My dad's truck is a 90 W350 Cummins 4x4 with auto tranny.

He's been having a problem with the transfer case coming out of gear. He uses it to pull a trailer hauling large draft horses. He say's when he get's into a hard pull the t case will sometimes sound like it's partially coming out of gear and it makes a "ratcheting" sound and slows down. When he lets off on the throttle it will stop making the sound and go back into gear and he can continue on. It dosen't seem to do it during normal driving only on hard pulls.

He called a tranny/t case shop and asked them about it. The guy said it's a common problem with those t cases no matter what brand of vehicle they were put in.

Someone on another site said they have had some internal C clip breakage with theirs. Could this cause the problem? Has anybody had this happen? If so what's the fix? The shop said it's no problem, nothing that $1000 bucks won't cure.

Will his truck have a NP208 t case? I've always thought that those big t cases would be nearly indestructable......Larry

 

I'm sure the transfer case is a NP205. And yeah, these things can take a beating

 

It’s hard to explain what is normal, but it’s very common for these trucks to rattle loudly from the transfer case lever under load. In most cases, there is nothing to worry about, the noise is just looseness in the shift linkage. Try holding the lever with your hand while he gets the truck under load, if it is just a loose linkage you will be able to silence it.

Search on this forum for transfer case problems, and you will find many hits for noises/rattles and very few hits for any other troubles. Other than that, the cast iron, single piece case, all gear drive NP 205 is the toughest, most reliable, and most durable transfer case ever built for light duty trucks.

Keep us posted.

 

I agree, the 205 is a tough unit. I'd have a look at the shift linkage. You may not have an internal problem at all, but just loose linkage. If you're not fully engaging 4x4, it may pop out.

A caution with regard to holding the lever in place though. I was in an international scout off roading with a buddy, who held his lever in place because it would pop out. It violently came out of gear and broke his index finger as he was reaching for it. He later fixed his linkage and the problem was gone until he rolled it. Now it's not doing much all.

Anyways. I hope it turns out for you

 

It calls for atf I believe I switched To gear oil and it seemed to tone down the noise a whole lot. They are a noisy sort but they do hold up to the diesel pretty well.Its whats inbetween the engine and the Tcase that my problems usually occur <getrag360>Althoug I love em they have leakage characteristics they completely befuddle me.

 

The gear drive 205 calls for gear lube from the factory. It is the chain drive cases like the 208 that use ATF.

Mine has GL5 in it right now, will be going to amsoil 75-90 as soon as I get the new seals installed, leaks bad enought as it is.

I am surprised mine does not have trouble (knocking on wood) since when I bought the truck it was almost bone dry, maybe a pint of lube in it at the most.

Andy

 

Crawl under and lift or wiggle the drive shaft at the front output and see if there is a lot of slop. Might be some wore out shims.

 

Not sure about a 90 but would assume the same as my NP205 in my 92. There is an adjustment for the linkage. I don't have manual in front of me but I believe you remove the shifter boot, Place 4wd shifter in N, loosen the 3 bolts, try and slide or push the shifter as far forward as possible, tighten 3 bolts, re-attach shifter boot. Then go for a ride to see if any better. It does just sound like loose or worn linkages. I also know that on mine there are a couple of think plastic slides?? that are on the shifter gate. They may have become worn which would cause shifter to be out of alignment. I have read where some people just reverse them so the worn part is at the other end.

With these heavy duty T/C's, they either work or they don't work.

 

Mine is a 91 auto, and min t-case kicks out onhard pulls somtimes and made a loud rattle noise underload as well, my linkage was loose, and it just quit kicking out of gear

 

Thanks guy's i'll take a look at the linkage and see if it needs adjusted.

I asked him today to describe the sound and what it's doing again. He said it sounds like two gears that have come unmeshed and are spinning against each other on the edges. He said the truck will actually start to slow down just like he's put it in neutral. When he lets off the throttle the gears slide back together, it goes back into gear and the way he goes.

Nuttymopar. If ya think about it could you check your manual on the linkage adjustments. Thanks, Larry.......

 

Redleg,

I have the slop you are speaking about happening. It doesn't pop out, but I'd like your advise on fixing the problem. I haven't worked on a 205 before, so I'd greatly appreciate your insight. I have also developed a humming sound down there when first moving on really cold mornings. it goes away after a mile or so. I thought it would be the bearings, and probably still is, but I don't know about the shimms.

Is she going to blow on me? I'd greatly appreciate your advice.

 

Mine had it when I got the truck. Had the thing taken out by a heavy truck/ trailer repair place, that I trust. They looked at it and said it had been worked on previously, but appeared that they used the wrong size shims. Replaced the shime and seal and everything was good for awhile. Then, when I pulled my tranny for a rebuild, the locktie on the front driveshaft must not have taken (middle of winter, outdoors). My bolts came out and the driveshaft fell loose. I had to get new bolts for the yoke (dealer only). When I put the shaft on, the slop was there again. I had been plowing and can only assume the shaft got loose and screwed up the new shims. I can't be without the truck right now to take it back to the guy, but plan on tackling it when the weather brakes. I have been doing A LOT of plowing with it as is, no problems. The only side affect is vibration when in 2wd, leaving the hubs engaged. You may just get it on the list, but don't let it keep you up at night. Shouldn't be too long and I'll have a better answer for you. I'm gonna be talking to him this week. I just replaced tie rods and stuff, that may be contributing to the vibration when hubs are engaged in 2wd. I did my own alignment for now, I don't really notice any vibration in 2wd, hubs unlocked, or in 4wd. I've just been waiting on a possible spring upgrade so I wouldn't pay for multiple alignments.

 

Thanks Redleg,

I have the same vibration as well in 2wd with the hubs engaged. I was going to do the bearings in there, but I'm not sure now. The seals are definately shot though, so I'll have no choice but to do this. I'm going to look in my manual and have a look what's involved with the shims. Keep me posted when you get to yours. I really appreciate the reply thanks.

 

I am going to say a stretched chain and worn gears sounds like your problem and its not going to get better.

 

I believe it's gear driven, not chain driven. Anyways, I'm going to do the bearings as I recently got a wholesale account, and can now afford to.