The mythical CUCV 4L80E swap

[richingalveston]

I got that three times before giving up. the first unit they sent me had an EFI program in it and not the trans program.
I wish I would have warned you sooner.

good luck. don't let it trash your tranny. one of the three ruined a brand new rebuild. it over pressured it.

Rich

 

[brazengoat06]

This unit doesn't even power up. The module that is, the interface just says no comm.

 

[richingalveston]

send it back. dispute it on your credit card and go get a US shift 1 controller. you will be happy you did.

 

[richingalveston]

and by the way, I had to pay them shipping for them to send them back to me. twice I did this and then gave up.
get your money back while you can

 

[rustystud]

The poster with all the output shafts shows one to use for the NP205. It says 9 1/4 long. This will not work. At least with the fig 8 adapter. You want the fully splined 8 + inch shaft that offers unlimited choices on trimming and makes sure you have full spline engagement with the transfer case input no matter what you choose to do. That's what I bought and with the 9/16ths thick NWfab adapter

As the poster of the chart I must clarify something. Those are all the "factory" shafts made. Also the one that says use for the NP205 is behind a TH400, not a 4l80E.
The NP205 you have is a 1982-1984 . They went away from the synchronized front shaft after repeated failures and recalls.
The later NP205's from 1985 to 1992 all work fine.
There still are supply houses that sell good-used parts. If you want I can tell you them. They are mostly wholesale though so if you are not a repair business they might not sell to you.
Also if you find a early 1990's Dodge 1 ton 4X4 with the Cummins diesel they used the NP205 with the 32 spline front and rear shafts.

 

[rustystud]

so i got my tci unit in this morning and got it all hooked up and guess what, it doesnt work. so what do i do, i call the tci tech assist phone number. but all i get is some guy with an attitude and no assistance. I was told to send the unit back to whom i bought it from and thats all. well guess what you guys still built the **** thing so what difference does it make! end rant...

Dont buy TCI!!!

All those in the transmission rebuild business know that "TCI" is garbage. They only sell aftermarket since most business's will not deal with them.

 

[Kaiserjeeps]

Well TCI is out. Thanks for posting on that.

Yes Rustystud my 205 is making noise. It was not the 205 my truck came with. The one it came with being a slip yoke got replaced with the fixed yoke syncro unit when the guy welded my TH400 cracked case a couple months ago. He had a HD driveline that fit perfect. And I had a fixed yoke 205 in the container gathering dust. I am going after a 4l80e swap right soon and I now know that version of 205 is no good. I just today received a rebuild kit for the slip yoke 205. When the 4l80e gets rebuilt, I'll freshen up the good 205. At the same time I bought the parts to convert the slip yoke to fixed yoke. So in the long run all will be dialed in and hopefully left alone when it is all said and done.

So is 2K right for a 4l80E rebuild? The guy whom I am choosing says it good for 1000 HP. It should live a good long time behind a 6.2. I called around and got the same number more than once. Thanks for the offer on the parts places. I think the syncro unit is a good candidate for a front shaft conversion. Most likely it's going to sit in a corner for a long time when it comes out soon. Why are all the fun hobbies expensive? Ha.

Interesting stuff on TCI. Total Crap Install?

 

[rustystud]

Well TCI is out. Thanks for posting on that.

Yes Rustystud my 205 is making noise. It was not the 205 my truck came with. The one it came with being a slip yoke got replaced with the fixed yoke syncro unit when the guy welded my TH400 cracked case a couple months ago. He had a HD driveline that fit perfect. And I had a fixed yoke 205 in the container gathering dust. I am going after a 4l80e swap right soon and I now know that version of 205 is no good. I just today received a rebuild kit for the slip yoke 205. When the 4l80e gets rebuilt, I'll freshen up the good 205. At the same time I bought the parts to convert the slip yoke to fixed yoke. So in the long run all will be dialed in and hopefully left alone when it is all said and done.

So is 2K right for a 4l80E rebuild? The guy whom I am choosing says it good for 1000 HP. It should live a good long time behind a 6.2. I called around and got the same number more than once. Thanks for the offer on the parts places. I think the syncro unit is a good candidate for a front shaft conversion. Most likely it's going to sit in a corner for a long time when it comes out soon. Why are all the fun hobbies expensive? Ha.

Interesting stuff on TCI. Total Crap Install?

