4r70w experts needed

[storlied]

Alright so the other night I got stuck and rallied my tranny way too hard. It now clunks into reverse, right before it actually goes into reverse.. It also sometimes makes a ratchet noise while going slow in reverse..........

A slight issue that has kinda gone away.. I think it may be a cold issue but my rpm's will drop at 40mph to 1k and then to 2k while jolting the truck a bit..

What did I break and what do I need to do?

I checked the fluid and it looks pretty good, but there is some black residue found on the dipstick..

Is it time for a rebuild?.....................................

I did crawl under the truck and had a friend put it into reverse and neutral so I could see if it was maybe the ujoints... the clunking is definitely coming from the transmission.....

 

[boominXplorer]

Is there any codes? Try taking the neg cable off for 10min to reset the computer. It will relearn Idle and everything and maybe smooth out your issues some but my best guess is you sir have internal damage. It could be anywhere from a damaged band, broken valve body spring or gasket ect.

 

[storlied]

That's the first thing I did. [Well, technically.. I re-applied my tune which clears the ECU..) Is there a separate computer for the transmission?......

Ugh.. so... time for a rebuild then?.... Or do you think this is more of a VB issue that can be fixed more easily? All other shifts are fine besides my usual harsh 1-2 shift... but this bang going into reverse... before it actually goes into reverse is pretty bad..
The OD issue has gone away from what I can tell, but I'm about to go for a drive to see if it happens again since the truck had time to cool down.

 

[Spdrcer34]

There is actually a part in the case called an 'anti clunk' spring. It keeps the center support (which sits on/in the planetary carrier) in place, pressed up against 'lugs' in the case. If that spring is not in place you CAN, and probably will (with the weight of the vehicle) break the case if you keep allowing to slam around in the case...

Ryan

 

[storlied]

Time for a rebuild then............
Reverse will slam before it actually shifts, hot or cold. My OD issue around 40mph only happens when cold.

This is gonna be costly.........................

 

[swetrid]

There is actually a part in the case called an 'anti clunk' spring. It keeps the center support (which sits on/in the planetary carrier) in place, pressed up against 'lugs' in the case. If that spring is not in place you CAN, and probably will (with the weight of the vehicle) break the case if you keep allowing to slam around in the case...

Ryan

I agree, it is the anti clunk spring.

 

[CDW6212R]

I'd bet on the trans also, but look really carefully again at the u-joints and driveshafts, axles etc. You don't want to make a trans repair and still have a problem elsewhere. manually handle the rear driveshaft, how much play is in it turning it in the trans, or diff?

 

[storlied]

No play in the ujoints, this is definitely transmission related. You can feel it, can crawl under and.. you just know... also... I'm getting slipping when cold.. this is the trans for sure... On the bright side, I may have found someone who will do it for $400 Labor plus parts cost. =)