Rear-end side yoke play
Thread Starter
Instructor
Joined: Jan 2011
Posts: 146
Likes: 2
From: Hillsborough NC
Rear-end side yoke play
In trying to track down the source of a noise I thought to be coming from the rear-end, I decided to take it apart after noticing the two side yokes could be pulled in and out to a different extent. Driver's side had 0.088" play and the passenger's side had 0.044". I believe I read one post saying the play should be 0.001 to 0.0015 and another post saying 0.030 was not a big deal.
What is the desired play and, if I have too much, what caused it and where do I look for damage? The diameters of the yokes were both indentical in as much as I could measure with calipers.
Thanks in advance for any help you can give.
What is the desired play and, if I have too much, what caused it and where do I look for damage? The diameters of the yokes were both indentical in as much as I could measure with calipers.
Thanks in advance for any help you can give.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
The play you've found is minor and might have been that way almost from manufacture. There is no factory spec for maximum clearance nor is it the source of the noise you're looking for. Most C2/C3 cars on the road have far more play than what you're seeing.
Burning Brakes
Joined: Oct 2001
Posts: 1,241
Likes: 4
From: Okinawa Okinawa
Mine had about 3/4 inch of play due to the C clips falling off.
When does it make noise? Putting it in gear or while driving or just while turning?
Putting in gear may be the differential mounting bushing.
Turning may just need to add more additive or change out the diff fluid all together.
When does it make noise? Putting it in gear or while driving or just while turning?
Putting in gear may be the differential mounting bushing.
Turning may just need to add more additive or change out the diff fluid all together.
Le Mans Master
Joined: Apr 1999
Posts: 6,134
Likes: 46
From: Raleigh North Carolina
In trying to track down the source of a noise I thought to be coming from the rear-end, I decided to take it apart after noticing the two side yokes could be pulled in and out to a different extent. Driver's side had 0.088" play and the passenger's side had 0.044". I believe I read one post saying the play should be 0.001 to 0.0015 and another post saying 0.030 was not a big deal.
What is the desired play and, if I have too much, what caused it and where do I look for damage? The diameters of the yokes were both indentical in as much as I could measure with calipers.
Thanks in advance for any help you can give.
What is the desired play and, if I have too much, what caused it and where do I look for damage? The diameters of the yokes were both indentical in as much as I could measure with calipers.
Thanks in advance for any help you can give.
If the diff has not already been messed with, there are factory C clips on the tips of the yokes which keep the yokes from sliding out. In this case, if you decide to replace the yokes, the diff has to be partially disassembled to first remove the C clips.
The tips of the yokes tend to "mushroom" which can also prevent them from being pulled out.
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Check how close the dust seal cup on the yoke is to the case. As the tip wears the cup moves inwards until it contacts the case and starts eating it. It will remove so much material that the oil seal in the case will fall out at which point you have to replace the entire case.
Also be aware that the tip is surface hardened and you are long through that hardening. It will wear fast now.
I would replace both yokes. I'd also replace the posi clutch packs if original. With everything set up properly the end play will be in the 0.005-0.015 range.
Also be aware that the tip is surface hardened and you are long through that hardening. It will wear fast now.
I would replace both yokes. I'd also replace the posi clutch packs if original. With everything set up properly the end play will be in the 0.005-0.015 range.
Advanced
Joined: Jan 2002
Posts: 77
Likes: 1
From: Stillman Valey Illinois
Check how close the dust seal cup on the yoke is to the case. As the tip wears the cup moves inwards until it contacts the case and starts eating it. It will remove so much material that the oil seal in the case will fall out at which point you have to replace the entire case.
Also be aware that the tip is surface hardened and you are long through that hardening. It will wear fast now.
I would replace both yokes. I'd also replace the posi clutch packs if original. With everything set up properly the end play will be in the 0.005-0.015 range.
Also be aware that the tip is surface hardened and you are long through that hardening. It will wear fast now.
