Can anyone figure this out?

[OneLethal87GN]

After having my tranny rebuilt I tested it before paying. The shifts were very firm like I wanted. The only problem came with the 2-3 shift. 1st to 2nd was fine but it would immediately shift to 3rd after going into 2nd. The tranny builder called it a "stacked shift". He couldn't figure out how the shift kit went back in so maybe that had something to do with it. He took the shift kit out and swapped another valve body in and the problem went away. This caused 2 other problems though. One, I didn't have a GN valve body anymore and my shift kit was gone. The shifts are at the right rpms now but are very soft. It is so soft that it won't hold the gear when I floor it and it downshifts into a lower gear. The guy took the valve bodt completely apart but couldn't find any broken springs or anything that looked to be causing the problem. After many discussions and such it was decided they would put my valve body back in since it wasn't your everyday valve body. The only problem is that the stacked shift may still be there. What could cause a shift like this and what do you do to fix it? By stacked shift I mean it shifts from 1st to 2nd at, say, 15 mph. It stays in second for maybe 2 mph then shifts to 3rd. I have a stock rebuild with wider 2nd gear band and hardened sprag. The shift kit was in there at the time but isn't now. The problem occured with the stock valve body and shift kit both installed. The reason the tranny needed a rebuild to start with is I was running the car hard and manually shifting it. When I went to shift from 1st to 2nd the shifter cable broke and the shifter went straight into Park. The car was still in 1st though. It revved very high and messed up something in the tranny. After manually putting the car in O/D I still only had 1st gear and had to drive the car home about 30 minutes in 1st gear. What would cause such a short length of time in 2nd gear? Are valve bodies rebuildable and are there oversized parts to compensate for worn valves? The builder thinks a valve might have fluid leaking past it because it is worn out and needs an over-sized valve to fix it. Any thoughts?

 

[chris718]

a knowledgable builder should be able to fix that with his eyes closed

 

[texasturbo]

Onelethal87. let me know what you find was the problem. I have the exact same thing happening to my own tranny. Thanks.
lenny.lopez@xo.com

 

[ZR1TR]

What about you TV (Throttle Valve) Cable. It controls tranny line pressure and shift points. Adjusting it is not recommended but setting it is. gnttype.org has a description of setting it. If the cable is too tight it shifts late and hardered. Too loose and it will stack the shifts. Try that first.

Jonathan

 

[OneLethal87GN]

He has played with the tv cable numerous times. The other shifts are fine and where they should be. It is only the 2-3 shift that we're having the problem with. He took the valve body completely apart but didn't find anything. Someone suggested a stronger spring in the 2-3 valve which I relayed to him. He said the spring in there felt nice and stiff. I'm supposed to get the car back today. I was hoping one of the builders on this board has had "stacked shift" problems before and could tell me what to tell him to do to fix it. The only thing he can come up with is that the valve has worn in the bore and is leaking fluid past the valve causing too soon of a 2-3 shift. Thanks for the help so far. Maybe he'll have it right today.

 

[A. G. Olphart]

The only 'stacked shifts' that I recall reading about related to non GN valve bodies. Have you physically seen the markings on the VB he's using to verify that it is indeed your original??

Try a search for stacked shifts and see what it snags (just memory here). I seem to recall that Chris made the post... but again, this is Oldphart memory.

 

[OneLethal87GN]

The stacked shifts occured with my 85 GN valve body installed.
When he put a regular 200-4R valve body in they went away. I got the car back yesterday. He cleaned the bore in the 2-3 shift valve with something to get it nice and clean. The stacked shifts are gone but now you have to get to 65-70 for the car to go into O/D. The tv cable is pulled almost all the way to the front of the engine. There may be 4 or 5 nothces left, if that many. I believe pulling it back would delay shifts and make it shift firmer but I need to get the shifts sooner. I may try pulling the cable even further forward to see if it helps. I believe it is set a little forward of the factory recommended setting. At least it shifts alot firmer with the shift kit and my valve body back in. If I can only get it to shift sooner into O/D it would be good to go.

 

[chris718]

wrong valve body.

 

[OneLethal87GN]

Originally posted by chris718
wrong valve body.

He said he put mine back in after finding out that all 200-4r valve bodies are not alike. The firm shifts are back. I kind of wish he had left the other valve body in and just put the shift kit back in. I would keep my GN valve body as a spare. He said it looks as if someone did something to the detent valve. He said it looks like a billet piece. I told him I'm not sure what parts were used with Bruce's shift kit but I wouldn't think that would be one of them. I'll play with the cable tomorrow. Good thing I'm on vacation. I'll have plenty of time to mess with it.