Hi Hummer enthusiasm
I Have a hummer h3 2008 the joy of my life with a milage of 125000 mile.
My problem is as follow, the car move normally but when i stopped in a traffic light then try to accelerate the car won't shift and move slowly feels like it in neutral position with high rpm.
I have to switch the transmission back to P then to D so i can move again.

Please help
​much appreciated

 

Change fluid

 

The transmission oil not that old 21000 mile only, what i know it should last longer.

If changing it will solve the problem i will do it gladly

 

I think Hummerz must have been half-asleep. He didn't mention Sea Foam Trans Tune

 

OP not concerned with maintenance,check fluid, fluid condition/color, drop pan replace filter, flush transmission etc...

 

What do you suppose the life of a 4L60e Trans in an H3 (heavy FT 4WD) is even if you do not beet on it and changed the fluid and filter every 30-50K miles?

Add towing, off-roading, and skip fluid & filter changes?

You need a rebuild, but you can try a change of fluid & filter to see if that does anything to buy time before the rebuild.

 

I don't know much, but OP symptoms tell me the truck is [simply] low on fluid.

 

Easy 200k+ miles! Most important to monitor the fluid level/color. Pan drop fluid/filter change every 30k, flush every other 15k:
Flush: 15k, 45k, 75k, 105k, etc..
Pan drop/filter change: 30k, 60k, 90k, 120k, etc...
Never had a 4L60e fail under me!

 

We had one old 2wd shop truck with the 4l60e make it to 200k.

Never had another one make it past 130K, and I only locally tow things a couple times a year. Plus size tires and wheeling take a toll. Just like bonus HP & TQ with a heavy foot.

 

Also, I ONLY drive in 3 (except when I get on the highway)
The 4L60E is a very reliable transmission if it is not abused. I've seen them go 300K-500K in work trucks without ever having anything more done to them than fluid and filter changes.