Transmission or transfer case?

[rsm688]

Okay guys, well I will make the back story short. I just purchased an 06 H3 Adventure with 95k miles that I was told needed a new transfer case for dirt cheap, $4600 for it (long story, guys mom had cosigned on it and he wasnt making the payments and so she made him sell it to me for the payoff so that she would not have it messing with her credit anymore). Anyways the guy told me he had a mechanic at the local shop (small town so don't trust them) and said the "clutches in the transfer case had gone out" and that it needed a new t-case or rebuild it. He said you could drive it a little ways and then it would quit pulling.

So, today I decided to see what he meant first hand and take it down the street. It started and drove just fine at first, I cycled through all the 3 positions in the transfer case, it felt like it was shifting between them all properly. When shifting into 4 Low it made a loud clunk that sounded like it was coming from the front end or below the drivers seat area maybe (didnt get a good listen). Is that normal when shifting into 4 low on the H3s? If not does that sound like shot front differential bushings or a T-case internal issue?

ANYWAYS, i drove about 250 yards and all of the sudden it quit pulling like he said. I tried all the gears in the transmission and all 3 positions on the t-case and it wouldn't move an inch. Just seemed like it was all in neutral. When I went to put it into park quickly it made a grinding noise, I pulled back and then eased it into park with no grinding. When in park, as well as all the other gears/t-case settings, the hummer would roll as if it was in neutral.

Apparently from the previous owners description, after they vehicle sits for a bit or cools down then it will go into gear again and pull but will quit again after driving a short distance.


So my question is, does this actually seem like the transmission is the problem and not the transfer case? My knowledge of transmissions is pretty limited.

If this does seem like the transmission does it sound like it's toast and needs to be fully rebuilt/replaced or could it be something that is repairable?

Last question, if the transmission is toast, does anyone know what the cost to rebuild one is? I'm guessing I could probably get one out of a wrecked vehicle for a lot less and swap it in.


Any help would be greatly appreciated, I'm a little bit bummed as if it was the transfer case it would have been a quick easy swap.


Thanks,
Spencer

 

[digglesworth]

Did you check the fluid in the transmission?

 

[Best4x4]

Didn't the plastic shift fork make it go into N vs 4HI sometimes if it's broken? Thought I remember reading something like that once.

 

[rollerlocked]

I had a 700R4 2wd transmission that did similar to that , you could drive it until it was at normal operating temperature, then it would feel like it fell out of gear. No matter what position the shifter was in, it felt as if it was in neutral, after letting the transmission cool down for 10 minutes you could then drive it again for 3-5 miles at which time the transmission fluid was up to temperature again and same occurrence . Had a transmission shop rebuild the transmission and problem was then resolved.

 

[alrock]

No clutches in a transfer case, so it would be tough for those to wear out.

When I had a transmission problem, it was similar to yours in that it would fail when it got warm. For me, it was a failing transmission fluid pump, which means pulling down the transmission, which means you might as well get it rebuilt or replaced.

Tired fluid could also create that issue in that it might work when cool but fails when warm. I second that you should check the trans fluid, both for correct fill and for any discoloration or burnt smell.

 

[MaxPF]

OWhen in park, as well as all the other gears/t-case settings, the hummer would roll as if it was in neutral.

If the truck rolls with the trans in park then it almost certainly means the t-case is stuck in a neutral position. My guess is either the shift fork or the shift motor is bad.

 

[rsm688]

Thanks guys, yes the fluid in the transmission was full or close. I just glanced at it for a second last night I will go look and smell it closely.


Max, could the t-case be stuck in neutral even if I can hear it shifting between 4hi/4lo/etc? I figured if it was a transfer case problem it wouldnt happen like it was where it goes out after a few minutes and then start working again after sitting.

Any ideas on the transmission grinding as shifting into park, other than slowly easing it in? And what about the clunking from the front end when shifting into 4-lo?


Thanks,
Spencer

 

[USMC_TOP]

If it rolls in park it must be the t case. Or someone took your driveshafts..............

 

[rsm688]

Thanks guys, that makes me feel better. I just instantly thought "oh crap, transmission" when I saw firsthand what it was doing since it only happened after warming up or driving a little ways. Does anyone know what might cause it to slip into neutral after a very short drive for a minute or two and then it would work again after sitting? I just couldn't think of anything that could make a difference based on warming up or a short drive in the t-case. I figured if the chain or something was shot it would not move at all, maybe when it gets rolling it jumps into neutral somehow? Still doesn't explain why it would work again after sitting which is what confuses me

 

[rsm688]

Other than losing the gears though it drove good, didn't notice any binding or anything and it shifted from 1-2 just fine. Maybe a slight bit harder than normal but its got 96k miles, I will probably swap a new valve body into the tranny after getting the t-case issue fixed to improve shifting.


Also, any ideas on the loud clunk from the front end when shifting into 4-lo? Front differential bushing? Another thing that confused me and made me think it wasnt the transfer case is that I could hear it engage into the different settings and it still would roll so I figured it wasn't in neutral but maybe it's just clunking trying to engage and not actually doing it

 

[alrock]

A loud clunk is normal when shifting into 4 low

 

[MaxPF]

Thanks guys, yes the fluid in the transmission was full or close. I just glanced at it for a second last night I will go look and smell it closely.


Max, could the t-case be stuck in neutral even if I can hear it shifting between 4hi/4lo/etc? I figured if it was a transfer case problem it wouldnt happen like it was where it goes out after a few minutes and then start working again after sitting.

If the coupler that slides into the range splines is barely engaged it can pop out. If it's a worn fork then you will hear the motor trying to shift but the coupler won't fully engage, if it engages at all.

Any ideas on the transmission grinding as shifting into park, other than slowly easing it in?

If the t-case is in low range and you are rolling even at a very low speed when shifting into park you will get a grinding from the park pawl as it skips over the lugs on the output carrier. Make sure the vehice is completely stopped before shifting into park, and release the brakes SLOWLY after you shift into park so the vehicle doesn't roll too quickly before the park pawl engages the output carrier.

If you park on an incline you should always engage the parking brake, ESPECIALLY in low range. Believe it or not vehicles have rolled off cliffs because of this.

 

[rsm688]

Thanks alrock and Max, I'm going to be pulling the transfer case out on Monday and going to tear it apart and see what it looks like. I am going to go ahead and order a new shift fork as I'm sure it's shot and it's an 06 so should be plastic anyways. I'm also going to order a gasket (if it uses one, gotta look if its gasket or rtv). Anything else that I will for sure need to replace while I've got it apart or is everything else all things that need inspected for wear/damage?