Transfer Case Q

zedbear · November 22, 2009

Well, I finally took the truck to a dealer to let them diagnose a clunk in the driveline and a "hum" from the front end at speed. The verdict was excessive backlash in the t-case. They wanted over 500 bucks to take it out and dissassemble to see what was wrong but I politely declined, paid the initial diagnostic fee and took her home.....

I do know the "clunk" when shifting to reverse was coming from the t-case because I could feel it when I had the wife shift it in and out of reverse with my hand on it. But the humming noise I'm not so sure. It SEEMS to be coming from the front end when I'm driving it but it's hard to tell for sure. Is it possible for the t-case to give that impression when it's bad?? It seems like the hum/growl kicks in when it shifts into o/d at like 45mph or more, like there is a resonance setting up when it's at low rpm's and in o/d. It comes and goes and isn't constant. The front hubs look pretty new......

Nytemare · November 22, 2009

Probably your front diff bearings.

minibike132 · November 22, 2009

Front diff bearings are alot more common for the growl. Excessive backlash will cause a growl though too. It's possible that it's both.

zedbear · November 22, 2009

I see....

So, what are my options as far as the t-case goes? Used would be cheapest but most of the ones I'm finding locally are 400 bucks or more and often have in excess of 100K miles.

List price for rebuilt GM units are around $1400. On rockauto.com, they have rebuilt units from "Retech" for around $900 (minus the encoder motor).....

Anyone know the going rate for having this one rebuilt at a trans shop?

Thanks.

Nytemare · November 23, 2009

About 900 bones would be my guess.

you need to have your front diff looked at too remember...you may have bad bearings in there.

minibike132 · November 23, 2009

About 900 bones would be my guess.

you need to have your front diff looked at too remember...you may have bad bearings in there.

Agreed, front diff is much more common. I would probably start my focus on making sure that doesn't need bearings first.

Nytemare · November 23, 2009

Also a lot cheaper...no use rebuilding a T-case for 900 bucks to find out nothing was wrong with it.

zedbear · November 23, 2009

Well, the dealer looked at the truck and didn't mention the front diff having a problem (they better have looked at it since I paid them to diagnose this! ). There is also the excessive slop coming from the t-case as well.

I changed the front diff fluid the other day and there was a pea sized "puff" of metal shavings on the drain plug magnet. Normal?

Nytemare · November 23, 2009

yeah...that's pretty normal...there is a chain in there, so shavings are common.

From experience, the bearings in the front diff do go out quite often. More often than a T-Case anyway. That's where I would start.

If you experienced the issues in 2WD, than just pop the front shaft out and go for a drive and see if your still hearing the same noises. Than you know the T-Case is totally out of the front system.

alwcurlz · November 23, 2009

Probably your front diff bearings.

+1 Yep, that's a problem I encountered with my truck. Cost about $700 to have it taken out, new bearings and seals put in and installed.

alwcurlz · November 23, 2009

I see....

So, what are my options as far as the t-case goes? Used would be cheapest but most of the ones I'm finding locally are 400 bucks or more and often have in excess of 100K miles.

List price for rebuilt GM units are around $1400. On rockauto.com, they have rebuilt units from "Retech" for around $900 (minus the encoder motor).....

Anyone know the going rate for having this one rebuilt at a trans shop?

Thanks.

What year and how many miles on that truck?

I have an extra front diff that may work for you if you need it. It was pulled from a truck with under 13,000 miles and works with the 373 ratio rear end.

As for the transfter case, I had the same shop that repaired my front diff look at the transfer case because of noises and some slop in the driveline but they found nothing wrong with the tcase and said that these tcases have a good longevity. I personally would just rebuild or replace the front diff first. My front diff had damaged races on the input and one output bearing which made a growling sound.

zedbear · November 26, 2009

Regardless of the front diff, t-case slop has been verified by the dealer (and me). I'm more concerned about correcting the clunking and sloppiness first before addressing noises that may or may not be coming from the front end. Does anyone know about or have experience with rebuilt ones you can by from the dealer or aftermarket?

Also, if I find the front diff has issues, can the truck be driven without it?? I could take it off and take it to a shop for a rebuild.....

minibike132 · November 26, 2009

Regardless of the front diff, t-case slop has been verified by the dealer (and me). I'm more concerned about correcting the clunking and sloppiness first before addressing noises that may or may not be coming from the front end. Does anyone know about or have experience with rebuilt ones you can by from the dealer or aftermarket?

Also, if I find the front diff has issues, can the truck be driven without it?? I could take it off and take it to a shop for a rebuild.....

I don't have any experience with any aftermarket units but the GM rebuilts are usually less then the price of rebuilding the old one and come with a warranty, not sure how long though. If I had to guess 12months 12,000 miles.

No the vehicle can not be driven without a front differential in it.