Grinding Noise at High RPM - Transmission or Transfer case? (1 Viewer)

[HitTheDirt]

After some searching nothing really matches the issue I'm having. I've recently done a full knuckle rebuild with wheel bearings, rotors, calipers and pads. The noise was present before and still exists; basically when I have the truck in gear it starts making this grinding noise whenever I go above 2500-3000 RPM's (lower when it's cold out). It does it in every gear, but in 4th on the highway it seems to "level out" above 3200 and get quiet again. It does not seem to be getting worse so I am not in a rush to tear into it, I am just started to get irritated enough to begin the process. Any ideas?

 

[PortFJ62]

Maybe t-case bearings are shot. Have you checked for play in the shafts? Gear Oil full?

 

[HitTheDirt]

OK finally got a chance to check gear oil, less than a quart came out and the skid plate and trans are covered with oil. SO I'm guessing there is a leak! The grinding noise is still there above 2500 rpm (it was 7 degrees here this AM) but it's a bit less pronounced. Forgot to check for play in shafts, will do that today. I imagine a T case rebuild is a repair shop and not DIY type of thing? Special tools and all that?

 

[SteveH]

Step one, remove the skidplate, clean up everything and refill the case(s). See if it's quiet. If not, then rebuild. If so, then watch for leak points and see where it's coming out. Whether or not hard-parts are fried is a function of miles, and how long you have driven it while noisy.

 

[HitTheDirt]

Oh forgot to mention, I put new gear oil in and that's what made the change in the grinding sound. Also a nice little puddle this morning on the ground! Out of curiosity, if and when I do a V8 swap will the T case be used? If not, maybe I will just drive it until it explodes.

 

[4Cruisers]

OK finally got a chance to check gear oil, less than a quart came out and the skid plate and trans are covered with oil. SO I'm guessing there is a leak! The grinding noise is still there above 2500 rpm (it was 7 degrees here this AM) but it's a bit less pronounced. Forgot to check for play in shafts, will do that today. I imagine a T case rebuild is a repair shop and not DIY type of thing? Special tools and all that?

If you have the place and tools to remove the transmission/transfer case, separating the transfer case and performing the rebuild is something you can do by yourself. Plenty of previous threads here on MUD on how to do it. If bearings need to be replaced, you can have the new bearings pressed on at a local shop if you don't have a press of your own.

 

[MANUCHAO]

You can use that TC with your swap.
I would not run it without oil.... find out where the leak is at

 

[HitTheDirt]

Allrighty a rebuild it is then, I imagine this will include new seals to stop the leak? One more repair on my wife's car then I can focus on the transfer case.

 

[CaptClose]

@HitTheDirt what year is your cruiser?

 

[HitTheDirt]

It's an '83, 152k miles

 

[HemiAlex]

I'm fighting a similar noise at 300k on my truck. I'm going to check preload on my front wheel bearings, but I'm mentally preparing for a tcase rebuild.

 

[CaptClose]

Perfect... I've got an 83 as well. I have a new spare Terrain Tamer transfer case rebuild kit. It's the best in the business. Send me a PM if you're interested bud. Thanks.

 

[HitTheDirt]

I'd be interested in a week or two in the kit.

Is it possible it's the engine or trans making the grinding? Or most likely the T Case? Since some on mud have 300k miles and the case is fine. Guess i'll find out once I crack it open!

 

[Landpimp]

For the heck of it, check the exhaust for rattles or even an exhaust leak.

Had a phone call friday , local fj62, owner said the trany was making clicking noise when it gear, I said probably
not trany, maybe t case output shaft, maybe u joints. OR.....as simple as the exhaust or a leak. Suggested a few tests to eliminate this or that. Called back latter, sure nuff, manifold leak, only really came when underload.

 

[HitTheDirt]

Thanks for the insight Landpimp, I thought about it some more and the sound did change when I replaced the gear oil, so maybe I am on the right path. Though I'd rather it was an exhaust rattle!

Question-I have a shop but can only leave my truck there on the weekends plus maybe 1-2 days. I am thinking this will take longer, because I have never done a t-case build and am expecting wrong turns and unexpected extra work. Does the transfer case unbolt as a unit from the tranny? I always see pics of the cover off but it's still mounted to a trans as far as I can see. I would prefer to drop it in the street in front of my house and disassemble in the shop and take my time with the rebuild. Thanks

 

[4Cruisers]

Thanks for the insight Landpimp, I thought about it some more and the sound did change when I replaced the gear oil, so maybe I am on the right path. Though I'd rather it was an exhaust rattle!

Question-I have a shop but can only leave my truck there on the weekends plus maybe 1-2 days. I am thinking this will take longer, because I have never done a t-case build and am expecting wrong turns and unexpected extra work. Does the transfer case unbolt as a unit from the tranny? I always see pics of the cover off but it's still mounted to a trans as far as I can see. I would prefer to drop it in the street in front of my house and disassemble in the shop and take my time with the rebuild. Thanks

The transfer case has to be disassembled to remove it from the transmission, so in your case you'd drop the combination and take it to the shop for transfer case disassembly and rebuild.

 

[Cruiserdrew]

If it's going to a shop, take it to a real Land Cruiser shop. Your average repair shop won't be able to do this (even though easy).

I'd say do it yourself, but it sounds like you're in a hurry and inexperienced which is a bad combo. The only hard part of the swap is the output bearings-pressing on and off the shaft and checking the outut gear bushings which may need to be replaced. So take it to someone familiar with the "split case" transfer case.

A big drippy leak usually means the output shaft seal has failed, which almost always means the output bearings are bad and have lost their pre-load. Shimming the output bearings for correct pre-load is another reason to take it to a cruiser shop.

One other thing-3200 is too fast for a 2F if you want it to live a long life. 3000 max. Ignore the tach that says 4000 rpm.

And just for grins, when it makes the noise, rest your hand on the transfer case shifter. If the grinding sound goes away, the square plastic bushing thing in the shifter mechanism is worn out and is easy to replace. It also makes a weird grinding rpm related sound.

 

[HitTheDirt]

I think I'll do it myself, I am inexperienced but not in an a hurry so I can afford to re-do everything at least once or twice.

For sure the truck absolutely hates going above 3000 rpms, I almost never do it unless I'm merging on the highway or trying to race a bicycle. The grinding used to kick in above 3k but now it's down to 2500 so it's resting on the street until I have time to tear into it.

I'm going to have to try the shifter bushing this weekend, maybe that's it. But I think it still needs rebuilt just because of the blown seal. If I can do most of it myself and let a local cruiser friendly shop handle the pre-load shims and bearing pressing I'll be happy.

 

[HitTheDirt]

Anyone have a rough estimate for time to finish the job - If I have everything I need could it be done in a weekend?

 

[Godwin]

It could be done in a weekend if you have all the tools, all the parts, the FSM, and the experience of having previously rebuilt one. It's not that hard but it's a job you do not want to rush. Plan on at least two weekends.

Time-wise expect something like this: 60% dismantling and cleaning, 40% rebuild and install.