350 or 700r4......no brainer?

Which is a better way to go? I have a line on a 700R4, an '84, I think. No computer. I thought there wwas problems that plagued that trans, no? The idea of having overdrive appeals to me as I'd like to drive my '37 all over the place (read, freeways). I was looking for a TH350, should I go for the 700? BTW, it's going behind a '75 350 truck engine.

 

unless it's been upgraded or you're going to upgrade it look for a 90 or newer 7004r. the early units had problems with pumps and valve bodies.

fwiw i'm leaning towards putting one in my 65 gto project if i don't sell it before i finish it.

no computer is needed with a 700r4.

mike

 

I don't remember which stock 700's were the problem. But I went from a 396/T-350 to a 454/700R combo. The best I did with the 396/350 was 14 mpg highway. The 454/700 has given as high as 19.5 mpg. The 396 was a 9.5-1 350hp motor and the 454 is a 425 hp crate

 

I switched from a 350 to a 700R4 in my Victoria. I've never had any trouble with either one, although the 700 was a little fussier to set up correctly (TV cable & governor). If you'd like more detail, PM me.
Tony

 

you can put a high gear in your car with t350 and have the same deal as the 700r4. really the improvement in performance is on the bottom end, the 700 with the correct rear ends up around 2.75-2.50 in od the same as a t350 with a 2.50 .or 2.75 rear.the real difference is in the take off of a 700 with a 3.00 to 1 low gear and a 3.73 rear. high gear ends up the same with both.

 

i've never liked the 700r's had many problems with them, mainly leaking issues... but pumps going out and such was anouther problem i had in my 83 chebby pickup

 

Theoretically, with a 700R4 and a 2.73 gear in my Suburban, I can run competitive laps at Daytona with it, I suppose. I have pegged the needle a couple times and it does it without a sweat. I can watch the gas gauge go down when I do that, but thats what happens with a 5000-lb truck that has all the aerodynamics of a brick.

It's the earliest 700R4s that are the real problem transmissions, but most shops are set up that when they rebuild one they upgrade it as needed. You can run it without a computer but it needs an electronic control to lock and unlock the converter, which I've seen on eBay for like $40. I'm not sure what year they upgrade, but I thought it was '86 or '87. I know I've pulled some rediculous things behind mine and haven't killed it yet - but I put a great big trans cooler on right when I got it. Plus it helps that it was a 57,000 mile truck to start with (a 1989).

I would get the numbers off the tag on the case and google them and see what I could come up with for info on it.

 

Amazing, but then again, the torque and no throttle to pull you along...Says, 20mper beats out a 13mper 396 gas hog right back to seeing how the 700 handles 425 crate hp.

If you have a core, go to the dealer, ask to buy a SRTA 700 by GM, (if still available). They are factory reconditioned transmission assemblies with a 36K mileage warranty. Sorry, Do not know a price with core?

Secret to the transmission is to fill the SRTA torque converter (to the brim) with ATF and let it keep settling into the blades. Clean the oil cooler lines (every) speck and span with whatever cleans dirty old oil. Use new oil fitting o-rings to the trans in and out fitting on the main case.

On the 700 cable ratchet set. Push the TV throttle housing ratchet tab so the ratchet slides in all the way back in the main plastic housing. You already have the cable hooked up to the trans and throttle. All you have to do after the ratchet set is to WOT the throttle linkage and the ratchet will click out and automatically preset to the WOT of the throttle linkage. Vacuum hose to the gov. It's that simple.

What did I miss?

 

1987 to 1993 are the best ones to get if you don't want to modify them.
I have been using a 1984 700 R4 in my Stude pickup for hauling and towing for over a dozen years, but I did all the upgrades (extra clutches, bigger servos, shift kit, better oil pump, etc) before I put it in the truck.

If you go any newer than 1993 or so, you will have to deal with electric speedo, and other controls.

The 1993 and earlier are self-controlling and are easy to use. Before 1987 you have certain internals to upgrade, so 1987 and later will save you some upgrade work.

I like 3.50's and 3.70's with the OD for MY type of general work truck use. I have been towing in overdrive a lot. If you use a 3.00 or other tall gear, do NOT tow in OD.
Use a good trans oil cooler a bit larger than you think you will need. I have never had a hot trans by doing it that way.

