Freightrain

Lucky I shouldn't have any issues with gearing, I don't need much first gear(plus if I keep the spicer it is 2.19 low), splits aren't an issue with a 237. It only needs 5 gears anyhow, but I like the ability to split. I can't lug the triplex anyhow. The 13 spd won't care. OD is covered also. All good questions when doing something like this. Quick(or cheap) decisions might lead to problems. I am going to look for a reman box because I don't want to have issues later. Money spent today makes my life easier later.

I'll take what I can get for OD. I can keep my Spicer for added OD for now. I don't use it a lot due to dropping Rpm and it really lugs on the triplex and that is rough on a worn out box(feel it in the shifter). Once I replace it, I can use it more but would like to maybe find a 8341 or the like to replace the 6041 since it is leaking also. Upgrades. Dave, if someone had one that was in good shape it would be an option.

I will fab up a mount once I have a transmission in hand. I saw that difference about holes also. Who would have thought? I see that that housing works for 12500 series transmissions. So I will check on a 12513 box with a forward shifter. Thank you for all the effort you put into this. It was very helpful and gave me a lot of insight on this matter. If this all works, it surely will help others with this kind of conversion.

Mounts on the bell are not a priority. I plan on making something I can bolt under/around the transmission. Maybe around the back box? Fabricating is not an issue. Not having that mount casting in the way is actually a good thing. I work at a machine shop, so machining something is not a problem. Here I am opening the holes in my single disc wheel to fit the oddball bolts in my 237.

I can put a pull clutch in, just have to revamp my linkage under the truck. It's been done before. I am just looking around to see if I can find the unicorn that will make this a bolt in. On a side note, I also need to look for a forward top cover. Just to help move the shifter more forward where it is with original transmission. That link you posted is awesome information. Kinda confusing but will need to do some reading and soak it in.

Something a long these lines? This for 18 spd. https://www.vanderhaags.com/detailview.php?manufacturer=fuller&model=rtlo18918b&inventorytype=transmission-clutch-housing&partnumber=K3672&wcf=parentmodel I guess you have to buy it for the particular model transmission? If I have a choice, I am going for something with a double OD.

My truck is together so there is no way to measure anything. Oops, I see I typed #2 up above. That wrong. I don't need mounts on the bell housing. I am going to have to fab up something else, maybe something underslung near the back of the box? That will have to be done after I get a transmission picked

So, if I start to research a 13 spd, try to locate one with side mounts. Then work on #1 bell with push clutch? Or parts for such. I can convert my linkage to pull, I have the technology....a lathe and a welder. Heck find me a fresh rebuilt triplex and I would be just as happy. I could try to rebuild mine, I heard most all bearings are available but if there is gear or slider issues I will be in a bad way finding parts.

Ok, so now it is all about the transmission Bell housing and trying to find a 13 spd with transmission mounts on the side of the box. Apparently they did offer it because they did come in R models. Finding that case may be hens teeth. If the Bell housing has mounts built in, it is not needed. Ya, I was thinking the same thing. Or come up with 3/8" shoulder bolts that have 7/16 shoulder and use them. Not a real concern though.

Never mind. Can't delete the ad.

Ok. My flywheel housing is about 6" ish. The transmission Bell housing is 6 1/4". You mentioned #1 SAE. But mine has 3/8" bolts like a #2?? So, the flywheel bells are the same, it is only the transmission side that is deeper. My dual disc flywheel stuck out about 1" from housing. I assumed that would be wrong. Guess not? You can see it near the end of my start up video. https://youtu.be/dkojHq2QnyI?si=I_sGrLVA3SuGBH-D Awesome, thank you for clearing that up. This gives me better insight on what needs to happen.

I made a lot of assumptions when I started this. I assumed that the deeper flywheel would need a deeper housing? When I started this 237 using a dual disc flywheel, it stuck out the end of housing about an inch. I assumed it would deep a deeper housing. I'm wrong? That saves a lot of messing around(removing and dialing in new one). Can someone measure their Mack flywheel housing and I can compare it. Mine has lower right starter, like a B model so I assumed it might be incorrect. I think most R models are upper left? Or maybe this is just another quirk of it being from a fire engine? The more times I get into finding information about this, the more I learn that I don't know much.

Heck, If I could just use my single push and get a shorter input for a 13 spd that would make things a HUGE amount easier. It would be a bolt in. I have a 2" input currently. Only reason is my triplex is just gone and want something that is smooth, quiet and stays in gear. I just need to find a box that has side mounts for a Mack application. I could even live with a 10 spd if I had to. Just needs OD.

Eaton

Interesting. I'm not versed in all this so it seems strange it was a twin disc? My 237 came from a fire truck and was a single disc. I want to upgrade so I can put a 13 spd in it.

Need a dual disc flywheel housing for 237-285. Closer to NE Ohio the better.

How easy to get? Part number? Someone have one laying around close to NE Ohio? I need to change out my single disc flywheel so I can upgrade my transmission. I have a flywheel already.

Mark? I met him at South Bend. Very cool piece. V8 cat if I recall?

A B model for more comfort? That is going in the wrong direction. Lol. My heat works great in the summer and the AC works good in the winter. 😂. Unless you do a lot of upgrades, they are drafty old trucks(kinda like an army truck). I've used mine for the last 23 summers to drag my race car around the East Coast. I added a 237 for some power, cruise control, AC, air steering, air ride. Still rides like a slow moving 50's buckboard. You will miss that 400 Cummins! I would recommend an R model with some factory power.

My hand pump clamp never comes loose? Just light snug and it is good. Never really use it much. I ran mine low on fuel once, sucked air and stalled. I pumped it up for 20-30 seconds and my air starter lit it off easily. Stumbled a few seconds and then was fine. I was on the side of road with no air available, so I only had once chance to get it running.

Bob's eyeing up that U hood. 😆. You'll see his post below about his start on it now that he is retired and bored to death. 😜 Nice project.

I keep my head up but we all know what happened the last time. We were in a good place but "they" couldn't handle it and just made a mess anyplace they could(of course in their cities).

That scene is from Planes, Trains,and automobiles. I think from where they spun out on the highway.

Depending on the OD, it could be 12 pitch which you could buy a fine thread bolt, cut it off and mill a slot. Presto, replacement.

Found this one finally. https://www.facebook.com/reel/755480683425230?mibextid=rS40aB7S9Ucbxw6v