less tappered area than the longer one showing.
Is it normal for the splines to be painted, and to need to grind the paint out of the grooves to get them in the gears?
Race Director
Joined: Dec 1999
Posts: 19,610
Likes: 778
From: Forked River NJ
Melting Slicks
Joined: Apr 2006
Posts: 2,084
Likes: 14
From: Airdrie Alberta
I pulled my diff apart last night to change the seals and check measurements. All looks well except for my side yoke play, right side is .022 and the left side is .042....from what i've read its time to replace them.
Question, I have seen them listed at Corvette Central with tool hardened insert and at Toms Differential with replacement tip...
anyone have a preferred supplier for these?
Thanks, Howard
Question, I have seen them listed at Corvette Central with tool hardened insert and at Toms Differential with replacement tip...
anyone have a preferred supplier for these?
Thanks, Howard
