new M656 first road trip

[sangamon]

So I finally got my insurance foolishness taken care of. I took the M656 out for a quick drive around the block (about five miles) this morning.

I know I keep going on about it, but it really rides smoothly. I had warmed up my Unimog 416.163 on the same path, and I could feel every bump and pothole. I didn't feel a thing on the M656.

The nice, long, flat sides make it easy to figure out where you are on the road.

The automatic transmission shifts very nicely, and shifts when it should. It's the first automatic that I actually like.

The temperature this morning was 23 degrees. The engine started in about five seconds. That seems pretty good to me for a fourty year old engine.

The steering is still a little stiff, and the low temperature probably didn't help. I'll do Bjorn's boiled joints treatment to take care of that.

It's a great truck.

The Border Patrol sees me in my Unimog firetruck all the time. Hopefully they won't be too surprised when I drive by in the M656.

The pictures are of the M656 in my yard - there wasn't a convenient place to get out on the road.

 

[Stalwart]

KEWL, I used to have to top up the power steering once a year or two, depending on how much I drove it. It was a nuisance leak that never reached the point of competing with the British vehicles. Even the HEMTT has a few of those, the only one I've fixed on it so far is an axle seal that was putting SAE 90 on the brakes.

The reservoir is under the doghouse cover on the drivers side aft of the seat, as I recall anyway. BTW, it had a load of fresh 50/50 coolant last fall, I completely drained it and I think I added 4-5 gallons of coolant and equal water.

 

[tm america]

awsome truck i need me one of them im ready for the pics of it swimmingwe need some videos of that fine piece of green you got there

 

[Stalwart]

TM A, swimming those trucks has the engine IN the water, not above it.

 

[tm america]

as long as the air intake is above your good to go.i seen some pics-video of one swimming thought it was crazy looked like the water was half way up the dooranyone got pics or video of one swimming

 

[cranetruck]

Good show! What tire pressure are you running?

Here are some steering maintenance details. When I first checked the joints, it took about 60 to 75 ft-lb of torque to turn each one. After the cookout, it was about 10 ft-lb or so (the cap of each joint was drilled for the oil to penetrate and then sealed with a screw). The joint was kept in the oil at about 250-275°F for 4 hours.
I can imagine how the power steering system must be stressed with 11 of those resisting every move.

 

[Stalwart]

as long as the air intake is above your good to go.

REALLY, no worries about water entering dipsticks, breathers, old seals; hot exhaust manifolds cracking, hot injection pumps doing likewise etc. Then there is the tranmission, transfer case and 4 axles not to mention 40 year old wiring. Hey, you don't have to pay for the damage. It's a TRUCK, not a boat, it had the ability to swim during time of war.

 

[tm america]

i know they are amphibious. and chances are if you can afford one you can afford to play with one .i play with my toys and when i have to do maintence i dont cry i just do it .i would figure those would have a deep forging kit on them to keep the water out of the axles ,transfer case,trans ,and other important things .i think they had rubber blatters in the doors to help with floatation to didnt they

 

[tm america]

thanks for the pic bjorn it.s nice to see them in action doing what they were built for looks like the guy in the pass seat is a little scared to get wet

 

[cranetruck]

i know they are amphibious. and chances are if you can afford one you can afford to play with one .i play with my toys and when i have to do maintence i dont cry i just do it .i would figure those would have a deep forging kit on them to keep the water out of the axles ,transfer case,trans ,and other important things .i think they had rubber blatters in the doors to help with floatation to didnt they

There are two pressurization systems, one "wet" and one "dry". They are separated by a trap to reduce the risk of contaminating the sealed brake drums, for example. The crankcase, transmission, transfer, axle housings, brakedrums, generator, door seals and cargo bed doors are all pressurized prior to swimming. The generator switches from 30 to 80 amps to provide power to the bilge pumps. Lots of cavities are foam filled to increase floatation.
The xm757 does not have enough buoyancy in the rear to float and is only qualified for fording about 4 ft.
The m656 is also fitted with bilge pumps to handle any leaks....a most interesting vehicle.

