4l80 manual VB fixed line pressure Q's

[85raiderburban]

im planning a '93 4l80 swap into my 80 sub. Manual shifting, already have the "DIY" wiring spliced together.

TERMINALS PINOUT WIRES "A" AND "B" From the pressure manifold are connected together and connected to the ground side of "SHIFT SOLENOID A". TERMINAL PINOUT WIRE " C" from the pressure manifold is connected to the ground side of "SHIFT SOLENOID "B". 12 VOLTS is supplied to the PINK WIRE on the outside of the trans

I will be building a pontentiometer/"trans pressure control box" to regulate the PCS/force motor. I will have to wait while some of the parts come in the mail though. I would like to get the late shifting 700r4 out of my truck anytime 2morrow or sunday.

Has anyone used a 4l80 mvb with fixed line pressure? How long will it last with constant full line pressure in every gear? Is the Reverse "clunk" as bad as some claim? Any info is appreciated. I will be doing this for another project also.

[GRADYS Performance]

Transmission Life will be fine. If anything last longer. No different than a race type TH400 with a Manual valve body or Trans Brake valve body. All the shifts will be firmer. Each person has their own version of what is too firm.

Why not just put a TCI transmission control unit in with a electronic valve body? Then you have Automatic shifting, Converter Lockup and you can tune everything to your personal taste.

[GRADYS Performance]

I have an 85 C20 Suburban with the same conversion. You can do search for it and several other posts about the 4L80E swap into 73-90 trucks and Suburbans.

[GRADYS Performance]

Here is a link to it and several others about the 4L80E.

http://67-72chevytrucks.com/vboard/s...d.php?t=608518

[85raiderburban]

Originally Posted by GRADYS Performance

I have an 85 C20 Suburban with the same conversion. You can do search for it and several other posts about the 4L80E swap into 73-90 trucks and Suburbans.

I do remember coming across your thread awhile back, good insight on the clearance issues. i will probably drill extra holes in the frame to move the cross member back.

Originally Posted by GRADYS Performance

Transmission Life will be fine. If anything last longer. No different than a race type TH400 with a Manual valve body or Trans Brake valve body. All the shifts will be firmer. Each person has their own version of what is too firm.

Ahh i see. yea i came across a thread on a another forum (but cant seem to find it now) on a guy that said the reverse w/ F.L.P. had a harsh jerk to it. I figured it to be true since that gear has highest psi of all of them. But just wanted to confirm that by anyone here

Originally Posted by GRADYS Performance

Why not just put a TCI transmission control unit in with a electronic valve body? Then you have Automatic shifting, Converter Lockup and you can tune everything to your personal taste.

Im old school 4 life, bro. carbed everything til my grave. my next project is in my sig so you can get an idea of where im at. Its easier (and less hassle) to have a drivetrain that doesnt have to rely on a computer. Too expensive for all those standalone units, the pressure control box im making will be less than $40.

[GRADYS Performance]

I understand the old school. My C20 Suburban has a 454 w/carb. I kept all that original. Yes the TCI Computer is more than what you are talking about in price, but in using it as manual shift transmission is NOT friendly to drive at all. And considering the added converter lock up control I would suggest you reconsider the computer. If you want to contact me I can give you pricing on the TCI unit.

The crossmember is just a matter of sliding it back and using the rear holes in the frame and the front holes in the crossmember with a 4L80E transmission mount and everything lines up. Then just drill the frame using the rear crossmember bolt holes as a pilot to drill with.

I built the transmission in my Suburban and it is upgraded from stock as I only use it for heavy towing. The reverse apply is not harsh in my opinion.

[85raiderburban]

Originally Posted by GRADYS Performance

using it as manual shift transmission is NOT friendly to drive at all. And considering the added converter lock up control

Seems friendlier than a T5 or T56 and having to use a "clutch pedal". Also the benefit of it being tougher to break than the latter two. Are you aware that 4l80 MVB TCC lockup is obtained the same way a 700r4 lock up is set up via toggle switch? Its backwards though, 4l80 TCC will be wired to ground (-) and not 12v (+). No reason to spend $600 for automatic lockup function when i do that already with $3 switch with my 700r4.

Originally Posted by GRADYS Performance

The reverse apply is not harsh in my opinion.

you dont have fixed line pressure, so i could understand that its not harsh. disconnect so its at default full line pressure in R and get back to me on that.

[GRADYS Performance]

Even in stock form the 4L80E Line Pressure when the shifter is in Reverse is boosted to the high side.

I prefer the ability to have the Converter Lock and Unlock automatically based on driving, road conditions, traffic and terrain. Your preference may vary.