Clunk from drive line / transfer case (NOT "The Clunk" from rear prop shaft) (1 Viewer)

[peeaa]

Hello all and greetings from Finland!

Sold my 2008 LC120 and bought a 2006 HDJ100 4.2TD (stock, one previous owner, 160.000km) some months ago. Otherwise the same as UZJ100 but different engine.

Since then I have been spending hours and hours on this great site. What a massive load of good info! Thanks guys!

And now to my problem, or actually so far it is rather a concern than a real problem. Searched and searched but did not find a thread so have to start a new one....


Symptom

When driving almost any speed and taking foot off from the pedal (letting engine to brake) and then accelerating again, I can both hear and feel a clunk from the drive line. And no, it is not "The Clunk" from the rear propeller shaft slide yoke which has been discussed here in many threads. This one seems to be coming from the transfer case and/or center differential.


Troubleshooting done so far

1. Suspected "The Thud/Clunk" and removed & cleaned & greased with moly the rear prop shaft. Slide works smoothly. Inspected the U-joints/spiders as well. No play.

2. With the rear prop shaft removed tried to turn the rear diff flange (where the prop shaft bolts to) forth and back to feel if the play is in rear diff or rear hubs. No it's not, minimal play.

3. With the rear prop shaft removed, turned the transfer case flange (where the rear prop shaft bolts to) forth and back. (ATM in "P", transfer in "H") Remarkable play. (Turn until all the play from the transfer, front prop shaft, front diff, CVs & front hubs is taken out)

4. Suspected front end of the drive line. Made a test drive with center differential lock on and off. With the CDL off the clunk is there, with the CDL on there is no clunk. Does not matter whether the transfer is on "H" or "L", same happens anyway.

5. Suspected the front hubs and/or CV joints. Protected the front drive shafts with thick cardboard, took a good grip with locking pliers and wiggled/turned the shafts front and back to see & feel the play in the CV joints and hubs. There was some play but not enough to produce the clunk. (I don't know how much play in CVs/hubs is ok).

6. Suspected the transfer case. Jacked one front wheel up and rotated the wheel forward and backward to feel the play (ATM in "P", transfer in "H", CDL on). I could rotate the wheel about 1,6 inches (measured from the tire tread). At the same time I was looking at the front prop shaft flange of the T-Case and it rotated with the wheel. (=The play was not in front diff)

7. Then did the same again with CDL off. Now I could rotate the front wheel about 3,5 inches forth and back, front prop shaft rotating twice as much as in step 6 above.

So looks like the play is in the transfer case, right?


Questions:

1. Is this (more or less) normal in LC100? (LC120 did not do this)
2. If not, anybody else has/had similar play in T-Case?
3. What could be wrong in there/in which parts the play could be?
4. Should I be worried or just drive and put the stereo louder to not hear the clunk...?


Looking at the price of a new T-Case does not feel very comfortable. On the other hand, according to FSM it's not a 1 banana job to disassemble it (not to speak about reassembly!) and it requires quite many SSTs as well, so this option is not too tempting either.


What next?


peeaa

 

[Gottagetone]

Did you fill the drive shafts until the grease went past the slip joint seals? The reason I ask is that I thought my drive shafts were properly greased and that was not the case. Also, there was some info about shaving or filing down a part on the inside of the shaft, not sure if you saw that or not.

 

[peeaa]

Yep, tried it all. Greased a little, greased a little more, greased a LOT (past the seals) and finally dis- & reassembled, no impact.

And forgot to mention, the clunk is there also when standing still (foot on brake) and shifting between R-N-D forth and back. So it is not related to the slides of the prop shafts (length remains the same when the vehicle does not move at all but you only shift between R&D).

It is confirmed that there is very little play (and no clunk) when the CDL is locked and a lot of play (and clunk) when the CDL is open.

 

[APKhaos]

There are two locating arms that support the front diff. The bushings on the arms have been known to fail, and at least one Mudder recently posted that replacing the bushes in these arms had silenced a nasty drive line clunk. Might be worth searching for the thread - search on the mobile app searches the entire Mud universe, so I couldn't find it.

 

[KlausVanWinkle]

I'm having the same problem. It started after I installed the slew diff drop kit, used antiseize to reassemble and then took it on a really rough, rocky trail.

I'm suspecting that the front diff mounting bolts loosened up some on the trail. I'll retighten to FSM torque value with some loctite and report back.

Also I can never get the grease gun onto the front diff propeller maybe grease zerk.

 

[peskareta]

I´m having the same symptoms. Have tried the grease thing - not much better.
No sound when standing still though.

KlausVanWinkle: I had to modify the grease gun - make it smaller on the tip. used a stone grinder. some mm on both sides.

Please keep posting if you find a solution.

 

[KlausVanWinkle]

KlausVanWinkle: I had to modify the grease gun - make it smaller on the tip. used a stone grinder. some mm on both sides.

I tired that too. Broke the grease nozzle. I think I might need to unbolt the drive shaft to get in there.

