JP86SS

iTrader: (1)

In reading on these for the 700R4, I thought putting one (or two) in may help my power through the trans better. My issue seems to be I can only put 300 HP through it. Motor revs harder but just isn't putting any additional power to the rear. Having higher pressure may help this (I hope)
The instruction sheet I saw on the Summit site shows that you can install these behind the pressure regulator spool in the pump assembly.
It states you do not have to remove the pump to do it but I don't see the port for the spools in the bottom of my trans.
I looked at all the pics I had with the filter off and just want to confirm I don't need to pull the trans apart to try this out.
TIA

'89 Iroc

If you look at your hole were your filter would go. To the left is another hole about the same size were you pressure regulator valve assemble will be. To the right will be a slightly smaller hole for your boost valve assemble. They are both held in by retaining ring. When you remove the ring, the spring will shoot everything out so watch how it comes out.

JP86SS

iTrader: (1)

OK, Thanks I'll be careful with that.
Oohh, my eye!

Does it sound like it would help the problem?

Just for refence, new converter, fluid clean and nice red, have aux cooler, TV adjust is good but could use that spring deal, hasn't gotten better or worse over the last 3 years. Just seems to not spin with the motor at all.
Below 2K the car doesn't push forward much at all, never has even with the old converter. The car pretty much lives between 2-3K rpm for all driving conditions.

Pat Hall

iTrader: (31)

I would think the bigger boost valves will probably help some. It's really about the only thing you can do to improve the holding power without major disassembly. Of course, if you did disassemble the trans, then you can upgrade the clutch packs, install a carbon fiber or kevlar band, hardened sunshell, 5 pinion planetary, etc. Also, if you get a transgo shift kit, they include a new pressure regulator spring that's supposed to help increase line pressures.

Pro Built Automatics

The boost valve assembly is on the drivers side, and has nothing covering it. The other side is the TCC valve assembly, which you do not bother.

JP86SS

iTrader: (1)

This is a B&M trans that is supposed to be good to 450 HP.
From what I'm seeing in my searches on this, the boost valve may already be the larger diameter with the stock sized low/rev valve but can't confirm exactly what they used.
The TCI valves indicate for higher HP levels the diameters get even larger than the regular boost valves (0.570 compared to 0.500) for greater than 450 HP.
I'm really beginning to believe that may be my whole problem because my milage has sucked with this car no matter how I tune it or drive it.
8 MPG is about the best if I stay out of it, maybe 10-12 on the highway at best with 3.73's.
Shifting seems fine and can be made hard/softer by the TV adjustment but you can definatly tell all of the torque is not getting through.
The trans came in the car when i bought it so i don't know how much it has been abused. I've put about 3,000 miles on it since i've had it and the operation has stayed the same. I'll probably end up putting a gauge on there to drive it around and see what is happening before making any major changes. Pressure may be fine but the mechanicals are not holding well.
Finally to the question,
Since it seems the valves will add pressure for shifting and alter the valve body calibrations when installed, If the clutch packs are worn/glazed from use, will the boost valves really make a difference?

JP86SS

iTrader: (1)

I think I found my problem.
During the current rebuild (by myself ) I came across an extra vane laying inside one of the "vent" cavities in the pump and...
The main item that I found was that the small o-ring at the base of the input drum was not installed!!!!!
This is the ID seal for the forward clutch piston housing within the 3-4 assembly. Whoever built before this did not do it right.

Makes total sense now that it would run but only up to a certain load level when the forward clutches could not be pushed any harder.
Manual 1 and 2 were always fine but never in Drive position. 3 and 4 were alway a problem with power transferring to the ground.
Glad I did this myself , and learned how this thing works.
Saved money and bought lots of good parts instead of paying for labor.
Boost & low rev valves, high pump spring, 29 sprag, beast shell, Torque drive input shaft/drum, 8 clutch 3-4, high TV spring,Carbonite band, 2-3 release check, pinless pistons, bigger 2nd piston, bigger 4th piston, stiff accum springs, wide sun bushing, all pump parts, Vette governor, other bushings (didn't replace all of them though).
(It has taken me 5 times longer than having a shop do it but is worth it to me to know every part is right now)
This thing should be killer
(If I didn't make the 3-4 too tight at recommeded clearance of 0.040)
Everything else is assembled and looks good.
Hopefully going back in this weekend.
Jp

