What would make my manual valve body upshift from 2-3 and down shift from 3-2?When i drive the car i shift 123 manually but if im driving throug town and stat to slow down i can feel it down shift from 3rd to 2nd,and if i go around a corner it will go from 3rd to 2nd and back to 2nd to 3rd.I didnt think a manual valve body was supposed to work this way,Any ideas?I dont want to burn this tranny up.

A true MVB should not do that at all. What tpe of VB is it? part #?

have you checked the linkage to make sure it's not casing it to shift between gears?

Im not sure what brand mvb .I have checked the linkages and all seem's fine.I did'nt know if something could have came loose.I called the tranny shop that built it and they said something about a rod or something coming loose,and if i brought the car to them they would pull the pan and the repair would only take an hour.I feel like they are giving me the run around.

If they said they would fix it how is that giving you the run around?

This is not the only prob ive had with this trans.

If you drop the pan the VB may have a # scribed in it. All my TA's have had them.

Does it still have the kickdown linkage attached? MVB's don't require it so I would question it if it was there.


I don't suppose you have a known good VB to swap in for a test?

If it acts up going around corners look to low fluid???

Is this a forward pattern manual VB ? If so, the gov circuit is internally connected but can sometimes cause trouble if you add a rollerized rear support and the gove circuit in the case leaks to lube oil.
AG

This is a forward pattern

To clarify, if it is a true MVB you should be able to place the shifter in D and it will take off in 3rd gear. If you place the shifter in 2 it should take off in 2nd. Does it?

I had a problem like this because of my statement above. Do you know if you have a rollerized rear support ? If so, you are lossing gov pressure in the rear lube circuit. The easiest way to fix this is to dissassemble the VB and seperator plate and JB weld around the supply and return gov passages in the lower casting. I done this before but don't have any pictures.
Allan G.

Yes if you place it in D it starts in 3rd,if you start in 2nd your in 2nd.

Im not sure if it has the rollerized support.