 

[SupraTuRD]

I'm having the same problem. It started after I installed the slew diff drop kit, used antiseize to reassemble and then took it on a really rough, rocky trail.

I'm suspecting that the front diff mounting bolts loosened up some on the trail. I'll retighten to FSM torque value with some loctite and report back.

Also I can never get the grease gun onto the front diff propeller maybe grease zerk.

Have you tried rotating the drive shaft to change the location of the zerk? Quite often that's enough to gain just enough clearance to get the grease nozzle in there. Then again, different manufacturers of grease guns will have different nozzle diameters. I have a Lincoln grease gun and it is a tight fit that requires rotation of the drive shaft to get it on there.

 

[KlausVanWinkle]

Yup. I've also tried 3 different nozzles.

 

[SupraTuRD]

The other thing that a lot of folks (including professional mechanics!) aren't aware of is that the tip should be "unscrewed" a bit before pushing it over the zerk, then tightened before pumping the grease in. I know it sounds so simple and dumb, but I've met several "pros" that had no idea the tip unscrewed for ease of use. =]

 

[APKhaos]

Saw one bozo trying to hammer grease chuck onto a zerk. I think a few of us saw it at the same time and hit him in one voice. Step away from the tools, sir......[but a bit edgier].

 

[SupraTuRD]

Saw one bozo trying to hammer grease chuck onto a zerk. I think a few of us saw it at the same time and hit him in one voice. Step away from the tools, sir......[but a bit edgier].

A hammer. That's classic. =]

 

[APKhaos]

Good mate of mine is facilities manager for a very large dealership. Spectacular shop setup for each marque, $4000 toolboxes for the techs, etc. You'd be amazed at the abuse even high end techs are capable of. Some scary/funny stories come out of those shops.

 

[peeaa]

May I interrupt the interesting discussion of hammers and grease guns and get back to the not-at-all-so-interesting driveline clunk...

I know one of you will jack up at least one front wheel of a LC100 in the coming days for whatever reason (tire rotation, brake jog, bearings...)

Could you please at the same time do me a favor? Rotate the wheel forward and backward as much as it goes (ATM in "P", transfer in "H", CDL both on and off) and measure the play (from the tire tread) and then report the readings on this thread. Just like in the steps 6 & 7 of my original post.

Those measures would give me an idea whether the play in my rig is exceptional or not and how worried I should be about it.

Thanks in advance!

peeaa

 

[SupraTuRD]

May I interrupt the interesting discussion of hammers and grease guns and get back to the not-at-all-so-interesting driveline clunk...

I know one of you will jack up at least one front wheel of a LC100 in the coming days for whatever reason (tire rotation, brake jog, bearings...)

Could you please at the same time do me a favor? Rotate the wheel forward and backward as much as it goes (ATM in "P", transfer in "H", CDL both on and off) and measure the play (from the tire tread) and then report the readings on this thread. Just like in the steps 6 & 7 of my original post.

Those measures would give me an idea whether the play in my rig is exceptional or not and how worried I should be about it.

Thanks in advance!

peeaa

I can do this in the next few days... how much movement do you have, and at what radius are you taking the measurement?

 

[peeaa]

One picture would tell more than a 1000 words, but I try the words anyway:

Mark the 9 o'clock position on the tire tread. Then rotate as much as there is play and mark the "new" 9 o'clock position. Measure the distance from mark to mark.

For me it is 1,6" when the CDL is on and 3,5" when it's off.

peeaa

 

[peeaa]

There are two locating arms that support the front diff. The bushings on the arms have been known to fail, and at least one Mudder recently posted that replacing the bushes in these arms had silenced a nasty drive line clunk.

I'm having the same problem. It started after I installed the slew diff drop kit, used antiseize to reassemble and then took it on a really rough, rocky trail.

I'm suspecting that the front diff mounting bolts loosened up some on the trail. I'll retighten to FSM torque value with some loctite and report back.

I checked the two diff support bushings on Sunday and they were in good shape. However, the third bushing (see picture) which supports the DS axel tube seems to be dead.

There is no part number for the bushing alone, it is the whole support assy (52380-60040) which is $$$.

Does anybody know if the bushing alone can be replaced and where to get it? Part nr?

I think this bushing is not the reason for the clunk but it needs to be fixed anyway.

peeaa

 

[TrekboxX]

Any update on this? I have the same "excessive" play in the center, and I also get the clunk. Done the rear propshaft, it's definately different. I haven't measured, but will concur that with a front wheel off the ground, when turning it you can see and feel the minimal play in all the components, and then the major play between the front and rear shafts. It's definately in the center diff, I just don't know how much should be concerning... But I'm concerned!

 

[TrekboxX]

Don't know if anyone but me is still intersted in this, but I checked again today. Sure enough, the OP's measurements were about what I have. Much less with the diff locked. Is this pretty normal? Anyone?

 

[00N8]

I'm going to check mine today too, I have a new clunk after greasing the drive shafts that wasn't there before. The clunk occurs both during use of CDL and not. I have a 2000 mile trip in front of me next week and am worried I'll break down somewhere on the road.