700r4 Torque Convertor

[___Brandon]

I picked up a 700r4 out of a 1988 2wd Suburban to put into my 1980 Camaro, and I'm wondering how the stock Suburban torque convertor will be in a Camaro.

I currently have a 3000 stall torque convertor in it with a TH350 and that's not what I want at all. It is good for the drag strip but the local drag strip has closed down. A 3000 stall just isn't getting it for neighborhood cruising, I feel like I'm slipping more than I'm moving unless I'm flying down the road.

I'd like the 700r4 to take off the same as a the stock TH350 did in that car. I've got somewhere around 300 HP or more so I should have plenty of power for sporting around town. I'm just worried the stall speed might be too low and I'll have to stand on the brake pedal to hold it back at an idle because it is set up for a 5000 lb truck not a 3000 lb car.

Any thoughts?

[MagicRat]

The converter should fit, and so long as the idle speed is reasonable, (under 1000 rpm) it won't creep much.

But the trans swap will present other problems. The length is different; you may have to get a custom length driveshaft, and the transmission support will require some mods.

Your 700 TC will not lock up unless you add an electric lock-up circuit. But it will do no harm to leave the lock-up feature disabled.

You will have to adapt the 700 TV cable to work with the Camaro throttle linkage.

[silicon212]

Just make sure you have the proper 700R4 converter for your transmission!

If you have a pre-1985 transmission, you will have a 27-spline input shaft. The torque converter for this transmission is usable on either the TH2004R or the pre-1985 TH700R4.

A => 1985 transmission has a 30-spline input shaft and will not work with the earlier converters! The 30-spline converter will physically fit a 27-spline input shaft transmission, but you will have no drive. A 27-spline converter will not index on a 30-spline transmission.

Edited to add the following:

I guess I misread your first post. You stated whole transmission, I saw "torque converter". The trans should work fine and the first gear has a 3.06:1 ratio, so it will rocket off the line (if you can hold the traction). These transmissions are longer than the 6" tailshaft TH350 (what your Camaro would have), so you will have to get the driveshaft shortened, and as MagicRat pointed out, the mounting point is slightly behind the TH350 mounting point by about 3/4 inch or so.

[Tony Silva]

The th350 torque converter definately WILL NOT work in a 700R4 transmission. You NEED a torque converter that is specifically designed for a 200R4 or a 700R4 transmission. Also, you will need to slide the trans x-member back about 3/4 of an inch. You will also need to shorten the shaft 3/4 of an inch. On the last swap I performed I bought an "Energy Suspensions" polyurethane transmission mount. I then cut all the material away from it. Then took the metal plate portion of this mount mount, drilled 2 holes into it then I welded 2 nuts onto the plate in such a way as to allow bolts to pass thru the holes as they are threaded into the nuts...tightening the plate to the x member. Basically you are gonna have to fabricate your own tranny mount. I looked on line to get an idea of what the mount needed to look like. It pretty much is a 3/8ths plate with 2 factory holes for the "trans mount to trans" bolts to go thru and also 2 nuts welded onto the plate for the "crossmember to trans mount" bolts to attatch to. Lastly you will also need to get the torque converter lock-up kit and a brake light/cruise control actuator switch. It is basically a brake light switch with an extra pair of prongs on it. I forget the price if the TC lock-up kit, but I think it was somewhere in the range of $150.00. As for the linkage and TV cable, a factory 700R4 or 200R4 TV cable will work, BUT You will need to buy a small attatching arm and bolt it onto the carb to connect the cable. NO DO NOT MAKE YOUR OWN. IT WONT WORK. IT HAS TO BE AN EXACT LENGTH...THE GEOMETRY OF THE ARC IN DEGREE'S HAS TO BE PERFECT. THERE IS NO ROOM FOR ERROR ON THIS PART.

[silicon212]

You're on a necroposting binge, aren't you?

[Ol'Jim]

Originally Posted by silicon212

You're on a necroposting binge, aren't you?

LOL

[Tony Silva]

Yeah, Might be a Dead Thread, but you never know the last time it was actually viewed by someone needing some info that just wasn't there. It's good and accurate info....very specific. (It's one of my faults). But Hey, That's how I became able to build these cars...thrash around till the MORNING before a show and drive a car to it. I hate trailers unless it's got a track or drag car on it.

