I am trouble shooting a problem my 700r4 is having manualy down shifting. It downshifts fine in D or OD but when downshifting to use engine braking it shifts but doesnt grab. I think I have some trash in a valve or channel and want to know which valve is responsible for manual downshifts and clutch engagment under low pressure with 0 Throttle to use engine braking. I have taken out the VB several times in the past before having it rebuilt and can do it again to clean it out, but want to focus my attention where it is needed. This has only happend during the last week after getting on it in through some twisties, engine braking was no issue then....

 

Basicly from my reading it is an issue with the over run clutch, I need to know if there is a valve that actuates a piston or servo that I can check for debre. A good diagram of the Valve body would do me good too, google just isnt cutting it.

 

Your issue with no engine braking in the lower gears would not likley be VB related but and issue with the overun clutch set or input sprag

 

yea, what I'm hoping youll tell me is that there is a possibility that a check ball or oriface in the VB or case could be clogged or stuck that I can clean out. Is there a overrun plunger or piston that could be stuck, and is there any way possible I can diagnose that from the underside without removing the tranny. My real issue is Im in Germany right now and any repairs I dont do myself are out of control. And I have a hard time explaining what exacly I want. quart of oil or I should say a liter is 18 bucks if you buy it on the economy....oh yea. Thanks for the reply by the way.