A 4b yes ,it could live if it was built right a custom converter with the right stall speed . I have talked to http://www.coanracing.com/ many times about building one and to me it doesn't add up.

I would use a 47RH any day of the week before a 700R .

Scott

 

Even if it can handle a 4BT, can it handle a 4BD1TT?

 

HAHA funny story, we were talking about this 700r4 and how it would have an unlimited mileage 1 year warranty and no matter what happens if it gets damaged due to engine power or from towing or whatever, they will happily repair it or replace it for no charge and even beef up the broken or worn area. I immediately suggested we toss it behind the ole 4bd1tt (ha I like that Dougal) and see how long it lasts. I even suggested that we give it a week or so and get everyone to pitch in a little cash to start a pot, kinda like a football pot but we can bet on how long it will last or how many full throttle hits it will take. I thought it would be alot of fun, I wanted to put my money on one full throttle puch from a stand still. I would be impressed if a 700R4 would handle that, I know none of the other ones could take it LMAO :happyfinger:

 

Well right off the start I am biased already because I don't really like automatics at the best of times and would never run one in any of my tow vehicles. That being said . . .

I don't think a 700R4 is going to make a good truck trans especially with a diesel in front of it. They are not a heavy trans. I don't think I remember GM actually using them in any of thier 3500 trucks.

I have had, had friends that have had, cars, trucks, and 4x4s with 700s in them and every one has had tranny problems.

I am also an avid drag racer and spectator/fan and I have witnessed many so called bullet proof, bomb proof 700s anihilated at the drag strip.

It is a good trans for moderate power in a light vehicle if built properly but don't expect it to last if it's abused, heavy towed with, or has some power put to it.

 

I agree, just wanting lots of varying opinons, lets hear all the opinons we can. I especially like to hear your reasons why you like it or dont like it.

 

I could destroy a mildly built one in about 20k miles with a banks turboed 6.2 in a k5 blazer. I'll admit that I was 23 (and drove like an 18 y.o.) when this was happening, but as Randy said, it only took one long tow of a fj40 on a car trailer to trash the 700r4. I think using a 700r4 behind most any diesel is sending a boy to do a man's job. My 2cents.

 

You sir have just summed this debate up in one sentence, thanks :beer: I like it.

So what do you guys think about this supposed 700R4 behind a 6bt? Supposedly been working fine for 4 months.

 

Awwright, where's the "it can be done, but why would you want to" option?:happyfinger:


Everything I read says the diesel 47RH is the way to fly.

Even if you kept the mods on the 4BT minmal enough, and he drove it sensibly enough not to have durability issues, there's still the TV cable and the 1-2 gap (yes, gap is an understatement :rasta.

As I understand it (haven't had a 47') all the "benefits" of the 700R4 are in the 47RH and the 47' should be bomb proof in that application.

I seem to remember several members commenting on the cost of the 47' should be closer to the 700' when done as the 47' won't need nealy the extensive mods that the 700' will.

Sure a more or less custom converter would be mandatory, but it will be no matter which he chooses.

So I come back to the same thing; yes, but why?

Oh yeah, never going to tow with it, never, ever, eeeevvvvver??? Really? Then why do a truck?

 

My 700r4 still works fine. Ive got the fuel screws turned up. I would rather have a manual transmission, but the 700 was cheap at the time.

 

Whats your setup? Is the vehicle light? Do you have the stock turbo thats laggy (could help out alot)? What gearing? Tire size? All this helps to factor in the life of a trans.

 

haha hoho hehe... I'm sure... They don't have the nuts to do the job long term, if it makes it out of a 1 year warranted I'd be really surprised. The torque will kill it and I think putting it in your truck is a humorous idea. It won't take that 6bt either long term. If it worked GM wouldn't have spent the money on the 4l80's. Just my opinion. GM didn't waste money on things unless they failed before or don't have the design overkill to safely handle the job.

Regards,

Rev. D.

 

I think that it can be built but it would be pretty costly. need a lower stall convertor and mucher stronger internals

 

Its a '90 GMC K1500 5200 lbs. 3.42 gears. Tires are 32.5" Only problem I had with the wave ring is 2 of the bolts vibrated out. Threadlock fixed that. Torque converter is for a 6.2 with a 700r4 with custom tabs welded on. I welded more weight on the governor to shift sooner. The key to making the 700 last is proper tv cable geometry and proper amount of pull at idle. You need to measure line pressure when setting it.
Why wouldn't it work? The 350 tbi that came out of the truck makes close to the same torque the 4bt does. Although it does launch hard from a stoplight, I don't do it all the time, and I wouldn't go pulling a monster trailer or anything.
The 700 came stock in 1500 and 2500 trucks

 

Its a '90 GMC K1500 5200 lbs. 3.42 gears. Tires are 32.5" Only problem I had with the wave ring is 2 of the bolts vibrated out. Threadlock fixed that. Torque converter is for a 6.2 with a 700r4 with custom tabs welded on. I welded more weight on the governor to shift sooner. The key to making the 700 last is proper tv cable geometry and proper amount of pull at idle. You need to measure line pressure when setting it.
Why wouldn't it work? The 350 tbi that came out of the truck makes close to the same torque the 4bt does. Although it does launch hard from a stoplight, I don't do it all the time, and I wouldn't go pulling a monster trailer or anything.
The 700 came stock in 1500 and 2500 trucks

I know it's an old thread, but any details on how much weight on the governor and your technique for the tv cable?
I've ran a 700R4 for nearly 100k behind a 4BT. Starting to slip a bit, so considering what to do when freshening it up.

 

The 700 simply does not have enough clutch area for high torque usage. Guys who build them to hold lots of power use Alto clutches and crank the line pressure. If the clutches hold, then the sprags, seals, and planetaries race each other to oblivion.

The 700 is a fine trans, but it simply wasn't designed to reliably handle that much torque. If it was, GM wouldn't have felt the need to develop the 4L80e.