The mythical CUCV 4L80E swap

[90Jimmy]

There it is...EMP problem solved....and no one will steal it or ask to borrow it.

 

[aztrekker]

Thanks all! I really appreciate the advice. I think I am going to go the 4L80e route and apply the faraday cage solution. Seems like this will be the best overall way to approach the problem. I was also thinking I could store an extra control module somewhere where it would be protected and swap it out if the faraday cage fails.

It will be a few months before I get to it as I am recovering from surgery and need to get healthy first. Will update the thread with the results of my effort. Again, I really appreciate the input!

 

[NWM1008]

My 6.2 is about to give up so I bought a 96 Surburban K2500 with a vortec 350 and 4L80e that I plan to swap in my M1008. I plan on using a painless harness and want to use the np208 transfer case (since the 32 spline passenger drop 241's are so hard to find). What is the best way to get the Output VSS for the trans from the 208? I've seen a Dakota digital converter that still lets you retain the mechanical speedo cable as well. Is this way to go or do you guys have any other ideas? Any help is greatly appreciated.

 

[Keith_J]

Now I see a certain company now makes a highly modified 4L80e. With two additional forward ratios! Ah, choices.

 

[Sharecropper]

Now I see a certain company now makes a highly modified 4L80e. With two additional forward ratios! Ah, choices.

Um....... which company?

 

[Keith_J]

Um....... which company?

TCI

Basically, it splits the lower ratios with the OD using slightly different ratios. The magic is in the valve body and control computer. Aside from the non-stock planetaries and valve body, it is a 4L80e. Ratios seem perfect for the 6.2 with 4.56:1 axles.

Now to get them to accept the idea it can be used with a NP205.

With stock 4.56 axle ratio, this makes wide open throttle shift points at 23, 34, 45, 60 and 73 MPH. With the torque converter contribution, its darn near a CVT.

 

[Sharecropper]

TCI

http://www.tciauto.com/tc/6x-six-speed-gm-automatic-transmission-850hphtml/

Basically, it splits the lower ratios with the OD using slightly different ratios. The magic is in the valve body and control computer. Aside from the non-stock planetaries and valve body, it is a 4L80e. Ratios seem perfect for the 6.2 with 4.56:1 axles.

Now to get them to accept the idea it can be used with a NP205.

Just so you and others will know, when I clicked on the link, my Norton Internet Security blocked a virus hack. You probably should take that link down. Just my 2 cents.

 

[True Knight]

My 6.2 is about to give up so I bought a 96 Surburban K2500 with a vortec 350 and 4L80e that I plan to swap in my M1008. I plan on using a painless harness and want to use the np208 transfer case (since the 32 spline passenger drop 241's are so hard to find). What is the best way to get the Output VSS for the trans from the 208? I've seen a Dakota digital converter that still lets you retain the mechanical speedo cable as well. Is this way to go or do you guys have any other ideas? Any help is greatly appreciated.

I did not need to get an electronic vehicle speed signal. The transmission knows how fast it’s spinning, and the transfer case has a mechanical speedo output for the gauge. The trans control computer only needs an ENGINE SPEED (RPM) signal and a throttle position signal. (And obviously the signals from the transmission itself.) Now if you wanted to use an electric speedometer then you would have to change some stuff to get the signal.

 

[NWM1008]

I did not need to get an electronic vehicle speed signal. The transmission knows how fast it’s spinning, and the transfer case has a mechanical speedo output for the gauge. The trans control computer only needs an ENGINE SPEED (RPM) signal and a throttle position signal. (And obviously the signals from the transmission itself.) Now if you wanted to use an electric speedometer then you would have to change some stuff to get the signal.

Thank you for sharing all the info about your swap and the reply about the VSS. I'm excited to get the swap going!

 

[Glockfan]

I'm in the midst of this swap now. Some of my photos will be reflective of me doing a dual transfer case at the same time as the 4L80E. I know, the ORD 203/205 “doubler” is expensive in itself so why not rub salt in the bleeding wallet wound and do the overdrive swap at the same time, right?


I am going to dump a bunch of photos in this thread as I make it through the swap. The cost of the doubler aside, I will say that I have $1,700 in my transmission ($200 for the core and another $1,500 for the rebuild). I chose to go with the US Shift “Quick 4” because I liked what I read in this thread about US Shift (Baumann Electronic Controls). The controller and harness was about $750. I chose to add the VSS to the output shaft of the NP205 and went with ORD’s $195 kit. Kevin from US Shift highly recommended that I go with the VSS on the output shaft of the tcase to allow maximum benefit from the features of the Quick 4. I chose to add a TPS to the injection pump. That was another $150. The Quick 4 needs a good TPS and VSS connection to work right.

