CUCV 4L80E Converison

[pigfoot63]

Just located a 4L80E transmission and would like to install it in my M1008. I have looked at the Compu- Shift controller and it seems to be a good option, has anyone installed one of these.

 

[Westech]

A couple of members have. If you search Im sure you will find a couple wright ups.


for exp: http://www.steelsoldiers.com/cucv/22070-m1028-trans-switch-th400-4l80e.html

 

[POOR WHITE BOY]

I have a 4l80e in 2 of my trucks

 

[pigfoot63]

What computer did you use and where is your speed sensor put on the 6.2 also do I need to change my stock 208 transfer case, output shaft is 32 spline on the 4L80E and the transfer case with adapter should bolt right up. Thank's in advance

 

[POOR WHITE BOY]

One of my trucks is a air force crew cab - it is a 1991 v3500 and is all stock with gas motor 4l80e and np 205 t case. The other is a 1980 k30 4x4 - with a 454 tci controlled 4l80e and np 205 t case with speed sensor on case. Parts are very hard to find for this set up . It is alot easier to find a np 241 t case from a 1990 or 1991 3/4 ton suburban - it will have 32 spline input and speed sensor.

 

[Ambulancechser]

did this on my m-1010 a while ago...worked very well.what version of 4l80 do you have?with the compushift a 2wd version with a 4wd output works best,as the 2wd version has an internal tone ring for speed ref'.use a tps sensor from a 6.2 with a 4l80e (88 to 91).you might be able to make some electronic adapter work to convert mechanical speedo output from the 208 to electronic for the compushift.



my,it's been a long time since i posted...


your 208 and adapter should be fine,with the appropriate length output shaft.an np-205 with the racetrac adapter can be used with some adapter machining.you'll need new/modified driveshafts,as the 4l is a bit longer than the 400.

mines currently being torn down for a cummins/nvg-4500 swap.

 

[POOR WHITE BOY]

WITH THE 2WD VERSION YOUR SPEEDOMETER WILL NOT BE CORRECT WHEN IN 4X4

 

[Ambulancechser]

correct,but only in low range...the compushift dosn't care in hi range.i never cared either,since i shifted manually in low,and never drove fast enough in low range that it ever mattered.

the compushift does,however,have a hookup for a low-range switch,that allows the computer to correct shifting profiles for low range use.it's a rather versitile system.not the cheapest though...

 

[POOR WHITE BOY]

True - i donot look at the speedo much when in 4 low.i spent a long time looking for a np 205 with a speed sensor - the whole tail shaft is different and they only used them in 1991 on v3500 models

 

[Ambulancechser]

that's why i went this route...the racetrac 205 and adapter was an easy find...i got hold of several for next to nothing.the indexing ring on the adapter just had to have about 35 thou' machined of the radius to make it match up to the 4l80 housing.if you then use a 4x4 "short" output in the 4l80 with about 1/4" cut of the end,it all bolts up with little fuss.

 

[POOR WHITE BOY]

That is alot easier way to do the swap. Finding all the peices from a 1991 model is almost impossible. Does advance make an adpater for the 4l80e/np205 combo ?

 

[Recovry4x4]

Dang. You guys now have me thinking about another 4L80E. Even if I was able to put all the stuff together, I still can't control it without dropping $750 or better on a computer, right?

 

[Ambulancechser]

AA,does in fact,make an adapter...i'd have used one if it didn't cost something like 650$,not including shipping.as it turns out,the aa adapter looks exactly like a racetrac adapter.it just has the right indexing ring...so i used my nearly free one,and spent 80$ to have a competent machinist give it a close shave...

Fleet Admiral...your correct,sort of.the compushift is rather expensive...about 1100$,options dependent.but it's very complete,and easy to both use and install.the so called "beumanator" controller is about 650$...but needs things like a wiring harness etc,and is little more than a set of switches.the pcs controller is more pricey,needs a laptop to program it,and requires both a wiring harness and a tps setup to work.it also is not friendly with people who need "tech supprt" on a regular basis.(and pcs has a rather poor rep for after purchase support).

that gives us only one really cheap option...manual control.a manual valve body mod can be made to the 4l-80,that turns it into a "manumatic".it requires little more than a vacume source for the line pressure control.about 300$ or so for the kit...not including install.

 

[Recovry4x4]

Thanks Chaser, helped me make up my mind. I'll go with the old school 700R4 behind the 6.2.

 

[POOR WHITE BOY]

Did they put the 700r4 behind a 6.2 from the factory ?

 

[Recovry4x4]

They sure did! I had an 84 with it and my current 91 Suburban has the 6.2/ 700R4 combo. I don't think the 6.2 has enough balls to hurt a decently built 700R4. I also like the idea of the 3.06 first gear and the .70 overdrive!

 

[POOR WHITE BOY]

That 91 suburban with a diesel is a good find. 4x4 ?

 

[Recovry4x4]

Yes it sure is 4x4! If it were a 3/4ton I might have got the 4L80E but being the half ton it got the 700R4. It currently has 3/4 ton stuff under it but once a parts 1008 comes by the house it will have that stuff under it. I need to stop by one day, we are pretty close!

 

[POOR WHITE BOY]

10-4 i f you come across a 1008 for parts i am in need of a good frame . Everytime i find one they are to far away . Will have to get together sometime my new place is off of 94th and hall

 

[fal_shooter]

I kicket this conversion around. for those of you that did it in a M1008 how much did it change you mileage? I am getting 15 mpg average now. What could I expect if I did a conversion?