Chevrolet 4WD vehicles

Date 09-10-2010 15:52

I have an '04 GMC 1/2 ton Z71 - I replaced my t-case at about 98K miles, due to a hole being rubbed in it. I'm no mechanic, so I can't be too technical, but here's what the mecahnic told me - this is VERY common on that style of t-case. The design is poor and most go out around 100K miles. It's supposedly due to poor lubrication and the chain heats up and stretches, which causes it to rub against the housing and eventually create a hole.

I didn't catch mine soon enough. I heard a noise that sounded like I was dragging an aluminum can down the road, waited to long to get it "professionally" looked at, and it was too late.

A rebuilt t-case was $1400, if I remember right. cost me damn near $1900 total. Yep, that t-case canceled my Colorado trip last year......

By jwright650 (*****)

Date 09-10-2010 16:00

This breifly explains the issue......from what I've found on the web(google "pump rub").

http://www.youtube.com/watch?v=afmcNkgKuMY&feature=player_embedded#at=23

By weldwade (***)

Date 09-10-2010 20:48

I've got a 93 GMC Dually. well over 200K don't know for sure because the odometer quit but I have never had this problem? I can't watch youtube here at work so is it just a model year(s) thing of 1/2ton thing etc??? I wanna check into this before I ruin something! Thanks for the info john, I never would have known till it broke.

By Cumminsguy71 (*****)

Date 09-12-2010 04:55

Might just be something on newer style Chevy's Wade. Can't recall what they are/were running in the trucks and such a few years ago when I was cranking wrenches but can say it is most likely not the same type/style t-case that is in your 93. Seems all the manufacturers have these little quirks that they neglect to inform us consumers about then something happens and you find out everybody and their brother has had the same problem. About 80% of the problems at the Caddy dealer were the same repairs over and over again, you would not believe. Parking lot diagnostics is what I called it. You could read the complaint, climb in the car and by the time you had it pulled into your stall you were headed towards the parts department(if warranty) and to the computer(if not warranty) to write up a repair quote, never popping the hood or raising it on the lift. Crank sensors on the Northstar are a good example, paid 3.8 hours or something, 1 hour diag, 2.8 or something like that to change them. Could diag before you got in the shop, have raised on the lift, sensors(2) put in and out the door in 30 minutes. I enjoyed those days, gravy was just drippin' on the floor around me!! Front diffs on the tahoes, yukons, escalades, same way. Guy doing driveline in the shop was always doing a front diff, seemed like he could close his eyes and bang them things out. It kinda sucks that something as common a problem is left in our(consumers) hands, not considered an issue they say......yeah ok. Anybody heard about a VP44 on a Dodge Cummins? It's not a matter of IF you'll replace it but a matter of WHEN, same situation.

By weldwade (***)

Date 09-12-2010 22:47

Thanks Shawn. It has been a good truck. I hate the front end but love the ride. I had a 04 Duramax it was a good truck also. My 08 Ford is going to get gone ASAP Worst truck I have ever owned. Looking at the Dodge but I may just forget the new ones and drive the old GMC and save money for a while. I hate all the new emissions BS on the new trucks, I'd like to take it all off and shove it up Al Gore's backside. tried to get my dad to sell me his 06 5.9 Cummins but he just laughed!!!

By jwright650 (*****)

Date 09-13-2010 11:27 Edited 09-13-2010 11:31

From what I can find through google....97-07 "4WD's", all Chevrolet models, gas and diesel. Friend of mine just had this issue with his 99' Tahoe on a trip to the beach.
Transfercase tailshaft housing is magnesium, pump inside is aluminum, the pump floats on the tail shaft and has several square tangs that keep it from spinning, these tangs have a little play between them and the square indentions, cast into the housing, that they are seated in. This slop allows the pump to rock a little each time you get on/off the gas and eventually wears a hole in the side of the housing allowing the fluid to escape while driving.

There is a plate that you can buy to go inside the housing that is supposed to remedy this problem.

http://www.thedieselpage.com/reviews/tcase.htm

Just keep a check on the transfercase fluid levels and you should be OK.