Superthermal's M813 Build, THE BOT

Had a great outing with the local MV guys here in Utah. I had to drop out a day early due to some clutch disengagement issues. The peddle lever connects to a shaft that is mounted to the top of the frame and a shorter shaft then pushes a forked rod that connects to the actual clutch fork. I could not see that either lever was twisting on the shaft so I can only conclude that the clutch fork may have gotten bent or something. Will check it out a bit more when the BOT gets its shower.
In any case the lockers were working absolutely solid and had no issues whatsoever driving where ever I pointed the rig. Ran 25psi in the rears and 35 in the front. I could have gone down to 20ish on the rears since I don't have much weight in there but the tires were biting plenty.
The sprag style transfer case was absolutely killer in the sloppy mud. I never once noticed the front be late to engage or anything like that with the sprag.
Did bend my flag pole for the umpteenth time. I might just remove that thing when wheeling in the trees for now on .
The 1 to 4 air chuck I made was used several times to lower my/others PSI evenly and raise them back up. Liking that thing and highly recommended.

The rest of the drive up.

Friends M916 6x6 having some fun on the way out

Another 1300 mile round trip, this time down to LA to picka part. I was able to find through a fellow 809er an in the can 6453 transmission. This is the same transmission that is stock to my rig, the 5 speed with an overdrive, but this will be one with some synchros that actually work.
I have thought to swap out the transmission for something more exotic, like an Eaton RTO 10 or 13 speed, but that would require some heavy modifications and a fair number of custom parts. Not to mention I would have to figure out how to drive a slit case, etc... LOL, this swap is not impossible as I have read some of the builds here on SS where this has been done, but an RTO would benefit mostly the on road drive-ability, where I am more concerned with wheeling. The 5 speed seems to be flawless off-road and would keep the truck stock simple enough for my wife to drive it.




Now modifying something important that will definitely be noticed, I am contemplating on how to change out the clutch foot peddle/release for a hydraulic setup so there isn't any issue with how the cab/frame/clutch all flex and shift when wheeling. It is very obvious that the clutch linkage gets bound when the passenger side goes high and the drivers side goes low, such as when you drive trough a ditch diagonally. I have also had the transfercase get knocked out of gear with the flex. I will be looking into that too. Either way the drive-ability off-road would be enhanced with a mod like this.
Volvo has these two. Looks like near 3/4 master or so. I'll need to go out and see what the mechanical advantage is on the manual linkage and what the stroke needs to be to have some better ideas.

Pulled the transmission today. Remember clutch issue symptoms were that the clutch began to release closer and closer to the floor, also the clutch would "snag hop" significantly when attempting to ride slip the clutch when doing precision maneuvering.
In the end the clutch throw out bearing had bit the dust and was wearing away at the pressure plate fingers. No choice but to pull and replace.

The newly rebuilt transmission I bought does have a throw out bearing on it but is slopped with 20+ year old grease. I expect to remove it from the housing and clean the grease as best as I can from it and then repack it with some grease that is thick and tacky. With the Transmission, I had been running Lucas full synthetic 90w but I have read that some of the synthetic lubes are not friendly on the syncros of older transmissions and actually desolve the brass. I wasn't worried about this with the last transmission as the syncros were very much gone when I bought the rig. I'll give Lucas Oil a call and see what they recommend as I consider what to pour into the new transmission. If anyone reading this has any suggestions on this subject let me know sooner than later.

Today I spent a few minutes removing the old throw out bearing I noticed it actually had a zerk fitting on the bottom of it. There would be no way to lube this fitting unless you removed the inspection plate and had someone fully press the clutch so the bearing was pressed fully forward, note: if the clutch is not pressed, the zerk would be hidden behind the steel pivot rod that is just below the bearing. Only with the clutch depressed could you even dream of putting some lube into it which looks like it would be a pain to get to up in the housing, but I would highly recommend doing if you haven't ever done that on your rig. If I had known it was possible I would have done that first thing after purchasing the rig when I did all the other zerks on the truck.

