My truck seems to have developed a problem with what I call "late downshifts". When the tranny is cold (and occasionally when warm) the following happens:
When slowing down from 30 or 40 mph, the tranny shifts normally, except for dropping down into first. When I come to a stop sign, and if I do not come to a full and complete stop for several seconds, when I hit the accelerator the tranny "crashes" into first. It's like it was in neutral and I am popping the clutch on it.

Any idea what that might be? I am sure I am not describing it well, but you guys are pretty damn smart about stuff like this.

Great site.

Regards,
Rip

Rip
You have not given us any history on the truck so this makes it tough. NSBU switch and spin on filter for starters.

Sorry.

It's all stock, only has 27k miles on it (yes, it's an 01). As far as I know no service has ever been performed on the tranny. The dealer did fix the rear axle seal leak about 5000 miles ago. Probably never had the tranny oil changed. I checked the tranny fluid yesterday (both hot and cold) and it seemed to be just slightly over full, although not by much, and I'm not entirely sure about it anyway.

Thanks for your help.
Rip

Rip
I suggest a scan first, then a trans service with filters. NSBU switch is due so change it. If scan shows no codes, clear and reset TAPs at the same time you do the service.
mike

I'll add to what Mike mentions above. I used to occasionally have a "harsh" downshift from 2-1 when taking off from a stop sign (most prevalent when driving around the hills near my house). This occured when doing a "rolling stop" at the stop sign.

I took the truck to the dealer and they reflashed the TCM software with the latest update. All 2001 and early build 2002 trucks had this potential problem. You can read a few sentences about it in the GM Tech document at the following link:

http://www.gmtechlink.com/images/issues/arcv_pdf/7_02_e.pdf

In particular, look on page 8, middle column, second paragraph under Transmission/Transaxle title. After the TCM software update, this issue went away (though my tranny has some other strange issues). If your TCM has the original software, this may be something you want to try. Dealer billed GM 1/2 labor hour, so should be in the $50 range.

Thanks for your help. I will do as you all suggest.

Still love the truck.

Took my brother in law for a ride yesterday. He'd never even been in a Chevy truck--always was a Ford guy--and he was awed.

Thanks again!

Rip