'clunk' in drive train?

[bigndn]

So I go for a quick ride in my friend's 80 today, auto trans, I think it's a 1994 with 209K on the clock. Letting off the accelerator, there is a noticeable 'clunk', then pressing on the accelerator, there is a more noticeable 'clunk' as we were rolling.

1) I have never had an 80 series.
2) no I didn't search for 'clunk', I wouldn't know what to search for unless it involves a clutch.
3) He's only had a TLC for 6 months and is a noob lurking here, but he's a good guy.

We crawled under his truck...

the drive shafts have no slop in them, thus ruling out a U-joint, right?

OK, if that's right, it's gotta be in the trans/Xfer somewhere.

So, what could it be? Someone has HAD to have heard of this before. TIA.

 

[bigndn]

Shoulda known.....a search for 'drivetrain clunk' yielded 30 some results. Any expert opinions/input?

 

[kidglove13]

It is pretty common place in the 80 series.
Especially when you shift into reverse or drive you will sometimes get a clunk as well.
I would also bet that the ujoints are on their way out depending on if they have ever been replaced.
I have found that if you really feather the gas in the 80 series it works well.

 

[SUMMIT CRUISERS]

The rear driveline slip joint splines cause this on my 92. I was always hesistant on greasing them reading all the problems about over greasing them. I grease them until the joint expands ( be very careful to watch for the movement) then I unscrew the zert and let the extra come out. This keeps my clunk away for at least 3 to 4 months. One note, I make sure the vehicle is on the ground and not on a lift with the axles hanging when I perform this.

 

[elprup87]

The PO of my 80 had the same issue when we test drove it. Thankfully it was a great price dropping tool for me. All I did was grease up the joints (they were dry) and the majority of my clunk went away. I had another cluck when I would shift from P to D (visa versa), but that was related to the intake hose being cracked big time (long story).

 

[bigndn]

Thanks for the responses. I'm sure Chris will appreciate it when he reads this thread.

 

[Atticus]

If it needs maintenance, the best thing to do is replace all the u-joints with Toyota OEM, take the drive shafts apart (making sure that you make an alignment mark for when you put them back together), clean off the old grease, grease the splines by hand, grease the u-joints, and put it all back together.

 

[Tools R Us]

The first, easy test is to grease the drive shafts, if the sound significantly changes, you found the problem. Care needs to be taken with the slip splines, don't want to over grease, hydraulic lock them, I only add ~4 pumps a couple of times a year. If grease quiets the sound, it is likely masking bigger issues, worn u-joint or splines.

If shifting between P & R will make the sound, have a helper do it, walk around the rig and find where the noise is coming from. The drive plate splines at the front hub are also a common cause.

 

[Lka1988]

Convert to part-time. Gets rid of the clunk entirely

And you can do donuts.

 

[thisilldefend]

I have a clunk too. Mine is when I am rolling at about 10-15mph and now and then it will clunk when it shifts. Mostly in traffic. It scares me. I want my 80 to last .I am looking for a backup.
I had great plans for my 80 when I got back from theatre. When I got back I had a huge fight over pay. They garnishished my wages and took back 12k. I fought as hard as I could to get my money back, Inspector General, Congressman , Governor ect. No one could help. Because I am in a wounded warrior unit I met MR Mc Hugh.. Secretary Of The Army and told him my ordeal. Within two weeks they made a decision on my case. The ARMY owes me almost 30K now. I doubt they will fix my credit rating and all the hell they caused me. But I am finally getting one of the last sets of Hanna Sliders in 2 weeks. Now that money is coming I can get my 80 right. I was so mad I havent washed my rig in 2 months. Caint wait to be medically retired in 2 -3 months. I will show you pics when i get her done.

 

[AustinCruiser]

I have a clunk too. Mine is when I am rolling at about 10-15mph and now and then it will clunk when it shifts. Mostly in traffic. It scares me. I want my 80 to last .I am looking for a backup.
I had great plans for my 80 when I got back from theatre. When I got back I had a huge fight over pay. They garnishished my wages and took back 12k. I fought as hard as I could to get my money back, Inspector General, Congressman , Governor ect. No one could help. Because I am in a wounded warrior unit I met MR Mc Hugh.. Secretary Of The Army and told him my ordeal. Within two weeks they made a decision on my case. The ARMY owes me almost 30K now. I doubt they will fix my credit rating and all the **** they caused me. But I am finally getting one of the last sets of Hanna Sliders in 2 weeks. Now that money is coming I can get my 80 right. I was so mad I havent washed my rig in 2 months. Caint wait to be medically retired in 2 -3 months. I will show you pics when i get her done.

thisilldefend:
Keep after them on the medical retirement, especially the yahoos who calculate your years of service, etc. Make sure to do your VA physical, etc. as early as possible too. The Army is overwhelmed and making lots of mistakes. Feel free to contact me if you have any questions about the process. I got wounded in 2004 and my retirement is still screwed up. Ed (austincruiser)

 

[reconranger]

thisilldefend:
Keep after them on the medical retirement, especially the yahoos who calculate your years of service, etc. Make sure to do your VA physical, etc. as early as possible too. The Army is overwhelmed and making lots of mistakes. Feel free to contact me if you have any questions about the process. I got wounded in 2004 and my retirement is still screwed up. Ed (austincruiser)

x2.