You don't need one of those $100 kits to gain control over the converter lockup. You can use a switch on the dash. I use a regular oil pressure switch in the 4th gear port, and use it to lock out any converter clutch when the trans is in a lower gear, so if I forget to flip off the dash switch, it automatically unlocks it for me.

Before that, I ran for many years without using the convertor lockup at all. You can leave the converter unlocked all the time if you run a low gear such as 3.90 while you DO need a lockup converter if you run tall gears such as 3.00's or you can overheat it in a hurry.

Others may argue with me, but I have been beating these trannys to death in my cars for almost two decades without a failure yet.

The only car I won't dare use it in is my 472 Cad powered Hawk. I believe that would break it quickly, so I keep the Cad TH 400 trans in that one.

If you put a 700 R4 behind a small block, I wouldn't worry. If you put it behind a big block, I would look for a bigger trans or a special-built one.
That's my 2 cents for what that's worth...

 

electric speedos came along around 1988, and the computer controls were on the 1993s.

lotsa folks have no trouble at all frying a 700 with a small block. You gotta be careful with them....although they can last if you do everything right.

 

WHAT vacuum hose to the governor? I think THAT'S what you missed. I've never heard such a thing

 

I love/hate 700's. They either work great or like shit. I think it's an art form to rebuild one right. If you get a bad one, it'll be a real bad one. One shift is too soon and harsh. The other too late and soft, etc.

 

Yep what you said, either love or hate em! I have one that was built by a tranny shop in Hunt. Beach and I love it, works great and have not had any issues, but I have had just the opposite.

 

I have never had any trouble with the shifting on mine. I used a few of those Gil Younger shift kits that came with the trans rebuild kits I bought from who knows where... Napa?? in the early 90's. Was that the trans-go brand, or something else?

That Gil Younger shift package with quite a few springs and some new valve body plunger valves seems to work great. It was purely by luck that I went into the right parts store to end up with the right brand, but that Gil Younger stuff worked out great for me.

I adjusted the LOKAR TV cable set to give me shifts that are firm enough to be able to count them so the clutches don't slip and slide, but not harsh enough to hit hard and bang something.
That has worked very well for me so far. That LOKAR cable is so adjustable and so adaptable that you can hook it to just about anything. I prefer it over the GM TV cables.

I am not suure when they went to electric speedos, I thought I read "early 90's" or "93" in Car Craft (maybe), but I did buy a 1988 trans with cable speedo, so I know they existed at least till then. I read "1993" somewhere but don't know where. I believe that's when the "-E" for electronic became common. In the 90's just about all the car mags recommended the 1987 to 1993 models as the last of the self-controlling ones that didn't need a lot of electronics to run. I had the impression that some had electric and some had cable speedos at that time... I do have an 88 with a cable speedo at least.

For what it's worth- A trans-shop owner that I know runs a 700 R4 behind his 454 in his pickup. He has had good luck so far, but I can't help think that he is running on the ragged edge of it's torque limits. The way he has his converter lockup configured (I think it's a B&M lockup controller), the 300 or so rpm drop when the lockup occurs makes the trans act and feel just like a 5-speed automatic. It's really cool to drive.

 

The biggest reason anyone has trouble is maladjustment of the TV cable. It is not a kick-down cable, so it is very sensitive and doing it wrong starves the tranny for line pressure and smokes the clutches. TCI has remedied this with a full pressure valve body where that will never be an issue. I would get the latest, lowest milage unit I could and put one of these valve bodies in it with all the performance mods you can stand as outlined in the ATSG service manual. When you're done, it will cost you a couple hundred more, but it will be as bullet proof as anything short of a turbo 400 can be.

 

The TV is the key. I've never dealt with this company, but this site is full of info and specs, they also offer some solutions to the problems people have with properly setting up 700r4's.

http://www.tvmadeez.com/

 

You may find that the Suburban and big trucks through 1991 have the speedo cable, while the pickups switch over to electronic in there somewhere. This because the Suburban and Crew Cab trucks keep the old style body those years. I know the '89 I have has a cable on it. The S10 is the one that goes electronic in 1989, for sure (and some of these did get light duty 700R4 trans in them, so be careful what you get one out of, there is one S10 version that's different internally).