Well $2,000.00 is a bit high, but if there installing good components like "Kolene" steels and "Red Alto" clutches then maybe. At that price I expect to have a new control module and wiring also installed along with new solenoids. Plus new bushings. The last race transmission I built two years ago cost $2,000.00 in parts plus labor. That was a full race 4L60E capable of handling well over 1000HP. This transmission doesn't need near the parts that transmission needed to reach that level of performance. Basically a 4L80E is a TH400 with a extra housing built into the forward clutch assembly for the overdrive. Yes the case is a little different and there is total electronic control of the valve body but it is the same design and almost all the same components. So for it to be able to handle 1000HP shouldn't cost all that much in hard parts. Ask the builder what he will be installing for the clutches and bushings and seal rings etc. Also will he be installing new solenoids and module ? That's important to know. Many rebuilders will not install new electronics unless there was a failure. Most reputable shops will install them in ALL their rebuilds. Also ask him his plan on beefing up the "intermediate clutch assembly" . This is a vital section of the transmission that needs special attention for it to handle 1000HP. Another thing to check out is the shop itself. Is it clean ? A transmission shop must be spotless in the rebuild area to prevent contamination getting into the transmission. If the shop is dirty and the work benches filthy then go somewhere else. When I was still rebuilding I had a stainless steel work bench that was clean enough to operate on people !

 

[brazengoat06]

2000$ is way high. And I should hope that every rebuild you do gets new bushings, "every transmission builder knows that"

 

[brazengoat06]

OP, did you wire the dsl-2 directly to the TCI or did you have to run it through the rpm module first?

 

[rustystud]

2000$ is way high. And I should hope that every rebuild you do gets new bushings, "every transmission builder knows that"

You would be surprised what a lot of shops consider a proper rebuild to be ! I always replaced all bushings, all thrustwashers and Torringtons and all seal rings including the Teflon ones. Also all steels and fibers. A lot of shops reuse the steels and fibers that they feel are OK. You go to a shop that says they'll rebuild your transmission for $400.00 and you'll get a $400.00 rebuild. Basically just fix what broke. Before I went to work at the transit agency I would go and "interview" my potential bosses . I turned down employment at over 10 shops before going to work at the one I chose. I was single at the time so I had leeway to do that. Plus I had my Master Certification then so they wanted me, or at least my credentials to put in their window. That is why I say to check out the shop your going to have rebuild your transmission. I would avoid all chain stores ! They stay in business doing fast and cheap rebuilds.

 

[brazengoat06]

You would be surprised what a lot of shops consider a proper rebuild to be ! I always replaced all bushings, all thrustwashers and Torringtons and all seal rings including the Teflon ones. Also all steels and fibers. A lot of shops reuse the steels and fibers that they feel are OK. You go to a shop that says they'll rebuild your transmission for $400.00 and you'll get a $400.00 rebuild. Basically just fix what broke. Before I went to work at the transit agency I would go and "interview" my potential bosses . I turned down employment at over 10 shops before going to work at the one I chose. I was single at the time so I had leeway to do that. Plus I had my Master Certification then so they wanted me, or at least my credentials to put in their window. That is why I say to check out the shop your going to have rebuild your transmission. I would avoid all chain stores ! They stay in business doing fast and cheap rebuilds.

Hey finally something you and I can agree on

 

[rustystud]

Hey finally something you and I can agree on

Oh Oh !!! We better watch that !

 

[Kaiserjeeps]

I thought 2K was high also. So before I took it down I called around. Same price at every place. Maybe they know each other... This guy was recommended by someone I bought a jeep from. I spoke with the trans builder several times on the phone asking about a few things before going there. He did rattle off a bunch of things while I was there. I remember bushings, some high temp seals, new steels, fibers, electronics, new sprags, and for my 93 an upgraded internal wire harness. He puts a shift kit in that address the overpressure issues and firms up the shifts. I also told him about the holley solenoid and he is getting one for the US shift Quick 1 trans controller that I ordered just today today. It was 585.00 with the GM wiring harness.
It also includes a total rebuild of my torque converter for a diesel. He said the rebuild would be better quality than replacing it with a new one. He mentioned some problems with the new ones. I can't remember the details. The shop looked like a shop. It was not super dirty, and there were projects spread out on benches. I did look and made a note of it. I know 2 K is a lot. Hopefully no issues at all. I'm going back to my original slip yoke 205 after a rebuild and fixed yoke conversion. Then adding a mount on the tail end of the 205 for strength.
I wanted to do this rebuild myself. I have done automatics before. But I am behind on a car resto for a guy in Seattle. So I don't have a lot of extra time on hand even for my own stuff.

I did learn one important thing today. The gasket on the NP205 that goes in between the adapter and 205 case MUST be .060 thick as the common ones (like I just received) at .030 will cause the adapter to crack and be ruined. The adapter with the .030 gasket will bottom on the bearing snap ring and cause the mounting ears to crack from trying to tighten them and close the gap. Quad 4x4 mentions this but won't say the dimension. An Ebay seller called me today and shed some light on this.
So check your fig 8 gaskets and make sure they are .060 thick. All other 205 gaskets are fine being .030 0r .015 thick.

