M818 gets a 7(6+1)-Speed

[WillWagner]

Looks good Brian! The only thing I would suggest is that you get a bit longer bolts for the T case mounts. The threads should protrude minimum 2 threads past the lock ring in the nuts. They will loosen as they are installed now.

 

[US6x4]

Great project and thanks for documenting it all. It would be cool to see a POV video of you driving it around and rowing through the gears!

 

[MyothersanM1]

Looks good Brian! The only thing I would suggest is that you get a bit longer bolts for the T case mounts. The threads should protrude minimum 2 threads past the lock ring in the nuts. They will loosen as they are installed now.

Thanks, Will!
In those pics I had only dry fitted the bolts. I later tightened them down. I made sure to also spec out all the hardware I replaced on those mounts.

 

[Superthermal]

PTO Operation (continued):

I installed the Winch Operation Plate just forward of the valve with 1/8" pop rivets.

View attachment 871566View attachment 871567View attachment 871568

I plumbed the air supply from the wet tank. The forward and reverse air lines were connected with slack. Once the winch drive shaft is hooked up, I can determine which line goes to which fitting for wind and unwind.

View attachment 871569View attachment 871570

Winch Operation Plate: 10910301

I am very much liking this option for the original PTO. I don't have any linkage for my PTO and was wondering if you have seen this setup on any of the original PTO models? If not I will perhaps make one if the cost is similar to getting linkage parts. Cool mod.

 

[MyothersanM1]

I am very much liking this option for the original PTO. I don't have any linkage for my PTO and was wondering if you have seen this setup on any of the original PTO models? If not I will perhaps make one if the cost is similar to getting linkage parts. Cool mod.

I have never seen the OEM PTO configured for airshift. The issue with those PTO's is they have five shift positions, R-N-L-N-H. The airshift cylinders I am familiar with will only actuate R-N-F. Maybe someone else has figured it out.

 

[US6x4]

I have never seen the OEM PTO configured for airshift. The issue with those PTO's is they have five shift positions, R-N-L-N-H. The airshift cylinders I am familiar with will only actuate R-N-F. Maybe someone else has figured it out.

My R&D group has been working with the Festo ADNM multi-stage pneumatic cylinder and it can be configured with up to 5 stages with stroke lengths starting at 1mm and incrementing 1mm at a time. This might be a solution but there are some limitations on stroke size (see pic) and you can't go backward one stroke at a time. It would have to fully reset first. You can go from stage 1 to any stage after that with the right valving but if you want to go from stage 5 to stage 3, say, you would have to go from 5 to 1 to reset and then to 3. There is only one return port and it completely retracts the cylinder.

 

[Superthermal]

I have never seen the OEM PTO configured for airshift. The issue with those PTO's is they have five shift positions, R-N-L-N-H. The airshift cylinders I am familiar with will only actuate R-N-F. Maybe someone else has figured it out.

EeeK! I never have had one of these PTOs before, mine is still on my garage floor awaiting more winch parts to install. I was thinking one of the air cyclinders I have on hand would be doing the trick to be going from Forward to Reverse and cutting pressure to spring return to Neutral. I was not aware they have R-N-L-N-H positions.. I am guessing from the acronym that this is Reverse,-Neutral-Forward at Low speed-Neutral-Forward at High speed? Looks like I am going to need to find some linkage to lower the complexity, but was very much looking forward to having a simple switch like what you have made up for your PTO control. Bummer.

 

[muthkw25]

Awesome build!

 

[msgjd]

a town did this mod to a M813 which they put a 16yd dump bed onto .. They installed a fuller RTO13-dash-a-buncha-numbers (overdrive 13-speed roadranger) .. It was larger in all dimensions than your 7-speed of course, and it was quite a project to relocate everything to retain the live front axle, including having to move the engine forward which made them have to lose the fan .. Even-so, they still had to cut the shifter and weld a horizontal extender to get the shifter to come up through the tunnel in a workable place .. Because of the tranny they used, they never need to put it in low range anymore .. You did very good engineering and planning for your build, appears to be the best most-workable option without going through the trouble the town did