4L80E or TH400/GV OD

[monte0185]

Currently I have a TH400 with a GV O/D unit attached. Both work fine so far but I have a 4L80 in the corner and was thinking of maybe just using it to get rid of the electronics of the GV O/D or maybe putting the GV O/D unit on the 4L80 and installing them both?? Bored at work so im coming up with hair brained things to do. What do yall think?

[Jabes1]

4L80E with GV and some steep 5.XX gears for fun...

[mrolds88]

Like the 4L80E idea. Should be able to use the TCM and harness from a 91-93 diesel truck to get it to work.

[bilfman]

I did a 4l80e swap, went very smooth and love the TCI controller. Was a lot easier then I anticipated!

Here is a link to the build.

http://67-72chevytrucks.com/vboard/s...d.php?t=537481

[1968vetL-71]

My 91 R30 crew cab has a 454/4l80 with an aftermarket OD behind it. I was pullin 18 mpg with it. I since have removed the trans/OD , just going different direction... Literally!

[monte0185]

Originally Posted by bilfman

I did a 4l80e swap, went very smooth and love the TCI controller. Was a lot easier then I anticipated!

Here is a link to the build.

http://67-72chevytrucks.com/vboard/s...d.php?t=537481

Originally Posted by 1968vetL-71

My 91 R30 crew cab has a 454/4l80 with an aftermarket OD behind it. I was pullin 18 mpg with it. I since have removed the trans/OD , just going different direction... Literally!

Bilfman I seen your thread on it thats what made the idea pop in my head. I have 410 gears in my cc dually and with the gv it still runs some rpms but with the 4l80 and a gv should be about right.

1968 did the gv bolt right to it instead of the 400 or did you have to change anything? With my speedo cable on the gv unit I shouldnt have to buy the adaptor box.

[nekkidhillbilly]

would be like a new 6l80 or allison 6 speed if you did that. i would go for it.

[monte0185]

Originally Posted by nekkidhillbilly

would be like a new 6l80 or allison 6 speed if you did that. i would go for it.

With the under/overdrive option in all gears like a half gear as well. Should be real good for towing I would think.

[Ziegelsteinfaust]

The 4L80 is a better DD option because you can use a lock up converter. Not to bag on the GV, but your limited on the hwy rpm due to converter stall speed. I wouldn't turn one down if I got it cheap enough.

Like the guy above said I thing a 4L80, and GV would be an awesome combo. Gear it so the double OD is perfect for hwy, and you have a low gear for towing performance. Or slow rolling down dirt roads if that is something you would need.

[monte0185]

Originally Posted by Ziegelsteinfaust

The 4L80 is a better DD option because you can use a lock up converter. Not to bag on the GV, but your limited on the hwy rpm due to converter stall speed. I wouldn't turn one down if I got it cheap enough.

Like the guy above said I thing a 4L80, and GV would be an awesome combo. Gear it so the double OD is perfect for hwy, and you have a low gear for towing performance. Or slow rolling down dirt roads if that is something you would need.

Can you elaborate more on the limited on hwy rpm issue cause of the converter?

[Rogier]

I started with the TCI, but replaced it with a USshift (Optishift) controller. I prefer the fact that it just works out of the box, but that if you want to customise it you can. The laptop interface is great.


And I would go for GV + 4l80E as well

Originally Posted by bilfman

I did a 4l80e swap, went very smooth and love the TCI controller. Was a lot easier then I anticipated!

Here is a link to the build.

http://67-72chevytrucks.com/vboard/s...d.php?t=537481

[monte0185]

Anyone know if the GV will bolt up to a 4l80 from a th400? My 4l80 is buried under a ton of my brothers crap in my old house to look at it and see for sure. Im thinking it has the same tailshaft and housing its just a longer transmission overall.

[Ziegelsteinfaust]

The torque converter has electric clutch to lock it up as it you drive so you can cruise at 1700 rpm, and your effectively direct drive.

With a old type torque converter you have to drive above the stall to avoid "slipping" or if you stall is 1700rpm you should drive around 2000rpm to avoid burning up the fluid.

