The transmission on my 2008 GMC shifts hard from 1st to 2nd gear when the transmission is cold on startup

Steve Allison

• 5569 Answers
• Posted on Jun 19, 2008

SOURCE: Auto transmission not smooth 1st to 2nd

Admitting a lack of familiarity with your car, this is often caused by an improper adjustment of the transition point from one gear (or clutch) to another.
1st is still not disengaged when 2nd is engaging but this is normally an adjustable point.

I've also seen this caused by the use (or adding) of the wrong fluid; the beasts are fussy about that sometimes.

SOURCE: automatic transmission shifts hard and

have u checked the tranny fluid

SOURCE: 1997 Mazda protege transmission, Hard shifting from 1st gear

I would try a flush. If its set up like my 96, and it likely is, changing the trasmission gasket and filter will be difficult. Mine has a medal plug on the bottom and takes an allen wrench, and possibly a breaker bar. If you take out this plug, drain, flush then refill via the dipstick tube and a funnel, it may help. You may need to do this a couple of times due to fluid still in the torque converter, pan, etc.
Lucas is good stuff, I would add it again when I was done. The tranny fluid should be pink, mine looked like used oil black before I flushed it.
Also, when adding the new fluid, shift slowly up and down through all of the gears to lube well and check your fluid levels after 100 miles or so, as sometimes a bubble will form and make it look full....then not after it pops.

SOURCE: Transmission won't shift!

Does it just not shift up to 3rd or when it shifts to 3rd it is just like neutral?

SOURCE: Hard Clutch and 1st and 2nd Gear Shifting is hard

The clutch bearing is supposed to have a groove on the inside where it slides on the shaft That groove is supposed to have a heavy grease applied to it to prevent the bearing running dry on the collar it slides on.Regardless of your driving style, that grease is intended to remain there for the life of the clutch, (generally every clutch I have ever replaced still had some remaining lube there unless the bearing itself failed from a material defect which caused it to overheat and cause that grease to then run out of the retaining groove) I'm not there and can't see the old parts, but in my opinion the first clutch may have failed partially because of your lack of skill in using a stick shift vehicle but the second failure obviously is not your fault if the information you have posted is correct.
Good luck