I had my 4L60e Rebuilt and am not very happy...not all the time but most of the time when it shifts its a loud clunking noise and you can feel it mid to rear of the car. I was wondering if anyone had any ideas on what this could be. I also have a strange s60 rear with a shortened driveshaft if anyone thinks that has anything to do with it. Since I had no problems with the rear before it was rebuilt, I wouldnt think It would be it but im not an expert. I got the Pro Race Rebuild and have a 3600 Vig Stall.Ive Pasted the description of their website of what the build included and would rather not say the company's name for the sake of bad advertising if im not sure they did anything wrong. Thanks in advance for your ideas.

RACE REBUILD: Custom shift kit, Fairbanks "Billet" 2 nd servo, Sonnax "Super Hold" 4th servo, .490" Sonnax pressure regulator boost valve, Alto "Wide" Red Lined 2-4 band, 7 Raybestos "Blue" 3-4 frictions, "Kolene" friction coated 3-4 steels OR Raybestos "Z-Pack", Sonnax "High RPM" pump slide spring, "The Beast" H/D sun shell, New Borg-Warner 29 element input sprag, Sonnax "full throttle upshift sleeve"

PRO RACE REBUILD: Everything in the Race Rebuild + the addition of the 4L65E front support, 4L65E hardened output shaft, and updated steel piston set for the input drum. Recommended for car's hitting sub 1.7 60' times

 

tranny mount maybe broke.....torque arm loose..

 

I would tend to think this is some sort of a drive train issue , I cant really think of anything that would cause a loud clunk from inside the trans on the 1-2 shift . I would look at the torque arm and bushings as mentioned and the mount along with the bushings etc for the rear end.

 

Thanks for the quick response guys im gunna look into that

 

The second servo that you are using might be the issue. I have used those in the past and have stopped using them due to the fact that I have seen issues such as yours. I will not get into all of them. As mentioned above (mounts) those are the obvious things to look at however you did say that it did not do it before the swap. Might be something to take up with your builder to see if you can tone the shift down a bit. Feed hole size for the 1-2, 1-2 accumulator valve spring or valve sticking( I have seen the sleeve installed upside down), line pressure, the servo itself, or the 1-2 accumulator are all a possibility that you guy's might want to address. I'm not sure who your builder is but I would contact him and ask him these questions. Good luck, Vince.

 

Thanks will check that out!

 

This is a CPT unit, call Frank your builder on this (bigfoot2thefloor) since it is his unit.

 

Agreed you should call the builder , Though im still not inclined to think the noise is and internal issue . We also use the billet servo and have never had and issue with a noise however our build specs also may be quite different in other ways.