Has anyone experienced a C6 engaging hard into reverse?

I just replaced my AOD last weekend with a used C6 (checked over first by a rebuilder who said it was good). I gave it new gaskets, fluid & filters, modulator etc, & adjusted the intermediate band

It drives & shifts fine; & selects all the forward gears normally, but is harsh going into reverse.

Engine mounts, driveshaft, idle speed, etc are all ok - the issue has only been since the swap.

Thanks

 

I certainly will defer to the experts but here goes. Auto trans have 2 clutches, 1 for forward and one for reverse. If you're having probs with rev then its prob that and the guy who checked over your c6 was wrong.

 

You could check the line pressure, maybe its too high. It can be adjusted by the modulator

 

Wouldn't that affect selecting the forward gears too?

 

I'd sure think it would. The easiest thing to do would be cancel your life insurance and have someone that likes you shift it into reverse while you are under it so you can check mounts and such under load it could also be a u-joint.

 

That's the thing........reverse is the only gear with this problem.
Universals are both good.

When reverse is selected, is full pressure be applied to the clutch immediately.......or should it engage at lower pressure, then increase?

I'm wondering if it's a valve problem.

 

Has the trans sat for a long time? I had an e4od that did the same thing for a while then i decided to stop doing it. What worked best is i put it from P to N then to R and that smoothed it out some and then one day I pulled it strait into reverse and it did bang, I'd call a local reputable trans shop and see what they have to say, if they utter the phrase rebuild go back to the phone book and find another one.

 

It had sat for a while, but I don't know exactly how long - I'm trying to find that out.

The governor was a bit sticky for the first day, but quickly freed up......I'm hoping this reverse problem will be similar

 

Pour about 8 oz of B12 or seafoam into the trans and run it for a while. If it has a sticking valve, that should free it up. The B12/seafoam will eventually evaporate from the system, but the cleaning will be done by that time. You can drain the fluid out later, and replace with fresh, if you prefer.
Sticking valve is highly suspect, since the governor was acting up at first. Was likely a sticking valve there, too.

 

Ok, I'll give it a try if it's the same in a few more days.

Seafoam engine additive is available here, but I haven't found anyone selling the trans additive yet.
LubeGard is available.....is that as effective?

Thanks for everyone's help. Even with this issue, I'm pleased with the swap - haven't checked mileage yet.

 

its called sea foam trans tune

 

Which is basically just seafoam's fuel system cleaner mixed with ATF.

Most auto trans "Tune up" products contain the same basic cleaning agents found in seafoam/B12, along with just enough ATF to give it a red tint.

 

Hmm i wasn't aware i shall save that tidbit of info for referance