So you can run a loser converter the ideal for towing or mpg, and you can effectively have the best of both worlds.

[monte0185]

Originally Posted by Ziegelsteinfaust

The torque converter has electric clutch to lock it up as it you drive so you can cruise at 1700 rpm, and your effectively direct drive.

With a old type torque converter you have to drive above the stall to avoid "slipping" or if you stall is 1700rpm you should drive around 2000rpm to avoid burning up the fluid.

So you can run a loser converter the ideal for towing or mpg, and you can effectively have the best of both worlds.

So If I run a 4l80e I need to run a looser torque convertor? Or will the convertor that is in it be fine cause ill be running above 1700 rpm? Im not much of a transmission person. I just take them to my racing buddy who has built just about all my transmissions and ive never had one fail yet.

[Ziegelsteinfaust]

No you do not need a looser converter. It just give you the opportunity to use one if you'd like.

Running above 1700 rpm makes no difference with a 4L80 because you can use a lock up converter. They supposedly will lock up as low as 1500rpm under light throttle.

A T400 you have to run above the stall speed of roughly 1700rpm stock. So if you gear it up, and drive slow turning 55 trying to tow something the converter will not achieve its fluid lock up.

[BigBlocksRule]

I'd go for the 4L80E without GV...you're going to end up with a ton of extra speeds/gears that you don't need. Just install a 4WD unit with t-case and don't hook up the front driveshaft, you'll have 4 low and 4 high speeds - how many more do you need?

[monte0185]

Originally Posted by Ziegelsteinfaust

A T400 you have to run above the stall speed of roughly 1700rpm stock. So if you gear it up, and drive slow turning 55 trying to tow something the converter will not achieve its fluid lock up.

Ahh gotcha and if im running to low of rpm's and it dosent lock up then it burns the convertor of from slipping and overheating. IC IC said the blind man.

Originally Posted by BigBlocksRule

I'd go for the 4L80E without GV...you're going to end up with a ton of extra speeds/gears that you don't need. Just install a 4WD unit with t-case and don't hook up the front driveshaft, you'll have 4 low and 4 high speeds - how many more do you need?

I like this idea also but the downside to this vs the GV unit is with the T/C i can only run High or low but with the GV unit i can use both at the same time with just the flick of a switch or push of a floor button rather.

[nekkidhillbilly]

Originally Posted by BigBlocksRule

I'd go for the 4L80E without GV...you're going to end up with a ton of extra speeds/gears that you don't need. Just install a 4WD unit with t-case and don't hook up the front driveshaft, you'll have 4 low and 4 high speeds - how many more do you need?

its just going to give him a extra overdrive. a new 6l80e or allison trans is the same way. have you ever driven one you can run 80 mph at 2k and still have deep enough gears to jerk down a house or melt a set of tires.

[Ziegelsteinfaust]

Originally Posted by nekkidhillbilly

its just going to give him a extra overdrive. a new 6l80e or allison trans is the same way. have you ever driven one you can run 80 mph at 2k and still have deep enough gears to jerk down a house or melt a set of tires.

That's what I am talking about.

[monte0185]

Hmm wonder how many thousands a 6l80 would cost me. LOL I was just thinking about the 4l80 and gv overdrive as a combo cause i already have the parts its just a matter of having the tanny gone thru and slapping the GV OD on it and putting it in the truck with a little shorter driveshaft. Total price less that 1k.

[nekkidhillbilly]

i cant see it costing alot more like a grand for the trans but idk if theres a stand alone for them. if there is im sure you could sell all you have and buy the 6 and a stand alone for equal money.

[monte0185]

Originally Posted by nekkidhillbilly

i cant see it costing alot more like a grand for the trans but idk if theres a stand alone for them. if there is im sure you could sell all you have and buy the 6 and a stand alone for equal money.

Well once I get my interior and doors straightened out the next shop is the tranny shop for fluid filter and shift kit and ill discuss it with him then. I could do it all but he does it better and I don't have to get dirty and cold. LOL

[nekkidhillbilly]

not being cold sounds so nice