Side Yoke problem..Need advice

[Andy]

Morning....Have an issue to raise with my car..a '79. This happens intermittently at best. When i am either going VERY, VERY slow turning a corner, or even stopped and then turn..I hear a noise coming from the rear. Again, this ONLY happens when i am turning a corner....It's like a faint grinding sound....Could this be the side yokes??? Appreciate anyones constructive comments , solutions and help..

Andy

 

[Vettehead Mikey]

Could be a side yoke. Could be a universal joint, could be the posi unit. Best get underneath and see for yourself.

First thing to do is see how much side play the yokes have. If they don't come out in your hand and have not left grinding marks in the diff housing, they may not be perfect but that's not the source of the problem.

 

[Bob Chadwick]

That is also one of the signs that you need the posi lube added to the differential fluid. It can be purchased at your local GM dealer.

 

[fine69]

Morning....Have an issue to raise with my car..a '79. This happens intermittently at best. When i am either going VERY, VERY slow turning a corner, or even stopped and then turn..I hear a noise coming from the rear. Again, this ONLY happens when i am turning a corner....It's like a faint grinding sound....Could this be the side yokes??? Appreciate anyones constructive comments , solutions and help..

Andy

Hi Andy,

I recently had similar symptoms to what you've described. My differential fluid was low, and I would get a chattering, or clunking noise when going around turns.

From what I understand, the positraction or "limited slip" differential utilizes mechanisms to apply more torque to one particular wheel when going around turns. If the differential fluid level is low, it becomes difficult for the gear mechanisms to work, and it can make noises.

I picked up two bottles of G.M. limited slip additive at a local Buick dealership. I replaced the differential fluid and added the G.M. additive --- and the problem went away.

Hope helpful....

 

[Andy]

Thanks all...I do appreciate....Seems to be a consensus at least to try and check the diff fluid and additive. I'll go that route.

Thanks Again..

Andy

Hi Andy,

I recently had similar symptoms to what you've described. My differential fluid was low, and I would get a chattering, or clunking noise when going around turns.

From what I understand, the positraction or "limited slip" differential utilizes mechanisms to apply more torque to one particular wheel when going around turns. If the differential fluid level is low, it becomes difficult for the gear mechanisms to work, and it can make noises.

I picked up two bottles of G.M. limited slip additive at a local Buick dealership. I replaced the differential fluid and added the G.M. additive --- and the problem went away.

Hope helpful....

 

[JohnZ]

Chances are the diff lube has been in there since the day the car was built; get a suction gun, draw it all out, and refill with GM Diff Lube and GM Posi Additive, then drive it in about a dozen slow figure 8's in a parking lot somewhere to get the new lube/additive worked into the clutches.

 

[Andy]

John........MANY Thanks.....Appreciate!!!!!


Andy

Chances are the diff lube has been in there since the day the car was built; get a suction gun, draw it all out, and refill with GM Diff Lube and GM Posi Additive, then drive it in about a dozen slow figure 8's in a parking lot somewhere to get the new lube/additive worked into the clutches.

 

[GTR1999]

As stated could be several of the above. The posi additive may help but a lot of the problem with posi's are the clutches and setup procedures. Doing them right would require removing the diff and that's a job if it was never out.
The 79 also had soft yokes so be sure to check to see if they are hitting the case which is a big problem if left too long to grind away.
I'll be at Carlisle at L116 if you go stop over and I'll go over things with you. I'm thinking of holding a differential class too if there is enough interest.
Try the additive and see if that solves your problem.