Hello everyone. I have a 2010 Hummer H3 base model with 56,000 miles on it. It has a Volant CAI, GM Performance Exhaust, and a PCM for Less tune.


When I leave the car outside and go in to work for the day and drive home it doesn't seem to want to shift as easily into the higher gears (around 70 + MPH). I can be going about 75 and had it at 3,500 RPM and it may not shift which has me a bit worried. It usually does eventually shift. As the car warms up it does get better but it takes me about 20 minutes to get home and it's still not as good as when it's warm out.


When I part my truck in the garage and drive to work no issues. It runs just fine.


Some background that may play into it:


I recently (about 2 weeks ago and maybe ~200 miles) changed the oil in my transfer case for the first time (both my first time changing oil in a transfer case any the cars first transfer case oil change). I used AC Delco Dextron VI as instructed in the manual. The day or so after I did this the temps dropped below freezing so I don't know if this could be caused by my t-case oil change or if it's just b/c of the weather. I haven't noticed this in past winters but I could be a bit paranoid b/c this was my first time changing the transfer case oil and I'm not a mechanic by any means.


So any ideas? Could this be an issue from me changing the oil from my transfer case? From what I know about transfer cases, they don't have anything to do with the transmission shifting, correct (I guess I want to be sure I didn't mess anything up).


Thanks in advance everyone,


Jason

 

I don't think changing the oil did anything to your problem,


it's just you are paying too much attention


my 1-2 shift will take about 2 mins of driving then it'll shift at about 1.5k rpm otherwise it'll be at 2k rpm ~ weather that is 50'f+ that with lightest throttle and slowest acceleration driving behavior


so just baby it until it warms up


many cars won't go to overdrive gear until they are pretty warm anyways,




good luck

 

Thanks for the response. I think I may be looking a bit too much into the issue also but wanted to be sure. If I messed up with the t-case oil change (to little oil, too much oil, a little water got in, etc...) what would the symptoms be?

- Jason

 

I really have no idea
but my assumption is the same as yours
I can think of TC as an organizer of the 4wheels since it's in 4hi it's awd (I assume) so really nothing is going there it's in HIGH * that's all it's not like it has few gears in the TC that keeps shifting through


so it's just your are being paranoid after oil change




I am not an expert so don't take my words , wait for more official (educated answer)

weather in my area won't get below 50'f and I have to drive for 2 mins
then it'll lower the 1-2 shift points


cooler temps will have more effect on the symptoms

 

I'm referring to a lot cooler than that. I see issues around 25 F if it's been sitting outside fit an extended period of time.

 

Exactly!!!!

thats my point;
the cooler it gets the longer warmup it require

 

When I have the spare time, I let it warm up in the drive until I see the temp needle begin to move. Seems like it helps the transmission tremendously. Atleast feels more smooth.

 

dont leave it in gear to warm up
either drive it gently and don't exceed 2k rpm or leave it idling in ( neutral) to pump fluid into transmission