What's a good tranny?

[Skunksmash]

It seems that my truck has a 700R4 in it. Some people seem to despise this transmission for some reason. Mine's been rebuilt as it was leaking when i bought the truck. I like it for the simple reason that it has a 4rth gear for the highway. I can remember in my 81, it had some lousy 3 speed auto in it. And at 65 mph it sounded like i was about to take flight or something. And as such the MPG went down the toilet. I know a lot of you guys here think that people who want more MPG are somehow like pansies or something, but sorry, I'm not rich. Saving money is smart. So here's my questions:

1. Why do people hate the 700R4 so much? Any tranny will die if you treat it like crap...

2. If a person wanted to replace their 700R4 with a newer better model 4 speed, which factory GM tranny should be used?

3. Is there a 5 speed automatic tranny that would work in one of these old trucks? Just curious. Back to the whole MPG thing.

[zieg85]

I am not a fan of any automatic in a truck but that is probably just me.  I think 700R4's get a bad rap because of when they first came out.  They where usually paired with a highway gear and had a hard time deciding what gear to be in at cruising speed unless you are doing 80.  All the appropriate upgrades and a knowledgable trans guy that has the tools to properly adjust them is what is needed IMO.  I am sure Vile can give some insight as well.  My $.02

[VileZambonie]

The 700R4 is a good trans.

No one is against getting better fuel mileage however if you're looking for an economical ride these trucks aren't them.

The 4L80E is the strongest 4 speed auto drop in available however you need a standalone computer or the factory harness and computer from the donor along with the appropriate sensors.

If you really want more gears http://6l80e.com/

[Skunksmash]

hmm whats the origin of the 4l80e? When did they start using them and what is the most desirable year to have one out of? I guess if they still make it, then the current year huh.

And what does the 6l80e typically come in? That is a little overkill lol. I was thinking of a 5l80e. Probly doesn't exist. But something that could be found in a junkyard.

[Chevalade]

The 4l80 is basically a TH-400 with OD. I believe they started either in 90 or 91. If you can get one that is 97 or newer it has all the factory improvements over the originals, but it does not take much to get the earlier ones up to par. With a transgo 2 shift kit, they are capable of handling 800hp. There is a kit to make them into a manual shift, but there are controllers for them to let them be electronically controlled. TCI makes one, and BS3 has an optional controller with their standalone engine management setup.

[Lt.Del]

I believe they started either in 90 or 91

My 91 V2500 4x4 sub has the 4L80E and it has 202,000 miles on it and runs like new.  I don't think there is anything wrong with the early 4L80E's.  Of course, I put an external cooler on it the instant I bought it.

I had a problem with one of the VSS sensor wires being stripped, but, I insulated the wires again to the sensor and she runs as good as ever.

[Skunksmash]

Think they are more parasitic than a 700R4? Typically, stuff that is tougher is harder to turn and sucks down more power. You know how you lose roughly 70hp from the flywheel to the real wheels? Think of the Ford 9" rearend. A lot tougher, and a lot harder to turn than smaller weaker ones. Something for me to consider, since i only intend to pull a bass boat, (and other small trailer tasks) with my truck. After all it's only a 1/2 ton.

Besides the price, the 6l80e looks nice if it isn't something that goes in a dumptruck. If you had a 6-speed, you could have the best of both worlds. You could have like 4.88's as your rear end gear ratio, and still be running 1900 RPM's at 75 Mph on the highway. Maybe that's not exact but you get the idea.

[Chevalade]

Yes the 80 will have more loss than a 700r4. How much power do you plan on putting to the transmission? And what are your intended usage for the truck. That will determine what you need, not what you want.

[Skunksmash]

Low Hp compared to most of the guys here. Probly around 320-350. Not real sure how it will turn out just yet. Slightly higher torque than that, im sure. I want to be able to do all the fun truck stuff with it like towing boats and jet ski's and light hauling and such. And i want to get somewhat close to the factory MPG, which was like 17-20. Cant do that with 480hp and a tranny/rearend on steroids lol

[Donut]

Yes you can...

As long as you have something else to drive.

FWIW, I've got a Ranger I drive most of the time, the Chevy is for the more serious work.

[Lt.Del]

Well, with a 91 sub, 4x4 on a 3/4 ton chasis with a 4l80e, I have gotten 17 mpg on the interstate with a 5.7 that has 200k miles.  And, that is with the family on board.  Going to the outer banks of N.C. 4th of July weekend, about 5 hrs away to Cape Hatteras, gonna check my mileage again then.
I dont loose too much through the drivetrain i dont guess, because the 350 has little problem pulling my 30' camper trailer over the Blue Ridge Mountains.

[Skunksmash]

Cool. So a pontoon boat should be no problem. Nice to know. The only pulling i have done has all been with Ford F-350's, and they can tow off with your house if you want to. So i was kinda wondering about a gasoline 5.7L.

[Lt.Del]

a lot has to do with the rear ratio and wheel size.  I have a 3.73 rear with 33's on it.  Not too low, not too high.
I saw on craigslist a set of 4.56 gears that came out of a sub and got me thinking about that, I could rip off the line so quickly with those puppies and that COULD then pull a house.  And with a 4l80e, the highway driving wouldn't be too terribly bad due to the lock up torque converter and overdrive. So, it got me thinking.

[Skunksmash]

Well my gears are 2:73's.  And i have the stock 15" rims and appropriately fitting tires. So i am hoping that will suffice. If not then oh well, i'll order one of those 700R4's from that monster 700R4 website. i was just thinking it would be real nice to have one more gear for the highway.

[Lt.Del]

it would be real nice to have one more gear for the highway

you will have plenty gear for the highway with 2.73 rear....that is a high rear, therefore very low rpm's on interstate.  If you put an overdirve on a 2.73 rear, the OD will probably kick in around 70mph--may be exagerating a little, but, you will have great speed with little rpms from the engine.   Top speed should be around 300mph.

A 2.73 is a high gear for pulling, but, if it isn't a heavy load, it should not be a problem.