I would replace both yokes. I'd also replace the posi clutch packs if original. With everything set up properly the end play will be in the 0.005-0.015 range.
.....we replaced two customers differential housings this year from the side yoke slamming into them.
Race Director
Joined: Jul 2001
Posts: 15,892
Likes: 42
Given that it is unknown how much play the unit had when new, it's impossible to know if the case hardening is worn through or not.
Last edited by Mike Ward; Aug 6, 2013 at 09:13 PM.
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Intermediate
Joined: Nov 2012
Posts: 48
Likes: 14
From: Rochester Hills MI
My passenger side yolk was worn down past the c-clip. C-clip was gone. Noticed it when I removed the half shaft to replace u-joint. Was able to pull the yolk out of the diff after removing the half shaft.
Thread Starter
Instructor
Joined: Jan 2011
Posts: 146
Likes: 2
From: Hillsborough NC
pics
Thanks a lot to everyone who replied.
The sound coming from the rear-end would happen while idling at a stop and while driving straight. It would come and go.
Hopefully the pics below are good enough to help respond to the replies. Of the two yokes, really only one of them has a wear pattern on it and the pattern is not deep. I can feel the wear pattern on both the one yoke and the pin with my fingernail but I don't think I could measure it. There doesn't appear to be any mushrooming going on.
The yoke seal caps look intact to me, but I've never inspected these before.
The differential case has a somewhat deep groove in it. Also, I can't tell if the case was polished with a Dremel or just shows wear (on what?).
Finally, the clips that hold the clutch pack in appear to be much looser on the side where the springs are further apart. Are those supposed to be snug?
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The sound coming from the rear-end would happen while idling at a stop and while driving straight. It would come and go.
Hopefully the pics below are good enough to help respond to the replies. Of the two yokes, really only one of them has a wear pattern on it and the pattern is not deep. I can feel the wear pattern on both the one yoke and the pin with my fingernail but I don't think I could measure it. There doesn't appear to be any mushrooming going on.
The yoke seal caps look intact to me, but I've never inspected these before.
The differential case has a somewhat deep groove in it. Also, I can't tell if the case was polished with a Dremel or just shows wear (on what?).
Finally, the clips that hold the clutch pack in appear to be much looser on the side where the springs are further apart. Are those supposed to be snug?
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Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Measure the yoke from the snap ring groove to the end. New was 0.187".
Carefully inspect the carrier for cracks, especially around the big openings.
Carefully inspect the carrier for cracks, especially around the big openings.
Last edited by zwede; Aug 6, 2013 at 10:06 PM.
Thread Starter
Instructor
Joined: Jan 2011
Posts: 146
Likes: 2
From: Hillsborough NC
good call
The passenger's side yoke (with the wear pattern) was right on at 0.187". The driver's side was considerably shorter at 0.137".
Is it okay to replace only one of the yokes?
Is it okay to replace only one of the yokes?
Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Safety Car
Joined: Mar 2007
Posts: 3,652
Likes: 49
From: Bridgewater nj
A worn bushing will creek loud at idle as you slow down the motor starts to torque up on the pinion.
I get a thump every now and then caused by the posi clutches slipping but I usually need to be turning and going slow for it to happen.
I get a thump every now and then caused by the posi clutches slipping but I usually need to be turning and going slow for it to happen.
Thread Starter
Instructor
Joined: Jan 2011
Posts: 146
Likes: 2
From: Hillsborough NC
shim pack removed
Pull the diff apart. Was expecting to see some damage but the parts looked ok to me, maybe even newish except for some darkening around the edges. Will others please take a look and tell me if you think differently?
Thanks
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Thanks
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Race Director
Joined: Sep 1999
Posts: 11,361
Likes: 383
From: Plano TX
Surprisingly good! Usually the snowflake clutch plates come out in pieces. Up to you if you want to replace them. You'll have a bit less lock in the posi than with new clutches. New clutches will also get rid of most of your 040 yoke play.