[silicon212]

Just remember what I wrote above all those months ago - the 2004R and 700R4 converters were only interchangeable for the first 4 years of the 700's life. After 1984, the 700R4 uses its own converter. Older 700R4 converters, will, however continue to be interchangeable with the 200R4 no matter which year it was made.

For others, the TH350 uses Imperial measurements (SAE, inches). The 2004R and 700R4 are metric units. So no, converters between the two designs will not interchange. Even if the 350 uses a lockup converter.

[___Brandon]

Thanks for all the help on this swap.

I've got the tranny in and just about ready to drive (its been a busy summer!)

I have been reading everything I can find about TV cable adjustment, and I bought the mounting bracket that bolts on the carb mounting foot and the geometry correction brkt for the throttle. I have the cable set such that at WOT it is pulling the cable out tight to its end of travel.

Does this sound correct?

I'm kind of gathering from my reading that most of the fuss is over people building their own brackets, hopefully I took the mystery out of it by just buying the brackets from TCI. Got my fingers crossed. I plan to check it for the shift speeds and crispy transitions. I also plan on accelerating moderatly until it shifts to second and then stomping it to make sure it immediately downshifts back into first.

[Ol'Jim]

Don't be disappointed if it doesn't downshift to 1st at WOT. Very few trannies will kick down to first unless you are moving VERY slowly, (approx 10mph or less), with a significant load, (such as pulling a trailer up an incline). Most of your kickdown activity takes place when cruising at moderate speed in high gear, and stepping into it, (as if to pass a slower vehicle). 4th gear down to 3rd, or 3rd down to 2nd.
No worries, even 2nd gear is quite low on the 700R4 and you will still accelerate quickly!
BTW, good job getting it all together. Did you end up relocating the cross-member? (or replacing it)? Or buy/fab a different tailshaft mount for it?

[___Brandon]

I moved the stock cross member back 3" by moving the front holes on the crossmember to the rear factory holes on the subframe, then drill new rear holes to fit. Unfortunately the front driveshaft yoke is now sitting right under the support rib for the floor and only has about 1/2" of clearance on the passenger side. If it hit the floor I will have to do some mods there. I also had my driveshaft shortened by 3" to accomodate the 700r4.

Does it sound like I adjusted the TV cable correctly? At WOT I've got the cable pulled out to the end of travel. I've got the TCI brackets to hold the cable to the carb base and the geometry correctory on my throttle.

Thanks

[Ol'Jim]

Originally Posted by ___Brandon

Does it sound like I adjusted the TV cable correctly? At WOT I've got the cable pulled out to the end of travel. I've got the TCI brackets to hold the cable to the carb base and the geometry correctory on my throttle.

Thanks

I haven't adjusted a TV cable on an aftermarket bracket. The old GM method was to press in the cable release button, and pull some cable back through, then release the button, and have one person slowly depress the gas pedal down to the floor, and hold it there, while a second person made sure the throttle blade/carb was indeed wide open. The cable adjuster was kind of like a zip-tie, it ratcheted, allowing travel in one direction only. In theory, I suppose the cable would be at or near full travel when the throttle was at WOT, but my concern with doing it your way, is that the cable may not return all the way when your throttle is brought back to idle. (Which could lead to some higher than normal trans pressures at light throttle, and possibly some harsh shifting while cruising).
Assuming the TCI bracket came with instructions, what did they say to do/did you follow them exactly? If so, you should be good.

[___Brandon]

I think I've got it!

I drove the car last night and the shifting felt a bit slushy, so I tightened the cable a bit - it is now pretty much as tight as I can get it at WOT.

The upshifts feel good now. It will do a bit of a lazy shift into overdrive if I'm running light on the pedal, but I probably shouldn't be running overdrive at that point anyway.

It still will not downshift when I floor it running down the road at any cruising speed say 45-65. It downshifts itself fine when I slow down though. I was running a twisty road from about 20-40 mph with the shifter in 3rd and it was shifting up and down probably just from 2nd to 3rd and back.

It sure is nice to click it into overdrive and flip the lockup switch at around 60 mph!

Thanks for all the help!