Wrecker wishlist of mods

[lakeydna]

Its not. Its a M812

 

[Csm Davis]

High enough for you?
View attachment 467966
This is how ALL the Australian M816's were modified (amongst other things) before entering service.



Has anyone else stopped to think of the shearing force that those two little pins in the transport legs have to carry???
When setting the boom for a sus tow, over half of the booms weight rests on those legs, with some preload if the hydraulics are powered down, then you pick up a truck... Those two pins have lasted for decades so I think if anything is going to fail - we should look there so long as rigging/tackle etc., is appropriately sized. .... and so too have the two pins in the shackles on the front bumper of the casualty.......

This is why I use tow bar pins in a pair of shackles that I keep on my wrecker so I know if they spread or bend. Also the transport legs only see around 5000lbs each if you let all the weight down on them and those are are huge pins and must be hard I have never pulled any that had any visible wear. And if you are referring to the 3/4" pins that adjust the legs they have a pair of pressure points to share the load. Also if the transport legs failed the rams would hold the load.

 

[73m819]

Front Counterweights

As all of you who own a STANDARD wrecker (not a m246 or m819), know how QUICK the front steering goes lite with a HEAVY LIFT, OVER THE REAR TOW. So I think I have found a solution to this problem while READING the 272 tms, (for those who DONOT know what a 272 series tm is, it is the 939 tms (this may be NEWS to some of the 939 owners)). in the tms there is a FRONT COUNTERWEIGHT kit for the a2s (a2 motors are lighter then the 250s), so if the military can do this to fix a lite steering problem why can't you standard wreckers owners do the same, all it would take is a bracket on both sides of the front winch, down sorta low and some old fashion tractor flat slab weights (these can be gotten almost anywhere). What I just described above is what the 939 counterweight kit is only COSTING the military least 10 times what you could build the same thing for (guess the GREEN PAINT is what makes then so expensive)

The REASON I say standard wreckers and not m246s and m819s is because these two have a longer frame with the crane FORWARD of the rear trunion by a good number of feet, thus making the whole truck forward of the rear trunion a COUNTERWEIGHT. In another words, the m246 and the m819 are about the PERFECT older military wrecker for a HEAVY LIFT, OVER THE REAR TOW.

 

[jesusgatos]

We have one of those M936A2 wreckers with the counterweights. Would be easy to reproduce and can take some measurements if anyone would like to take a crack at it.

 

[zebedee]

....... there is a FRONT COUNTERWEIGHT kit for the a2s (a2 motors are lighter then the 250s), ....... all it would take is a bracket on both sides of the front winch, down sorta low and some old fashion tractor flat slab weights (these can be gotten almost anywhere)..

Interesting Ron. Jeff and I were talking a while ago about the same issue (light front end) and I had wondered if a bumper box for all the heavy kit (Bii) - snatch blocks, chains etc., could be used when sus towing. Would save dragging around dead weight (tractor suitcase weights are a premium up here - all the tractor pull boys snag them). It would also get some of the kit lower to the ground when needed for rigging etc. Just like the new Oshkosh 10x10 wrecker. The box could be stowed by the crane, up on the bed when not needed on the front as a counter weight. The down side is that the nose is already in the middle of next week when pulling up to a Stop sign/T junction etc..., and this would make it worse.

 

[Welder Sam]

We have one of those M936A2 wreckers with the counterweights. Would be easy to reproduce and can take some measurements if anyone would like to take a crack at it.

How bout some pics of that set up?

Tractor weights are plentiful here.

 

[Csm Davis]

Okay my two bits are build boxes behind the bumper on both sides to hold bii the real heavy bits no need to add weight to a heavy weight truck. Weighed my 936 with very little BII on it the other day and it came in at 38,000lbs!

 

[zebedee]

.... Weighed my 936 with very little BII on it the other day and it came in at 38,000lbs!

Just overheard some joker mention New Years resolution diet.... Some comic!

How goes the locker 3 rebuild Jeff? Posts #80, 89, 90, 92....

 

[rangereter]

I have been in the process of fabbing a front end counterweight for my M936 too, it will also double as a center pin hitch point for anchoring/pulling purposes. It should be between 1000 and 1200 pounds when completed. I have found the front to be too light on the steer axle with more than 5 ton on the hook. This problem is compounded with icy roads and rears that don't have a power divider/IAD (inter axle differential). With 25,000 pounds on the trunion, (coupled with a short wheelbase) the truck has a strong tendency to go straight regardless of road conditions.
Regards, Bob

 

[Csm Davis]

Just overheard some joker mention New Years resolution diet.... Some comic!

How goes the locker 3 rebuild Jeff? Posts #80, 89, 90, 92....

Work and life keeps getting in the way. But I love the new tow bar placement so much easier to use!

