posi chatter question
Thread Starter
Instructor
Joined: Sep 2005
Posts: 206
Likes: 6
From: Bayside California
posi chatter question
I have posi chatter on turns-the diff has new 80-90w with 2 bottles of additive-i drove about 200 miles before it started chattering-i added about 2oz more additive and the chatter went away for about 50-60 miles and it came back very harsh-do i have too much additive ( about 2 1/2 to 3 bottles)-should i suck it all out?
go to GM and get there fluid and there additive?
any recomendations
the posi clutches are the originals to the car-about 90k
I put new bearings and changed ratio in the diff-clutch break away torque was good so I left the clutches alone-as far as I remember prior to doing the rear end there was no chatter.
Pro
Joined: Jun 2005
Posts: 581
Likes: 60
From: USA
my rear end on my 75 chattered. I drained the fluid and filled it up with GM fluid and GM additive and problem went away permanently. it's odd that your problem came back. is your additive compatible with your fluid?
I've also used non-GM fluid with the same-brand non-GM additive, with no problems.
I've also used non-GM fluid with the same-brand non-GM additive, with no problems.
Melting Slicks
Joined: Feb 2004
Posts: 2,040
Likes: 105
From: State of Confusion!!!
2018 C2 of Year Winner
I have posi chatter on turns-the diff has new 80-90w with 2 bottles of additive-i drove about 200 miles before it started chattering-i added about 2oz more additive and the chatter went away for about 50-60 miles and it came back very harsh-do i have too much additive ( about 2 1/2 to 3 bottles)-should i suck it all out?
go to GM and get there fluid and there additive?
any recomendations
the posi clutches are the originals to the car-about 90k
I put new bearings and changed ratio in the diff-clutch break away torque was good so I left the clutches alone-as far as I remember prior to doing the rear end there was no chatter.
go to GM and get there fluid and there additive?
any recomendations
the posi clutches are the originals to the car-about 90k
I put new bearings and changed ratio in the diff-clutch break away torque was good so I left the clutches alone-as far as I remember prior to doing the rear end there was no chatter.
Burning Brakes
Joined: Aug 2005
Posts: 1,126
Likes: 0
From: Hudson Falls, N.Y. 76 Vette Modified L-48
I had the chatter also, took it to Valvoline, they changed it and added the appropriate additive....and still had it now and then....guys here said take it and do figure 8's, I did it forward and backwards for about 30 minutes at walmart parking lot and the grind as gone for a year now...just my 2 cents....
Tech Contributor
Joined: Aug 1999
Posts: 15,164
Likes: 3,966
From: Connecticut, USA
If you left the posi stock with the springs you may never get rid of it unless you tune the posi. The 90 wt and GM additive would be enough to resolve the chatter if it was just sticking clutches. You also have 10-18 spiders which are not the best.
My posi's don't hammer.
My posi's don't hammer.
Drifting
Joined: Jul 2002
Posts: 1,995
Likes: 110
From: Garland Texas
Many years ago I made the mistake of using 80-90 bulk to top off. I ended up pulling the diff and scrubbing the clutches to get rid of the chatter. You make have some broken slotted clutch discs if you haven't replace them.
Mike
Mike
Melting Slicks
Joined: Feb 2004
Posts: 2,040
Likes: 105
From: State of Confusion!!!
2018 C2 of Year Winner
If you left the posi stock with the springs you may never get rid of it unless you tune the posi. The 90 wt and GM additive would be enough to resolve the chatter if it was just sticking clutches. You also have 10-18 spiders which are not the best.
My posi's don't hammer.
My posi's don't hammer.
Thread Starter
Instructor
Joined: Sep 2005
Posts: 206
Likes: 6
From: Bayside California
i quess i should say that chatter may have been understated-
when driving 55 and going around turns it feels like you are hitting the bumps in the center of the road -when at low speeds-( parking lot ) turns it is like a heavy snapping noise and you feel it through out the car-i thing it best to drain the fluid and try that route first -i see the lusas oil - any others?
thanks keith
when driving 55 and going around turns it feels like you are hitting the bumps in the center of the road -when at low speeds-( parking lot ) turns it is like a heavy snapping noise and you feel it through out the car-i thing it best to drain the fluid and try that route first -i see the lusas oil - any others?
thanks keith
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