Here is a pic of my new bearing where the zerk would be on the drivers side pointing down at the inspection plate.



I was also able to get the old input shaft out of the old transmission so I could have an alignment tool for the new clutch when I get to that step.
Took the pressure washer to the inside of the cab since the passenger bench and the floor plates were out. Cleaned up nicely.
I may get some motivation to mount the 100 amp 24 to 12 Volt step down into the cab so I can wire up a few items that require the lower voltage. I would definitly like to get the rig wired while it is warm outside.

Had some extra time today and pulled the pressure plate and flywheel. I was hoping the flywheel would look brand new... Which never is the case..LOL

I will need to find a shop to refresh it here locally. My clutch plate looks different than all the others I have ever seen listed for sale. I was almost interested in having it re-done due to having significantly more pads on it than the others that are for sale and it looked like it could have three more pads put on it as well. The only one that is anything close is the one on Erik's Military parts that is a full surface pad in his picture. He shows he is sold out of that model so I sent him a note asking about it.


Erik's military clutch pic:


I also put 4 of the 5 air breather stems on the axles and the T-case using the DOT hose and Stainless quick connect fittings. After getting the transmission tied in the hose will head up to the top of the engine bay where if I get around to it will be a switchable valve that will go from open vent to pushing 2-3lbs of pressurized air into the lines. This would be used for deep fording to keep any water out of the axles, trans and tcase.

New pressure plate and disc came from an EBAY purchase from SECO parts. Flywheel is refinished by Truck Pro here locally, They actually turn timed it in just 3 hours. Nice of them . New throw-out bearing came with the transmission and pilot bearing I had I am reusing as it has Zero play in it, both are repacked with red and tacky 540°F drop point grease, bunches of grade 8 replacement bolts and lock washers purchased, 3 gallons of new 90w Transmission Valvoline Synchromesh gear oil ordered and for fathers day I even bought me a Freight liner shifter boot cover to keep the draft from the hole in the floor as a sweet memory. I also grabbed some triple layer 3" vent tubing for the defrost as I noticed it was looking a bit rough when I was peering up under the dash.


With this being apart, I will get the front axle air disengagement switch installed since getting to the underside of the dash is a breeze right now with the floor pan and passenger side seat removed.

With the clutch, the problem I am running into has to do with the adjustment of the pressure plate. I thought I was buying the version that was NON-adjustable so I didn't have to deal with trying to figure that out. But with my luck, here I am. Wasted a fair amount of time thinking through this as the TM is garbage on this particular point of interest on what the exact relationship is being measured for the two specific adjustments. See from my post above. If I don't have some solid feedback I am just going to set the new one up same as the old one and call it good.

Got a response from the guys at Lucas who said that none of their oils I was looking at were good for the brass. So I purchased 3 gallons of Valvoline Syncromesh gear oil to dump into the transmission.

When getting this done I will also mount for the first time the new PTO gearbox I bought way back on my trip from Detroit.
Also packed the throw-out bearing with the Lucas Red and Tacky #2 540 degree drop point lube. I sure hope this keeps me from ever needing to do this project again. LOL.

I found out on closer inspection that the zerk on the throw-out bearing is only for the bearing sliding on the transmission throat assembly and doesn't actually pack anything into the bearing itself. Too bad.
Adjusted the new pressure plate to the same height as the original since I didn't get any info from anyone else on that. See that other thread if interested n that dilemma.


Mounted the flywheel with the original bolts with a good helping of blue lock tight. I also ensured that the flywheel was clocked the same exact way it was when I took it off just incase there was any way the flywheel was balanced with the crankshaft.
I would have replaced the flywheel bolts but couldn't find anywhere a set of these with the solid shoulder and the same length. They appeared perfect so I am crossing my fingers that was a good choice. Used new grade 8 bolts and washers for the pressure plate mounting and torqued them to spec.
Will get the new transmission mounted this weekend after I try getting the front air disconnect for the transfer-case kit installed and the air breathing lines done.
Pic below is when I was test fitting to see how much compression I was getting for the plate being so different. I ended up pulling the pressure plate back down and doing the adjustment.

