Is My Diff About To Die? Please Help!
Thread Starter
Heel & Toe
Joined: Sep 2005
Posts: 24
Likes: 0
Is My Diff About To Die? Please Help!
This just happened after I've picked up my car from my mechanic (overheating engine issues - all fixed now) -
The diff in my 1980 makes a strong clunking sound when I hit the accelerator AND when I back off suddenly - I've got a saginaw 4 speed with 3.73:1 diff gears
It never happened before - then all of a sudden I noticed it - if I ease into the gears, it doesn't happen - but as soon as I tap the accelerator it clunks badly -
Had diff fluid replaced flushe & refilled a while back - so it can't be from fluid
I gotta admit I do drive it like a real idiot sometimes - ie - keep it in 1st - rev it to 4,500 then back down to bout 3,000 then plant it again
However my engine makes about 245hp at the wheels & 350 torque at the engine - do u guys think that I may have stuffed up my diff from driving it in this manner
any advice/replies much appreciated
The diff in my 1980 makes a strong clunking sound when I hit the accelerator AND when I back off suddenly - I've got a saginaw 4 speed with 3.73:1 diff gears
It never happened before - then all of a sudden I noticed it - if I ease into the gears, it doesn't happen - but as soon as I tap the accelerator it clunks badly -
Had diff fluid replaced flushe & refilled a while back - so it can't be from fluid
I gotta admit I do drive it like a real idiot sometimes - ie - keep it in 1st - rev it to 4,500 then back down to bout 3,000 then plant it again
However my engine makes about 245hp at the wheels & 350 torque at the engine - do u guys think that I may have stuffed up my diff from driving it in this manner
any advice/replies much appreciated
Premium Supporting Vendor
Joined: May 2000
Posts: 4,312
Likes: 70
From: Clearwater FL
Check the u-joints and the pinion bushing. If your pinion bushing is bad, replace it with poly. They take a lot of beating and the poly will hold up. Your diff is probably jerking up whenever you hammer it and the clunk is the front of the diff bottoming out on a worn out bushing against the frame.
Melting Slicks
Joined: Jul 2005
Posts: 2,740
Likes: 3
From: Aurora Ontario
I got that for the longest time. Not sure if your car is the same. But in my case it was a rubber bushing infront of the diff. and above the drive shaft. I was hitting the frame on accel and decell....
Jim
Jim
Melting Slicks
Joined: Oct 2004
Posts: 2,662
Likes: 8
From: Knoxville Tennessee
That is probably your problem. The bushing on the front of the diff support is worn, letting the diff move up and down when you accel and decel, clunking when it meets resistance. Easy to change, I used rubber but poly should do good as well.
Bernie
Bernie
