Which T-case to use?

TheBac

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For the 1/2 ton:


Can I use another Tcase in place of the 261XHD? These are as rare as hens teeth for sale, and people want a fortune for them.

I see quite a few 261HD from behind a 6.0/4L80E in the want ads and wondered if they'd work behind an Allison.

If so, would it simply bolt on and mate to the Alli output shaft, or do I have to change the Tcase input/output shafts/sockets?



Funny how 5 years later Im regretting selling the 261XHD I had from the donor. :roflmao: I can always stay 2wd.
 
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JoshH

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The input will be your biggest hurdle. I'm not sure how you would get the correct input to mate up to an Allison because there isn't one available that I'm aware of that is a direct replacement, but I'm sure it is possible to do it.
 

TheBac

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Question: then how have the guys gotten the 246 case to work with an Allison? New input socket in the tcase?
 
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TheBac

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Dmax truck with manual Tcase. NP261XHD


I dont necessarily need it, Joe. I can always stay 2wd. Was just exploring options now that I have a 4wd chassis. Back in the day, Chris used the Dmax tcase with the 1/2 ton axles. I was just wondering if something else could be used.
 

TheBac

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To add: I have found multiple NP263Xhd Tcases for sale for reasonable prices.....but Im not sure just how difficult it would be to wire them to work properly in a manual Tcase truck without the OEM harnesses, or if its possible to convert them to manual.
 
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wilsondiesel

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To add: I have found multiple NP263Xhd Tcases for sale for reasonable prices.....but Im not sure just how difficult it would be to wire them to work properly in a manual Tcase truck without the OEM harnesses, or if its possible to convert them to manual.

Following, I am interested to know as well, as I’m building a gutted 2.6 pull truck but only have 263xhd cases around
 

Chevy1925

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I don’t see why you couldn’t make a 263 a manual shift. Rig up a manual shift linkage to the shift shaft that the encoder motor goes too and just do it that way. Iirc the shifter shaft could be turned and felt like there were “detents” on each spot. It’s been a while since I had a t-case open though and never really studied that part
 

Chevy1925

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Hell, even if there are no detents or shifter wants to move out of selection, just build a shifter gate for 2wd, 4wd, etc
 

lutzjk913

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To add: I have found multiple NP263Xhd Tcases for sale for reasonable prices.....but Im not sure just how difficult it would be to wire them to work properly in a manual Tcase truck without the OEM harnesses, or if its possible to convert them to manual.

What if I knew of a 2003 truck that’s a parts truck

I saw a transfer case in the bed and all the wiring is still there. Truck has been sitting a while outside but I’m sure the wiring is salvageable.
 

JoshH

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Question: then how have the guys gotten the 246 case to work with an Allison? New input socket in the tcase?

I’m afraid I can’t answer that question. All I know is nobody makes a 32 spline input for an xhd case, and an input from an hd case will not fit according to multiple sources I checked with. Perhaps you can ask in that thread how they’re making it work.

For what it’s worth, it would probably be easier to make some sort of linkage to manually shift a 263xhd than to put a 29 spline input in a 261hd.
 

ikeG

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There are detents on the shifting mechanism of a 263. When we used one on our puller, ypu could shift it into ranges using a crescent wrench if the encoder was removed

Sent from my SM-G960U using Tapatalk
 

TheBac

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Joe, if you think about it, next time you're by there, check on that Tcase....ya never know.

Did some more digging. It might be possible to fab a lever to use on a 263 case, but then you run into "how do you trigger the front diff activator?"
Ferm knows quite a bit about these from the posts Ive read. Would be interesting to get his perspective on it.



Meh, it doesnt hurt anything to stay 2wd. Less weight, less complexity. Just have to resort to old-fashioned tried-and-true chassis setup theory. No big deal.
 

Chevy1925

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Joe, if you think about it, next time you're by there, check on that Tcase....ya never know.

Did some more digging. It might be possible to fab a lever to use on a 263 case, but then you run into "how do you trigger the front diff activator?"
Ferm knows quite a bit about these from the posts Ive read. Would be interesting to get his perspective on it.



Meh, it doesnt hurt anything to stay 2wd. Less weight, less complexity. Just have to resort to old-fashioned tried-and-true chassis setup theory. No big deal.



put a hummer front shaft axle shaft in (makes it a solid shaft, no shift fork or collar needed) or buy one of the upgraded ones from dhd or another place

As for shift linkage, just grab a floor shifter from any gm truck/suv in your body year range. You may not use the full linkage but the shifter will bolt in easier and carries the pivot and just may have to do some modding time the linkage side.
 

clrussell

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Just leave it in 4hi all the time. Use a crescent or pliers to put it there and send it.

As for the front axle hummer shaft or slide the collar over and throw a couple heavy tacks on it.

This is a budget race truck if I remember right. Keep it simple
 

TheBac

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Just leave it in 4hi all the time. Use a crescent or pliers to put it there and send it.

As for the front axle hummer shaft or slide the collar over and throw a couple heavy tacks on it.

This is a budget race truck if I remember right. Keep it simple
Good point. Sometimes I overlook the obvious. Thanks Corbin.
 
Oct 16, 2008
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Just leave it in 4hi all the time. Use a crescent or pliers to put it there and send it.

As for the front axle hummer shaft or slide the collar over and throw a couple heavy tacks on it.

This is a budget race truck if I remember right. Keep it simple

Hell. Yes. A crescent and some tack welds are the answer to a lot of life's hurdles.
 

lutzjk913

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May 5, 2010
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Joe, if you think about it, next time you're by there, check on that Tcase....ya never know.

Did some more digging. It might be possible to fab a lever to use on a 263 case, but then you run into "how do you trigger the front diff activator?"
Ferm knows quite a bit about these from the posts Ive read. Would be interesting to get his perspective on it.

Meh, it doesnt hurt anything to stay 2wd. Less weight, less complexity. Just have to resort to old-fashioned tried-and-true chassis setup theory. No big deal.

Need wiring also or just the case?

It’s a 2003 lb7
GMC extended cab shirt bed truck
 

TheBac

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Probably the harness, too. A pigtail off the Tcase encoder at the very least. You know, just in case I come up with something off the wall.....



Im going back and looking at FM and CL too.