big johnson
New member
how hard would it be to put a built allison in a 02 7.3? just a thought. or would i be better off to go with building up the stock trans?
allison transmission?
- Thread starter big johnson
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willholl79
New member
Allison is just a name. It's a marketing tool for GM. The allisons found in GM light duty pickups aren't the mother of all transmissions. Basically an updated, electronically controlled TH400 thit "allison" stamped on it.
Get a BTS.
Get a BTS.
big johnson
New member
ok thanks
washingtoncoastie
New member
Imo, bts or a jw is a way better way to go. Go get on a duramax forum and see how many of them have troubles with that pile. Any stock trans is not gonna last long with more than stock hp. They just aren't designed for it. I have a bts in my excursion. I love it and it never complains no matter how I drive. I think once you had upgraded an allison, and an adaptor plate, and getting the electronics/pcm to work with it, you could buy two bts trans.
But the Allison 1000 series do have larger hard components comparatively correct? Would sure be nice to have a couple extra gears as well comapred to the 4r100
They do make a flexplate / bell housing adapter to mate a Allison to a 7.3
They do make a flexplate / bell housing adapter to mate a Allison to a 7.3
Mike's Diesel Performance
New member
Um I know of a Allison bolted to a 7.3 :lookaround: But you'd be cheaper going with a BTS more than likely.
jdgleason
Active member
That is correct. The parts in an allison dwarf the other trannies. The downside to the allison is it is tuning limited. That is the reason they dont last long above 400 horse. But for what you would gain vs what you would spend.... go with a BTS
Tuning limited? Even with a stand alone controller? There seems to be some built up one handling as good bit more than 400HP; a lot more. If we are talking stock a 4r100 can not even hold that without work. Figure if you were going to use a stand alone controller regardless. Both built up my GUESS would be even cost but you then need to add in the adapters etc so more cost. But you are also gaining gears. On the street could be very nice. After all we are talking about a 10 yr old tranny design here
Mike's Diesel Performance
New member
:whs: There are quite a few built Allisons holding up above 800-900+ hp.
Diezel Dawg
New member
I wouldnt waste the money. BTS or JW would be the way to go. Would be money ahead. I hear about more BTS's behind some very high HP PSD and Cummins.
jdgleason
Active member
Built allisons are a different story I was referring to stock. But yes even with a stand alone controller.
G Racing
New member
A well built Allison will handle 800 to 1000 hp. A stock Allison does not like 500 hp. You can buy all the upgraded hard parts just like you can for the 4r100. money wise you will be way ahead to get a built 4 r100 especially from John wood. They make all the parts to put the Allison behind the 7.3 but it will cost you your check book to do the conversion and the build. If money is not an option put the 6 speed ally in it:rockon: it will be different. If you are on a budget stick with a John woods 4r100. Just my .02 worth
Hotrodtractor
Moderator
Ooops. I slipped and fell in the shop a few months ago and this was the result:
I went Allison 1000 behind the 7.3 so I could stock replacement parts that would be common between my trucks - my Dmax has a 6 speed ally, my '79 Ford has a 6 speed ally, my sister's '85 chevy will be getting a 6 speed ally, it will just be better and easier to make the Ally work (which it can, will, and does) for my application and take advantage of 6 speeds.
I went Allison 1000 behind the 7.3 so I could stock replacement parts that would be common between my trucks - my Dmax has a 6 speed ally, my '79 Ford has a 6 speed ally, my sister's '85 chevy will be getting a 6 speed ally, it will just be better and easier to make the Ally work (which it can, will, and does) for my application and take advantage of 6 speeds.
jdgleason
Active member
Thats sweet lol I love how much of a chode allisons are lol
Tom S
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I agree on a built 4R100 is going to be the way to go unless you are wanting to get into a pretty complicated project. JW or BTS are good choices.
Beside the adapter fly wheel and stand alone control what else would we be looking at for moddification to make this work in a 4x4 aplication?
Drive shaft length
Mating to the stock NV273 transfer case? Would you need to swapnto the 34 splie input like the ones used with the 5r100 to mate with the allison?
Cross member movement or modifiaction?
Any tunnel sheetmetal issues?
Drive shaft length
Mating to the stock NV273 transfer case? Would you need to swapnto the 34 splie input like the ones used with the 5r100 to mate with the allison?
Cross member movement or modifiaction?
Any tunnel sheetmetal issues?
G Racing
New member
You have to get the adapter for the transfer case, modify/move cross member, modify drive shaft length and yes you will have to check the clearance of the trans to the tunnel. The allison is quite a bit bigger than the 4r100. You might have to run a 2" body lift. Not sure if it will fit without it or not
Hotrodtractor
Moderator
You just need to swap input shafts on the tcase, elongate one hole on the Allison flange and locate a single speed sensor that is typically found in the tcase on the Dmaxes. No adapters necessary.