Does Lucas have any oil that's good for brass or was it just the ones you were looking at?

Drove in the Provo Grand Parade with an estimation of 350,000 spectators in attendance!
Pulling a late night July 3rd getting to new transmission, PTO and clutch all installed. THE BOT looking sweet next to the Dodge showing it who is boss in the driveway. Don't think bad of me for all the oil under my dodge's nose as 18 years ago or so it dropped the killer dowel pin into the gears and instead of grenading my engine to pieces it only cracked the timing housing and it has leaked oil when parked ever since. I let it leak as a tribute to the lucky Gods as a inconvenient reminder that it could have made life so much worse.

I think the parade guys liked the extra dirt on my rig making it look "AUTHENTIC" as they gave me a "Most Patriotic Military rig" trophy for my rig being quite the Military look..

Here is a pic of the Trophy they awarded me as we began to line up in the festivities! I was very honored as there were some very cool tributes there aside from my contribution to the USA. There were HEMTTs, Willies, a tracked troop carrier among some other eye popping rigs.

Superthermal said:

With the clutch, the problem I am running into has to do with the adjustment of the pressure plate. I thought I was buying the version that was NON-adjustable so I didn't have to deal with trying to figure that out. But with my luck, here I am. Wasted a fair amount of time thinking through this as the TM is garbage on this particular point of interest on what the exact relationship is being measured for the two specific adjustments. See from my post above. If I don't have some solid feedback I am just going to set the new one up same as the old one and call it good.

Click to expand...

Several years ago @98G and I replaced the clutch in a Deuce that was similar looking…we set the adjustment up using some wood spacers and just tried to get the three fingers the same level, so that there would be equal pressure on the plate from the fingers. It’s been a few years and we got it Good Enough For Government Work, and it worked great. The objective was to ensure that the fingers were the same measurement from a known point, for equal pressure engagement…

@98G might have a better recollection than I do.

silverstate55 said:

Several years ago @98G and I replaced the clutch in a Deuce that was similar looking…we set the adjustment up using some wood spacers and just tried to get the three fingers the same level, so that there would be equal pressure on the plate from the fingers. It’s been a few years and we got it Good Enough For Government Work, and it worked great. The objective was to ensure that the fingers were the same measurement from a known point, for equal pressure engagement…

@98G might have a better recollection than I do.

Click to expand...

I don't have any detail to add. I remember thinking at the time that it needed to be uniform pressure, and to not drag.

It has been a decade ago...

Since then we put a new transmission in @RGS20inophir 's deuce and I may be conflating some of what happened during that.

Time flies when you're having fun...

@silverstate55 @98G Thanks for the input
I do have an issue that I am going to need to solve the long, hard way by tearing the whole thing back apart or maybe a few attempts at the easy way.
The issue is this new pressure plate, as stated above, was adjusted and installed to the same height as the pressure plate I took out. However when testing the clutch engagement/disengagement I found that the throw of the linkage total moves the throw out bearing lever arm 1.085" when pressed. This distance is just barely not enough distance to have full release of the clutch and still have full "release" of the throw out bearing to ensure it isn't spinning when driving down the road, or idling. Since I was in a rush to be able to make the parade I just went with disengagement as my priority, Ahhh yes shifting with syncros that work was so nice, but I need to get this corrected ASAP as I don't want to eat up another throw out bearing and have to do this all over again.
So three things to solve here:
1. Get full needed travel of the fork arm go get full throw out release and get full clutch engagement/disengagement.
2. Get the clutch not to "chatter" Which I am still getting with this clutch and pressure plate which I am guessing is that the entire motor/trans shifts as torque is applied and gives the clutch chatter on engagement with the mechanical linkage from the body to the frame to the transmission flexing, as it doesn't seem to be related to RPM when engaging the clutch. If this chatter is not related to the "play" in the engine/trans mounts and is related solely to the pressure plate there is nothing that will fix it except tearing everything apart and again, using a micrometer and measure the height of everything as I adjust the pressure plate. However I did all this checking/adjusting when I put it in this time so I feel confident that this is not my issue... please don't be the issue.... LOL.
3. Solve the binding flex issue I get when wheeling when I can't get the clutch to release when in a serious frame flex.
The possible solution to all of these is a hydraulic clutch. Knowing I will need over 1.1 inches of travel makes me a bit worried but maybe it will all work out.