Images of my deuce in water, which required an extensive maintenance checkup as a result. There is no way of knowing if there is water anywhere unless all oil filled housings are visually inspected.

 

[sangamon]

Bjorn,

I appreciate your writeups on your steering and torque rods. I have them both bookmarked. The picture with the joints circled is also great.

You asked about tire pressure - I don't know, but I'll check Friday when I'm up north.

I have some questions on your hot joints procedure.

You mention both motor oil and hydraulic oil. I have both. Did one work better than the other?

About how long did it take to remove the joints, and how many of them needed a bigger hammer?

My shop isn't built yet, so I'm working in my gravel driveway. It looks like I can do all this with the tires on, right?

When removing the joints, is anything spring loaded that's going to go "boing" and throw me across the yard? Looking at the truck it doesn't appear so, but it never hurts to ask.

Did anything happen during the entire procedure that made you say "hmmmm, I never expected THAT to happen"?

Thanks.

 

[PorscheTech911]

That's a really nifty truck, it would be really cool to see a video of it in action

 

[cranetruck]

Brad, no real problems after the procedure was established...

Firstly, get the front two axles up on blocks and keep in mind that the supports must be rated at least 6,000 lb for each axle.
Remove the wheels for access and try turning the steering wheel without the engine running, it should be fairly effortless, if not, then you know there is problem with the joints.

I had little trouble knocking the tapered pins out, but sacrificed one of the nuts in the process making it a "removal tool" along with a 3 lb hammer. I have extras, if you can't find one.

The joint on the power steering cylinder was cooked on the spot after dropping it down as shown in the image below.

I used motor oil and hydraulic oil with equal success. Don't get the oil too hot or there may be permanent damage to the seat in the joint, which is partly made of Delrin (a Teflon-like plastic).

I'll look for some pictures of the drilled ball joint caps, which were sealed with screw after they were done.
BTW, the joints are still perfectly good today, almost 3 years later.

This may also be a good time to check the alignment of the wheels and axles...see your -20 TM.

Edit: Added images.

 

[Scarecrow1]

Thats a very nice truck .......I can see why your so proud,,,, keep on having fun with it and a smile on your face life is short enjoy

 

[davidkroberts]

after being the proud "former" owner of a Gama Goat I would advise against swimming any 40 yr+ vehicle. Even when new they leaked like crazy and swimming wasnt recommended.

 

[Stalwart]

We've had more than a few "amphibians": Gama Goat, M656, V100, 5 - Stalwarts and there is only ONE I would EVER swim . . . Stalwart. They have the best protection for keeping the running gear dry, all seals are doubles, one keeping the oil in and the other to keep water out. Even those take any where from 1.5 to 5 hours of maintenance after every swim, not to mention of 1-2 gallons of SAE 90 for the suspension.

The M656 is not a BOAT as I said earlier, just a VERY COOL truck that is fantastically easy to drive. I don't even have a clue where to find all the inflatable door seals required to keep the water out when swimming the 656. I do miss it, but I couldn't keep everything, my garage is only 40' by 90' and MV's aren't our only hobby, plus I need room to finish restoring the V100 and the Dingo.

We are both thrilled that the M656 went to someone who will love it and care for it, I doubt there are more than a few complete ones left. Following Bjorn's lead, I'm sure Sangamon will have a beautiful, peach of a truck, in due time. I myself can't wait to see it!

 

[Stalwart]

Swimming

 

[AaronW]

Awesome pic Stalwart. Looks like it could be any summer day on Lake Sammamish.(I grew up in Issaquah)

 

[Stalwart]

Aaron, that's exactly where it is, I live on Lk. Sammamish at the Redmond end.

 

[cranetruck]

Stuart, the Stalwart is remarkably level in those pictures, is it loaded? The m656 is level in the water only when loaded. Empty, it tips forward (aft up) from the images I have seen.
What is the speed in water for the Stalwart, looks like it's moving right along?