Will it work (4L80e swap)

[skyhigh4by]

Have a TBI with 747 ECM and painless harness. Want to swap in a 4x4 4L80e using the TCI EZ-TCU. I want to piggyback the TPS signal off of the TBI and I also want to retain my 32 spline 208 T-case. The problem is the 208 doesn't have a VSS and I need a 40 pulse VSS signal for the EZ-TCU. I know that swapping to a 241 case would be ideal but that's a lot easier said than done. I Won't be able to find one close enough to make it sensible. Jagsthatrun doesn't have anything for 40 pulse but I found this painless inline VSS unit. http://summitracing.com/parts/prf-60117
Will it do the job?

 

[dyeager535]

I would probably ask TCI just to be sure, but I would suspect the answer is yes. I doubt they would have done something weird with the signal that wouldn't work with the "standard" GM 40 pulse setups. Might get a straight answer out of Painless if you told them you need the proper 40 pulse signal from that unit to feed a stock '90+ truck DRAC vs. using a competitors product.

Is there a reason not to just swap to the proper GM PCM to control the trans? I assume perhaps that's an availability issue for you as well?

Swapping to a VSS 241 would need you to swap the gauge cluster too, so i can understand the hesitation to go that route in any case.

 

[sweetk30]

skip tci unit . member here recently had major problems . go check these guys out . http://www.usshift.com/index.shtml use to go by the name optishift .

lots of members here have it and like it .

also might be faster to use the 4l80-e as 2wd if you have the rear tone ring in the rear sensor hole . pull the plug were the sensor would be and look inside for a tone ring .

lots of guys do this also .

I piggy backed off a few sensors on a 4l80-e swap years ago with a factory computer setup for stand alone and no problems at all.

 

[dyeager535]

Has anyone stated how the 2Wd trans work when in 4 low? I know I've read of people using the 2WD units, I'm curious what impact if any that has on the shifting. I would think if it were problematic we'd hear more about it.

 

[skyhigh4by]

You guys mean using 2wd and divorced T-case?

 

[skyhigh4by]

skip tci unit . member here recently had major problems . go check these guys out . http://www.usshift.com/index.shtml use to go by the name optishift .

lots of members here have it and like it .

also might be faster to use the 4l80-e as 2wd if you have the rear tone ring in the rear sensor hole . pull the plug were the sensor would be and look inside for a tone ring .

lots of guys do this also .

I piggy backed off a few sensors on a 4l80-e swap years ago with a factory computer setup for stand alone and no problems at all.

For some reason I thought the price of the US shift unit was way more than the TCI and that's why I was going to go that route but I see it is actually cheaper and I usually find smaller businesses have better customer support. I'll contact the and see what kind of solutions they suggest for the VSS

 

[sweetk30]

no . . . still 4wd tranny but just let it get the rear signal from the 2wd rear sensor position . only if your tranny has a rear tone ring inside in that position . first few years had them in all . then true 4wd units didn't . way to save money . but if tranny apart just add it .

You guys mean using 2wd and divorced T-case?

 

[skyhigh4by]

Gotcha! I can understand how 4lo would confuse things that way. Trans output speed vs actual wheel speed.

I don't have a 4L80 yet. Any particular years I should look for or try to stay away from?

 

[Hogback Fabrication]

Jagsthatrun doesn't have anything for 40 pulse but I found this painless inline VSS unit. http://summitracing.com/parts/prf-60117
Will it do the job?

The problem with that one is that the 208 cable output isn't one cable revolution per output shaft revolution, the speedometer parts are geared down and that varies depending on OE gearing. If you go with an adapter like that, you'll need another box (like a speedometer reprogrammer) to re-interpret that signal to get to 40 pulses/rev.

 

[skyhigh4by]

The problem with that one is that the 208 cable output isn't one cable revolution per output shaft revolution, the speedometer parts are geared down and that varies depending on OE gearing. If you go with an adapter like that, you'll need another box (like a speedometer reprogrammer) to re-interpret that signal to get to 40 pulses/rev.