The pay personnel are total idiots.

The Marines are no better when it comes to outprocessing.

They claimed they overpayed me and my SRB still has missing data for schools I attended.

I H8 admin.

To keep this tech: double check your u-joints. Also, my clunk on braking and accelerating happened to be a combo of broken u-joint and a broken nut off the rear stabilizer bar.

 

[trk204]

I had a clunk when slowing down, checked my rear ujoints with the shaft in, and there didn't seem like alot of play in the joints. Pulled the shaft anyways, and found one ujoint that had a stiff spot when cycling. Replaced that joint, greased up the splines and the other joint and good as new.

Ryan

 

[bigndn]

Thanks for the responses!!!! He greased it up really well and says that cured the problem!!!

 

[dblnot]

Transfer case ills?

Thanks everybody for the feedback- it's my cruiser w/ the clunky attitiude. I did grease things up nicely and all noise went away...for about 6 miles- then it returned. I ended up yanking out the front driveline, here is the odd spot; once I did that the rig (full time all wheel right?) would not drive at all. So I engaged the diff lock and we had power to the rear wheels. The sloppy clunk was in the transfer case (maybe 15 degrees of movement in the drive line) but this whole time it appears the All wheel drive has not been working and has been running as a front wheel drive! Now that the rears are doing the work, it drives great, but what is the fix? Is there a celonoid in there that has outlived its' usefulness? Thanks in advance!

 

[Atticus]

Thanks everybody for the feedback- it's my cruiser w/ the clunky attitiude. I did grease things up nicely and all noise went away...for about 6 miles- then it returned. I ended up yanking out the front driveline, here is the odd spot; once I did that the rig (full time all wheel right?) would not drive at all. So I engaged the diff lock and we had power to the rear wheels. The sloppy clunk was in the transfer case (maybe 15 degrees of movement in the drive line) but this whole time it appears the All wheel drive has not been working and has been running as a front wheel drive! Now that the rears are doing the work, it drives great, but what is the fix? Is there a celonoid in there that has outlived its' usefulness? Thanks in advance!

Hi dblnot. The vehicle has (likely) been operating correctly. Because your center differential was unlocked, the front output shaft was just spinning. If you had detached the rear drive shaft, but left the front on, the same thing would have happened. That's what unloaded differentials do: find the path of least resistance (why only one tire spins in a 2 wheel-drive car stuck in the snow).

Are you saying that taking off the front shaft made the clunk go away? That means that you've probably isolated it to the front output shaft of the transfer case, the u-joints on the propeller shaft, the front propeller shaft itself, or the pinion shaft on the front axle. Have you checked for play on the front shaft u-joints?

 

[bigndn]

Thanks everybody for the feedback- it's my cruiser w/ the clunky attitiude. I did grease things up nicely and all noise went away...for about 6 miles- then it returned. I ended up yanking out the front driveline, here is the odd spot; once I did that the rig (full time all wheel right?) would not drive at all. So I engaged the diff lock and we had power to the rear wheels. The sloppy clunk was in the transfer case (maybe 15 degrees of movement in the drive line) but this whole time it appears the All wheel drive has not been working and has been running as a front wheel drive! Now that the rears are doing the work, it drives great, but what is the fix? Is there a celonoid in there that has outlived its' usefulness? Thanks in advance!

Welcome to the party, Chris! That's a bummer that it came back. I can't wait to read the diagnosis on this.

 

[dblnot]

more info

Thanks Guys- So all u-joints are in perfect shape and the front drive shaft splines are very tight too. Yes, the clunk is totally gone by removing the shaft- I will check the front output shaft and the pinion this afternoon. Am I just looking for slop? Cheers-

 

[Tools R Us]

Thanks Guys- So all u-joints are in perfect shape and the front drive shaft splines are very tight too. Yes, the clunk is totally gone by removing the shaft- I will check the front output shaft and the pinion this afternoon. Am I just looking for slop? Cheers-

What year is the rig? On the early rigs, the birf to drive plate splines are shorter, subject to wear, causing a clunk that will disappear when run in RWD.

 

[dblnot]

it is a 92