Newbacon

So I've been lurking around here for the past month or so after my daughters car's transmission started acting up. Decided to attempt a rebuild myself. Built a few regular autos but this was completely new for me. Used a transtec master rebuild kit and a superior shift improver kit. Everything seemed to go smoothly. Noticed a lot of gunk and black crud on the magnet and also blocking the filters on the valve bodies. Got it all back together and installed. First start up was really to ensure nothing major was wrong. Sounded great. Shifted through all the gears smoothly. Now I is on jack stand so I trying to accelerate slowly but when it got up to about 25 the TCS light came on and there was a shudder from the transmission. Not sure what is causing it. Got too late to troubleshoot farther so I am posting here to get some ideas. Once thing I do know is the shift cable needs to be adjusted because it didn't seem to go into park. Any help is greatly appreciated.

01acls

TCS light on is to be expected if you engage the trans on jack stands... False alarm.

Midnight Mystery

Rebuilding a tranny as about as hard as it gets, ya know....

Newbacon

I figured I would get a TCS light with it on jack stands but it only came on when I felt the shudder. I didn’t want to keep accelerating for fear of damaging something. It goes out as soon as I let up on the accelerator. No CEL either just a quick acceleration, light and shudder and let up on throttle.

horseshoez

iTrader: (2)

The shudder may be because the TCS system is assuming the front wheels are slipping (on ice for instance) and is trying to apply the brakes in an effort to help them gain some traction.

Newbacon

I admit I do not know much about the TCS and am trying to do some research this morning. After a restless nights sleep thinking of "what could be wrong" I thought that maybe that was what it should be doing and I was to nervous to keep the accelerator down. lol

whitetiger5

You don't want to keep the accelerator down. You want to disable TCS. the TCS system uses the wheel sensors to detect wheel slipping. When the wheels are being spun in a system with no resistance (the road) the system detects some unloaded movement (similar to slipping on ice) in the wheel and tries to apply braking to the wheels.

Is there something wrong with the vehicle? the service manual will only suggest jacking up and putting into drive after a much convoluted troubleshooting path so trying to understand why it is up on jack stands and being put into gear. the Service manual also instructs to disable TCS/VSA when doing so. If it's just to see if the transmission works: if no CEL lights, and shifts into each gear just fine then go for the test drive.

Another note: Please keep in mind the wheels are now much further down than their normal ride height and the axles are too now in an unusual geometry which could add some unwanted stress if you bring it up to a high speed.

Newbacon

It is up on stands because I just installed the transmission after I rebuilt it. I wanted to make sure I didn't hear any obvious grinding and such before road testing it. I did the same thing after I rebuilt the transmission on my F250 without issue but it doesnt have a TCS lol. The shudder just kind of made me worry that I missed something. I plan on getting it on the ground and giving it a go this afternoon after work.

whitetiger5

Makes sense now. Can't wait to hear how it turns out; I've heard it's a very difficult transmission to rebuild.

Newbacon

I actually found it a little easier than a standard auto. I rebuilt my 4R100 out of my F250 Diesel and a TH 350 and these are typical automatics. I have also done quite a few manuals so I think that helped out a lot too.

Newbacon

Thank you all for the replies. Took it down off jacks and drove like a dream. I’m completely happy with it so far. Thank you again.