M923 13 Speed Swap

Crf450x

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Figured I’d start a thread showing my swap progress. Maybe it will help someone in the future as there is very little info out there on it.

Very short version of the back story...about 3 months ago I bought an m923a2 and an m923 as a package deal. Plan was to keep the a2 and sell the a0. Wound up liking the nhc250 more than the 8.3 so my plan got reversed. Further complicating those plans, exactly one week after buying them, the transmission took a dump in the a2 truck. So I hatched a new plan. Automatics suck anyway so I’ll throw a real trans in the a0 and use that auto in the a2. And here we are.....

I found an Eaton fuller rto9513 with sae 2 bell housing, rebuilt 14” clutch, flywheel, etc for a fair price. Also came with a clutch pedal and some linkage parts. I bought it from a junk yard so if the pedal and linkage parts don’t work, I can swap them for any others he has. They’re just a starting point for now.

I don’t have a garage big enough for a 5 ton so I have to do this in my dirt floor barn. The best option I could come up with is to pull the cab off for the swap. I got the cab ready to come off today and hopefully will have it off tomorrow or Friday, depending on the weather. Plan to use the front end loader on my tractor to lift it. Should be interesting.

I will be sure to post progress pictures and info as I go along.
 
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74M35A2

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Your initiative may prompt me to finish mine. I could see where losing a trans would push the project. Pics mandatory! Post any snags or differences. I think the 9513 is a physically smaller trans than a traditional Eaton / Fuller Roadranger dual shaft unit?
 

Crf450x

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Your initiative may prompt me to finish mine. I could see where losing a trans would push the project. Pics mandatory! Post any snags or differences. I think the 9513 is a physically smaller trans than a traditional Eaton / Fuller Roadranger dual shaft unit?
I hope so! Yours will be quite the project.

I’m not sure about the size. This is the first one I’ve ever done anything with. I do know it’s an older model. The newer ones have a different od ratio and some other small differences. They also cost 2-3x as much.

What I do know is to do this, with an nhc250 at least, you want the “f” model. So this one would be an “rtoF9513. The best measuring I could do so far shows the shifter will come out right below the battery box. So I’m probably going to swap the top plate to the forward one to help with that.
 

74M35A2

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I think the 250 engine has the trans sitting rearward more?

Here are a few pics I snapped today of the 13 speed Roadranger RTO-12513 bolted up to a 400hp ISL RV engine, dual disc clutch, and hydraulic throwout bearing. Wondering how it compares in sight to your 9513. I bought the old style leaf spring rear trans support piece to add since using an SAE #2 housing, just to be safe.

3F103630-AD9C-4291-9A42-BAF0D513A99C.jpeg
341B8435-FC99-4EE0-8B27-36AFB495B93A.jpeg
CD82100F-5F25-4F21-8C73-34F14BAAD8DD.jpeg
 

Crf450x

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Yes the trans definitely sits farther back behind the 250.

I’ll post some pictures tonight. Mine is a lot rougher looking than yours. Those stainless air lines sure look nice.

I pressure washed it today. Gonna paint it tomorrow and set the cab off.
 

74M35A2

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Not sure if the forward shift tower location on your trans means middle position vs rear, but here is a mid shift bar plate complete for yours for $50 if it helps you:

 

Crf450x

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Not sure if the forward shift tower location on your trans means middle position vs rear, but here is a mid shift bar plate complete for yours for $50 if it helps you:

Yes that absolutely helps! Thanks! The guy I bought the trans from said if he could find one at his place he would swap with me. I’ll call him tomorrow and if he doesn’t have one I’ll get that one. The only one I found on eBay is $300.

I think that will get the shifter right in front of the pass seat/battery box. There may be room to bend the stick forward right where it comes out of the tower but I think it will be too close to the cab.
 

74M35A2

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Yeah most I am seeing are $250-$400 for the plate complete with bars and forks, so that one was a deal.

I think mine is pretty far forward, may need to bend stick rearward.
 

Crf450x

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Yeah most I am seeing are $250-$400 for the plate complete with bars and forks, so that one was a deal.

I think mine is pretty far forward, may need to bend stick rearward.
As long as you can get it in the cab you’re good. I’m gonna try to measure that better tomorrow. May be plenty room. The towers are just so tall. Worst case you could even use something like this.
B9D4B6DF-255F-48EE-9142-BC8161C3003B.png
 

Crf450x

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You can easily move the batteries to the outside tool box under the passenger door. This would eliminate any concern about the battery box at all. Plus you could put a better seat on the passenger side. Just a thought
Long term I would like to do something like that so I can have air ride seats. I just hope I don’t have to do it right now. But if it comes to that, not a huge deal I suppose.
 

wheelspinner

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Long term I would like to do something like that so I can have air ride seats. I just hope I don’t have to do it right now. But if it comes to that, not a huge deal I suppose.
It’s an easy swap, the same cables and all. Will be an easy update and open up significant cab space. Of course there is only room for 2 batteries but I’ve run two in all my trucks since 2012 with zero issues. Good luck, live the swap. Hopefully Clint will get his moving again too !
 

Crf450x

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How far back would the 8.3 cause it to sit back?
With an 8.3 the front of the bell housing would be pretty close to the front of the cab. With the 250 it’s considerably farther back.

A note on that for anyone wanting to do this...the 8.3s have a deeper flywheel housing to accommodate the torque converter and would not allow an input shaft to make it to the pilot bearing. Nhc250 trucks have a standard depth housing and use a spacer.
 
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