driveline "clunk"??

[SkoonMA67]

Hey guys,

My 82 MA67 with W58 has a weird problem of clunking going into first gear. It doesnt seem to be the tranny though, almost like its coming from the diff.

It only happens when I put the tranny into first after it has been in reverse or neutral (at a light) The driveshaft is all tight and dandy, so thats no problem. Could it be diff mounting bushings or somthing of the sort?

Thanks,

Aaron

[82Spearco]

That is a pretty common problem with the LSD. Try running some Redline 90W gear oil with friction modifier. That might quiet it down a little.

[SilverMk2]

What you are talking about is normal (to a certain degree). It's the result of the backlash in the gearing of the rear diff. When you reverse directions the contact point between the gear tooth has a gap before it touches the gear tooth in the opposite direction. Basically it slams into the tooth making a clunking sound. Technically the diff makes this noise any time you shift gear or deaccelerate, you don't hear it over the other car noises. You can mimic this noise by getting under the car and twisting the driveshaft in both direction. The noise will get worse with wear, and some diffs are worse than others. You can also add to this noise when u-joints and CV joint are giving out.

[SupraFiend]

Nice to see you here Aaron. I never got around to putting synthetic in that diff, it could probably use a good change about now if your keeping it. But it sounds more like you need a new one.

[SkoonMA67]

Seamus,

great... just what I need =) I just sold that other diff to my friend in town. DOH!!! =(

I guess Ill just throw in sythetic then...

Aaron

[SupraFiend]

I gave you that diff for a reason man! :wink: Hope you got some good coin for it. The synthetic won't help much, I have similar clunk in my current diff and its running synthetic too. Rebuild or replace it when you can. Parts are cheap at your wreckers, you shouldn't have much problem finding a good one there.

[mAcr0s]

Crap...

Sounds like mine is giving way.

Ive got a 5-speed box attached to my 5M-E and it makes a considerable 'clunk' noise between upshifts. It does sound like its comming from the diff too.

Altho i am converting my engine to a 1JZ-GTE automatic. So it maybe a good idea to get diff changed too...LSD of course! Any suggestions on the diff i should get? Cause they are gonna make up a custom tail-shaft for my current diff anyway :roll:

[ZZT231]

Hey All,

My Automatic 5M-E Supra makes the clunk when i change from park into drive or reverse... The noise comes from the back. I believe it is common because my old Celica (Automatic) makes the noise just that everyone can hear it.

Don't know if i need to get the diff reconditioned or do i needit fixed...

Just have to live with it or does anyone have an idea?

Cheers.

[Tommy]

Just one note on this. When I had my 4.30s in last summer it quickly developed this clunk. (and now I notice the 4.10s are starting to do it as well) It turned out to NOT be the R/P backlash but the LSD clutch-pack clearance.
Mine will be getting the necessary Toyota replacement pieces to restore the clutch pack clearance (per TSRM) soon (as a stop gap until a good lsd can be purchased,...) About $50.00 from Toyota for thicker adjusting washers and the two friction washers that ride between the side gears and the clutch bar.
Choosing the right adjustment washers requires specialized (large) mics or calipers the most diy-ers may not have.
Ihth,
Jamie

[SupraFiend]

Nice to see you here Jamie, haven't seen you online in awhile.

I think I'm going to give up on my search for 3.73 and rebuild the spare 4.1 I've got then drop that in. Hopefully my clunk will go away then.

[Supra Bob]

You could do what I am... Take a LSD diff... gut it, add in a Tru Trac, and a 3.73 R&P from a Toyota Pickup... stir well and bake at 300 hp :)

[jaMes]

I have the same sort of problem. I have an 85 auto and when i go from drive to reverse, or back there is a loud "clunk" and the whole rear seems to shift up/down. There is some free play in the driveshaft and i was told that was the problem. Now my question is how to fix such a thing

[Norbie]

If the freeplay is in the driveshaft, you need new uni's.

[SkoonMA67]

what about the spider gears pin. If the LSD pack is worn out and you do one too many one wheel smoke shows, that can wear out the pin damned fast.

That extra clearence would also explain the clunking. I have talked to many techs and diff shops and all have said that if there was too much gear clearence, then the unit would howl like a mofo regardless of wether or not Im on power or coasting.

Great, now I need a new case too... grrrrr :(

Aaron

[jdk_ii]

I can attest to the clunking because of the LSD.

Sometimes it can sound like a click.

What occurs is the LSD clutch packs just eat away at
the side spider gear faces.

High HP MK2's experienced exploding the spider gears.

Now, if you have whine at ~70mph, then it can also
be the pinion pre-load. This is common on the MK2.