Archived Help -- Transfer Case grinding, can't drive truck

[Coalsmoke]

If anyone thinks they may know what is wrong, please add your 2 cents. It started with myself and another rebuilding my transfer case over the weekend. After re-installation, I test drove it and within 5 seconds of driving heard a deep twang / knock sound. Then, shortly after, I would get a grinding sound from the transfer case, but only when accelerating hard and in 2wd, (no noise apparent when in 4wd). I pulled it back into the shop suspecting the somewhat common tailshaft c-clip to be broken and expected to fix it with the improved version of that clip, only to find that the original c-clip is still in position Now, I was pretty sure that everything went back together ok (unless we put something out of placed), and there is no unusual slack in the system when I turn the tail-shaft by hand, but obviously something is not right. I am afraid of pulling out the transfer case (big job), opening it all up and seeing nothing out of place, just as was when we put it together.



I am wondering if a c-clip came loose inside, but we made sure that they were snapped down good, and there is no crunching sound as if it were caught in gears. Thinking about it, those clips were really tightly snapped in, and I doubt that they could slide off, but I am completely bafled???



Ideas? help?



thanks in advance,

Stephan

 

[JFaughn]

Sounds like its possible that the shifter does not have enough reach or through to put all the way into fully ingaging the gear , worn or maybe missing plastic pads on fork, I havent been into one of these for a long time , this is just a generic guess.

 

[Coalsmoke]

The forks were worn down, but I have built them back up and have put on new pads, the pads fit nice and snug into the collars.



I took the transfer case apart for the third time everything seems to be in place, replaced the snap ring the is known to go with the inproved version, put it all back into truck and it still makes a grinding noise in 2wd when under load. I have run out of ideas. I would be very greatful if anyone could help.

 

[crudd]

Switch the vaccum lines on the t-case (basically shifting front axle into 4x4 while t-case is in 2x4). Does it make the noise now? You could have a vaccum problem. Check the lines and the switch in the t-case. I recently went through the same thing, however when we pulled my case apart, it looked like a box of marbles... totally junked. Good luck.

 

[Coalsmoke]

Ok, thank you. I'll try that. I'm confused though how a faulty vacuum system would mess up the transfer case because it didn't seem like there were any parts in the transfer case that would move due to vacuum, except maybe for the little switch on the top of the case? Or, is it maybe that if the CAD doesn't engage / disengage right it would spin the rest of the front drivetrain, and transfer case internals, even when the transfer case was put in 2wd, thus messing something up? Either way, I'm going to try switching the two lines that run infront of the transmission support. Might even be a good idea to try opening the CAD up to see if the collar is sliding over. Thanks for the info. I'll get back to you.



Stephan

 

[Coalsmoke]

Still no luck

Alright, I took off the CAD and the little collar was not slid over the two axle shafts, and the CAD does not seem to be working. I tried shifting into 2wd and 4wd with the truck running and I also bypassed the transfer case switch with some tubing to see if the switch was broken but the CAD forks still didn't move, so I guess I can rule out that idea of the CAD hooking up the axles while in 2wd. I do know that I need to fix the CAD though, but that is the least of my worries right now.



A few of us were brain-storming and thinking that maybe the spring that forces the transfer case shift-fork back to position has lost its springyness and is not pushing the big shift fork clear of the gears. Sound plausible? The only thing that bothers me is that the transfer case always seems to work fine on the bench but once we put it in the truck, it grinds / rattles under 2wd acceleration. This leads me to think that maybe the torque when in 2wd is shifting something inside, but I can't think of how that would actually work, as all snap rings look fine

 

[crudd]

Man... that's getting over my head now. If it's not one thing it's another, especially with these trucks.

 

[Coalsmoke]

No worries, I guess I'll pull it for the 4'th time and try the spring. Texas Diesel gave me a parts diagram on pdf for me to check over too.