You are totally right I didn't even consider that. Guess I'll just contact US shift and see if they can help me out. Would really like to retain my 208

So does anyone have any experience using the 2 speed sensors in the trans and nothing in the t-case? 4lo would be the only hang up..

Also any input on using an early model 4L80e out of a diesel and using the diesel torque converter?

 

[dyeager535]

The problem with that one is that the 208 cable output isn't one cable revolution per output shaft revolution, the speedometer parts are geared down and that varies depending on OE gearing. If you go with an adapter like that, you'll need another box (like a speedometer reprogrammer) to re-interpret that signal to get to 40 pulses/rev.

Painless seems to be living up to the name painful. Their instructions are lacking any useful info: http://www.painlessperformance.com/Manuals/60117.pdf and I can't find anything on the web either other than it being a 40PPR signal.

I can't think of any 1 to 1 cable drive setups, all were ratios? All GM cable drive was 1000RPM @ 60MPH, one would think that the signal generator input would be designed around that output from the trans.

 

[1-ton]

An issue many used (especialy early model) 4L80E tramsmissions have is the internal wiring harness leaking from the inside of the tranny through to the terminal outside connection. When you get a used 4L80E it is best to replace the internal wiring harness and shift solonoids, because as they get old and dry rot out, they leak trans fluid through them. There are some low price kits starting at about $125, which will have all the wiring harnes, pig tails, and solonoids you will need.

 

[Russell]

Painless seems to be living up to the name painful. Their instructions are lacking any useful info: http://www.painlessperformance.com/Manuals/60117.pdf and I can't find anything on the web either other than it being a 40PPR signal.

I can't think of any 1 to 1 cable drive setups, all were ratios? All GM cable drive was 1000RPM @ 60MPH, one would think that the signal generator input would be designed around that output from the trans.

I'd highly recommend against running a cable drive type signal generator with an adapter for transmission controls. The resolution simply isn't up to par and you will have trouble with it behaving oddly. If all you were doing was operating a speedometer I'm sure it'd work fine, but the PCM needs better information than a speedometer.

The only proper solution AFAIK is to track down a 32 spline pass drop NP241 with the correct tone ring in it. They are not super easy to find but not impossible either.

 

[Larry]

Skyhi4by,

I did a similar project for my Father in-law last year little 1993 C1500 Sportside. Albeit my project was 2wd. It started life off as a 4.3L 5 speed then in 2011 I dropped in a TBI 454HO on a 411 ECM. I just reworked the 4.3L harness to run the 7.4L. It only took 1 year for FIL to wipe out a brand new 12” clutch and I was struggling to find someone to tune the ECM properly to run with a manual trans (damn thing kept wanting to die when doing a high speed stop). So I decided to drop in an automatic 4L60E running on a TCI EZ-TCU and run a 1990 454SS ECM PROM for a TH400 (non-computer controlled trans). With FIL in his 70’s he was looking forward to a juicebox transmission after rowing the NV3500 around for almost 20 years.

Like yourself, I read conflicting reports from forums and old farts at car shows bragging or complaining about the TCI system and Usshift system. The thing I found common with the complainers of each system was those guys did the hackiest installs like using scotch locks wrapped in electrical tape to tap into TPS sensor signals, and poor power and ground connections. In all reality, I think both are pretty good systems when installed correctly. From personal experience I can vouch the TCI EZ-TCU has worked great for us for the last year. I chose the TCI system because I got it from a board member for $400 new in the box and I can reuse the entire system if this 4L60E 's the bed and have to upgrade to a 4L80E later.

On mine, I also chose to mount the TCU under the seat and rather than tap into sensor wires under the hood, I piggy backed the TPS, TAC and speedometer circuits right at the ECM behind the glovebox out of the elements. Regarding the VSS, I agree with Russell where taking the time to find a 1990/1991 pass drop 241 with VSS would be the ideal route to go but until you find one I don’t see why one of these sensors from Howell wouldn’t work to hold you over.

 

[skyhigh4by]

awesome information thanks everyone