700R4: TCI Constant pressure Valve body

[jknight16]

I was hoping I could get some input from you guys on a fairly new product that's available for the 700R4. It's a constant pressure valve body from TCI that provides 200 psi of line pressure no matter if the TV cable is mis-adjusted. You still use the TV cable to run your shift points, downshifts, etc., but the risk of burning up your trans is supposed to be eliminated. Anyone have any insight on TCI's solution for this problem? Pro's, Con's?
http://store.summitracing.com/egnsea...5&autoview=sku

My 700R4 is now slipping, but there has been no debris in the fluid and it has been working decently in this car for probably nearly 10K miles. Despite my best efforts to reinstall the TV cable properly after this latest round of restoration, I'm confident that the TV cable still isn't adjusted properly.

Is it reasonable to think that the additional line pressure created by the constant pressure valve body would stop the trans from slipping, or am I most likely guaranteed to be needing a trans rebuild (which I'd rather not do). For clarification: the trans isn't blown yet, I just can't give it much throttle without it slipping, acts like the line pressure isn't building along with throttle. But still no debris or burnt fluid, so it doesn't look, from that perspective, like the trans is hurt. (I should have gotten a 4l60!!! but this was done too many years ago)

Thanks for your input

[critter]

I'm curious as well. They're so new I wonder if anyone has experience with them yet?

[critter]

(Sound of crickets chirping)

[jknight16]

ttt

If no input on the new TCI valve body, which is understandable, anyone have any opinions on a good transmission builder in AZ?

[buddyholly]

Couple of things...
If it is slipping it needs going through. The constant pressure valve body won't reverse the damage you have already done to the clutches.
The constant pressure valve body sounds like another baind aid. The 700 has many charms but many well known flaws. The 3-4 clutches don't have an exceptionally long life even with stock setups.
This thing from TCI makes it sound like it solves all your problems but then you get issues with pump wear and added strain and hp loss for running the pump at 200psi all the time just to fix something that should be addressed with a proper cable adjustment. You can do something similar by just locking the TV valve down and running max pressure, which some kits do with the manual valve bodies. Not great for longevity.
My two cents is that it is not that hard to adjust the tv cable correctly. Do it right and you have no need for the TCI valve body.

[Texas Hotrod]

It doesn't make sense. The TV cable controls both the shift points and line pressure. If line pressure is pre-set then the governor can't function properly, it too relys on the changes in line pressure for sorrect shift timing.
Most valving that locks in line pressure requires manual shifting.
Max pressure shifts on a 700R4, even at light throttle/mid RPS will probably cause your dash to fall out. A healthy 700 with those mods would shift really hard (a high stall converter would soften the shifts).

Adjust the TV cable until there is no slack at 100% throttle. Swapping a Holley in the pallce of a Q-Jet has issues too. It's hard to get the cable throw/pre-load correct. Anyone who has had these issues, knows what I'm talking about.



I rebuild 700R4s/4L60Es on a regular basis. All of my 700s get a Trans-Go shift kit (the "Jr. kit"). I always install 3rd gear heavy duty (Z-pack) clutch kits, even on stock builds. Suburbans, Camaros and farm trucks get a performance "power band/red band" for 2nd/4th.
There's a lot to one of those. Slippage usually means big trouble.