Question About The Rear End
Thread Starter
Racer
Joined: Sep 2001
Posts: 407
Likes: 10
From: Maryville Tennessee
Question About The Rear End
Hi,
I had an alignment done on my '75 today and they pointed out to me some play in the rear end where the halfshafts enter the differential. The shaft can be moved in and out about half a centimeter or so by pushing and pulling on the top of the tire. This shop aligns quite a few older vettes and he says that it's not uncommon to see but he wasn't sure whether or not this was a sign that something needs to be replaced. Do you guys know? This is not the same play that's sometimes felt in the rear wheel bearing. Maybe the first thing I should check is my posi-traction fluid? Thanks for any help!
Rob T.
I had an alignment done on my '75 today and they pointed out to me some play in the rear end where the halfshafts enter the differential. The shaft can be moved in and out about half a centimeter or so by pushing and pulling on the top of the tire. This shop aligns quite a few older vettes and he says that it's not uncommon to see but he wasn't sure whether or not this was a sign that something needs to be replaced. Do you guys know? This is not the same play that's sometimes felt in the rear wheel bearing. Maybe the first thing I should check is my posi-traction fluid? Thanks for any help!
Rob T.
Drifting
Joined: Feb 2005
Posts: 1,738
Likes: 2
From: San diego ca
Originally Posted by 75SHARK
Hi,
I had an alignment done on my '75 today and they pointed out to me some play in the rear end where the halfshafts enter the differential. The shaft can be moved in and out about half a centimeter or so by pushing and pulling on the top of the tire. This shop aligns quite a few older vettes and he says that it's not uncommon to see but he wasn't sure whether or not this was a sign that something needs to be replaced. Do you guys know? This is not the same play that's sometimes felt in the rear wheel bearing. Maybe the first thing I should check is my posi-traction fluid? Thanks for any help!
Rob T.
I had an alignment done on my '75 today and they pointed out to me some play in the rear end where the halfshafts enter the differential. The shaft can be moved in and out about half a centimeter or so by pushing and pulling on the top of the tire. This shop aligns quite a few older vettes and he says that it's not uncommon to see but he wasn't sure whether or not this was a sign that something needs to be replaced. Do you guys know? This is not the same play that's sometimes felt in the rear wheel bearing. Maybe the first thing I should check is my posi-traction fluid? Thanks for any help!
Rob T.
Unfortunately I dont know of any factory published specification for this movement, I would imagine the lesser the better.
Thread Starter
Racer
Joined: Sep 2001
Posts: 407
Likes: 10
From: Maryville Tennessee
I checked the fluid in my rear end and it seems pretty low, but I don't see any evidence of leaking. I imagine that the level should be at the bottom of the thread opening. I hope I didn't damage the rear end with the level running low.
Instructor
Joined: Feb 2006
Posts: 140
Likes: 1
Half a centimeter (200 thousandths). Car must have a few miles on it. They all do this what happens is the camber change is exaggerated by it. I bet if you actually measured the movement at the differential it's probably more like 30-60 thousandths which is pretty typical.
Thread Starter
Racer
Joined: Sep 2001
Posts: 407
Likes: 10
From: Maryville Tennessee
Half a centimeter was just a very rough estimate. I checked it again and it's probably a good bit less than that. My question is should I do something about it or is it usually fairly safe to drive them like this?
Le Mans Master
Joined: Jan 2006
Posts: 9,192
Likes: 27
From: Boca Raton Florida
Gary is the rear end god here, he has a thread and a paper on the subject. Do a search on diferentials and you should find him.
try this
https://accountservices.msn.com/Emai...=1033&urlnum=0
try this
https://accountservices.msn.com/Emai...=1033&urlnum=0
Drifting
Joined: Oct 2004
Posts: 1,496
Likes: 1
From: Lafayette Louisiana
Originally Posted by 75SHARK
Half a centimeter was just a very rough estimate. I checked it again and it's probably a good bit less than that. My question is should I do something about it or is it usually fairly safe to drive them like this?
