I have a clunking noise that is coming from the transmission/transfer case area that happens mostly when I let off the throttle to shift or coast in gear, and sometimes when letting the clutch out. If I have my hand on the shifter, I can feel it there. I have an almost new NV4500 from standard trans in texas, and all my ujoints are tight. This leaves me suspecting the transfer case, since I know I've never worked on it in the last 80,000 miles anyway.

What should I be looking for as the source of a noise like that? If it is the transfer case is it easily fixable or should I be scouting for a new one? I do a lot of light towing with this truck.

Thanks!

 

I thing the best bet would be draining an refilling boxes( tyranny,t-case and the rear end or rear axle)

They are probably do for a service any way. Us a magnet when you pull the drain plug.

You will find the problem, if you see silver or gold in the oil.....you have probably found you problem.

Don't forget the rear end! if you can fill it in the t-case,.....it could be coming form the rear and thru the drive line!!!!

 

coupler sleeve between the tcase and trans shafts.

 

I dont think there is a coupler sleve between the tcase and tranny on these, like the chevy 205s have. The couse spline chevy 205 couplers could wear, but these are fine spline, i havent seen one wear before. I believe it is female in the tcase and male out of the tranny.

could be a lot of things, i lost a ring and pinion about 5 years ago, clunked a bit before letting go. It ended up being a few teeth breaking off the pinion.

Dont overlook the obvious, if you just did a NV4500 swap like i did, look for the tranny or t case actually banging into the floor board or crossmember. Check and make sure the tcase to crossmember mounting bolts are tight too. Really old rubber mounting donuts dont support well.

Also do a sanity check on your motor mounts on each side, i had one of the mounts shear completely off and it actually wasnt that obvious other than some subtle shaking and clunking. That was a really long time ago for me though.

The 205s are easy to rebuild, swap the bearings, They usually dont wear out too fast, in 2wd high, none of the gears carry load, and the gears are massively oversized in those things. I swapped the bearings in my 205 when i swapped to an NV4500.

 

The coupler is female/female. Mine is wore pretty bad and will get replaced the next time I break something in that general area The intermediate shaft in the t-case is what was making so much rattle for me. I re-shimmed it to spec and the noise is gone

 

I would have assumed that if the coupler was close to wearing out, the tranny shop that installed my NV would have recommended a new one. I will try and find some schematics and specs on the transfer case and see what I can figure out.

 

Is my mind going or is the coupler eliminated with the nv 4500 conversion?? I cant remember too clearly... i did my conversion around 2001.

 

The double female coupler is retained from the Getrag when doing the conversion to the NV4500.

 

It's the yoke on the output shaft of the transfer case. It has just a little bit of slop in it. I had this happen to a toyota truck once that had about as many miles on it. Hopefully it will be an easy fix like the toy was. All I had to do on that truck was retighten the nut and that was that.

Any sources for a new yoke if it is too worn out?

 

Well, I was wrong. The yoke is not loose on the output shaft, but there is some play inside the T case, I guess between the input gear and the output shaft. The coupler may also be contributing. But the WORST part is that the most play and noise seems to be coming from inside the bellhousing. I can hear it clunking and squeaking around in there when I move the t case output shaft back and forth...

??!? I don't hot rod this truck. I've done no bombing, no peeling out and leaving big smoky clouds behind. I do tow, but never more than 7-8000# and usually not even that much. I'm a careful and deliberate shifter, and this clutch was new about 40-50,000 miles ago!

It's not a great time for me to have to spend the $ and time on a new clutch, but I guess no time ever is...

Anybody else ever experience this kind of weird clutch trouble? Is the hub disintegrating? ack!

 

What clutch did you put in? Could be the center coming apart just like mine did. I just talked to South Bend today about my clutch woes, and the guy basically said that the centers on 12" clutches are weak.

 

It was a factory sized clutch that came with the rebuilt tranny from Standar Transmission in Texas. I noticed that you had a similar prolblem with a SBC clutch. I've done no mods to this truck, where can I get a clutch that will last? Was yours a 12" clutch?

 

Yes, mine was a 12 inch clutch. I cheaped out when I bought it, I figured it would be plenty strong if they said it would hold 400 HP / 900 ft. lbs. of torque. It held fine, it just broke.

I don't think you can go wrong with a Sachs clutch like was in there from the factory. I know of several that have gone past 200k. They can handle around 300 HP with no trouble.

 

Well, something went wrong, and in not that many miles considering how I use the truck. When I go to the Standard Transmission website, it looks like I bought a 12" OEM clutch. I've got an email into SBC asking for pricing on the 13" clutch. And while I've got it apart, I'll put a new coupler in there and see if I can tighten up the t case too. Looks like Standard Trans is making a cast iron t case extension housing now to replace the aluminum one, and I may go for that too as long as I am tearing everything apart...

 

I would go with a Sachs over a 13" Con-O. I think it's a tougher clutch and the price is lower.