ok , I've read alot here and now I actually have to ask for help. On my 96 Suburban w/ auto tranny 460le it would shift from 1st to 2nd, but not from 2nd to 3rd. I changed the transmission fluid & filter and the 1-2 , 2-3 shift solenoids and I am having the same problem still . there was a check engine code that i got on a reader that said O2 sensor . My question is would an O2 sensor cause a shift issue? and if so which sensor would that be? also there was minimal sludge on the magnet in the pan and no slippage and all other gears work. any help would be greatly appreciated.

I am also wondering if it could be the valve body, and if this is difficult to fix

Does it stay in 2nd when it should into 3rd or does it shift into neutral instead of 3rd.

Could be a stuck 2-3 shift valve or bad wiring to the solenoids. Another possibility is the bad servo seal.

//2000CAYukon

Your '96 has the OBDll system. Really need to get a scanner capable of getting into the tranny system module for DTC's and look for both active and history codes. If you can do that and there are codes stored please post them back to us. (Most over the counter scanners cannot read the tranny.)

An O2 sensor, in my opinion, would not cause this tranny problem. Also need to have the DTC for the O2 sensor to help with that.

Does it stay in 2nd when it should into 3rd or does it shift into neutral instead of 3rd.

Could be a stuck 2-3 shift valve or bad wiring to the solenoids. Another possibility is the bad servo seal.

//2000CAYukon



when it should shift from 2nd to 3rd it does not and the rpm's shoot up and nothing happens, feels like it loses ability to pick up any speed not sure if it is neutral though

I should have said "that is feel like neutral". It could also be a failed 3/4 clutch pack which requires a rebuild.

This is a real good link on 4l60e failures http://www.impalassforum.com/vBulletin/showthread.php?t=95721

//2000CAYukon

Also, when the problem happens, shift into neutral, rev the engine once and then shift back into OD. Does that make it shift into 3rd?

//2000CAYukon

thanks i appreciate it. will work on it some more tommorrow

Also, when the problem happens, shift into neutral, rev the engine once and then shift back into OD. Does that make it shift into 3rd?

//2000CAYukon



Will go for a quick ride in a few and see

went out and checked fluid this morning and it seemed high on the dipstick even though after I closed up the pan I only put in 2.5 quarts I am wondering if there is something that would keep the fluid from getting down to the pan like a pump or something ( it also seemed like only three quarts came out when I dropped the pan.) thanks in advance guys One more question. What does the force motor do?

Also, when the problem happens, shift into neutral, rev the engine once and then shift back into OD. Does that make it shift into 3rd?

//2000CAYukon
Tried this and it did shift into 3rd