Driveline Clunk. I don't like it. (1 Viewer)

[WarWagon]

I've heard the bullet ping sound with the clunk before and because of that I concur it isn't the flanges; never had that sound with my '91.

 

[RDC76]

@Aggiesdm Sorry, but I haven't put any time into this in a while. We have had temps under 25degrees and I don't like being cold. A torpedo heater is OK for general stuff, but when you have to lay under the cruiser to do anything, that ground is COLD.

My "clunk" includes a ringing sound like a bullet hitting a hard steel plate. It is the same frequency as the sound in the video above. Because of that I don't think this is a drive-flange issue. Just going off the sound I get from playing with the output of the transfer case, I have a feeling that is where the majority of the play is. I have a feeling there will be some worn gears or splines in there.

I won't know for sure until I drop the T-Case and I'm just not ready to do that until it warms up a bit more. I'm removing the front axle/drive shaft today(its 30 degrees). After that I'm going to fiddle with the t-case and see if I still get the noise. That will isolate it to either the front axle(if he sound goes away) or the t-case(if it is still there).

My 80 makes the same bullet ping sound noise. Mine is a 95 lifted on 35's,locked and with 222,000 miles. Front axle rebuilt about 3000 miles ago and RCV chromoly axles. But mine only makes the sound when I shift into reverse and apply the throttle. It also does it more once the driveline is warmed up from driving. This noise started recently and before I had no clunks or noises prior. If I listen with the door open me in driver seat , it sounds like it is coming from the rear axle or transfer case. But mostly rear. Sometimes a couple ping bang noises. I've checked and greased everything. And changed all fluids. I did find a tiny piece of gear (pencil tip small) in the transfer case fluid. But I could not identify it? I'll be going into the rear axle soon once it warms up here or breaks. Which ever comes first. I will post my findings but will be following this as the sound described in this thread best describes mine as well.

 

[Golgo13]

Wow, thanks for the awesome pictures, Kurt!

 

[Aggiesdm]

HI all, so after lots of standing around and staring at the truck, I started reading Summit Cruiser's thread regarding the Kick-Down cable and decided to revisit mine. As it turns out, I replaced the TPS not too long ago and during the process had to remove the throttle and tranny cable. When I reinstalled them, I obviously changed their position. I went in and readjusted both cables and the clunk is definitely improved. It's still there, but definitely better and not as critical sounding/feeling. I would suggest that any of you guys with a 3FE definitely make sure to adjust your kick-down cable. I honestly didn't think it would make that big of a difference... I was wrong.

I'm still going to look into changing out the drive flanges as I believe that they are pretty worn and causing some of the clunk. Right now, I'm at least a little relieved and don't feel that my driveline is about to fall out, so I'll live with it for now.

 

[landtoy80]

Found my ringing noise.
https://forum.ih8mud.com/threads/ringing-drive-line-clunk.836962/

 

[RDC76]

My 80 makes the same bullet ping sound noise. Mine is a 95 lifted on 35's,locked and with 222,000 miles. Front axle rebuilt about 3000 miles ago and RCV chromoly axles. But mine only makes the sound when I shift into reverse and apply the throttle. It also does it more once the driveline is warmed up from driving. This noise started recently and before I had no clunks or noises prior. If I listen with the door open me in driver seat , it sounds like it is coming from the rear axle or transfer case. But mostly rear. Sometimes a couple ping bang noises. I've checked and greased everything. And changed all fluids. I did find a tiny piece of gear (pencil tip small) in the transfer case fluid. But I could not identify it? I'll be going into the rear axle soon once it warms up here or breaks. Which ever comes first. I will post my findings but will be following this as the sound described in this thread best describes mine as well.

Mine turned out to be a bad rear u-joint. I checked it a couple weeks ago and couldn't get any slop out of it by hand or with a pry bar. But this week it presented it self quite obviously. One of the cups actually cracked. Rebuilt the the rear driveshaft and all is quiet and smooth again! I did manage to score a transfer case with 160k miles on it the other day to for 100 bucks at a local junkyard. Picked it up just in case. Probably gonna put crawler gears in it from marlin and go threw it while it's on the bench. And swap mine out in the spring. This universal was toast. Lol

 

[hammerheadfistpunch]

Going through this tread makes me sad that there aren't any answers here that I haven't already tried. MY slop is getting so bad that in low range if feel like the throttle is being manipulated as the lash loads and unloads. New gears in the diff, new u joints on both driftshafts. I guess it could be the T-case...thats about the last place I can think to look excepting that the diffs lash is way out.

