Trans Issues 99 GMC 2WD

kknepper29 · April 4, 2019

Good evening folks,

I have a 99 GMC Sierra with the 4L60 trans. It has 456 gears limited slip and shift kit installed about 10k miles ago. I was driving down the road today and it felt like it pulled it's self out of gear. The truck cooled off and i tried to put it into drive, the dash says its in drive but it won't drive anywhere, so I don't think that the trans blew up as it was just rebuilt 10k miles ago. If anyone has some incite on this it would be much appreciated!

Mikebtte · April 4, 2019

Did you check the fluid level? Sounds dumb, but that would be the first thing to do.

Add fluid if needed.

kknepper29 · April 4, 2019

Thanks for the reply, I did check fluid levels and honesty it looks like I have a bit more in there than I should. Going to drain some out tonight.

Mikebtte · April 5, 2019

10 hours ago, kknepper29 said:

Thanks for the reply, I did check fluid levels and honesty it looks like I have a bit more in there than I should. Going to drain some out tonight.

Good call, over filling will burn up a transmission quickly.

How did it turn out.

alpinecrick · April 7, 2019

On 4/4/2019 at 10:01 AM, kknepper29 said:

Thanks for the reply, I did check fluid levels and honesty it looks like I have a bit more in there than I should. Going to drain some out tonight.

A pint over won't hurt it at all. Is the fluid bright red?

Drop the pan and see what is in the bottom of the pan.

A trans doesn't have to blow up in a mushroom cloud to break............