 

Quote:
Originally Posted by phat rat
The 454/700 has given as high as 19.5 mpg. The 396 was a 9.5-1 350hp motor and the 454 is a 425 hp crate

Amazing, but then again, the torque and no throttle to pull you along...Says, 20mper beats out a 13mper 396 gas hog right back to seeing how the 700 handles 425 crate hp.
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Well the trans has just over 35,000 mi on it behind the 454 and I don't baby it either. A few here on the board can verify that.

 

The best site thatI have found for parts and information is BowTie Overdrives. They have a TV kit that is fool proof and easy to adjust right the first time. They also hace all of the corect speedo gears no matter what tire or rearend ratio you run.

 

A local guy used to build those for older cars. He said 86 or newer I think, due to better internals

He did mods to make the converter lock & unlock automatically and it worked sweet....something about putting a ball bearing in the lock-up solenoid passage? I put one in for a guy, and the builder gave me some strict specs on how to set the TV cable and said it's critical, not just important.

The only thing I did not care for was the ultra low first gear. Sort of annoying on city driving between lights. It shifts out of first in a few feet. We ran a 3.73 gear with a 250 six and it was a nice driver.

 

I would say that's true. I pulled a 350/700r4 out of a 1988 suburban for the 48 pickup I'm building and it still has the cable speedo.

-Rich

 

Timely post as I am thinking of going to a 700R4 in my Olds , I have a 3:31 rear in it. How will the 700R work w that gear set? After this post I am more convinced that I will do the 700

 

Damn, what I'm getting from all these replies is that the 700 is a hit or miss transmission with funny shift points. I'm sure these can be awesome, but I just want a blood simple (like me!) auto trans. The 700 trans in question is owned by a buddy of mine and is an '86. I think I'll go with the T.H.350.

I need to check the gears in the 8 inch (late 60's Mustang) that I'm going to use. I'd bet they were 3.00 or 3.20, something kind of mid range....If they are, then I think I'd be fine with the 350 trans.

 

That's what I want to hear. My truck is going to be pretty light too.

Thanks El Jeffe!

 

I run a 3.42 gear in mine and wouldn't want anything higher as the rpm would be running too low

 

I'm running a 330 HP 350 and 700R4 in my roadster with 30 inch tall rear tires and 3.70 rear gears. It snaps your neck on a hard launch, has great top end and gets 18+ mpg. What more can you ask for?

 

I'm thinking of switching to a 700r4 as well. I need that overdrive because i like to get in my car and go, and the gas is killing me. The years to get are 88-92. Adjustment of the TV cable is crucial i hear, although I don't know how to do it.

 

Adjusting the TV cable is actually easier than it sounds in print.

You adjust it to either make it pull the cable tighter or give more "slack" in the cable while you pay attention to how it shifts when you drive it around town.

If the shifts are easy and you sometimes have trouble noticing when it shifts, then it is slipping the clutches and will wear them out fast. Don't accept the smooth invisible shifts they used to brag about in their luxury car commercials.

If the shifts are hard enough to tell you when it shifts, but they do not bang hard, then you have it adjusted just right for a long life.

If it shifts with a pretty hard tug as if you had a racing trans, then it will be hard on the gears, the clutch splines and the "shell" that sometimes breaks when the engine torque is too much for the trans.

Tighten or loosen the TV cable to bring the feel of the shifts into "medium ground", and the trans will last a long time.

If you want to use a 700R4 in a car that didn't have one-----

B&M (possibly Lokar too?) says that the TV cable-end should be hooked up with a lever length of 1.094 to 1.125 inch. That means find or drill a hole in the carb lever that is about 1-1/8 from the throttle shaft to get the right amount of travel for the cable.

Opening the throttle should pull on the TV cable. Picture it as working opposite of the throttle cable.
When the throttle cable gets shorter (open throttle), the TV cable gets pulled longer.
Make sure you don't hook it up the other way...

Knowing those few basic things should allow you to hook it up and adjust it correctly with any carb or any engine you wish. It is not as hard as the printed words make it sound.

 

Hey Jeem, Just put 2000+ on my 37 PU last week. Figured up the MPG last night for the trip, 19.5 MPG. I'm running a 283/4spd, 67 Camaro rear, not sure on the gears put must be highway. Old stuff I had laying around when I put it together.

So I take it you got the 37!

Later,