 

[Golgo13]

Given the information shared in this thread, the only thing I can think is that the clunk is caused by cumulative slop in a lot of places and there really isn't a robust solution/fix for it. It also seems that it sounds a lot worse than it really is.

 

[onedaatmc]

so "the clunk" then is normal ? from what I summize on this thread ? mine clunks a little here and there ... thought I'd grease the zerks and see if it helps ... was just trying to figure out where all of them are ?... I assume one at each end of each driveshaft ! where else ? ... I know I know , I could crawl around and look for them , but it would be nicer to just know , ya know ?

 

[FJ80HI]

so "the clunk" then is normal ? from what I summize on this thread ? mine clunks a little here and there ... thought I'd grease the zerks and see if it helps ... was just trying to figure out where all of them are ?... I assume one at each end of each driveshaft ! where else ? ... I know I know , I could crawl around and look for them , but it would be nicer to just know , ya know ?

My 91 FJ80 must have 20 grease zerks- best to get an owners manual with the pic of all the locations.

 

[hammerheadfistpunch]

so "the clunk" then is normal ? from what I summize on this thread ? mine clunks a little here and there ... thought I'd grease the zerks and see if it helps ... was just trying to figure out where all of them are ?... I assume one at each end of each driveshaft ! where else ? ... I know I know , I could crawl around and look for them , but it would be nicer to just know , ya know ?

The ones you want to know about are the front u joint on the front shaft (in between the yoke) then the slip joint (on the yoke) then the back u joint on the front shaft (in between the back yoke) and the same story with the rear driveshaft.

 

[onedaatmc]

if the drive shafts are solid with no slop at all in them , am I good ?

 

[hammerheadfistpunch]

if the drive shafts are solid with no slop at all in them , am I good ?

Gotta keep grease in them.

 

[RFB]

Most of my clunk was eliminated when I went P/T

What kit did you use when u went part time.

 

[LandCruiserPhil]

What kit did you use when u went part time.

I have two Land Cruiser with PT one uses Marks and the other Lokka spool both with Aisin hubs

 

[RFB]

I have two Land Cruiser with PT one uses Marks and the other Lokka spool both with Aisin hubs

If you did it over and could only pick one. which. and thanks

 

[ozarkmud]

I know this is an old thread, but I think still relevant. I've got a clunk on one my rigs and have assumed it's the motor mount. Reminded me of the clunk I had on my FJ60.

How common are broken motor mounts on a FJ80? The motor definitely moves some if I rev it in neutral. I know all will move some, but I think this might be more than normal and indicate a bad mount.

 

[John McVicker]

Don’t know on an 80, but with my 60 it’s very easy & quick to determine if you have a bad motor mount.

The driver side always breaks 1st. Get a bottle jack & a 2x4. Jack up at the oil pan…using the 2x4 for support. As you are lifting up the motor keep an eye on the motor mount to see if it separates into two pieces. Pretty simple fix…at least on a 60

 

[Dave 2000]

I know this is an old thread, but I think still relevant. I've got a clunk on one my rigs and have assumed it's the motor mount. Reminded me of the clunk I had on my FJ60.

How common are broken motor mounts on a FJ80? The motor definitely moves some if I rev it in neutral. I know all will move some, but I think this might be more than normal and indicate a bad mount.

This is a common issue with diesels however, you don't realise it as the weight hides the problem.

To prove it:

Open the bonnet and have someone stand to one side looking at the engine.

Left foot hard on brake, select drive and give the throttle a quick blip, that's a blip! If the engine mounts have failed, the engine will lift on one side due to the torque reaction.

Check both sides, as one side remains under compression when you test, the other side will lift.

Regards

Dave

 

[ozarkmud]

This is a common issue with diesels however, you don't realise it as the weight hides the problem.

To prove it:

Open the bonnet and have someone stand to one side looking at the engine.

Left foot hard on brake, select drive and give the throttle a quick blip, that's a blip! If the engine mounts have failed, the engine will lift on one side due to the torque reaction.

Check both sides, as one side remains under compression when you test, the other side will lift.

Regards

Dave

Thank you, Dave! Great suggestion.

Looks like not the motor mount after all. Seems like it'll be more work to resolve the clunk.

Also kind of wonder about swapping in a viscious coupled transfer case from the FZJ80 into the FJ80, although not something I want to undertake now.