ok, so last night i was coming back from a softball game in which i really screwed up my foot, 1st highlight of the evening! so on the expressway i started getting a really nasty vibration between 40 and 50 mph. so i took it slow and got home and parked her for the night. also, within about a mile of my house i also started hearing a pretty loud grinding noise coming from the tcase/tranny area at slower speeds, prolly 30-40 mph, and mostly when it shifted gears. so today after work i got under the truck and noticed that everything from the transfer case just behind the allison pan to the back of the truck is covered in tranny fluid. i did some reading on the pump rub threads and it pretty much sounds like the problem but what im wondering is where exactly should the hole be in the tcase? if anyone has a picture or a diagram that would be so much appreciated cause ive never messed with a tcase so i really dont know much about it. and im going to call eric at MA tomorrow to hopefully order the parts that is if i can afford it this week, anybody have a rough estimate for me on how much its all going to be to fix it correctly so this doesnt happen again? im gonna do the work myself so i really only need the parts cost. also by fixing this is there any chace that it will help with the horrible clunking that ive been getting from the drivetrain when accellerating and shifting from park to drive and so on? sorry for the long post and thanks in advance guys

i did some reading on the pump rub threads and it pretty much sounds like the problem but what im wondering is where exactly should the hole be in the tcase? if anyone has a picture or a diagram that would be so much appreciated cause ive never messed with a tcase so i really dont know much about it.

I think they say the rub hole developes 5 flange bolts counter-clockwise from the drain plug. Not positive.

http://www.dieselplace.com/forum/attachment.php?attachmentid=6635&d=1121902060 (http://www.dieselplace.com/forum/attachment.php?attachmentid=6635&d=1121902060)
http://dieselplace.com/forum/attachment.php?attachmentid=11087&d=1131842051 (http://dieselplace.com/forum/attachment.php?attachmentid=11087&d=1131842051)

If it is the loss of oil in the transfer case that is causing the grinding and clunking you are probably going to have to rebuild your t-case. I would venture a guess that the inards are toasted if it was ran very long without oil especially to the point of making noise. Mine never made any noise and was totally wrecked.

If it is the loss of oil in the transfer case that is causing the grinding and clunking you are probably going to have to rebuild your t-case. I would venture a guess that the inards are toasted if it was ran very long without oil especially to the point of making noise. Mine never made any noise and was totally wrecked.

wonderful, thats just what i need! after it started vibrating i probably drove about 5 miles thinking it was either a tire seriously out of balance or maybe a bad u joint then the grinding started on my street probably only 1/4 mile from my house and i havent driven it since then. going to try to pull the tcase tonight after work so maybe i can get a good assesment on the damages, also have to call eric today and see how much its all gonna cost. this whole thing is really pissing me off cause this problem should never have happened and GM knows it and hasnt done anything about it. and this is my first GM product ever and i love the truck but as far as quality goes im a little dissapointed right about now. anyways, thanks for the help so far guys

Again, I would say my truck got at least 3000+ miles dry before any weird noises caught my attention, then another 300+ miles to get home and found out about this whole pump rub issue. I did not have any damage on the forks or anything other than the rear case half and maybe alittle scoring on a bearing, But I replaced the rear half and pump housing with the M/A Upgrade, and filled it up and all is well. I do have a slight sing of a bearing, but nothing to noticable, I would have to point it out to the novice, but the motor oil made it quieter, and less noticable.

Do not write off your case yet, take it out and inspect it first, then figure out if you need a new case.

Is GM or NVG who makes the T-case even acknowledging that this is an issue yet?

