RMVB

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Mopar Sam

Mopar Sam

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I have always used rvmb's in my mopars since I was in my teens. Being a cheapskate. I have always bought used ones. I picked one up for a good price a few years ago and put it in my wife's 904. It only had 1st and reverse, so I had another one on the shelf and put it in and everything was fine.

Now my middle son needs one for his project, so I thought I would tear the one that wouldn't work apart. Anyone have any ideas on what to look for?
 
Just my opinion, but if you don't know the brand and history you are wasting your time........unless you are a trans expert

To put this another way how do you know "did it ever work?"

Maybe the guy before you tried some mod that didn't work, or had it apart and lost "some balls"
 
67Dart273 said:
Just my opinion, but if you don't know the brand and history you are wasting your time........unless you are a trans expert

To put this another way how do you know "did it ever work?"

Maybe the guy before you tried some mod that didn't work, or had it apart and lost "some balls"
Click to expand...

Not a trans expert by any means, but I always build my own. I tried a google search for an exploded view of one, but came up with nothing. It is a turbo action brand if I remember right, I can check for sure tomorrow. I just thought someone on here may have an idea of what to look for.
If I have to, I will take one out of one of our other cars to compare with this one, but that would be a hassle.
I should probably mention it is not LBA.
 
Sorry for the stupid question... but what is a RVMB and an LBA
 
Dana67Dart said:
Sorry for the stupid question... but what is a RVMB and an LBA
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Not a stupid question, I always have to ask my wife what all the abbreviations people use these days! RVMB should be RMVB { I misspelt !} reverse manual valve body. LBA is low band apply.
 
I have a stack of valve bodies that l've removed over the years for customers who wanted more of a cruiser shift. If you post a bunch of pics of your valve body, l'll look and see if l have one like it for comparison.
 
The rmvb deletes a lot of valves and springs. The separator plate is totally different. But u still can change everything over to another vb as long it’s the same number. Kim
 
To make reverse; the trans simultaneously engages both the L/R band and the Hi-drum, called front clutch by Mopar.
That same drum is used to select third gear, but now together with the Forward clutch, called rear drum by Ma.
And that same rear clutch is used together with the KD servo to make second gear.
We know the hi-drum works cuz you got reverse. So by process of elimination, the Fwd clutch (called rear clutch) is on vacation. Ima thinking the 1-2 shift valve is blocking flow to it; it may be either stuck, or in backwards.
I suppose the connection port to the accumulator might not have lined up and the VB couldda been hemorrhaging fluid there. I know somewhere in the mid to late 70s they changed the cases in that area. I also seem to recall that the backside of the accumulator cavity is ventilated and if you remove that piston or if it breaks, that will hemorrhage fluid too. So you might want to check those before jumping into the VB.

Edit; I screwed up; My daddy used to say "the night is for sleeping" . As noted below by CFHJ, If first gear works, then the forward clutch must be working as well. That more or less just leaves the VB, and or the accumulator match up
 
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AJ/FormS said:
To make reverse; the trans simultaneously engages both the L/R band and the Hi-drum, called front clutch by Mopar.
That same drum is used to select third gear, but now together with the Forward clutch, called rear drum by Ma.
And that same rear clutch is used together with the KD servo to make second gear.
We know the hi-drum works cuz you got reverse. So by process of elimination, the Fwd clutch (called rear clutch) is on vacation. Ima thinking the 1-2 shift valve is blocking flow to it; it may be either stuck, or in backwards.
I suppose the connection port to the accumulator might not have lined up and the VB couldda been hemorrhaging fluid there. I know somewhere in the mid to late 70s they changed the cases in that area. I also seem to recall that the backside of the accumulator cavity is ventilated and if you remove that piston or if it breaks, that will hemorrhage fluid too. So you might want to check those before jumping into the VB.
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Thanks AJ, I will check the 1-2 shift valve.
 
He said he has first so the forward clutch is okay. They made some changes in the case and like you say the vb might just be venting. It might work on the correct case. I just retrofitted an old vb to the new case; blocked off two holes and drilled two new ones. Pics to see if they match up.
 
CudaFactHackJob said:
He said he has first so the forward clutch is okay. They made some changes in the case and like you say the vb might just be venting. It might work on the correct case. I just retrofitted an old vb to the new case; blocked off two holes and drilled two new ones. Pics to see if they match up.
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Right you are!
 
I am not sure of the year of the trans in my wife's car that the VB did not work in, but the one I put in it that worked had previously worked in a 1967 727.
I will be in the shop some tomorrow, I will look at the part # on the VB.
 
Mopar Sam said:
I am not sure of the year of the trans in my wife's car that the VB did not work in, but the one I put in it that worked had previously worked in a 1967 727.
I will be in the shop some tomorrow, I will look at the part # on the VB.
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I cant believe ur wife would be ok w/ a manual shift ! Mine wouldn`t !
Heck I aint either , so much nicer to have ur left arm resting on the window, and still blow the doors off of corvettes and mustangs.
 
famous bob said:
I cant believe ur wife would be ok w/ a manual shift ! Mine wouldn`t !
Heck I aint either , so much nicer to have ur left arm resting on the window, and still blow the doors off of corvettes and mustangs.
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I met her at an 1/8 mile drag strip, been married almost 26 years. Her car is a 70 4 door satellite that I built a stoked 5.7 Hemi for. Last summer she said she wants a bigger cam. It has a comp 268HR which is pretty mild in the stroker. She wanted the manual shift! I love them too!

My newest vehicle is a 98 durango and I hate not having a rmvb and the power brakes. Manual discs on all our good cars! In fact, I believe if people still had to DRIVE their cars there would be a lot less accidents, but what do I know, I don't even own a smart phone.
 
Mopar Sam said:
I met her at an 1/8 mile drag strip, been married almost 26 years. Her car is a 70 4 door satellite that I built a stoked 5.7 Hemi for. Last summer she said she wants a bigger cam. It has a comp 268HR which is pretty mild in the stroker. She wanted the manual shift! I love them too!

My newest vehicle is a 98 durango and I hate not having a rmvb and the power brakes. Manual discs on all our good cars! In fact, I believe if people still had to DRIVE their cars there would be a lot less accidents, but what do I know, I don't even own a smart phone.
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LOL.... funny post. you have a point, more "driving" would equal less "texting" ???
 
318willrun said:
LOL.... funny post. you have a point, more "driving" would equal less "texting" ???
Click to expand...

Yeah I couldn't imagine anyone texting and driving in my sweptline! Of course that would be impossible right now as it is awaiting a new motor. Got to get it going again soon. Seem to never have time and money at the same time!
 
CudaFactHackJob said:
I have a stack of valve bodies that l've removed over the years for customers who wanted more of a cruiser shift. If you post a bunch of pics of your valve body, l'll look and see if l have one like it for comparison.
Click to expand...

CudaFactHackJob , I will try to get some pics, for you. I missed your post this morning somehow, or I would have got some today. Do you think I should use an older case for my son? I have a couple to choose from.

The valve body is a turbo action part # 17156. I guess I will take it apart , clean and check for anything obvious, and take some pics.
 
The newer cases had more meat near the low reverse arm and the newer valve bodies covered that cavity. I think the change might have been when mopar went to the part throttle kickdown valve body; which was over a span of a few years; depending on application.
 
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