Pat Hall

iTrader: (31)

Right on dude. While I have to admit that time spent is somewhat valuable, I totally agree that it was worth it to not spend all that cash on labor for some other schmo to do all the work for you. Like you said, at least now you know exactly what parts are in there instead of just hoping someone else did what they said, and you also learned how to do it yourself. It's so nice to learn how to do it yourself! That way, the tranny shops don't have you by the shorthairs, and your wallet, when your next tranny goes south. One of these days, I'm gonna grab that 700r4 core I've got sitting on the back porch, and do the same as you did.

JP86SS

iTrader: (1)

Well the deeper I go into this the more things I find.
1.) The "Mod TV Up valve" cap will not come out and is pushed in too far keepeing the spool from actually returning to the default position.
It is only about 1/8" in but I can see the oil port will not be closed with the spool in that position. The spool moves easily but there is no spring behind it!

Do I need that one or was it removed with a shift kit?

2.) Line bias valve spring has been replaced by a short rod.
I'm thinking this is from a shift kit due to the plating on the rod is gold.
Why was this done?


3.) TV valve is definatly aftermarket with a small spring inside the small end ID and a limiting bar within the main plunger spring.
The bar reads "Shift kit US Pat 4711140-SK"
Who made the kit?

I'm just about done with the assembly, this was the last before putting in the new 2/4 pistons. Hoping to undo everything that the previous guy did except for the new TV valve.
TIA
Jp

Pat Hall

iTrader: (31)

Yeah, I'd say on number 1 and 2 things that you listed, you definitely oughta put springs back in for the TV and the bias valve. I've never heard of replacing the bias spring with a rod. Sounds pretty odd to me. On your TV valve, I'm betting it's a TransGo unit with that SK prefix, since their 700r4 shift kits start with the same SK designation.

JP86SS

iTrader: (1)

Well I went to the hardware store and got a spring (something close) to put in the Mod TV up valve. Hit the cover with a torch and used some creative tools to massage the lug out. (45 minute job by itself)
Called around before drilling it and no shops would part with one if they even had it.
I have no idea what the bias spring should be so I left the rod in there.
That is the only thing "odd" that is left so if there's a problem I'll start looking there. Its all back together except the tailshaft housing.
I feel pretty good about it at this point.
Jp

Z69

I probably could track down a stock spring from my spares JP.
Might try calling Transgo on what it does or the Probuilt guy seems to not mind helping people. -oh yea, you didn't buy from him-
My 4l60e came in at .035 from the factory so your "ok". With the extra plates in your 3rd that might be better....IDK
Some say to leave the little springs in some out for the 3rd pack.
I think the Sonnax site may have some bias valve info. Or was it their catalog?

JP86SS

iTrader: (1)

I just left the bias as is and buttoned it all up.
Garage is all cleaned up for "the big lift" back into place.
Getting it out was not easy, going back is going to really be a PITA cuz I have to rotate the trans sideways to get the ears between the collectors than turn and put it on the motor.
I left the 3-4 return springs in there. Read they help keep the 3-4 from dragging at high rpm. Doubt if I'll even be able to tell the difference.
Lots of things can be done by shift kits, un-doing them and finding the stock springs seems to be quite a task. Local shops won't help at all, NAPA was willing to buy me a box of each spring if I wanted but individual qty was not available.
Was a toss up between Probuilt and PATC for the main rebuid parts. Didn't really have a favorite and they both advertise here. PATC had all the torque drive stuff and had many of the small parts listed separate that I could pick and choose my mayhem. If i were rebuilding a trans I knew worked correctly then I would have just done the PB kit.
Will be sure to update once its in

87zjeff

iTrader: (4)

hte solid rod in the lline bias line-up is the riggers way of avoiding a shift kit. it keeps the line pressure at maximum. i would get a spring in there. the transgo shift kits are awesome and used valve bodies can be had cheap. we sell them at work all the time. if you get the tranny in and it will not shift, that rod is the first thing i would look at.