The actual work began yesterday. The Muncie PTO, shaft, and crossmember with the carrier bearing will not be reinstalled.

Do all of the M1008’s have the TH400 “HD” or did they just put the Heavy Duty TH400 in my truck because it was an M1031 originally? I'm curious...

 

[Glockfan]

“Quick 4” Controller ($750 w/harness) from US Shift...


My $200 core 4L80 (removed from a 1995 4WD)


Back from the transmission shop with a new torque converter ($1500 lighter in the wallet)


TH400 and NP205 w/Muncie PTO removed


What came out...


New transmission going in...


And another $185 for a cooler that will keep the 4L80 happy...

 

[Sharecropper]

I'm in the midst of this swap now. Some of my photos will be reflective of me doing a dual transfer case at the same time as the 4L80E. I know, the ORD 203/205 “doubler” is expensive in itself so why not rub salt in the bleeding wallet wound and do the overdrive swap at the same time, right?


I am going to dump a bunch of photos in this thread as I make it through the swap. The cost of the doubler aside, I will say that I have $1,700 in my transmission ($200 for the core and another $1,500 for the rebuild). I chose to go with the US Shift “Quick 4” because I liked what I read in this thread about US Shift (Baumann Electronic Controls). The controller and harness was about $750. I chose to add the VSS to the output shaft of the NP205 and went with ORD’s $195 kit. Kevin from US Shift highly recommended that I go with the VSS on the output shaft of the tcase to allow maximum benefit from the features of the Quick 4. I chose to add a TPS to the injection pump. That was another $150. The Quick 4 needs a good TPS and VSS connection to work right.

The actual work began yesterday. The Muncie PTO, shaft, and crossmember with the carrier bearing will not be reinstalled.

Do all of the M1008’s have the TH400 “HD” or did they just put the Heavy Duty TH400 in my truck because it was an M1031 originally? I'm curious...

Man that thang is gonna be Killer.

 

[Glockfan]

Man that thang is gonna be Killer.

Not even close to yours Mike...

 

[Sharecropper]

Not even close to yours Mike...

I'm looking forward to seeing how that 4L80e goes in and performs. Please post plenty of notes and photos to assist other SS members who are contimplating the same install.

It seems that you are beginning to think like me. It's only money. Can't take it with you when you are gone. I've never seen a hearse pulling a U-Haul.

 

[Glockfan]

I'm looking forward to seeing how that 4L80e goes in and performs. Please post plenty of notes and photos to assist other SS members who are contimplating the same install.

It seems that you are beginning to think like me. It's only money. Can't take it with you when you are gone. I've never seen a hearse pulling a U-Haul.

Will do Mike...

 

[rsh4364]

Both my 1009s have the hd th-400 trans.

 

[True Knight]

Very nice GlockFan. The 4L80 swap is the best thing I’ve done to my CUCV. 2nd best was the turbo.

 

[Keith_J]

My mind is set, I will scrimp, save and even sell myself to do this upgrade to my 1031. Yes, it is a 4L80 swap, externally but using TCI's highly modified 6X Six Speed. Yes, SIX speeds. How do they do that? Custom valve body which uses the overdrive to split the first 3 speeds.

They also modified ratios 1 and 2 to a 2.97 first (very nice) and 1.57 "second" (because first multiplied by the 0.75 OD becomes second at 2.23). Fourth is just 1.57 multiplied by 0.75 or 1.18. Fifth is 1:1 and OD is 0.75.

TCI states they do NOT make it for 4WD applications but looking at images shows a buildup at the factory and they use the full spline output shaft. So a trim down to fit, removing the tail housing and modification of the TH400-NP205 adapter is the limit of modifications.



I will move the engine forward instead of moving the TC back to accommodate the longer transmission. This means no change to shift linkage or the transfer case PTO interlock (needed for SECM generator function). I already need new power steering hoses (weeping) so these will be ordered longer. There is plenty of room for the fan to move forward in the shroud and doing so will make it more efficient. Radiator hoses will be an issue, so be it.

Full RPM (3600) shifts with converter locked are 26, 39 and 49 and 65 MPH with current 33 inch tires. I have no need to go faster, the OD will make highway quieter.

Yes, this will cost more than I paid for the truck. Call me crazy but it is a manageable mid life splurge.

 

[rsh4364]

The 6x has been on my wish list with summit since 2012.I have read they will build to your specs.also.

 

[Keith_J]

A baseline 6X is plenty for my needs. The programmer is included, the only option is the torque converter..with only a fuel pump turned up a 1/4 turn and water injection, it should last for hundreds of thousands of miles. The only non-4L80 parts are the modified ratios.