Tc Problems again

JoshH

Daggum farm truck
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Feb 14, 2007
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Here's a crazy idea. Why not put a transfer case in it just for the low range? You could probably find one for fairly cheap, and it would solve your gearing issues without killing the daily drivability. It would also help keep your trans from overheating and killing seals.
 

dmax tim

just wanta have fun
Aug 16, 2006
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Freddyville, Ohio
also get rid of the 35" tires, work on the dually set up but drop down to 30" OD or something.

a deeeeeeeeeeeeeep pan w/ more oil capacity is going to help keep it cooler. maybe even make an extra deep one. if you want to play and are a decent welder, add some lines to the pan to run cold water thru, maybe even pump it from the tank you use for weight. when done pulling let the truck idle and circulate the cool water to lower the tranny temp fast. put all the ice you can in the water tank.

also we only pull one time up here vs your 2 pulls then the pull off if FP. limit it to one good pull the do the pull off if you make it.
 

speedy03

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Nov 19, 2007
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Here's a crazy idea. Why not put a transfer case in it just for the low range? You could probably find one for fairly cheap, and it would solve your gearing issues without killing the daily drivability. It would also help keep your trans from overheating and killing seals.

I was thanking the same thing.
 

LBZ

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Jul 2, 2007
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Here's a crazy idea. Why not put a transfer case in it just for the low range? You could probably find one for fairly cheap, and it would solve your gearing issues without killing the daily drivability. It would also help keep your trans from overheating and killing seals.

Now that is a helluvan idea!!:)
 

duramaxin14

Just Keeping Up
May 25, 2007
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Wauchula fl
Josh thats not to crazy of and idea i have been thinking the same thing for quit some time. I just need to figure out how to do it
 

Bluemax

???????????
Sep 25, 2006
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You won't get your TC to lock in first gear, there is no table for it in the tcm tune. And with a stock engine I don't think you can get it up to 4850 rpms successfully even if you could, it wouldn't be a very good idea.
 

Bluemax

???????????
Sep 25, 2006
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Missouri
I know this is probably a stupid question, but is it possible to get Low Range in a 2wd?


Can't get one from the factory that I know of.


What I'm thinking is gear vendors under drive. I don't know if they make them for the Allison but they do for many others. That's where I'd look. I pretty sure at one time they were making the overdrive and the underdrive both for a lot of different trannys, and it would be the right thing instead of 4wd components stuffed in a 2wd. The floor would have to be cut and the "dog house" from a 4x would have to be welded in for the transfer case to fit(which moves the seat mounts,console,firewall...ect) Then the 2x and 4x trannys are different so he'd have to get the trans and transfer case, new crossmember, driveshaft, then you run into the driveshaft angle being off so he'd have to change the carrier bearing to make the angle right....and the list just keeps on going. It would be a never ending deal that's not ever going to be worth it.:)
Gear vendors might have an underdrive sitting on the shelf for around $1500 or so that would take 1-2 hrs to put on and have to shorten the driveshaft a foot or so for about $35 and be done right. Click a button on the dash and have an instant low range.:cool2::D
 
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JoshH

Daggum farm truck
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Feb 14, 2007
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I would be very surprised if the floor on a 2wd is any different than the floor on a 4wd, but I've never compared them so I can't say for sure. I think it would be much easier and cheaper to bolt in a transfer case than it would be to buy an aftermarket underdrive unit. The only difference between a 2wd and 4wd Allison is transfer case adapter/tail housing and possibly the output shaft (they very well could be the same though). A stock 4wd driveshaft would bolt right up and a lot of times the hole for a manual shifter is already in the floor (at least on older vehicles they are) with a plate bolted over it and covered with carpet. The biggest hurdle I see is the slip yoke front output on the transfer cases used in our trucks.

No matter what route you go I think a selectable low range unit of some sort would be your best bet and something well worth looking into if you plan to keep pulling with your truck.
 

McRat

Diesel Hotrodder
Aug 2, 2006
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I know nothing, but here's what I'd try.

Pull in first gear with tuning that is optimized for 4000rpm operation. Torque should be low enough so the converter will "bite" up there, and wheel speed will be right between a 4x4 running 4th low range, about 30mph with a 35" tire assuming 20% slip. This will save the TC clutch since first does not use it.

For the heat, get a trans cooler and run it in a water bath. If you use pure water, the oil will be limited to 212
 

dmaxfireman

'Can do' kind of guy
Apr 8, 2007
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CT
You could always go scavenge a two speed rear end from a heavy duty dump truck or box truck and fab that up and then you don't have to hang a transfer case or underdrive off the back of your trans.

I know its a little overkill...:rofl: but you'll never have to worry about breaking an axle :D

-Kyle
 

dmax tim

just wanta have fun
Aug 16, 2006
215
0
0
35
Freddyville, Ohio
I know nothing, but here's what I'd try.

Pull in first gear with tuning that is optimized for 4000rpm operation. Torque should be low enough so the converter will "bite" up there, and wheel speed will be right between a 4x4 running 4th low range, about 30mph with a 35" tire assuming 20% slip. This will save the TC clutch since first does not use it.

For the heat, get a trans cooler and run it in a water bath. If you use pure water, the oil will be limited to 212
 

dmax tim

just wanta have fun
Aug 16, 2006
215
0
0
35
Freddyville, Ohio
You could always go scavenge a two speed rear end from a heavy duty dump truck or box truck and fab that up and then you don't have to hang a transfer case or underdrive off the back of your trans.

I know its a little overkill...:rofl: but you'll never have to worry about breaking an axle :D

-Kyle

most pulling classes don't let you change rear end until mod class.