No Reverse After Valve Body Replacement?

[CDNFB]

I removed the valve body from the 4L60E and had a transmission place install the Sonnax TCC kit into it. Re-installed the valvebody into the trany and buttoned everything up.

Go to test it and everything works except reverse! When I select reverse, you can feel it go into gear, but no movement at the rear tires. Almost like there was a line lock holding it. As I rev the engine, it strains at trying to move the rear wheels (as if I was preloading the torque converter for a launch). All other gear selections work fine. Double checked fluid levels, let everything heat up, still no go.

Dropped pan, drained oil, and checked everything. All linkages look good and are attached.

Now check this out! Put the selector in park and tried to manually move the drive shaft, as expected the drive shaft will not move(park pawl is doing it's job)

Puting the selector in 1 or 2 or 3 or D, I can only turn the drive shaft in one direction and not the other.

But when I put the selector in the N detent, you would expect that the drive shaft would be able to turn both directions. It only turns in the one direction, the same as the direction that I can turn it in the forward selections.

And when I put the selector in the R detent, again the drive shaft can only be turned in the same direction as the forward gears. You would expect that it would only turn in the opposite direction as compared to the forward gears.

Something is limiting the output shaft rotation to only one direction.

Has anyone seen this before or have any Ideas about a fix!

PS, the SES light is not illuminated.

DZ

[BLLDOGG]

Re: No Reverse After Valve Body Replacement?

Are you sure that all the little balls got left or put back in there correct locations. Im not sure if this would cause your problem but i know its a big mistake when people remove their own valve bodies

[BLLDOGG]

Re: No Reverse After Valve Body Replacement?

This is what i pulled of SI for GM

No Reverse or Slips in Reverse

Checks:
Input Housing Assembly
Causes:
* 3-4 Apply ring stuck in applied position
* Forward clutch not releasing
* Turbine shaft seals missing, cut or damaged

Checks:
Manual Valve Link
Causes:
Disconnected

Checks:
Valve Body Assembly
Causes:
2-3 Shift valve stuck
Manual linkage not adjusted
Spacer plate and gaskets incorrect, mispositioned or damaged
Lo overrun valve stuck
Orificed cup plug restricted, missing or damaged

Checks:
Reverse Input Clutch Assembly
Causes:
Clutch plate worn
Reverse input housing and drum assembly cracked at weld
Clutch plate retaining ring out of groove
Return spring assembly retaining ring out of groove
Seals cut or damaged
Restricted apply passage
Porosity in piston
Belleville plate installed incorrectly
Excessive clutch plate travel
Oversized housing

Checks:
Lo and Reverse Clutch
Causes:
Clutch plates worn
Porosity in piston
Seals damaged
Return spring assembly retaining ring mispositioned
Restricted apply passage

I havent gone through automatic transmission is school yet so I cant help much further but i hope this helps.

[CDNFB]

Re: No Reverse After Valve Body Replacement?

All the Check valves above and below the spacer plate are in position. The trany place gave me diagrams to pin point their positions and I assembled them with a little vaseline to make sure they didn't fall out when I installed the valve body.

That's a great list of possibilites, thank you very much. Alot of the items can be disregarded, like anything to do with wear because the tranny worked perfectly before I did the valve body replacement (Except the TCC slip thing).

Checks:
Input Housing Assembly
Causes:
* 3-4 Apply ring stuck in applied position ------------------Possible
* Forward clutch not releasing ----------------------------Possible
* Turbine shaft seals missing, cut or damaged -------------Don't think so

Checks:
Manual Valve Link--------------------------------Checked, looks ok
Causes:
Disconnected

Checks:
Valve Body Assembly
Causes:
2-3 Shift valve stuck ----------------------------------------Possible
Manual linkage not adjusted----------------------------------Checked. looks ok
Spacer plate and gaskets incorrect, mispositioned or damaged -----Possible
Lo overrun valve stuck-------------------------------------------Possible
Orificed cup plug restricted, missing or damaged ------------------Possible

Checks:
Reverse Input Clutch Assembly
Causes:
Clutch plate worn------------------------------------------------Don't think so
Reverse input housing and drum assembly cracked at weld---------Don't think so
Clutch plate retaining ring out of groove--------------------------Maybe?
Return spring assembly retaining ring out of groove ---------------Possible
Seals cut or damaged--------------------------------------------Don't think so
Restricted apply passage ---------------------------------------Possible
Porosity in piston ----------------------------------------------Don't think so
Belleville plate installed incorrectly-------------------------------Don't think so
Excessive clutch plate travel------------------------------------Don't think so
Oversized housing-----------------------------------------------Don't think so

Checks:
Lo and Reverse Clutch
Causes:
Clutch plates worn ----------------------------------------------NO
Porosity in piston -----------------------------------------------NO
Seals damaged -------------------------------------------------Maybe
Return spring assembly retaining ring mispositioned ---------------Possible
Restricted apply passage----------------------------------------Possible

I'll be talking to my trany guy tommorrow and will be mentioning these things.

Thanks again for the great response. I'll let you know what comes of it.

DZ

[CDNFB]

Re: No Reverse After Valve Body Replacement?

Talked to my trany guy yesterday, explained the problem. He knew exactly what the problem was, seen many “do it yourselfer’s” like me make the same mistake.

I had accidentally installed a bolt that was too long in a bolt position (right in the center of the vavle body) that required a short bolt. The long bolt interferes with an outer planetary gear and causes the problem I had.

When I removed the valve body I drew a diagram of the bolt pattern and noted where each length bolt goes. I compared my diagram with the print out my trany guy gave me, and yup….had it wrong. Don’t know how I did that!!

So long story short, exchanged long bolt with a short bolt and all is now fine.

DZ