This whole 4l80E conversion has costs more than anticipated. I just sold my deuce and trailer and that is taking the financial pain out of this. No biggie I guess.
Thanks for the replies.

 

[rustystud]

I thought 2K was high also. So before I took it down I called around. Same price at every place. Maybe they know each other... This guy was recommended by someone I bought a jeep from. I spoke with the trans builder several times on the phone asking about a few things before going there. He did rattle off a bunch of things while I was there. I remember bushings, some high temp seals, new steels, fibers, electronics, new sprags, and for my 93 an upgraded internal wire harness. He puts a shift kit in that address the overpressure issues and firms up the shifts. I also told him about the holley solenoid and he is getting one for the US shift Quick 1 trans controller that I ordered just today today. It was 585.00 with the GM wiring harness.
It also includes a total rebuild of my torque converter for a diesel. He said the rebuild would be better quality than replacing it with a new one. He mentioned some problems with the new ones. I can't remember the details. The shop looked like a shop. It was not super dirty, and there were projects spread out on benches. I did look and made a note of it. I know 2 K is a lot. Hopefully no issues at all. I'm going back to my original slip yoke 205 after a rebuild and fixed yoke conversion. Then adding a mount on the tail end of the 205 for strength.
I wanted to do this rebuild myself. I have done automatics before. But I am behind on a car resto for a guy in Seattle. So I don't have a lot of extra time on hand even for my own stuff.

I did learn one important thing today. The gasket on the NP205 that goes in between the adapter and 205 case MUST be .060 thick as the common ones (like I just received) at .030 will cause the adapter to crack and be ruined. The adapter with the .030 gasket will bottom on the bearing snap ring and cause the mounting ears to crack from trying to tighten them and close the gap. Quad 4x4 mentions this but won't say the dimension. An Ebay seller called me today and shed some light on this.
So check your fig 8 gaskets and make sure they are .060 thick. All other 205 gaskets are fine being .030 0r .015 thick.

This whole 4l80E conversion has costs more than anticipated. I just sold my deuce and trailer and that is taking the financial pain out of this. No biggie I guess.
Thanks for the replies.

Well from what you just mentioned the shop sounds like they know what their doing. I would get a written estimate and a written guarantee stating what would be repaired on a return.

 

[brazengoat06]

I knew it would be a close fit and wondered if they had different thickness gaskets. Where did you find the .060

 

[Kaiserjeeps]

Well the 4L80E is already on their work bench. So after a pretty long conversation on it I am going to have to go with that. Gotta have faith sometimes. It will go well.


On the .060 gaskets, Quad4x4 a Montana company has them. Honestly everything they have is priced so high it makes a guy want to shop around. And alternatives are out there. The Epay seller I found is a great guy. After a short question to him after purchasing a gear, he called me the next morning and confirmed the gasket question. His Epay name is airgordont. His name is Tod with one D. I hope it's OK to recommend him on here. He is an outstanding guy to go out of his way to call. He had a lot of information on the NP205. He has set aside a box of NP205 parts till I know more after tearing apart my NP205 and seeing what I need. I'm getting jazzed about my conversion. The US shift 1 controller is on it's way. I'll have fresh gearboxes, and I am installing a mandrel bent dual exhaust as soon as the drivetrain is in.

So here is the big question for my NP205... Gear oil or ATF? It seems to be a wash. I was planning on gear oil.

 

[brazengoat06]

I always recommend going with the factory fill.

 

[rustystud]

Well the 4L80E is already on their work bench. So after a pretty long conversation on it I am going to have to go with that. Gotta have faith sometimes. It will go well.



So here is the big question for my NP205... Gear oil or ATF? It seems to be a wash. I was planning on gear oil.

The NP205 was designed to run gear oil. The only time they ever mentioned using ATF was with the (failed) front synchro shaft design (1982-1984) . I have run Synthetic gear oil in mine for years now. Works great !

 

[brazengoat06]

ok so finally got the tci situation resolved and was able to drive my m1010 today. needless to say i got the big smile on my face when the torque converter locked up and i was cruising at 75 lol. i did discover that i have a bad alternator voltage regulator to the front battery which i will have to resolve before i do anymore driving because it is sending too many volts to the tci module and im afraid it will burn it up. Also i am going to install a stand alone transmission cooler because the 4l80 does not like the radiator cooler (maybe someone has chimed in on this before).

p.s. does anyone know which alternator feeds the front battery (my m1010 has the standard cucv setup) thanks