Here's some more pics. Last one is my entry application to the pump rub club.

http://www.dieselplace.com/forum/attachment.php?attachmentid=12968&d=1135737108

http://www.dieselplace.com/forum/attachment.php?attachmentid=12967&d=1135737108

http://www.dieselplace.com/forum/attachment.php?attachmentid=38884&d=1178475996

Currently no GM dealership in my area seems to know of the issue, the problem is that when the rub happens most are unaware of the problem until its too late. At this point the transfer case is replaced either under warranty or the customer pays. Either way the problem is never corrected and a new transfer case is installed, its bound to be out of warranty the next time around. I found out no one believes you when you discuss this apparent poor design in the case. I only gained creditbility after showing the dealership, my company fleet manager, and my friends my case half and original pump part. At this point the dealership said it was a random problem. The only way to gain any national creditbility is if some other problem surfaced as a result of the transfer case failing, such as the leaking fluid was to start fires under several trucks and god forbid some one died. As for me, I will make anyone willing to listen aware of the problem.

well, we pulled the tcase last night and even before we started pulling it we noticed a nice size crack in the rear adapter housing between the ally and the tcase. so we took the case off and the adapter housing is cracked six ways to sunday, inside, outside, it really looks pretty bad like if i drove a couple more days like that it could have cracked right in half. you could actually push up on the tcase and watch fluid pour out of the adapter! luckilly it doesnt look like i lost much fluid at all so im not really worried about anything else being bad. i am wondering what caused it to crack but from looking at the description of the new part on erics website it looks like bad ujoints can cause it and i know mine have been bad for a while ive just been too busy and lazy to change them, guess i learned a lesson there. so thanks again for all the help guys, i really appreciate and ill try and get some pics up to show the damage later on.

oh, and MGWSSTG1, i did stop in to the local chevy dealer yesterday to ask about the pump rub problem and the service guy seemed to not really know anything about it, said it wasnt really a problem that they see... dont really know if he was lying to me or not but its just another reason that i would never take my truck to them for anything!

So, while you've got it out and waiting for another rear adaptor, time to install a Merchant Automotive pump plate and invest in a transfer case brace?

What is it about the cracked adapter plate that causes the grinding noise you were talking about?

What is it about the cracked adapter plate that causes the grinding noise you were talking about?

that im not sure about yet, maybe the transfer case was moving enough so that the drive shaft was rubbing on the yoke or something? im really not sure but im going to hope for the best, nothing else looks damaged at all so im hoping im ok. im also going to look into getting the fix for the pump rub to prevent it from happening in the future, not sure if i can afford it along with the adapter housing this week or not but im gonna make sure to do it real soon.

Hey, Check your u joints if you knew they were bad thats probibly your clunking noise too. Definately pull the trans when you put your new rear adapter housing on, the trans starts to fall apart when you take the housing off in the truck I tried it and learned the hard way. I would also put the brace on...I built my own if you have a mig welder and some patience.

Best of luck, J

Hey, Check your u joints if you knew they were bad thats probibly your clunking noise too. Definately pull the trans when you put your new rear adapter housing on, the trans starts to fall apart when you take the housing off in the truck I tried it and learned the hard way. I would also put the brace on...I built my own if you have a mig welder and some patience.

Best of luck, J

new ujoints will definetly be going on. i talked with eric this morning and hopefully i will be able to get the housing in the next day or two. he did tell me about the tranny, i would rather not pull the whole tranny out if i dont have to but if its not that hard to do maybe i will. eric suggested getting the back end of the truck up as high as possible as well as the tranny so nothing slides out if i dont pull the trans. so from your experience does that sound doable if i can get the back end up really high or should i still pull the tranny? what happened to yours when you pulled the housing and from where im at now with the tcase and driveshafts out is it that much more to pull the ally? as im typing this im starting to think i shouldnt be a pu**y and just do it right but i really need the truck this weekend and i only have one or maybe two evenings to work on it this week so time is very limited.

You really should take the tranny out it isnt that bad once you get the crossmember out. I jacked the back end of my truck up and the tranny up and when i took the housing off i still had something in the center of the tranny fell and when i went to put the housing back on it wouldnt go. I would just do it right the first time and dont go through cracking a new housing or having your tranny fail after you get it back together. If you do it in the truck you might end up where i was reassembling the back half of the trans with the atsg manual.

J

guess i should just bite the bullet and pull the tranny and ive had the crossmember and all that out before when i did my lift so thats no big deal, from there is it just the bolts on the bellhousing then slide the tranny out? also, is there a gasket that i should replace when putting it back in? i didnt see one listed on erics site but i would think there would have to be something there.