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Considering a 4L80E in my 82 crew cab

red

stubborn Texan displaced to Utah
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Thread starter #41
The ALLISON stand alone trans controller is called the factory ALLISON TCM. NOBODY out there has been able to make an aftermarket controller RELIABLY shift an ALLISON AND maintain adaptive shifts which is needed for a clutch to clutch transmission. What everybody is selling as a stand alone is a factory ALLISON TCM with a gateway that converts the signals into GM code and feeds that to the TCM. Or you run a stock GM tune but leave the GM LAN disconnected, in that even the TCM will default back to the hard wired TPS input and shift that way. There is a couple of different gateway's out there, but I won't go into that right now. As to the 5 to 6 speed conversion, there is only 2 out there, Suncoast's and calibrated, all the other's are either rebadged SUNCOAST or a hacked copy.
LAN acronym translation? The rest I know that one I'm not familiar with yet haha. There's 4 things it translates to not GM/Allison related that I know.

So in order to effectively run an Allison behind a mechanical injected engine all that would be needed is to wire in a TPS, VSS from the tcase, and a stock TCM from a donor truck? Would it still lock up the torque converter clutch and provide engine braking, or does it require more inputs?
 

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FRANKENBURBAN
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Staff #42
LAN acronym translation? The rest I know that one I'm not familiar with yet haha. There's 4 things it translates to not GM/Allison related that I know.

So in order to effectively run an Allison behind a mechanical injected engine all that would be needed is to wire in a TPS, VSS from the tcase, and a stock TCM from a donor truck? Would it still lock up the torque converter clutch and provide engine braking, or does it require more inputs?
LAN=local area network, data stream. Several have wired in 6 speed tcm's and wired them up like you say, and made them work. Keep in mind though this method GREATLY limits what it can do. With a 6 speed tcm you would be greatly limited on gear selection unless you wired in the tapshifter(this only applies to lly/lbz, NOT lmm tcm's), but then you wouldn't have a gear display. You would be limited to only 1 trans mode(no tow/haul mode) unless you wire in something to trigger tow/haul. Without tow/haul you only get grade braking to 4th gear, and only get lockup at higher speeds. You could try and run a medium duty/kodiak tcm tune, but to my knowledge nobody has tried one with a swap. There's also alot of other things that will be different, hut the biggest will be how it shifts and the shift quality(or lack there of). With a mechanical injected engine you just don't have the repeatable power, smooth application of power, or defuel on shifts, and it WILL show in how it drives. I say this because several learned early on in the duramax power game that eliminating or even just reducing defuel could let a stock lb7 destroy even a built allison. There's alot more I could go into, but I'm trying to keep it brief.
 

red

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Lack of shift quality, like the higher line pressure shifts that my th400 currently has? (need to get off the throttle when it shifts). So essentially it would behave like it had a manual valve body with a ratchet shifter is what it sounds like which isn't good for a long trans life.

Anything different on the older 5 speed models that would make it a better option?
 

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Lack of shift quality, like the higher line pressure shifts that my th400 currently has? (need to get off the throttle when it shifts). So essentially it would behave like it had a manual valve body with a ratchet shifter is what it sounds like which isn't good for a long trans life.

Anything different on the older 5 speed models that would make it a better option?
No, 5 and 6 speeds will be about the same. And I would say it would shift more like a dump truck or something, just a solid push on you during a shift that gives you that jiggle on a shift. These transmissions were never really meant to go behind mechanical injected engines, but when they did there was a calibration setup to make it shift once the power started tapering off. Iirc the 6 speed was rated at 650 ft lbs of input torque with defuel, but only around 520 without defuel. The clutch to clutch allison trans does not like harsh shifts, there's just nothing to give, and harsh shifts normally mean tie ups(stuck in 2 gears at the same time). It's doable, but if it was mine, I would want a compatible tune to the style engine so you don't end up like one of the many that curse trying to swap an allison in. I hate saying it, but I would swap a torqueshift in long before I would an allison.
 

red

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Thread starter #45
I'd rather stay with the GM transmissions because of the adapter. Not because of brand loyalty, just the simplicity with fewer specialized parts. Going with the Ford trans would require a custom made flex plate which would be a bitch to have remade in the middle of nowhere. Compared to the GM trans where it's just a round spacer that in a worst case scenario can be pretty easily remade in a lathe. Not a likely problem but a just in case kind of situation.

Which brings it back to 4L80E, or Allison 1000. Would the 4L80E with the overrun clutch upgrade mentioned earlier be a better option for the mechanically injected 4BD1T engine, or would the Allison 1000 still be the better option? Kind of sounds like the 4L80E would in this particular situation.
 

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The BEST option in my opinion would be the ALLISON 1000, but don't run any of the normal swap setups most use. I've seen the 1000 behind the 3.9l CUMMINS in bread trucks. If you could get a calibration like that loaded in it, that would be your best option.
 

red

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Thread starter #47
The BEST option in my opinion would be the ALLISON 1000, but don't run any of the normal swap setups most use. I've seen the 1000 behind the 3.9l CUMMINS in bread trucks. If you could get a calibration like that loaded in it, that would be your best option.
Any clues on where to search for that particular calibration other than contacting Allison?
 

red

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Found one so far that's made the Allison 1000 work behind a mechanical engine, link here http://www.competitiondiesel.com/forums/showthread.php?t=127092

Lots to read through but the basics with the trans is that he used a TPS from CAT, rewired the plug for the transmission, and used a TCM for a medium duty application along with EFI live to adjust things. Got torque converter lock up working and good shifts but never was able to get tow/haul working. He did have to play with EFI live alot.
 

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FRANKENBURBAN
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Staff #49
Found one so far that's made the Allison 1000 work behind a mechanical engine, link here http://www.competitiondiesel.com/forums/showthread.php?t=127092

Lots to read through but the basics with the trans is that he used a TPS from CAT, rewired the plug for the transmission, and used a TCM for a medium duty application along with EFI live to adjust things. Got torque converter lock up working and good shifts but never was able to get tow/haul working. He did have to play with EFI live alot.
I've read that one before. Like I said earlier, you can get it to shift, but you lose alot of functionality. Without having access to the Allison DOC software, you're very limited as to what you can do. The calibration for the 3.9l with a 5 speed I'm sure can be gotten from Allison. Your biggest hurdle is it is in a light duty truck. An allison dealer can do ALOT for somebody with a medium duty truck, but because of the terms of the Allison sale from GM, light duty truck's are off limits to Allison dealers.
 

red

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Thread starter #50
Gotta love contracts right? Well that seems to have sealed the deal for the 4L80E then with the few upgrades mentioned earlier. The upgrade for the overrun clutch is much cheaper than I was expecting (about $120 from Jegs) but looks like the swap can be done with the upgrades for less than $2500, and roughly half of that is a torque converter haha.
 
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