4L60e question. May be on it's way out....

[Emmettology 101]

Ok, I have a 99 Tahoe. It's been a good "truck" so far.. But lately it has been doing something weird. There is a hill that goes to my house. With the truck in OD, I get about half way up the hill and it will downshift(or possibly the converter will unlock).. When thhe tranny shifts again(or locks the converter back up) I get a bad shudder..... The rest of the gears seem fine and if I leave it in "3", I dont get this problem.. Although if I am on the highway(or higher speeds in "3") it feels like it wants to shift into OD..

A friend of mine said it sounds liek the tranny is going. Another said that it could just be the converter.

Any suggestions? Going to call another friend of mine tonight that does tranny work and see when I can get it into him to check it out.

**EDIT** I pulled the dipstick the other day.. The fluid is still red, but smells weird to me. I've been wanting to get the fluid changed since I dont know when it was done last...

 

[Thunder]

Sounds like the TC lock up clutch may be slipping a little. Change the fluid and see if it helps. When you drop the pan it will tell you if you need a new trans or not. If there are no chunks in the pan clean it out change the filter. Be best to do a complete fluid flush if you dont know how old the fluid is. Who knows what the PO put in it?

 

[Emmettology 101]

If the TC is going out, would there still be crap in the pan?

 

[Thunder]

I really dont think there will be any chunks unless the clutch fell apart.
Your TC lockup needs full line pressure to lock properly. A clogged filter or wore out fluid will affect its performance. Best thing to do is drop the pan change the filter and flush the old fluid.