M923 13 Speed Swap

[74M35A2]

My RTO-12513 has 2 PTO access covers. One is a 6 bolt off the side, and the other is an 8 bolt off the bottom. The bottom one looks like it would be a much more expensive unit plus hang down. If I could not get a side one to mount, I would switch to belt driven, which is kind of what I really want anyway. Make the bed dump while driving slow during cruises, etc....

 

[Jbulach]

Pull the hand throttle all the way out with a little clutch popping action, and I’m sure belt driven would be better for getting your hydraulics to bounce.

 

[Crf450x]

What’s the trick for getting the spacer off the crank? Tried a slide hammer and a heat gun. Don’t wanna get too wild with heat so close to the rear main seal.

 

[Crf450x]

My RTO-12513 has 2 PTO access covers. One is a 6 bolt off the side, and the other is an 8 bolt off the bottom. The bottom one looks like it would be a much more expensive unit plus hang down. If I could not get a side one to mount, I would switch to belt driven, which is kind of what I really want anyway. Make the bed dump while driving slow during cruises, etc....

Ah mine has that too. Based on what I’ve seen so far there’s no way it will fit on the side. When I get it mounted I’ll get some pictures of that area.

 

[charlesmann]

What’s the trick for getting the spacer off the crank? Tried a slide hammer and a heat gun. Don’t wanna get too wild with heat so close to the rear main seal.

Heat (around 230 F and some penetrating oil. Try just hammering on it to help break the rust loose and let the oil soak in.
i ran into seizing issue with my water pump. Heat beat and oil worked, especially after i broke a flange and exposed the oring. Them it didnt matter, i was forced to heat beat and oil more till it fell off.

 

[74M35A2]

Here is some info on mine if you are considering a hydraulic clutch. My flywheel housing depth measures 5.25” deep. The SAE #2 clutch housing is for the hydraulic throwout actuator. One large window on the side with 2 bolts is access for clutch adjustment, the other on the bottom with 4 bolts is for the hydraulic fork slave cylinder. Pic inside is dual disc clutch, throwout bearing, and clutch brake disc.

 

[Crf450x]

Heat (around 230 F and some penetrating oil. Try just hammering on it to help break the rust loose and let the oil soak in.
i ran into seizing issue with my water pump. Heat beat and oil worked, especially after i broke a flange and exposed the oring. Them it didnt matter, i was forced to heat beat and oil more till it fell off.

That doesn’t sound like fun.....

I used a propane torch for a little more heat, hit it one time with a hammer, and it popped right off. The crank wasn’t even warm so I was worried over nothing I guess.

 

[Crf450x]

Here is some info on mine if you are considering a hydraulic clutch. My flywheel housing depth measures 5.25” deep. The SAE #2 clutch housing is for the hydraulic throwout actuator. One large window on the side with 2 bolts is access for clutch adjustment, the other on the bottom with 4 bolts is for the hydraulic fork slave cylinder. Pic inside is dual disc clutch, throwout bearing, and clutch brake disc.

Ah that system makes more sense now. I still may go that route. I can’t decide. It sure would be easier.

Your flywheel housing is 5-1/4 from the block? Mine is 6-1/4 and matched the other housings I measured....

 

[Crf450x]

Bolted the flywheel on today. The spacer on the end of the crank has to come off. Measured for the input shaft again. The shaft will stick 1/2” into the pilot bearing so that should be just fine.

When I tried to put the flywheel on, it hit the starter.

Checked the ring gear to crankshaft distance and it’s the same as the flex plate. So the starter will need a .330” spacer, the same thickness as the crank spacer. Took the starter to my brother and he is going to make one. Cummins 3908328 looks like it would work, but I’m not sure. I’ll look into it more if I need to.



Edit: Ordered the spacer and it will work with modifications. See post #79.

 

[74M35A2]

Cool. Exciting to see it come together. Are you doing the dual fuel line mod while you have access to the back of the head?

Yes, my 5.25” was from the back of the block, but that is on an 8.3L based engine. My stock military flywheel housing on my 8.3L for mate to the Allison is deeper, but other manual trans flywheel housings measured at 5.25” also, so that is what I went with. The one I compared it to was an 8.3L with 5 speed in a Freightliner box truck.

 

[Crf450x]

Weird. I guess there’s a difference somewhere that I don’t know about. All this is new to me anyway.

Yes while the cab is off I’m definitely going to do the dual fuel line and a valve adjustment. Also need to move my front valve cover to the back to move the breather so my 6” intake will fit. I’m still in the middle of a turbo install.

Also considering raising the cab/hood an inch to make jakes easier. Probably will wait on that though.

 

[Crf450x]

Answered my own question

 

[74M35A2]

Found the missing one huh? I can look back at the pics of mine if you need any reference info.

 

[Crf450x]

Found the missing one huh? I can look back at the pics of mine if you need any reference info.

Well I found that they're always sold in sets of 6 so that was enough evidence for me. I think I'll just go ahead and put all new ones in it.

I'm kinda at a stand still on the trans right now. Got the valves adjusted and got that dang fuel plug loose. Been finishing the turbo stuff. And trying to decide what to use for the dual fuel lines.

 

[charlesmann]

Answered my own question

what was your question?

 

[Crf450x]

what was your question?

My flywheel only has 5 pins for the clutch floater plate and it didn’t look right. The missing one is on top, kinda hard to see. I still don’t know what all this “5 button” business means.

 

[Crf450x]

Any reason not to use the factory trans mount? I planned to use the leaf spring style but the location will be close enough to just weld an adapter plate to the stock bracket.

 

[charlesmann]

im not seeing/understanding the 5 button thing either, nor when you said they are sold in sets of six. I'm assuming the buttons are sold in 6, but where are the buttons you are referring to?

 

[Crf450x]

im not seeing/understanding the 5 button thing either, nor when you said they are sold in sets of six. I'm assuming the buttons are sold in 6, but where are the buttons you are referring to?

What I’m talking about are the pins around the flywheel. What looks like the flywheel face in that picture is the floater plate. The slots around the outer edge slide over pins to keep the floater spinning with the flywheel. I’m not sure what the writing on it means. “5 button” is wrote all over the clutch.

 

[charlesmann]

gotcha. my dual disk south bend i had in my hopped up cummins had similar pins (looked more like dowel pins) to keep the intermediate plate from riding on the first and sec stage clutch plates while the pedal was depressed. which is what give it its rattling sound.