700R4 1-2 shift issue, please help!

[Matt69olds]

Personally, I’d drill them to the larger size. Like I said, TransGo tends to be conservative. I like a solid shift. If you feel the same, drill it larger. If your worried it will be too firm, you can start small and drill larger later. Kinda hard to make a hole smaller!

 

[AlexK10]

Your going to have to pull the servo out to get the casting number.

I did change to a corvette servo and have photos of all the parts somewhere. I could check that.

In which case drilling larger without ordering specialty bits could be at 7/64" = 0.1093. Based on .095" original hole size, a 0.109 hole will be between a 30 and 40% area increase (Sonnax guide), which I think is ok.

I also like a firmer shift.

Should I drill holes for 2nd, 3rd and 4th as Sonnax suggests (above). Or only 2nd (C) and 3rd (A) as the Transgo plate instructions suggest (also above)?

 

[AlexK10]

Just noticed that on the plate, Transgo and Sonnax holes to be drilled for the 2nd shift are noted different. Holes for 2nd are side by side but based on the illustrations (on either side of the plate) Transgo says to drill one hole and Sonnax instructs to drill the other hole. So I drilled based on Transgo (from where I got the new plate) to 7/64ths=.109". Also drilled for the 3rd shift hole. Left the 4th shift hole alone, as it came on the plate.

I just received today the pinless accumulators, will start working on figuring out check ball locations on VB and case.

 

[AlexK10]

Ok, now I need help in trying to figure this out:

I don't want to go by the check ball locations I had when I removed the VB because I do not trust it. You will see why here.

Image 1
This is what I had when I removed the VB. Marked in blue.
On valve body:
Notice I didn't have #3.
And I had a loose check ball doing nothing (blue circled in red)

Case:
5 check balls total and two of those are noted by B&M "do not install".

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Transgo vs B&M Check ball locations do not coincide the diagrams I found.

A Transgo document I found online shows two extra check balls in the case. Maybe this diagram is for AUX only VB?
B&M for my Non Aux says ""Do not install".


Image 2
B&M Image

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Image 3
Transgo Image
Mine is a type 1 VB, disregard the pencil marks on the document, I found this image online.
It shows an auxiliary VB on the page, I think as an option or is this document for an aux VB and not for the non aux that I have?

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I've concluded that for the VB side I need to place a check ball in #3 position, and remove the "loose" check ball that I marked in red/blue in the first image.

But what about the case side? 3 check balls like B&M suggests or 5 like what I had?

Remember this is an 1984 Non Aux 700R4 with Type 1 VB.

 

[Matt69olds]

I don’t have my ATSG book handy, that explains the function of each check ball.

If the case “bathtub” has 2 holes in the spacer plate, it needs a ball. The check ball hydraulically isolates 2 circuits. One hole in the plate over a bathtub, no ball. If a check ball has a small hole in addition to the hole the ball seals, then the ball forces fluid thru a orifice. The ball forces fluid thru the orifice during apply, and then unseats and provides 2 paths for the clutch to release.

Do you still have the old plate to compare? Can you see where the case casting has been polished from the check ball cycling?

 

[AlexK10]

Yes I have the old plate and have circled the areas where I noticed wear.
On the VB side I confirmed wear on the 3 locations were it takes a check ball, even though I had a loose check ball that goes in #3 position as per B&M diagram, that's the one with the exclamation sign "!". It'll go were it belongs. So VB side is clear to me. And the 4th larger check ball next to the TV plunger (not circled). So the VB takes three small and one large check ball.

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The case side shows wear on 5 locations I had check balls when I disassembled.
Image is upside down and cant get it right side up, sorry.

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The Transgo SK700 kit instructions I have has a diagram and indicates to install 5 check balls, where I had them.
B&M says not to install two of them (the ones without numbers in this image, correspond to B&Ms diagram "Do not install). next to #6 and next to the accumulator.

Which is right, Transgo SK700 kit or the B&M diagram I found online?

