hwkchief

with a vehicle that old it could also be the u-joints on the drive shaft especially if the are oem. the oem u-joints are sealed and can't be greased. mine started to make noise around 130,000 mi.

beasticles

Thanks. I inspected the driveshafts last night for play and there was a little in the rear. If the center caps aren't the culprit, I will swap on the old wheels to see if it goes away. If the noise persists, I will look into swapping out the old u-joints.

beasticles

Quick update on this thread, I had my wife drive the vehicle while I walked along side it. The clicking noise was clearly coming from the center of the vehicle near where the transmission case/trans was (as far as I could tell). So I think I may have ruled out tires/wheels (unfortunately) and it may be coincidence I started noticing the noise when I swapped on new wheels. To put it in perspective though this could be very likely, considering I had only driven the vehicle once since I bought it before swapping on the new wheels. The "ticking" could have been there all along and I just didn't notice it.

Anyways, I went to change the transfer case fluid today...undo the fill hole, then undo the drain hole and... *drip* *drip* *drip* - the thing was damn near dry. PO really didn't take care of this thing which is concerning.

I filled it back up with Auto Trak II fluid but then got started on the power steering pump pulley replacement and didn't have a chance to drive it. I wonder if the ticking will be gone now that the T-Case is nice and full. I also wonder if my T-Case will need to be re-built soon as a result of the neglect.

73shark

Probably depends on how much the PO used it in 4WD.

beasticles

The good news is on that front, he told me (who knows how true it is) he only used 4WD once. It engages fine so hopefully with the some fresh fluid it will be okay. Will post an update about the ticking later once I finish the power steering pulley (which has turned into a full pump replacement since the tool I rented from Advance Auto stripped the existing threads on my pump for reinstall of the old pulley).

V70tdi

Its the oilpump in transfercase that make that rattling noice. Take a close inspection and i think you can find a hole in the case. Blow my transfercase last summer just because that fault and oil leak from the hole. Search on youtube and you will find where to inspect the case.

beasticles

Thanks. Are you saying the rattling is a symptom of the oil pump in the transfer case failing, or are you indicating that my transfer case as a hole in it somewhere I am not seeing? I am pretty sure I would notice if there was a hole in it, since I just filled it with fluid and didn't see Auto Trak II blue fluid pooling on the garage floor. I still have not yet had a chance to drive it since adding the fluid up to level, but hope to do so soon.

beasticles

V70tdi - I watched the video and will take a look for a hole in the location on the back of the tail housing for the rear driveshaft that it was indicating could be the culprit. I feel I would have noticed a hole, but perhaps it is just the noise from the anti-rattle clip inside the t-case indicating it will be about to give way.

How much of a PIA is dropping the t-case? In my Jeeps, I was always able to service them without removing the t-case from the vehicle, but there seems to be too much crap (e.g., cross-members for the frame) in the way on the Suburban. Thanks.

V70tdi

My English is not the top of the class but what i trying to say is that the pumphousing start to moves in its position at transfercase casing at the antirattle clip and if its going on for a time it will grind a small hole in outer case. See the videoclip i thing that explains it better than my swenenglish
I really hope that this isnt the fault in your car. For me it was to late when i find it out and got to change the whole transfercase
Drive it for a while and then lock for fluidleak.

beasticles

Thanks for your advice - very helpful. Pointed me to an issue I did not even know existed. Even if my t-case doesn't end up having a hole (which it very well might, where did all of the fluid go?), then as preventative maintenance I may install the pump upgrade kit to save myself down the road.

Here are some more useful links on this subject:

GM Transfer Case - Averting Disaster - Diesel Power Magazine

Hole in my Transfer Case - 2000-2006 & 2007-2014 Chevrolet Silverado & GMC Sierra 2500HD/3500HD - GM-Trucks.com

Will report back with an update once I inspect more thoroughly and put in a bit more seat time with the t-case filled.