4L80 Swap
 

I'm new to this forum and i had a couple questions. This past weekend i blew up the tranny in my 2001 silverado 5.3. The truck is used strictly for offroad use, so keeping it street legal or performing "nicer" on the street does not matter to me. I have a built 4L80 lined up to buy that has a stall on it set to about 3,600 which i think is a bit to high. It is also a manual valve body so the wiring harness will not be needed. I wanted to know a few things:

1. What stall would work best for my application?
2. What am i going to need to be prepared for when swapping the tranny out?
3. Will the 4L80 bolt right up to my bell housing?
4. Are there any other surprises i should be ready for?

This is my first transmission swap so any and all help would be appreciated.

Here is a picture of my truck.

http://i76.photobucket.com/albums/j2.../truckback.jpg

is the 5.3 bone stock?

won't you need the wiring for the lockup torque converter?

I think a 2800-3000 would be better.

is your truck 2wd or 4wd?

The only work i have done motor related is:

Gears 4.88, intake, exhaust, chip

The truck is 2wd

Honestly with the abuse it looks like you put that truck through, I would go with the stock 80e torque converter. The swap appears to be extremely straight forward in a 2wd extended cab. The crossmember is moved back 6 1/4 inches (this is what I've read, I'm goign to physically measure it myself when i get a chance) and Speed Engineering can sell you a custom yolk that will just bolt right up to the 80e and your driveshaft. Speartech also has a custom wiring harness, but there is a sticky in the tranny section by nonniesman that shows you how to modify your current 60e main harness to adapt the 80e for free. You also need 1 front VSS sensor that has 2 wires that you run to the PCM. So other than modifying the x-member, the 4l80e pretty much bolts right in.

So it sounds like i will have to be doing some rewiring even with it being a manual valve body. Is that correct? And yes it does get put through a lot of constant high rpm usage and the stock tranny just couldn't take it. Do you have any recommendations for trans coolers?

the best tranny cooler to get is the tru cool max 40k btu unit. It runs about $130

Awesome truck! I agree, the stock converter for offroad apps.

Thanks. Why is the stock converter best? And do you mean i should use the stock converter from a 4L80?

Why would you want to increase your stall speed for off-road use...maybe I'm not clear on your application but for crawling a low stall would be preffered I'd think....:confused:

A high stall will create a ton of heat and would lead to premature transmission failure. Also, I agree with Bill above.....I'd think you'd want a low stall when did climbing/offroading.

I was saying the one i am buying has a high stall but i was saying i need to lower it to around 2,400.

the stock 80e converter stalls to 2500 or so

Depends on how much power you have..
Mine stalls up to 2900 on 5# boost.



here is a link..
https://www.performancetrucks.net/fo...d.php?t=413157

The trans comes with a high stall and i am looking at lowering it especially with the motor i have.

Will the 80e be able to handle constant abuse? Is there a way to upgrade the internals?

no you cannot upgrade it.

You could always go with a FLT Lvl5 ha, if you can break that with a stock 5.3 let me know how..
my stock 80 has a HD2 shift kit, and right at a year of abuse with boost and nitrous..
Get it put in and go play in the dirt.

If your crossmember looks like the one below you can just cut off the mount, flip it backwards, and reweld it. :) It is already flipped in the pic below. Oh, you will have to ream the hole out a bit too but, not much.

http://hauln.net/LS1Tech/jpegs/cross3.jpg

Thats for the 1999 trucks... some of the 2000s had that xmember like mine.. then some of them have the big xmembers.

Yeah, my 2000 had it. I put it up just in case!! :D

for the drive shaft your going to need to just put a different yoke on the front, unbolt the flage from the trans (in the 80e) and pry it out, your shaft will not need to be shortened or anything. And if you have a crossmember like the normal ones you will need to extend it backwards about 5.5-6". Measure it just in case. I just put an 80e in my truck and no problems. Also buy some rubber trans cooler hose from auto zone or whatever to extend the rear line, the front line can just be wiggled or pulled a little bit to reach.

and when you extend the rear line make sure you dont cut it on the bend or urs will leak... like mine... (not saying any names Jeff... :jest:)

When was your 2000 made? It must have been a very early one. Mine was built in march I believe and it was one of the first ones built with 4 doors. It's got the big fat x member

I don't know when it was made and don't have it anymore. It was a rcsb.

I dont see why everyone is recomending a small stall for offroad, its obviously a pre runner truck, so its not for crawling, its a desert truck. I ran a 3k an loved it, my PI is a 3400. Trans temps arent any worse than with the tb stall. I would run a 3k stall with a stock 5.3 that would be perfect for ur app.

That thing looks fun. Some good info in here already. I'm quietly considering an 80 for my truck, but it's a 4 by. Is it as easy to swap an 80 into a 4 as it is a 2?

4wd is much more complicated.

I'd have to agree with silveradol33 here on this one.

You all are correct, a stock/low stall converter is a great choice for rock climbing and slow speed traversing through obstacles or inclines. Look at the picture though. That truck is meant for racing off-road, am I correct dezertrunner22?

A 3000 is a good recommendation I could stand behind, but there is a lot more to a torque converter than just it's stall speed. Unfortunately a forum is not the place for a direct answer. Call a local torque converter specialty shop and tell them what you're doing, what the 80E is going into and what it will be used for. They should be able to set you up with a converter to fit your needs based off the info you give them. If you have a hard time finding a local converter shop, call around to some of the local transmission shops and ask where they get their rebuilt units from.

Thanks for all the help. I do not know to much about transmissions or torque converters. All the info above has been really helpful.

As for the truck, I am going to try and race it maybe a couple of times towards the end of the year and then possibly race a full 2010 campaign. And yes it is meant to go fast and not climb boulders and what not. For the motor being stock, a 2,500 - 3,000 stall sounds like it would probably work best.

I think your on the right track with a 2500-3000 stall speed. I would find a great cooler with a electric fan on it to keep it cool.