 

[AlexK10]

Ok this could be the end of this project. Last weekend I got the VB, accumulators, TCC Solenoid, new case plug, filter gaskets etc... all of it put back together.

I did install all 4 check balls in the VB and all 5 in the case. One in the VB was a Torlon plastic ball as specified in the SK 700 instructions.

New Sonnax pinless accumulators, New TCC solenoid with a check ball in the snout trick to get lockup without 12v or solenoid actuation (As specified by the SK700 instructions and by a you tube video from Precision Transmissions).

I initially tested with the black and blue governor springs I had installed last. Shifts were at 15-25-35 barely touching the gas pedal, taking it easy with the new shift kit. Then I went back to the original purple and white springs and shifts came up on the 3rd and 4th gear. 15-28ish-40, with light pedal. Now if I give it more gas it will hold gears longer in relation to how much gas I give it, sort of like holding the gears for more power I guess. 18-30-45 etc. I'm happy with that.

Down shifts are good when I stomp on it specially when on 4th and it shifts down to 3rd and then back up to 4th.

Lockup with a 12v dash switch straight to the case plug-4th gear pressure switch-TCC Solenoid, and grounded to the interior of the case. I tested its function before putting the pan on. Ground to a VB bolt and 12v to the TCC solenoid, the solenoid worked.

Lockup itself when on 4th is unnoticeable, I didn't notice any change in rpms when I flipped the switch. Could this be because its going into 4th gear lockup with the TCC snout check ball immediately? I don't now, but that trick is meant for that; getting lockup when your case plug isn't getting 12v power.

Next upgrade will be a trans cooler to extend its life.

 

[Matt69olds]

If the converter is locking up as soon as it goes into fourth gear, you would definitely feel it. Especially if you have the solenoid on a switch. If you can hear the solenoid click, then electrically it works. Did you check the condition of the converter clutch valve in the pump?

 

[AlexK10]

Yes, it clicked when I tested it installed (grounded to the VB and 12v on a switch). However It also has a check ball in the TCC snout and the 12v goes through the 4th pressure switch before activating the TCC solenoid. So, I think its engaging TCC lockup immediately on 4th with either the check ball in snout or the 4th pressure switch.

The only thing is that if I leave the 12v switch either Off or On I do not feel anything different. It could be going into lockup with the check ball regardless of having 12v or not. That's the purpose of the check ball.

Am I correct in my assumption?

In addition I have headers and straight cherry bombs which makes a very loud ride, cant even talk to the passenger without screaming when driving at highway speed; so that makes it really difficult to pinpoint TCC lockup a second after it goes into 4th.

As for the converter clutch valve in the pump... there was something about the SK700 instructions that didn't seem right or I couldn't figure out to tell me the correct procedure for that upgrade. At the time I decided not to mess with it based on:

• Not sure about instructions and what I had in there now.
• Difficulty of removing that valve with the circlip upside, down under the truck, upside down.
• Risking not being able to reinstall that valve assembly and forcing me to drop the transmission.
• Not introducing more variables to the repair and messing more with unknown results, since I had reworked all the VB valves on both sides with new springs and new TV Valve setup, all check balls locations corrected, new TCC solenoid, eliminated the 3-4 pressure switch and rewired to 4th pressure switch, new 1-2 and 3-4 Sonnax pinless accumulators, new case plug and pigtail.
• And that week we had a storm coming in with flooding expected and I didn't want to leave the trans in pieces and not being able to move the truck in case this area flooded, which it didn't.

So for now Im happy with the results and will focus on wiring the wipers, horn etc next with a mess of cut wires I have in the fuse panel. Ill either connect all this as close to factory as possible or do my own setup with fused relays and start disregarding/eliminating the factory fuse/relay box. Also get some paint on it (roller job).

Someday Ill go back into the trans, but will try to use the truck first for its purpose since its been over a year in engine, trans, electrical, and many odds and ends work on very limited time to get anything done.

And the Hayden 679 cooler is on the way.