This Wilwood clutch assembly pictured below has a 1.38 stroke which may solve my 1st issue due to the increase stroke. The 2nd issue would be solved due to the motor and transmission not "torquing rolling" physical linkage in the frame and the 3rd issue similar to the 2nd would be solved when the frame no longer flexing the linkage between the body and frame as well as the frame to the transmission. I will be looking on how it would mount as they do have several options there. (there are several single output master cylinders available to ensure that the maximum travel can be had out of the slave cylinder). The one in the picture may not work as the slave has a .60 cubic volume and this master pictured says it only has a travel of 1.2" at 7/8" diameter with a volume of .55 which is not enough. I am thinking something with at least .60 + just a bit for the flex in the line going down to the peddle. The High Volume single output master cylinder that has a 3/4" piston and a 1 7/8" travel that has .62 cu/in of volume would be the ticket. This will also get me back the loss in lever arm advantage and actually get me a slightly softer peddle due to it adding a 36% hydraulic mechanical advantage.
Did a bit of checking, currently the peddle moves 9" down to the floor. to create 1.085" of motion to the clutch lever arm. Basically 9" to 1.1". The Wilwood peddle here is a 7:1 so my peddle with it would be stiffer by 29% according to Google AI assistant. With the hydraulic advantage but longer throw of the peddle I could get a softer peddle overall but with a longer throw.
As I was taking these measurements I noticed I could get about 1 more inch out of my current peddle travel. I will try that first but should only get me to 1.205" on the lever arm, but maybe it is enough. If so then the Wilwood clutch would definitely be a solid solution.

Update:I made a cardboard cut out of the Wilwood peddle and it would definitely work inside of the cab. In fact it is excellent. I would later buy a 2nd peddle for the brake Hydro max system. The way it would work is there is a "pair of vertically placed but slightly diagonal pates that run from the firewall to the dash to give the steering wheel full support. I would make a bracket to bolt into that "fin" for the top two bolt mounts on the peddle and then bolt the firewall side as well. The firewall is a bit wavy at that particular section but I would either clamp it or bridge the space to ensure a solid fit. This way the clutch and brake are near centered around the steering wheel. It would also give the peddle for the clutch a press forward feel rather than a stomp down feel as your pressing it which is more natural to me.
I need to verify what is on the backside of the firewall at that point but I think it is only the resistor and the relay box which I could scootch to one side or the other to make this solid.

Forgot to mention I did get the "front wheel drive" kit air switch installed.
I think this kit was originally designed for the M35 I would guess from the documentation and extra parts that the kit came with.
To install it, I tapped to the air from the original sprag supply air line that comes up the passenger side of the frame rail and adapted it to the DOT 3/8" tubing, up through a 90° bulkhead fitting mounted in the removable forward floor access plate, this supplies the IN OUT three way air valve supply air side which then routes back to a second 90° bulkhead fitting to a flexible rubber line that connects to the supply air side of the sprag. This Valve when put into the OUT position will dump the air upline of it which is supplying the sprag switch with air which allows the sprag to relax/self shift into a "nutral" position due to two springs located on either side of the shuttle cylinder that is on the front of the transfercase. When in "nutral" neither the forward or reverse sprag will engage.

I am understanding that the leaving it in the "OUT" position for long periods of time can cause the sprag shuttle cylinder to gum up or to become sticky. I am not sure how much I will use this "OUT" position as I have had zero issues with my setup, but it is nice to know I could shut off the air going to the sprag transmission switch if needed.
I did remember as I went out and took these pics that I still need to look in the manual to see which of the power lines I need to hook the power up to.