Transfer Trouble

[bram]

I have 500 miles on a new H55, clutch, and rebuilt transfer case (rebuilt it myself according to FSM). Its been great right up until monday afternoon, returning from a 4th of July road trip. I started to notice a jingling noise coming from the area of the t-case. I can only hear it with the window open when there is something on the outside to reflect the sound back at me. I have also noticed that in 4 hi and 4 lo the TC sounds very grumbly, like there are a bunch of rocks in it or something. I checked both tranny and xfer for fluid this morning and they are both full. Overall the driveline still feels really smooth with the exception of a little driveshaft wobble around 50-60 which has been there forever.

The jingling only happens when the vehicle is moving and doesnt really get any louder after about 25mph but its hard to tell exactly. Same noise with the clutch engaged and disengaged, transmission in gear or in neutral. If I leave the xfer in neutral and run through the transmission gears with the vehicle stopped there is no noise. I hear the jingling in hi an low range.

To me it sounds like a bearing binding up but I have never heard a bad bearing before. Its just the only thing in there I can imagine making a noise like that. I am thinking I might have a problem with one or both of the front and rear output shaft bearings. My current plan is to dump the fluid and look for metal and then check the output shaft preload. If both of those are fine I am not really sure what to do next.

Any suggestions?

 

[Cruiserdrew]

Did you replace the bushings and plastic square thing on the shifter mechanism? If not, they get loose with age and tend to vibrate.

I would drain the oil and look for wear and chunks. Are you sure you got the output preload right on the transfer case? I can't imagine much else being wrong if it drives well and is otherwise OK.

 

[bram]

I did rebuild the shifter but I did not replace either of those parts. I can't imagine that plastic piece making a sound this metallic.

I used a dial indicating torque wrench to set the preload. It was about 18 in lbs as I recall.

The jingling sounds very similar to how a roller bearing sounds when you shake it before you grease it, except higher pitched

 

[TLC Norway]

Sounds familiar... I get that sound if I'm rolling around with hubs locked, in 2wd.
Or if I drive with hubs unlocked and in 4wd.
So for me it happens when front driveshaft is turning without load. The spline on the driveshaft/propshaft is pretty worn on mine, noise goes away if I put fresh grease into it.

So you can check that your hubs actually disengage when in free, and that your transfer actually disengage the front output.
Try removing the front driveshaft and see if noise changes. Separately try greasing/removing rear driveshaft to diagnose further.

Late or early transfer case? Vacuum?
How is the state of your front axle/knuckle/hubs/driveshaft/u-joints?

 

[DirtRoads]

I'd check the seal dust covers on the output flanges for the case. I'm honestly not sure if an FJ60 even has them but my samurai crawler does. I have had the welds on the little dust covers come loose and cause them to shake around and create this exact sound, it usually happens after a rebuild.

 

[bram]

This is a Frankenstein case based on an 87 lage idler manual shift housing. The output shaft and bushings from the original were toast so I swapped in some others that I had laying around. everything measures well within spec per the fsm. The front knuckles have been recently serviced. I guess the diffs have not been touched in this vehicles 160k mile life.

The front driveshaft spins freely with the hubs unlocked but I can't say how sticky they are. In general I think the driveshafts need to be rebuilt and balanced but they were good enough 500 miles ago and I think they are good enough now.

 

[Tapage]

Did you already check your U joints ?

 

[roadstr6]

I had a similar rattley noise and it was the Hi-lo shifter linkage bushings. Does it quieten down when pushing/pulling the lever side to side? If it does, easy fix.

 

[too tall]

Your t-case shouldn't sound like there are rocks in it . I would open the pto cover and try to get a look in there . Put the trans in neutral and spin it by hand ( you will have to lift a rear tire off the ground or remove the d-shaft ) unlock the front .

 

[bram]

All good suggestions. I think the rumbling sound may be the front driveshaft . Going to spend tomorrow morning in the shop figuring this out

 

[bram]

The rumbling sound was the front DS. I installed it backwards and it was rubbing against the cross member.

I checked the oil in the tcase and the rear diff, both were fine with no metal. The rear driveshaft seems fine, no play in the joints. There is a little play in the rear pinion but I dont think that happened in the last 500 mi. Also, the sound seems like it is coming from the transfer area.

I put the rear of the truck in the air and ran it through the gears and i did not hear the jingling noise. However, when I put it back on the ground and took it for a spin I could hear it clearly. The dust covers on the output flanges were intact. I forgot to try to put pressure on the shifter to see if that is the source of the noise and I did not have time to recheck the preload.

 

[cruisermatt]

Check all the exhaust clamps sometimes they like to make noise if they are loose.

 

[bram]

Finally got to take out the rear ds and test the output shaft preload. It was effectively zero. I took off the rear output housing, put another shim in, put it together and it tested at 30 in*lb. I figure its gonna loosen up a bit again so I just left it there. I will say the rear bearing definitely looked like it was riding funny in the race. BUT, the preload adjustment had no effect on the jingling noise. Its definitely not the shifter or exhaust clamps. I cant say 100% for sure, but I am pretty sure the noise is coming from the case. I guess there is nothing left to do but to take it back apart.