Front diff 4x4 noise ?

[Maverick]

My 2500HD has been a very quiet truck in 4x4 operation. I drove it 2 weeks ago in 4x4 and all was quiet. I drove it last night and wow, is that front diff (or t-case) loud. Humms and has a bad vibration, especially above 50 mph on a slight acceleration. I just turned 50K miles on it and this problem just started within the last couple weeks. I tried a search but didn't find any answers. Anybody got a fix or answer? I thought I read there was a TSB on this?

[ 03-25-2003: Message edited by: Maverick ]</p>

[WillowCreekStable]

I did have this happen once, but couldn't get it to do it again. Same description exactly. Only once though. Does yours do it all the time?

Maybe out to lunch, but had a similar problem with my last truck, a

[Maverick]

Its at the stealer now. He told me its a $500 bill to pull and replace the front diff just for labor, no parts. Six hour job. Sounds like I am getting hosed big time. I'll find out the total bill and if its fixed later today.

[Maverick]

They said the front pinion bearing was shot and also replaced the side bearings as they were pitted. I guess the stock oil is junk that they put in these trucks. I brought Amsoil with me so they are changing the front of course and also the rear diff and t-case over to Amsoil. This is sad with only 50K. My dually has almost 120K and all is well so far. Been running the Amsoil in the dually for most of it life though. Everyone....change out that front diff oil ASAP! They are also updating the breather for synthetic oil use. Wasn't there a TSB on this? I'll find out the bill later.

[Modified]

Maverick ;


Hoot had a post about this earlier. Problem with using stock conventional 80W90 in 9.25 inch front axil in climates &lt;-10 Deg. F.
See Hoots post: http://forum.thedieselpage.com/cgi-bin/ultimatebb.cgi?ubb=get_topic&f=7&t=004654&p=

http://service.gm.com/gmtechlink/images/issues/feb03/TLFeb03e.html#story13

GM's new recomendation is 75W90 Synthetic Lube in front 9.25 axil and ensure new, white, synthetic compatable breather cap is installed.

[Maverick]

Modified,
Thanks for the link. I remember reading Hoots post. Unfortuatly I bought my 2500HD used and was not a new retail customer. If it was purchased new maybe I could get my money back? Bill was $748 bucks. 6.5 hours of labor. They did swap out to the white cap for me.

Looks like the TSB came out last month. Feb03.....its a little late ya think. I imagine the damage was already done mid winter and finally decided to show up.

[ 03-26-2003: Message edited by: Maverick ]</p>