1985 C4 Clunking in Drive Train
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Joined: Apr 2019
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From: NH
1985 C4 Clunking in Drive Train
So I needed to find were the clunk was coming from when you shift from Park to Reverse, Neutral or Drive, and back again to each.
I had the brakes depressed fully and C4 on jack stands. There is excessive turn in the drive shaft / propeller shaft going into the Rear Differential.
The Half Shafts of both Drivers and Passengers side don't seem to move much.
Could this be an indication of a bad Rear Diff or Universal Joints. There seems to be a lot of Movement for something that had it's brakes fully on.
Drive Shaft / Propeller Shaft
Drivers Side Half Shaft
Passenger Side Half Shaft
Any input would be very welcome
Thank you
D4D4U1
I had the brakes depressed fully and C4 on jack stands. There is excessive turn in the drive shaft / propeller shaft going into the Rear Differential.
The Half Shafts of both Drivers and Passengers side don't seem to move much.
Could this be an indication of a bad Rear Diff or Universal Joints. There seems to be a lot of Movement for something that had it's brakes fully on.
Any input would be very welcome
Thank you
D4D4U1
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Joined: Apr 2019
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Likes: 18
From: NH
Team Owner
Joined: Sep 2001
Posts: 62,160
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From: Athens AL
C7 of the Year - Unmodified Finalist 2021
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U-joints, be sure to get Spicer forged joints without zerk fittings. Just do them all. x1310 and x1350 I think.
Burning Brakes
Joined: Nov 2004
Posts: 1,193
Likes: 176
From: Hillsborough NC
If you are going to pull the driveshaft to do the universals, I would highly recommend removing the tailshaft of the transmission and replacing the rear shaft (drive shaft yoke) bushing. This is like an $11 part and they wear out, allowing the driveshaft to move around. I had a clunk/chatter that I thought was universals, so I replaced those, then I thought it was the exhaust bumping as it was close to the cross brace under the car (mine is convertible), then I replaced the rear bushing in the tailshaft of the tranny and it went away.
I had 92K miles when I did it.
With the driveshaft out you are like 8-10 bolts away from having the tailshaft out, so it is pretty easy.
-Enjoy
I had 92K miles when I did it.
With the driveshaft out you are like 8-10 bolts away from having the tailshaft out, so it is pretty easy.
-Enjoy
Last edited by SLVRSHRK; Aug 9, 2019 at 10:55 AM.
Thread Starter
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Joined: Apr 2019
Posts: 85
Likes: 18
From: NH
If you are going to pull the driveshaft to do the universals, I would highly recommend removing the tailshaft of the transmission and replacing the rear shaft (drive shaft yoke) bushing. This is like an $11 part and they wear out, allowing the driveshaft to move around. I had a clunk/chatter that I thought was universals, so I replaced those, then I thought it was the exhaust bumping as it was close to the cross brace under the car (mine is convertible), then I replaced the rear bushing in the tailshaft of the tranny and it went away.
I had 92K miles when I did it.
With the driveshaft out you are like 8-10 bolts away from having the tailshaft out, so it is pretty easy.
-Enjoy
I had 92K miles when I did it.
With the driveshaft out you are like 8-10 bolts away from having the tailshaft out, so it is pretty easy.
-Enjoy
Racer
Joined: Sep 2017
Posts: 275
Likes: 34
From: Stoughton Wisconsin
My vote is on worn out U-Joints.
Last edited by Randy M; Aug 9, 2019 at 01:50 PM.
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Joined: Apr 2019
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From: NH
Ok, but then what can account for the 3/4 turn on the drive/propeller shaft and the 1/4 to 1/3 turn on the passenger side half shaft?
OR...
Which I would have doubts about, normal operation of switching between gears on the automatic 700r4, drive / propeller shaft and half shafts.
Last edited by d4d4u1; Aug 9, 2019 at 08:41 PM.
Le Mans Master
Joined: May 2006
Posts: 7,708
Likes: 266
From: indy indiana
crawl your butt under the car and turn those shafts by hand, with the radio off. You will hear where its comming from and possibly see where the slack is. There WILL BE some in there gue to spacing between teeth in the rear end, tranny, lots of tiny gaps in there. If its a u joint, you will SEE which one it is.. This is a pretty simple exercise and you should be able to do that with out tools.
Thread Starter
Advanced
Joined: Apr 2019
Posts: 85
Likes: 18
From: NH
crawl your butt under the car and turn those shafts by hand, with the radio off. You will hear where its comming from and possibly see where the slack is. There WILL BE some in there gue to spacing between teeth in the rear end, tranny, lots of tiny gaps in there. If its a u joint, you will SEE which one it is.. This is a pretty simple exercise and you should be able to do that with out tools.
It just looks like a lot of rotational slack to just be the U-Joints, but I will find out
Drifting
Joined: Mar 2015
Posts: 1,275
Likes: 165
From: Utah
The early 700r4 was known to have a clunk/tink sound when putting it into gear.
Not really a problem, on my old phone i had a nice picture of it...
Only way to really "fix" it is with the trans out.
I installed the low/reverse housing with the updated assembly from a later 4l60e, and then replaced the "anti clunk" with a fresh one...
I still get a little clunk sound if i shift it into gear if the rpm is too high, or if i have my tv cable too tight.
And sorry, i don't recall the exact names of the parts.
And I'm too lazy to break out the manual.
Just remember as long as everything checks out, the transmission issue is a non issue.
Just a little embarrassing...
Not really a problem, on my old phone i had a nice picture of it...
Only way to really "fix" it is with the trans out.
I installed the low/reverse housing with the updated assembly from a later 4l60e, and then replaced the "anti clunk" with a fresh one...
I still get a little clunk sound if i shift it into gear if the rpm is too high, or if i have my tv cable too tight.
And sorry, i don't recall the exact names of the parts.
And I'm too lazy to break out the manual.
Just remember as long as everything checks out, the transmission issue is a non issue.
Just a little embarrassing...
Last edited by Gibbles; Aug 10, 2019 at 01:41 PM.
Thread Starter
Advanced
Joined: Apr 2019
Posts: 85
Likes: 18
From: NH
The early 700r4 was known to have a clunk/tink sound when putting it into gear.
Not really a problem, on my old phone i had a nice picture of it...
Only way to really "fix" it is with the trans out.
I installed the low/reverse housing with the updated assembly from a later 4l60e, and then replaced the "anti clunk" with a fresh one...
I still get a little clunk sound if i shift it into gear if the rpm is too high, or if i have my tv cable too tight.
And sorry, i don't recall the exact names of the parts.
And I'm too lazy to break out the manual.
Just remember as long as everything checks out, the transmission issue is a non issue.
Just a little embarrassing...
Not really a problem, on my old phone i had a nice picture of it...
Only way to really "fix" it is with the trans out.
I installed the low/reverse housing with the updated assembly from a later 4l60e, and then replaced the "anti clunk" with a fresh one...
I still get a little clunk sound if i shift it into gear if the rpm is too high, or if i have my tv cable too tight.
And sorry, i don't recall the exact names of the parts.
And I'm too lazy to break out the manual.
Just remember as long as everything checks out, the transmission issue is a non issue.
Just a little embarrassing...