Rear end Clunk

[MadCow23]

So this is going to sound stupid, and i feel stupid for not noticing this before.

When driving my 87 turbo i would hear a clunk from the rear end on acceleration, deceleration, and changing gears. you might think its a U-joint, or bushing or even something in the diff. I checked all that and then i noticed some basic shit:3d_frown:

The two front bolts on the Differential case that connect it to the frame were about a turn or two from being completely out!
I didn't think of checking them because i never messed with them but i learned to always check someone else's work. so if anyone is having trouble like this just check all the differential mounting bolts!! should be torqued down to 122 ft-kb (http://www.cygnusx1.net/Supra/Library/TSRM/MK3/manual.aspx?Section=RA&P=23)

 

[DeMoN2318]

Did that fix your noise?

 

[Brewhaha]

I have a loud clunk/clank on accel, decel, and shifting... It's a 91 NA but it looks like I'll be checking them bolts tomorrow :S
The previous owner has turned out to a be a award winning moron regarding work done on the car so I wouldn't be surprised.

 

[MadCow23]

Yeah same here, last owner also had some nasty black gear oil in there too. I can't wait to drop it out and replace the seals!

But yeah it completely fixed the problem, never felt as smooth as it does now. I guess i was so used to it i forgot how that car should feel :/

 

[Brewhaha]

I'm kind of hoping I crawl under there tomorrow and that it's something as simple as that. My drive-train has a has a certain "slop" to it since I bought it and that solid clank I get when I go from off throttle to on the throttle just makes me cringe.

 

[MadCow23]

That sounds like exactly what was going on with my car, so defiantly check it out. I went under expecting u-joints or rear trans mount, so seeing that was an awesome free fix. let me know how it goes! I'm hoping i can help someone who had my problem haha

 

[Brewhaha]

Well, I went under and all the bolts holding the diff to the frame seemed to be in good order. I did however find that I could rotate my driveshaft just a smidge by hand creating a audible noise. I could also wiggle it all around inside the center support driveshaft bearing. I'm going to go out on a limb here and say that it's totally shot. I'm not sure if the small rotation is normal or not. The replacement driveshaft bearing is 255$ on drift motion. For a ~100 dollars more I could get a 1-piece. What to do... what to do.

There also seemed to be something off with the transmission mount. That middle piece sticks down and I could push it up a bit.

 

[SupraStoked]

^^^^as for your predicament, your exactly where I am right now. You can actually take your car to a driveshaft shop and get them to make you a one piece with new u joints that are serviceable for around $200. They make sure to balance them too. Thats the route I'm going to take.


HA i wouldnt be surprised if i get under my car tomorrow and see those bolts loose.. The PO was just a complete bag of bull shit when it cane to my car. But i know my diff is going bad and my center support is completely shot. I wonder if the vibrations caused by these center bearings being bad could cause those diff bolts to slowly turn out over time?? Gives you a new appreciation for the importance of driveshaft balancing..lol

 

[suprasick]

You guys could also install a center bearing from a Ford Ranger for cheap! I did mine about 2 years ago and all is well. I believe I spent all of $30 from rock auto.

Here's the link: http://www.supramania.com/forums/sh...ace-a-MKIII-Driveshaft-Carrier-Bearing-for-50

 

[MadCow23]

yeah my trans mount looks a lot like yours with that piece hanging down, as far as i know its normal. On the other hand mine is soaked in oil so I'm just going to replace it anyway, i have found them for about 45 so its not too bad.

For real though i have a whole new appreciation for the beating my MkIII's differential can take. Other than a blown seal i can't find anything else wrong after being thrown around for awhile.

 

[Brewhaha]

^^^^as for your predicament, your exactly where I am right now. You can actually take your car to a driveshaft shop and get them to make you a one piece with new u joints that are serviceable for around $200. They make sure to balance them too. Thats the route I'm going to take.

New one piece for $200? If that's true I might have to start making a few calls around town.

You guys could also install a center bearing from a Ford Ranger for cheap! I did mine about 2 years ago and all is well. I believe I spent all of $30 from rock auto.

Here's the link: http://www.supramania.com/forums/sh...ace-a-MKIII-Driveshaft-Carrier-Bearing-for-50

I was reading through the thread earlier. If I don't end up going for a one piece I'll definitely look into it. How annoying would you consider doing that for someone who has minimal fabricating skills?

 

[SupraStoked]

Well, I went under and all the bolts holding the diff to the frame seemed to be in good order. I did however find that I could rotate my driveshaft just a smidge by hand creating a audible noise. I could also wiggle it all around inside the center support driveshaft bearing. I'm going to go out on a limb here and say that it's totally shot. I'm not sure if the small rotation is normal or not. The replacement driveshaft bearing is 255$ on drift motion. For a ~100 dollars more I could get a 1-piece. What to do... what to do.

There also seemed to be something off with the transmission mount. That middle piece sticks down and I could push it up a bit.
View attachment 70699

It's typical for the trans mount to be shot too because of a very bad center support bearing. I had ordered both the trans mount and the center support bearing at the same time. I too can wiggle my driveshaft up down left and right almost 2-3 cm because of how bad that bearing is. When I took my old trans mount out, I noticed that the rubber part of the mount was completely detached from the metal bracket holding it on.. lol so I was able to replace that but the center bearing I bought didn't fit by any means (the store swore it was compatible for our cars..he'll to the no it wasn't). I felt a huge difference after replacing the trans mount, there was no more shaking of the drive line while getting the car moving from a stop. Well, for about a week, then all the shaking came back. So my guess is my new trans mount couldn't take the play from the center bearing for very long.

Point is, it's best to replace the trans mount once you get your center support problem fixed (whether by replacing it with a one piece, or getting a new center bearing).

And yea, if you can push that thing hanging from the mount up and down freely, your mount is bad. Mine did the same thing too, and after replacing the mount it was solid and did not move.

 

[DeMoN2318]

Well, I went under and all the bolts holding the diff to the frame seemed to be in good order. I did however find that I could rotate my driveshaft just a smidge by hand creating a audible noise. I could also wiggle it all around inside the center support driveshaft bearing. I'm going to go out on a limb here and say that it's totally shot. I'm not sure if the small rotation is normal or not. The replacement driveshaft bearing is 255$ on drift motion. For a ~100 dollars more I could get a 1-piece. What to do... what to do.

There also seemed to be something off with the transmission mount. That middle piece sticks down and I could push it up a bit.
View attachment 70699

Being able to rotate the driveshaft a "smidge" is normal, and the audible noise is just the LSD clutches and gear teeth engaging and disengaging some...also normal. Now "smidge" is a relative term...your smidge and my smidge might be different.

I would go 1-piece driveshaft

The middle piece on the tran mount...how much could you push it in? did it come right back? was it just rubber compressing?

 

[suprasick]

How annoying would you consider doing that for someone who has minimal fabricating skills?

The rubber bearing part fits right in, the only fabricating required is a 1"x4" (roughly) piece of iron, or the like, with two holes drilled in it. It takes all of 15 minutes of fabricating.