Hummer Forums - Enthusiast Forum for Hummer Owners

Hey I just completed my first transfer case oil change (just hit my 50,000 mark). This probably isn't a big deal for most but for me it's a real confidence booster b/c I have no experience with this (I am very interested though) and don't know anybody close who can show me the ropes. So it's just me and the internet usually.

Just so you have an idea of my skill level here is what I've done myself so far:

Battery terminal replacement
Added a Volant CAI
Cleaned TB and MAF
Replaced TB w/a bored TB
Changed original PCM for a PCM For Less PCM
Installed the Lux gas cap cover thing
Installed the OEM mud flaps
Changed side view mirrors
Changed door handles
Installed Grill Guard
Replaced factory stereo w/aftermarket head unit, front and rear speakers, sub, and amplifier (this is the only thing I have previous skills with)

The transfer case oil change went well but I did run into a few things and wanted to post this to help anyone who it may help:

(I have a 2010 Hummer H3 Base Model btw)

The first mistake I made was the truck wasn't level (I know I'm a complete dumb ass). I drove it up on my oil change ramps (still haven't done my own oil change yet) to get some clearance under the truck to work. But I didn't think of the problems this might cause. What happened (as you can guess) is as I was filling there was a dribble of oil coming back out the fill hole. Nothing alarming but I did notice it. As I got down to the last bit of ATF and removed the filler a bit more came out so I quickly put back on the filler plug.

I saw I had a bit of ATF on the ground (not a lot but maybe 1/4 - 1/8 cup and still a bit in the bottle that I couldn't suck up) so I figured I should add a bit more. (Just an FYI - at this point I still didn't realized the truck incline was causing these issues.) I knew you could fill from the speed sensor port so I removed that and added in the 1/4 I figured leaked out plus a bit more. I then screwed in the speed sensor port thing and plugged in the sensor.

I took it out for a test drive an I initially noticed the delay in shifting. I looked at the RPMs and the Speedometer and the speedo was going wildly from 0 to around my current speed and back to 0 and such. Knowing I did mess w/the speed sensor I took the plug back out and unscrewed the sensor port thing and wiped it all down to make sure everything was clean. I then carefully put things back together making sure things were tight (but not too tight) and that fixed it.

I did realize that the truck should've been level so I did go back out and check to ensure I didn't overfill it by filling from the speed port (removed the fill plug and nothing came out). I've been driving it for a few days now and all is well.

So just in case any first time mechanics try this make sure things are level and if you fill from the speed port (you shouldn't have to if it's level :) ) and run into a speedometer issue it may help to clean things off and ensure everything is tightened.

-= iZzbO =-