 

[Csm Davis]

I have been in the process of fabbing a front end counterweight for my M936 too, it will also double as a center pin hitch point for anchoring/pulling purposes. It should be between 1000 and 1200 pounds when completed. I have found the front to be too light on the steer axle with more than 5 ton on the hook. This problem is compounded with icy roads and rears that don't have a power divider/IAD (inter axle differential). With 25,000 pounds on the trunion, (coupled with a short wheelbase) the truck has a strong tendency to go straight regardless of road conditions.
Regards, Bob

Would love some pictures or drawing of your modified front, have seen several with a pental on the front.

 

[Welder Sam]

Jeff, that's a med in there right?

 

[Csm Davis]

Jeff, that's a med in there right?

Yeah Sam I am probably going to put lockable doors on the ends and then I can put a couple of the pry bars in with it.

 

[Welder Sam]

Killer

 

[73m819]

As all of you who own a STANDARD wrecker (not a m246 or m819), know how QUICK the front steering goes lite with a HEAVY LIFT, OVER THE REAR TOW. So I think I have found a solution to this problem while READING the 272 tms, (for those who DONOT know what a 272 series tm is, it is the 939 tms (this may be NEWS to some of the 939 owners)). in the tms there is a FRONT COUNTERWEIGHT kit for the a2s (a2 motors are lighter then the 250s), so if the military can do this to fix a lite steering problem why can't you standard wreckers owners do the same, all it would take is a bracket on both sides of the front winch, down sorta low and some old fashion tractor flat slab weights (these can be gotten almost anywhere). What I just described above is what the 939 counterweight kit is only COSTING the military least 10 times what you could build the same thing for (guess the GREEN PAINT is what makes then so expensive)

The REASON I say standard wreckers and not m246s and m819s is because these two have a longer frame with the crane FORWARD of the rear trunion by a good number of feet, thus making the whole truck forward of the rear trunion a COUNTERWEIGHT. In another words, the m246 and the m819 are about the PERFECT older military wrecker for a HEAVY LIFT, OVER THE REAR TOW.

The 939 weight kit mounts on both sides, behind the bumper, next to the winch under the vice plate, I will try to find the 939 kit drawings in the -xxp tm and post the page and tm.

A front mounted weight box would be a REAL PIA

 

[zebedee]

A front mounted weight box would be a REAL PIA

Never said it would fly - just an idea! Would be nice though, to pick up all of the heavy tackle and put it down on the ground right where you were going to hook up for a big pull without having to lift and lower each piece/snatch block/chain etc., by hand....
Look for Youtube of new MMRS.

Interested in seeing the 939 mod when you have time....

 

[73m819]

The weight kit is for over the rear, heavy left tow, so ALL the stuff in the weight box would be on the WRONG end of truck from where needed.

Look in tm9-2320-272-24p, figure 616 for the picture of the kit, the next page will give you the part break down.

 

[zebedee]

The weight kit is for over the rear, heavy left tow, so ALL the stuff in the weight box would be on the WRONG end of truck from where needed.

OK - now I am confused, I think we are at crossed purposes... I thought you said the weight was for the front bumper to assist in keeping the steers on the ground. That is where I was thinking of putting a weight box only for when lift towing. Stuff in the box - snatch blocks etc., is for winching not lift towing.
When that tackle would be needed for rear winching, recovery work etc., the box would be lowered to the ground at the rear (like the MMRS, http://www.youtube.com/watch?v=BgSDbLA6EpU - box is seen at 37 and 43 secs), once the casualty was recovered, righted, unstuck etc., all the kit goes back in the box, it is swung onto the front bumper as ballast, then the casualty is lift towed as normally.
BUT - as pointed out earlier, it needs to be a QD hookup, and quite slender so as not to extend the nose of the truck by too much. It could be a pair of 'saddle bag' boxes that hang down behind the front bumper with a rigid link that goes tight to the grille and up and over the winch, but the vise/vise plate would have to move - maybe a 'V' mount on the side of the truck - like for the Ward la France wreckers.

Again - this is all healthy speculation and needs to be treated rationally. None of this may come to pass - ideas need to be developed and maybe shot down - but pushing the design envelope, at least 'on paper' is fun. (For me anyhow!)

 

[Csm Davis]

The 939 weight kit mounts on both sides, behind the bumper, next to the winch under the vice plate, I will try to find the 939 kit drawings in the -xxp tm and post the page and tm.
A front mounted weight box would be a REAL PIA

Yeah this is where the a2s have the weights. Not sure why a front box would be a pain unless you mean in front of the bumper.

The weight kit is for over the rear, heavy left tow, so ALL the stuff in the weight box would be on the WRONG end of truck from where needed.
Look in tm9-2320-272-24p, figure 616 for the picture of the kit, the next page will give you the part break down.

And like Zebadee not sure about this post Ron?

 

[jesusgatos]

Will take some pictures of the M936A2 counterweights next time I go over to the yard. Think toolboxes or maybe hydraulic reservoirs or something, anything, would make a lot more sense. Seems stupid to add weight to something that's already so heavy.