Transmission problem
2002 GMC Yukon V8 Four Wheel Drive Automatic 41000 miles

The Yukon seams to be stuck in 2nd gear. No lights on dash are on. will not shift manually except into reverse. Fluid level is good.

What should I check next?

Craig

if the vehicle has second,first,or reverse it needs a forward sprag assembaly.

Could it be a speed sensor. How long is the warrnty on these?

it's not a speed sensor because you said the vehicle is stuck in 2nd gear,that's more of an internal trans issue. as far as a warranty,it expired 3/36 is factory warranty after 3/36 your on your own. if you have an extended warranty it should be covered.you will probably have to have the trans torn down and checked.might want to scan for an codes,check to see if the trans fluid is burnt.running the trans in 2nd gear can burn up the clutches and burn the fluid.post back with a follow up.

I let it sit for 4 hours and now it is working fine. I think I'll look for a shop to get the fluid changed. also maybe a test.

I drove it home with no problems. After having the fluid changed and filter. The ride home was 600 miles. It got stuck again on the wife. Does anyone have a idea what I should be looking at?

No codes at aamco. Fluid looked good so I was told.

did you have aamco drive this vehicle?this might be a mechanical issue.changing the fluid might only be a temporary fix. have the vehicle diagnosed properly.it will prevent you from throwing parts at it.

Yes they drove it before the fluid change and after. It did not act up for them.

I would still suspect the sprag. I think Brian is correct on a possible sprag failure. I have seen some fail and work correctly one day, then not work the next.