Stg2Suby
Active VIP Member
I bought a 2009 Duramax last Feb with 28k on it, seemed to be well taken care of don't think it was chipped or abused but it did tow a 5th wheel or gooseneck so may have seen heavy towing.
Right away I noticed it was a bit noisy in 4wd, kind of a howl/whine seemed to be coming from Tcase. I didnt' worry too much about it last spring and didn't use 4wd all summer until last week.
Anyways a couple days ago (40k on truck now) at -30c the 4wd howl is worse to the point I think something is wrong. Howls at all speeds but really noticeable on deceleration in lower gears.
Any thoughts what this might be? Any known issues (besides pump rub) with this t-case or front diff? I'm assuming it's not front driveshaft balance issue although this would be nice as relatively easy to fix/upgrade with a CV shaft.
I deleted DPF and programmed it with EFI live so assume any warranty is voided, otherwise I would just have dealer fix it. I may still have to take it in and have them diagnose it but I won't be paying them out of pocket, if it needs work I'll take it somewhere else.
edit: how does the 4wd work by the way, is there a vacuum or electric de-couple sleeve built into front diff? Or is the frontend always turning the driveshaft back to the t-case?
Right away I noticed it was a bit noisy in 4wd, kind of a howl/whine seemed to be coming from Tcase. I didnt' worry too much about it last spring and didn't use 4wd all summer until last week.
Anyways a couple days ago (40k on truck now) at -30c the 4wd howl is worse to the point I think something is wrong. Howls at all speeds but really noticeable on deceleration in lower gears.
Any thoughts what this might be? Any known issues (besides pump rub) with this t-case or front diff? I'm assuming it's not front driveshaft balance issue although this would be nice as relatively easy to fix/upgrade with a CV shaft.
I deleted DPF and programmed it with EFI live so assume any warranty is voided, otherwise I would just have dealer fix it. I may still have to take it in and have them diagnose it but I won't be paying them out of pocket, if it needs work I'll take it somewhere else.
edit: how does the 4wd work by the way, is there a vacuum or electric de-couple sleeve built into front diff? Or is the frontend always turning the driveshaft back to the t-case?
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