 

[JamesRoss]

Well I sure hope you find the problem, I'm experiencing the identical problem. When I accelerate, go around a corner or when it just feels like it I get a sound like someone raking a stick across a washboard. Only I know its not that simple. Its the gremlin of the month, I've already replaced in the last week the injector selenoid with a manual cable, $19. 00 (sorry Chrysler I'm not giving you $380. 00 for a selenoid when this is the third one that went) a bad front u joint on front drive shaft $15. 00 ( Chrysler wanted $78. 00) installed a new right front hub assy $#128. 00 (Again Chrysler wanted $580. 00) and just this evening installed the posi lock to manually lock out the 4 wheel drive in the front axle. This was a break even cause again Chrysler wanted close to the posi lock amount for the vacumn switch for the CAD And guess what, I STILL have the noise. The rest of the front end feels great but this noise is telling me its time to get expensive. Let me know if you determine the cause. As with mine when I engage the 4 wheel drive the noise/problem ceases. I'm at a loss.



1995 2500TD 5 spd Completely stock, work truck, Plows, hauls, Pulls, I love it cept when these gremlins appear.

 

[Coalsmoke]

It sounds like the snap ring is broken on your transfercase. Get a new seal for the rear of the TC, get some RTV and get the snap ring fix. Take off your rear drive shaft, have a bucket handy for a few drips. take off the rear snout of the transfer case. There should be a snap ring holding the main-shaft to the bearing you now see. If broken or bent, replace with the fix and re-assemble.



For me, I labbeled only one part and I managed to label it wrong, go figure eh. Once we figured that I had the collar in backwards, everything worked fine. Tooks five times though.

 

[JamesRoss]

After speaking to a friend with a trans shop and letting him examine the truck he's provided me with a solution that so far sounds the best. We placed the truck on a lift and were unable to duplicate the grinding with all four wheels off the ground. He sumizes that the trhrust bearings either in the trans or the case are worn allowing the gear clusters to basically "torque up" moving back and forth on the shaft independent of other drivers actions, like when you let of the pedal, hit a bump or go around a corner etc. As you accelerate and decellerate one shaft will ride against the other moving in back and forth (all actions having an equal and opposite reaction), from how he describes it all it would take would be a few thousanths to allow those gears to mesh and collide causing this noise. Fortunately you sound like you have the ability

to do the work yourself. I called the guys at standard trans, I think they're in TX, OH 18007838726. I got the number out of the TDR. They were half the cost of a rebuild here in NJ and the shipping wasn't bad. Here in the socialist state of NJ they want $2600. 00 for a rebuild BEFORE they put the truck on the lift. Good luck. Not a happy camper.

 

[Coalsmoke]

check your snap ring first. That is what happens when the snap ring goes, it allows the mainshaft to walk so the gear clusters interfere under load. it will cost you $20 for the kit, extremely easy to install, and all you need are two wrenchs, one for the driveshaft and one for the 4 bolts on the tailshaft housing. Do yourself a HUGE favour and check into this first. It will save you $2560.

 

[JamesRoss]

Advice dead on the money.

Hey Coalsmoke ! Thanks a thousand times over, your advice about the snap ring was dead on. The unusual thing about the ring though when it was pulled was NOT that it had broken but that it had worn thin, specifically in the middle area of the clip (opposite side of the opening) where it finally became so thin that it just felt into pieces. My son discovered a few micro thin slices of the ring left in the end of the case. No abnormailities about the bearing races could be found. I guess they go every so often. I'll have to keep another one in my glove box for the next 215,000 miles Thanks again JR

 

[Coalsmoke]

Hey, glad to hear it worked out well for you and I'm happy to have been able to pass along the info. Having to split your transfer case 7 times (5 times in and out of the truck) will make a person familiar with its internals :-laf

 

[BILLYGEE]

same problem maybe

I got the noise and feel also... Only problem on mine is to get the tailshaft off of the transfer case, there is a snap ring that you have to spread while wiggling the tailshaft to get it off... bigger problem is the access port is on the top of the tailshaft housing... how do you accomplish this with transfer case in vehicle? I can see the snap ring behind the bearing that causes problems from the rear where driveshaft goes in, it looks okay from that view but as yours was maybe mine is worn thin... Noise isn't getting any better. Ain't looking forward to pulling transfer case but I may have to. Rather spend my weekend fishing.