TV modulator upshift valve

[Russ Merritt]

This valvebody came out of my old tranny and would never, no matter what we did shift hard 1/2. Rebuilt the unit twice, billet servo(s) tried 3, shift kits (never had a trans-go), blocked 1/2 accumulator, differant govenors, just about everything. On the table last night I started to take the VB apart to really check for anything binding/sticking. I noticed on the TV modulator upshift valve there is no spring. What would that do to a full throttle upshift? Thanks.

 

[WE4]

Russ...

It has NO effect and the more you look for answers the less you will probobly find. Mtv oil is effected upon tv oil. Nice observation tho.
You KNOW what you need to do.
Hey I gots an idea... The kid's piggy bank is ungaurded right now......... There's a thought


LOL

Good Luck Russ.

Bruce
WE4

 

[Russ Merritt]

Just havin a little fun while it rains out. Who ever thought how to build an automatic must have been a genius. This old tranny will end up in your hands Bruce, I don't have any kids to steal from or I would! I have 4 core 2004rs here and I was just tryin to learn somethin today. Pretty interesting stuff. Thanks.

 

[chris718]

bruce is right russ .the only thing the tv upshift spring missing will do is allow slightly later upshifts with no or bare minimum throtlle .the spring disengages the delay function until about 10 psi of modulated tv pressure overcomes the spring,upshifting the vale and sending oil to the shift valve sleeves to fight the governors upshift forces when the valves are in the downshifted position.when they are upshifted it exhausts.most gn and ss valve bodies didnt have the spring because driveshaft rpm/governor pressure with a 3.42 or 3.73 ratio final drive rises very quickly with a flyball style governor.

 

[Otto J]

i just had a trans that i did for a guy and a week later there was a problem with part throttle upshifts, anything more than 1/3 throttle and the trans would not upshift until arou 5800, pulled the valve body to find that the MTV upshift valve was stuck back in its bore, cleaned it and and the problem was solved.
Otto

 

[Russ Merritt]

Otto, was there a spring on it or was it just floating in there?

 

[Otto J]

no spring, i have a couple BRF valve bodies and none of them have a spring . But if you take the vavle body and tip it back and forth that valve should move freely(maybe a slight jolt to move it)
Otto