Weird trans pressures, no reverse, 2-3 bind

[olds403]

The ribs on the reverse is what Bruce is talking about. I use .500/.296. I got them from pro built automatics.

 

[PonchoMan]

Ok guys, thanks for your patience. I just got the trans back in and check out these pressures. Sorry I would’ve called you Bruce but I got at it 7am east coast time; not a cool wake up call! Here are the numbers per the sheet you gave me.

IDLE TV @1000 rpm
P- 93
R-135
N-93
D-93
3-93
2-93
1-93

1/2 TV @ 1500 rpm
P-150
R-220
N-145
D-145
3-149
2-149
1-149

FULL TV @1500rpm

P-230
R-230
N-210
D-210
3-210
2-220
1-215

I decked the pump halves where the rotor clearance is .0015” and the slide is .0025”. I changed the PR valve train but putting the original lo/int boost valve back in (it was .035 longer than the one that was in there when I was having issues).
Please let me know if you think any of these pressures are of concern. Thanks again for all of your help!

 

[Steve V]

Ok guys, thanks for your patience. I just got the trans back in and check out these pressures. Sorry I would’ve called you Bruce but I got at it 7am east coast time; not a cool wake up call! Here are the numbers per the sheet you gave me.

IDLE TV @1000 rpm
P- 93
R-135
N-93
D-93
3-93
2-93
1-93

1/2 TV @ 1500 rpm
P-150
R-220
N-145
D-145
3-149
2-149
1-149

FULL TV @1500rpm

P-230
R-230
N-210
D-210
3-210
2-220
1-215

I decked the pump halves where the rotor clearance is .0015” and the slide is .0025”. I changed the PR valve train but putting the original lo/int boost valve back in (it was .035 longer than the one that was in there when I was having issues).
Please let me know if you think any of these pressures are of concern. Thanks again for all of your help!

Max pressures should be 250+ if you want it to live. Base looks good. Is your TV plunder giving max boost in valvebody.

Good luck getting ahold of Bruce, been trying for 3 weeks now he is MIA.

 

[INEEDAGN]

I’d assume the max is lower than it could be because the line bias valve isn’t blocked/piggybacked. If it IS blocked, you probably have a problem.

 

[PonchoMan]

I’d assume the max is lower than it could be because the line bias valve isn’t blocked/piggybacked. If it IS blocked, you probably have a problem.

When you say “Blocked” what do you mean? When I went through the VB everything was just cleaned up and the only mods done was the accumulator spring was changed. The line bias spring was changed (with tightly wound spring) and the 3-2 control valve had the spring removed and a plug installed at the end of the valve. I basically did the CK shift kit (instructions attached)

 

[olds403]

What boost valves are in the pump ? The CK .550 has been problematic for me on a DIY. Some of the Ck kits were. .550/.300. I tried that and pressures were low on a 7 vane rotor.

The .500/.283 combo seems to do me just fine with a sonnax regulator spring. You can swap with trans in the car. I’ve only used BR, CZ , and CR valve bodies behind my Olds motors and don’t know your VB codes but I know those have the .430 TV valves.

I just build these 1-2 times a year. All my recent pumps came directly from Ck already done.

 

[PonchoMan]

What boost valves are in the pump ? The CK .550 has been problematic for me on a DIY. Some of the Ck kits were. .550/.300. I tried that and pressures were low on a 7 vane rotor.

The .500/.283 combo seems to do me just fine with a sonnax regulator spring. You can swap with trans in the car. I’ve only used BR, CZ , and CR valve bodies behind my Olds motors and don’t know your VB codes but I know those have the .430 TV valves.

I just build these 1-2 times a year. All my recent pumps came directly from Ck already done.

It’s a CR VB with the CK .555 valve, I swapped out the CK .300 for the .300 (unknown make) that came out, and also swapped back to the original spring and the pressures got in line mostly. Now it’s just trying to get the 1 -2 pressures up a bit. I haven’t road tested the car to see how it feels. I also should have run the engine up to 2000 to see if the pressures continued to increase like they did from 1000 to 1500.

 

[TexasT]

This is some VB info jakeshoe posted yrs ago and what I did to mine. Of course use at you own risk, but the 3-4 return spring is in mine and works for me. Other wise there is some info on what he does to block it.



VB mods.

Drill the 2nd feed hole .093-.125" depending on servo, accum mods, etc.
Drill the 3rd feed .125-.140.
4th feed to .096 maximum.

Remove the line bias spring, install it in the accumulator valve.
Install a 700-R4 3-4 return spring in the line bias or otherwise block it.
Install a .500 boost valve, pink 700-R4 pressure regulator spring, and larger reverse boost valve.

Use a GN or billet servo.

I use commonly available 700-R4 accumulator springs for the 1-2 and 3-4 accum and calibration depends
on the unit but usually I use white.

You will use 5 checkballs in the case.
Rule of thumb on a 200-4R. If it's a bathtub it gets a checkball always.
There are 4 in a line from front to rear. 2 small checkball locations and 2 bathtubs,
install in the bathtubs, leave out of the small locations (3rd accum and 3-2 )

I do the same thing on the line bias--remove and use in the accumulator--I block the
line bias using a 1/8 in. roll pin ground down to .860 long.

 

[PonchoMan]

So it’s obviously been a while. I just wanted to update the group that the issue is still not resolved. I swapped back to the original PR valvetrain and pressure came up but it was still only 215 in 1st at Max TV. So I thought maybe the old PR system was worn so I went back with the sonnax o ring style TV and LO/Int boost valves. To no avail. Pressure is still low in 1st and 2nd. What I’m left with (as far as I can tell) are possible valve body causes? possible culprits- TV plunger, TV valve, throttle valve, Line Bias, or tv limit? Any challenges or insight? Thanks!

 

[TexasT]

SO, I'm guessing here, is this sonnax a .500 boost and .283 rev boost valves and the 700 spring? When reassembling are you sure you put the seal under the slide and the one on the edge of the slide? Have you pulled out the over pressure relief set up and inspected the ball and seat? I like the bison washer mod as seen below.

Under that roll pin is a spring and ball. If the spring has been damaged and isnt holding the ball down it could be bypassing. But with that there is usually a buzzing sound and some get trans fluid out the breather tube on top of the trans.
Only other things I can think of is worn parts(vane, slide, spring) or the slide spring could be weak but that is a volume thing not pressure.

 

[PonchoMan]

SO, I'm guessing here, is this sonnax a .500 boost and .283 rev boost valves and the 700 spring? When reassembling are you sure you put the seal under the slide and the one on the edge of the slide? Have you pulled out the over pressure relief set up and inspected the ball and seat? I like the bison washer mod as seen below.

Under that roll pin is a spring and ball. If the spring has been damaged and isnt holding the ball down it could be bypassing. But with that there is usually a buzzing sound and some get trans fluid out the breather tube on top of the trans.
Only other things I can think of is worn parts(vane, slide, spring) or the slide spring could be weak but that is a volume thing not pressure.

All of the pump parts are new and I’ve had it apart once and everything looked great and in the proper places, rotor and slide clearances good. Relief spring an ball all good and went back with the washer at the base that’s all in place. The tv is .500 and the lo/ int is .300. Funny thing is I now have 3 PR complete valve trains and hardly a difference when I change them. Thinking it’s something wonky coming from the VB. But running out of things to change.