700R4 Information Thread

[tayto]

I still haven't gotten the opportunity to make up a pressure gauge setup. I feel the pressures are OK as it shifts pretty good. It may have a Corvette servo in it. The 2nd and 4th shifts are pretty crisp and 3rd feels like factory. Only ill effects are the late 1-2 shift,TCC locking up as it's going into 3rd and the relock delay in the TCC when you roll back on the throttle and those are probably in the ECM program.

with the throttle valve at WOT. take a pair of vice grip pliers and pull on the end of the tv cable. should have like 1/32” of play. from that spot you can try backing off a click or 2. should have no more than a 1/16" play with throttle at WOT, IMO. The only other thing i can think of for a late 1-2 is maybe servo pin travel is very large and/or 2/4 band slipping. i have seen a poorly modified pin dig into the band and cause a really late 1-2 shift. eventually it slipped so bad you'd have to get it to 4500 rpm for it to shift.

 

[Erik the Awful]

with the throttle valve at WOT. take a pair of vice grip pliers and pull on the end of the tv cable. should have like 1/32” of play.

Pulling the pan is a pain in the rump, but it ensures the TV cable is good. Little tricks like this don't work if you've had to modify the cable bracket, and some tips are just dead wrong (not saying this one is wrong).

 

[PlayingWithTBI]

I tried the Sonnax TV Cable Corrector Kit AS1-01K (it come with 3) just for grins and giggles. My trans was firm shifting 1 - 2, hard shifting 2 - 3, and smooth shifting 3 - 4. My biggest problem was it wouldn't shift 2 - 3 at WOT. After installing the kit, it raised shift points way too high, 1- 2 from 15 MPH to 25 MPH, 2 - 3 from ~35 to 45 MPH. It raised my line pressure from ~80 in Drive to ~90 PSI. I wound up releasing the adjuster by 2 clicks before it went back to what I had before, including no shift 2 - 3 at WOT. It does guarantee the cable is tight enough to achieve full line pressure at WOT. IMHO, it's for improper dimensions but, it is also cheap insurance you got it right. YMMV
www.summitracing.com/parts/SOX-AS1-01K

Sonnax Transmission Company AS1-01K Sonnax TV Cable Corrector Kits | Summit Racing

Free Shipping - Sonnax TV Cable Corrector Kits with qualifying orders of $109. Shop Automatic Transmission Brackets and Levers at Summit Racing.

www.summitracing.com

Here's where I had the corrector (spring) installed. FYI, i've had it installed since the middle of March with no other issues than I started with)

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[tayto]

Pulling the pan is a pain in the rump, but it ensures the TV cable is good. Little tricks like this don't work if you've had to modify the cable bracket, and some tips are just dead wrong (not saying this one is wrong).

ya it doesn't hurt to check it this way. I like to use a gauge as it's alot cleaner and tells you the same thing as dropping the pan (IMO) the only time i ever had an issue was the first 2004R swap i did back in 2005. used a carb that was from a TH350. trans burned up in about a 1.5 years, but probably had 50,000 miles on it as i was driving a lot for work then. once i learned about TV spring length and having the geometry setup per GM I haven't had an issue since. Have help many people set them up especially with Edelbrock or Holley carbs.

if the WOT setting isn't setup correctly the trans will burn up quickly. if incorrect geometry it may take serval years. YMMV


EDIT: here is a really good article, though it is hard to read..it has been gone for a number of years now but you can still find it with archive.org

Wayback Machine

web.archive.org

 

[Scooterwrench]

I went one more click past WOT and it made a very noticeable difference. 1-2 shift is just right now.