VB interchangeability 904 vs 727

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DentalDart

DentalDart

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Will a VB from a 68 727 work in a 69 904?

Turned over the car today, put car in gear and no movement of the driveline. We tested air pressure tested the clutch packs after assembling the rebuilt transmission and they were engaging. Fluid filled to proper level.

We heard the TC engage into the pump when we set it on and tested to make sure it was working properly before installing the transmission.

I modified my VB from my 904 with a TF2 kit so we are thinking easy problem maybe the VB not functioning properly. We will hook up a pressure guage tomorrow to the transmission to see if we are getting the correct fluid pressures when cycling through the gears. Other potential problem maybe the TC came unseated on the pump.

Another point for the devil dart... :wtf::BangHead:
 
Most do interchangeable.

Not sure on the years you are asking about tho.
 
Cope said:
Most do interchangeable.

Not sure on the years you are asking about tho.
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1968 727 valve body into a 1969 904 transmission.

We rebuilt my transmission started the car today to to cycle through the gears and check to make sure it was functioning properly. The flexplate and TC spun but driveline did not move.

We can hear gearshift lever engaging into the different positions on the VB but the driveline does not spin in any drive gear or reverse.

Figured it could be my VB that I "modified." I have an extra 727 transmission with a stock VB, if interchangeable I could throw that one in and see if it works.
 
I think they interchange but there are differences in valve bodys throughout the years. I prefer later ones with part throttle kick down. I also like reverse manual VB but thats not for everybody.
 
MoparMike1974 said:
I think they interchange but there are differences in valve bodys throughout the years. I prefer later ones with part throttle kick down. I also like reverse manual VB but thats not for everybody.
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Unfortunately I had a modified VB in my 904 and I added 2 steps from the TF2 kit to it; the only steps that weren't added to it from the TF2 instructions (everything else was the same).

Now my transmission is not turning the driveshaft/rear end. So we are hoping it's just the VB not functioning properly.
 
Yeah I would find a stock VB and swap it in. Sure is much easier than pulling the trans to check it out. I assume it was working prior to the VB work?
While you have the VB out you can air test it and make sure your bands are applying and clutch packs engaging.
 
MoparMike1974 said:
Yeah I would find a stock VB and swap it in. Sure is much easier than pulling the trans to check it out. I assume it was working prior to the VB work?
While you have the VB out you can air test it and make sure your bands are applying and clutch packs engaging.
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Yes it worked. It was already modified as well. I only added 2 things to what was already done. Sucks if it is the VB but better than pulling the transmission.

We air tested the clutches and the bands before installing the transmission but hopefully it is something easy... but it never is with this car.
 
DentalDart said:
1968 727 valve body into a 1969 904 transmission.

We rebuilt my transmission started the car today to to cycle through the gears and check to make sure it was functioning properly. The flexplate and TC spun but driveline did not move.

We can hear gearshift lever engaging into the different positions on the VB but the driveline does not spin in any drive gear or reverse.

Figured it could be my VB that I "modified." I have an extra 727 transmission with a stock VB, if interchangeable I could throw that one in and see if it works.
Click to expand...

Make sure the linkage tab engaged into the manual valve correctly.
It's kinda easy to forget with everything else about installing the VB going on.

It would feel and sound like it was going into gears but without the manual valve moving it won't.

With the manual valve not connected to the linkage it could also start in any gear or no gear so be careful there.

20200428_131142.jpg
 
@TrailBeast you might have won the internet for the day? This is incorrect I believe?

Since everyone sees everything I do **** up heres a super cute sleeping baby. She fell asleep while I was sweeping and mopping this morning and she is definitely something I didnt **** up :thumbsup:

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Also when attached to the arm it only goes this far, when not attached it goes all the way down. First picture attached to arm second not attached.

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Got it all put in and bent correctly per the instructions. Pics are where it ends when it's all the way in park.

Also attached is a picture of how my converter valve is installed, I have the 2 hump one and I originally put it in with the divot on the outside because it matches the PR valve. I also didnt drill a hole in the PR wall in the valve body like the "how to article" on this site calls for because per the instructions it didnt say to do it, it actually stated if there was a hole there to plug it.

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Oh man, you did it the wrong way right. Like TB said, it can take off on you if it's in gear when you start it.
 
Got the VB put back together and installed in the transmission and took her for a drive around the block! It was great! I need to clock the speedometer. Then adjust the kickdown linkage and the console shifter a little more and we are good to go.

I should also adjust my suspension then take it in and get it aligned. Then mess with the brake lines some more.

Thanks for all of the help everyone!
 
MoparMike1974 said:
I think they interchange but there are differences in valve bodys throughout the years. I prefer later ones with part throttle kick down. I also like reverse manual VB but thats not for everybody.
Click to expand...

Hey look part throttle kick down vb w/ TF2 :D didn't do shift command feature because I don't trust my ability to grind my governer and don't want to go looking for a machine shop. I think I'll be ok with not downshifting at "any speed." The part throttle kd this vb has will hopefully be good enough.

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kursplat said:
you get used to it. i had a manual VB in my daily driver for 10 years and never did any permanent damage :rolleyes:
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I will only have the stock part throttle kickdown, not the any speed downshift that you can get with the tf2 kit because I didn't grind the governor from this vb. I have a grinder but don't have faith in my abilities to do it good enough. Maybe one day I'll try to do it on a spare governer valve or ill find a machine shop to do one.

New vb is in. Only problem with it is 1 bolt hole doesn't line up. Its in the middle of 2 others it should be OK though as it doesn't go to anything else (or so I'm hoping).

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