The Dodge Challenger Message Board

HI, does anyone know if a 74 valve body will work in a 71 904? I can see there are some visible differences, mainly in the area of how they attach things on the valve body. It will definitely screw in etc, just wondering if the springs and internal workings will be the same so it can go straight into the 71 box.

Also, what is the best fluid/solvent to soak and wash out a valve body with? I didn't want to soak it in petrol, just in case here were rubber seals inside. I was thinking of water based degreaser, then heaps and heaps of compressed air everywhere to blow it out, then soaking in clean trans fluid, then another blow out.

Does that all sound OK??

thanks!

I posted this same question on the Oz Mopar Forum and got a few replies - it will go straight in with no problems. It seems they did make some internal changes to the valve body for improved shifting, this can be seen on the slightly different orifice sizes. The 74 VB is a known good one, the 71 is slightly doubtful, although i have been told the valvebodys do not wear much. The housings either crack or shit gets in them, preventing the pistons and balls from properly doing their job and perhaps scoring the inner bores.

I did not pull the VB apart, i just blew out with air, poured a little acetone on it, blew out well again and then soaked in a mixture of Trans fluid and transmission oil conditioner, then a quick blow out again.

But as you can see from the shift shaft seal post, the seal is being a pain in the A.

I wasn't 100% sure as all my information is on the 727 box. Good to know though.

As for cleaning I have only stripped the parts down for cleaning. I have never tried to clean any part as a unit. I don't think it is possible to do it that way to be honest. Too many places where muck can collect and not flush through.

I believe that they are interchangeable.
Best for cleaning valve bodies is a product we call in North America - Brake Cleens. It is primarily used in te auto industry for cleaning brake part, but over here we use it to clean lots of stuff.
Don't be afraid to take the valve body apart. If you can get a blowup of the unit (shift kit instructions are pretty good) or look on the net for a factory diagram, dig into it. After you've kind of cleaned the unit externally, place the valve body on a clean surface (shop rags work well) and take it apart. Keep all the valves, springs, check balls etc. in the order they were removed. Clean the parts, clean the valve body and then reverse assemble it. You can only get all the junk out of a valve body by taking the thing apart.
When reassembling the valve body, transmission people here typically used vaseoline to reassemble the valve body back together. The product desolves when the hot trans fluid picks it up.

transman

Thanks for the reply Transman. It was posted a month after mine, so didn't see it until now. Wasn't being rude! We don't have Brake Kleen, but i assume it would be similar to the aerosol brake cleaner. I did not end up pulling the valve body apart as it was out of a (supposedly) fairly fresh 904. I am driving the car soon, so will be able to tell how it shifts.

At some point they started using a different neutral saftey switch. They went from a 1 wire switch to the 3 wire switch. The section of the valve body that contacts the switch was changed. At the very least you would have to change to the correct switch or the car may only start in D or something.

Again I don't know when they made the change.