Transfer case sound

[RHanna]

So I'm trying to pinpoint the sound I'm having with my TJ. I removed the front driveshaft and it seemed to go away so I purchase the rebuild kit that includes the centering yoke from denny's driveshaft. I've never replaced u joints or any of that but I thought this would be good practice. I replaced the driveshaft and it seemed to work well for about a week and the sound came back. At this point I wish I had just bought an adams or tom woods driveshaft. This morning I decided to remove the driveshaft again and measure for ordering. I spun the yoke on the transfer case and it wasn't as quite as I would have expected so I filmed it and attached the video. I'm assuming what you can hear the most is just the bearings and there is a slight scraping sound. At the end of the video I start spinning it closer to where I heard the scraping.

I don't know. If I'm just extra sensitive to noises just let me know. Still getting use to owning a Jeep.

 

[RHanna]

Went for a drive and the noise is still there without the front drive shaft. I dropped the rear driveshaft so I could grease the cv joint. After putting the rear back on the noise is still there so I guess the problem is the transfer case.

I did install a ucf transfer case skid plate which ended up raising the driveline some

 

[Steel City 06]

Is there any play in the transfer case output yokes?

You could also eliminate the possibility of rear driveshaft noise by removing it and going for a drive in 4WD, or essentially front wheel drive.

 

[Goatman]

Try the front shaft in, rear out, transfer in 4H as suggested. Triple check fluid levels in transfer and go for a test drive. Make sure the outputs are tight.

 

[RHanna]

Try the front shaft in, rear out, transfer in 4H as suggested. Triple check fluid levels in transfer and go for a test drive. Make sure the outputs are tight.

I'll try that. I recently drained and filled the transfer case with redline C+ ATF.
Also drained and refilled the NV3550 transmission with redline MTL 75w80 GL-4 gear oil

 

[RHanna]

Disconnected the rear drive shaft from the transfer case. Even though the front drive shaft is out and the rear is disconnected. I'm still doing this experiment uneasy. I don't want to run my jeep through my garage wall at 50 just because I forgot something stupid.

Anyway the video is from inside the cab with the transfer case in 4 hi so both yokes turn. This is the popping that I've been hearing all along. The PO replaced front driveshaft "in recent months" when I bought it a couple of months ago.

I don't think I heard anything in 2wd in my experiment but I could definitely hear it yesterday when I was driving around with the front driveshaft out. That's interesting because I would think the front yoke wouldn't be turning. Maybe there is more wrong with the TC than just some bearings.

 

[Goatman]

That 'thing's sound...more like something hitting hollow metal. Driveshaft, exhaust, etc. If you are hearing the transfer try (still both driveshafts disconnected) shift into each range. 2h, 4h, n, 4l. Does the sound change, or is it same in all positions? We'll get this figured out soon.

 

[RHanna]

That 'thing's sound...more like something hitting hollow metal. Driveshaft, exhaust, etc. If you are hearing the transfer try (still both driveshafts disconnected) shift into each range. 2h, 4h, n, 4l. Does the sound change, or is it same in all positions? We'll get this figured out soon.

So that's usually the start of the noise. Once it's done popping it will start squeling. In 4hi and 2hi. It's pretty loud once it start going. My father in law thought maybe it was something loose in the transmission but I would think I would hear that immediately and it wouldn't have to warm up. I think I'll go back to the garage and run it a little longer and see if I can get a good video with all the random noises.

 

[RHanna]

Ok, no more playing around. I've linked 2 separate videos on youtube that I uploaded.
The longer video is where I've warmed the jeep up and it starts popping. I kept going to you could hear the squealing.
29 seconds a few pops
49 seconds more popping
About 2 minutes I change out of 4 hi into 2hi. Still some popping but not as much.
5:40 I change back to 4 hi, I'm trying to get it to start squealing.

This next video is after the longer video. Since I have both driveshafts off I could keep it in 1st gear without the jeep stalling.

 

[L0jik]

Ok, no more playing around. I've linked 2 separate videos on youtube that I uploaded.
The longer video is where I've warmed the jeep up and it starts popping. I kept going to you could hear the squealing.
29 seconds a few pops
49 seconds more popping
About 2 minutes I change out of 4 hi into 2hi. Still some popping but not as much.
5:40 I change back to 4 hi, I'm trying to get it to start squealing.

This next video is after the longer video. Since I have both driveshafts off I could keep it in 1st gear without the jeep stalling.

Sounds like you have a cartoon mosquito plaguing you .
My two cents would be to start at that slip yoke eliminator, either a failed component installed during the SYE or improper installation could cause the t-case to be making that noise.

Try seeing if the squealing stays the same, or gets slower in 4 low, this will tell you if its coming from the input side or output side of things.

 

[RHanna]

Well I thought about buying a remanufactured transfer case or pulled a junk yard transfer case but at the end of the day I would have had to uninstall the SYE from my old TC to put into whatever I decided. I also thought about rebuilding the TC myself and I think I could have handled it on my own but I would have worried that if the sound kept going then I wouldn't have known if it was because of my lack of mechanical skill or if I just missed the problem.

I ended up taking it to a transmission shop here in town that had great reviews (My brother in law had his truck's transmission fixed at this shop apparently and they did a great job, found that out after). I dropped it off and called at the end of the week to see if they found the problem. They couldn't replicate the sound. When I brought the jeep into the shop I only connected the rear driveshaft since the front is such a pain. I picked it up and drove around town and couldn't get it to start making the sound so I put it into 4hi. That was enough to get it to start popping so I dropped by the shop again and the owner rode around a couple of miles and heard the sound. He asked me to bring him the driveshaft so he could replicate the sound when they get to it.

He called yesterday and let me know he found the problem in the transmission and had to pull that and replace a bunch of stuff. I wasn't really paying attention because I was thinking WTF, how much is this going to cost, why didn't they call me before doing all of that. Well he's a real jokester, the problem was the dust boot on the front output yoke and they already replaced it and the jeep was ready. Glad it was a simple fix but I don't think I would have ever caught that. $150 total bill and was glad to pay it.

It's kind of hard to see but in the first picture you can kind of tell that it's been worn down. I can't believe this piece was causing that much noise. Drove it home and didn't hear anything so I'm thinking I'm all good now.

 

[tworley]

I suspect your yoke was loose. There isnt a way that dust shield would make the noise in your video. Plus there aren't any wear marks in it. To replace it though they had to remove the yoke and with the new shield on I bet it was torqued to spec with an impact. If you begin to hear noise again, or a vibration I would rebuild the tcase.