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what would it take to put a d-max/allison in my 89 suburban

muddysub

muddysub

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i might be able to get a good, used, duramax/allison/transfer case for next to nothing... see my thread in the garage for details... but what would it take to make it work? i know i need to fab motor mounts and crossmembers, make the intercooler work in the front end, floor mounted shifter/cable, eliminate the comumn shifter, eliminate the case shifter, install the new transfercase buttons, driveshafts, fuel transfer pump and exhaust. all the wiring harness is perfect, i would have the complete harness to make it work. anythiing else you guys can think of?
 
have to install a drivers drop front axle.

id try to put everything in about the same place to avoid too many wiring harness mods. probably could fit the inst. cluster to your truck, which would be cool. i dont see why you would have to use a floor shifter. unless the column is bent, id try to reuse it. just swap steering wheels. i think that using the column would be good too, because it might be able to keep the cruise control (if the dmax was optioned).

i would try to use as much as the dmax fuel system as you can, as the supply/return side will really be important. dont leave a fuel cooler out on the return side. the exhaust usually comes out on the pass side, right about where the front driveshaft will be. good luck there. should use a nvg263. i think it may be a little wide for the framerails, but who knows. ORD can hook a doubler to it, so anything is possible.

i think that is enough info for now.
 
yeah i just realized that the front axle wont work... hmmmmm. ill have to find a drivers side axle, yeah im not sure if im gonna even bother with the cruise control and steering column.... i assumed the shift linkage wont work out of the column from my th400 to the allison, but i dont know. any help any GM techs can provide would be greatly appreciated! i know my diesels pretty well i just dont know about the swapping thing.
 
im pretty sure the allisons only have 4 detents. which means maybe a 700 style column would work. but then maybe the shift linkage will get in the way of the driveshaft (assuming you go to a driver's drop). only one way to tell.
 
yeah im still leaning toward the floor mounted shifter and cable setup like steve fox has for his reverse pattern th400.... how about we consolidate this to one thread, bouncing between here and the garage is getting old quick... see you in the garage!
 
scott if the frame is toast on the other one, just purchase the whole thing and do a side by side swap. take all the new stuff and swap it to your chassis and body. run the newer dash and column and all the eltrical will be less of a headache.


btw if you get this you royaly suck,LOL
 
thats what im planning on is a side by side job... my toyata will be kicked out of the garage to make way for the two big trucks.

and most of the stuff in the dash wont be affected... all the HVAC stuff in my sub will stay the same except for the a/c compressor on the Dmax.
 
the third gen swap I saw was huge amounts of work and about a 50k investment.... using new parts... I believe it was promo'd in 4 wheeler some time ago

2nd gen swap,, yeppers swap as much as you can.. unbolt your front clip.. go for the pass side (60?)will be needed because of weight on the axle,,, a 44 or 10 bolt wouldnt last... clean off the inner fenders as they will get filled with diesel stuff,,, its like a cummins swap but worse because its wider...
I would go over to the duramax diesel forum and start sniffing around
Would be one awesome conversion....
if you decide to go for it please post up in the diesel forum so we can have it as a permanent conversion post
 
For third generation vehicles, GM developed the 4L85E (upgraded 4L80E) because they could not fit the Allison into the transmission tunnel on Suburbans. I'm not sure what the compareable clearance is in a gen 2 vehicle but it's something to consider.
 
ccj8008 said:
For third generation vehicles, GM developed the 4L85E (upgraded 4L80E) because they could not fit the Allison into the transmission tunnel on Suburbans. I'm not sure what the compareable clearance is in a gen 2 vehicle but it's something to consider.
Click to expand...

but why would you go through the trouble of putting a 4l85 behind a dmax? if he is buying a complete truck with the ally, why not make the ally fit the truck? not to mention he'd have to buy a tranny control module, and then figure out how to bolt it to the dmax.

the reason it wouldnt fit in the subs, is that the HD trucks have a 2 inch frame lift. the ulitities dont. but his sub already has a 2 inch body lift, so he should be ok.
 
muddysub said:
i might be able to get a good, used, duramax/allison/transfer case for next to nothing... see my thread in the garage for details... but what would it take to make it work? i know i need to fab motor mounts and crossmembers, make the intercooler work in the front end, floor mounted shifter/cable, eliminate the comumn shifter, eliminate the case shifter, install the new transfercase buttons, driveshafts, fuel transfer pump and exhaust. all the wiring harness is perfect, i would have the complete harness to make it work. anythiing else you guys can think of?
Click to expand...
Just something to review
http://www.fourwheeler.com/featuredvehicles/129_0407_suburban/
:D
 
I just mean't he needed to consider creating space for the Allison (body lift or...). I did not mean to suggest that he use a 4L85E. Sorry for the confusion.
 
you would be best off taking the colum, ENTIRE wire harnes, rear axle if you can get it and then find a ford front axle and the dash out of the donor truck. this way there is less spent on getting the adaptors and what not to go from VSS to whatevr spedo you want to use. the ABS might be easier to use than to not use as well to make the brake lines fit.

would take a lot of time and deep pockets. i dont know of any stand alone computers for a D-max or allison.... might want to look into that to ease things up. that would help
Grant
 
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