Air Pack for M52A2; Will a M35A2 one work

[CARNAC]

I was going to offer up my spare M35A2 airpack to a local member in a bind for use on his M52A2.

I have since found out that an M35A2 air pack will NOT work on a M52A2 series truck. I want to ask in hopes it would.

My spare air pack will now remain as my spare air pack in storage for when I rebuild my deuce....hopefully within the next year.

Thanks to all that have responded.

 

[bigmike]

every 5 ton i've had (M818, M543) have had a larger airpack.

 

[dmetalmiki]

A deuce ( 2 1/2) ton pack is incorrect for a 5ton. truck.

 

[Old Lincoln County Iron]

I am looking for an air pack for an M35A2!

 

[73m819]

What I understand is that the boost piston is to small for the 2" wheel cylinders on a 5t

 

[CARNAC]

OK, thanks folks. Got it, it won't work.

Can a mod delete the thread.

I think I should have just PM'd one of the inner circle. Was looking at helping a guy out who has been good to me in the past. Bummer.

 

[Tracer]

It's the thought that counts. : )

 

[silverstate55]

Instead of deleting thread, it might help other members contemplating same to see this and know....

Thanks Carnac!!

 

[USAFSS-ColdWarrior]

Thanks for NOT yet deleting this thread.

It answered EXACTLY the question for which I was SEARCHing for an answer regarding Air Pack interchangeability as well as CONFIRMATION that the braking systems on the M44 series Deuces and the M809 Series 5-Tons are, in fact, BOTH "AIR OVER HYDRAULIC" Systems.

Hence, the 5-Ton M809 Series DO NOT have Air Brake Canisters on the axles, and therefore when towing, caging of the brakes is not only unnecessary but also effectively impossible since the braking systems "just ain't made that way".

Correct me if I'm wrong, but an M818 Truck with no air pressure (and with the parking brake released) SHOULD roll freely when towed, since no air pressure is required to RELEASE the brakes, only to assist in the service brake application, RIGHT???
In towing, air connected from the tow vehicle to the towed M818 is used to APPLY (or "SLAVE") the brakes on the unoccupied vehicle.

Thank you in advance for any confirmation (or reversal) of this understanding.

 

[Valence]

Thanks for NOT yet deleting this thread.

It answered EXACTLY the question for which I was SEARCHing for an answer regarding Air Pack interchangeability as well as CONFIRMATION that the braking systems on the M44 series Deuces and the M809 Series 5-Tons are, in fact, BOTH "AIR OVER HYDRAULIC" Systems.

Hence, the 5-Ton M809 Series DO NOT have Air Brake Canisters on the axles, and therefore when towing, caging of the brakes is not only unnecessary but also effectively impossible since the braking systems "just ain't made that way".

Correct me if I'm wrong, but an M818 Truck with no air pressure (and with the parking brake released) SHOULD roll freely when towed, since no air pressure is required to RELEASE the brakes, only to assist in the service brake application, RIGHT???
In towing, air connected from the tow vehicle to the towed M818 is used to APPLY (or "SLAVE") the brakes on the unoccupied vehicle.

Thank you in advance for any confirmation (or reversal) of this understanding.

Correct! M809 Series are air-assisted hydraulic brakes, just like the deuce. I have an M816 wrecker in my driveway to prove it.
No caging of brakes needed (or possible). Also, yes, I believe air supplied from the lead vehicle would be used to APPLY the brakes on the unoccupied, towed M818. EDIT: I don't honestly know if the previous sentence is true and I don't want to mislead anyone! Sorry.

If you're flat towing you can completely ignore the following:
One word of caution: I believe I've read that if the front end of the M809 series is LIFTED when towed, this would created excessive wear on the sprag since the front wheels are not turning. Same result would happen if one were to put lockout hubs on the front WITHOUT a modification to the air pressure routed to the transfer case. Please talk to member 73m819 for much more detail and clarification about this! (I spent an hour on the phone with Ron as he carefully explained a lockout hub scenario. I should have written it down!)

For reference, part of what 73m819 was talking about can be found here, in Post#234
http://www.steelsoldiers.com/showth...lockout-hubs&p=1753357&viewfull=1#post1753357

 

[USAFSS-ColdWarrior]

Valence,
Thanks.

That's an interesting thing about towing with the front axle lifted.

Since this truck in question has had its front driveshaft removed (and we don't know if it was driven or towed to its present location), I've got to ask: Would pulling the front driveshaft eliminate or neutralize this problem?? It seems it would at least minimize the wear on the sprag, wouldn't it?

 

[sandcobra164]

It might help eliminate the wear in a lift tow scenario as the sprag wouldn't be trying to turn much. If the truck was parked in any position other than reverse, the sprag will engage when the rear wheels are moving faster than the front. From my simple understanding, I'd take the actuator off and set it to the middle position if I were attempting to lift tow one of these M809 series trucks. I've flat towed a few and only had one issue. I had one that the vent hole for the sprag selector had been blocked off by a bolt. It was a flat tow and no airlines were connecting the M936 and the M818. About 2 miles from home on a 70 mile trip, the M818 would occasionally make a loud banging sound. It perplexed me but we made it home. I got it up and running and decided to try it out. It would not make it through my ditch while checking the articulation in any forward gear but would back out just fine. It dawned on me that it wasn't making the usual psst sound when switching between a forward gear and reverse. I took the transmission tunnel off and the problem was obvious. It worked fine after I removed the bolt that was threaded somewhat in. It was a course thread bolt in a fine thread fitting but made just enough of a seal that it kept the sprag selector from working.

 

[USAFSS-ColdWarrior]

Sorry for the thread hijacking.
Thanks for the GREAT information though.

We now return you to our originally posted topic....


Carry on.

 

[CARNAC]

Shall I pack the loaner towbar????? I think I should.

 

[USAFSS-ColdWarrior]

Shall I pack the loaner towbar????? I think I should.

Yes, Sir. I was about to PM you with that request. Looks like flat-towing is the best option indeed.

I will arrange a POC for drop off and PM that info to you asap.
Do you know your ETA at Midland?

Thanks.
John

 

[Valence]

Valence,
Thanks.

That's an interesting thing about towing with the front axle lifted.

Since this truck in question has had its front driveshaft removed (and we don't know if it was driven or towed to its present location), I've got to ask: Would pulling the front driveshaft eliminate or neutralize this problem?? It seems it would at least minimize the wear on the sprag, wouldn't it?

I'd talk to 73m819, but my gut says (meaning use this with a grain of salt) that without the front drive shaft it would still appear to the sprag that the front axle isn't turning and thus be engaged, leading to the excessive wear scenario.

Also, report back what the Kinder, Gentler Ron says. PMing his contact info.

 

[USAFSS-ColdWarrior]

I'd talk to 73m819, but my gut says (meaning use this with a grain of salt) that without the front drive shaft it would still appear to the sprag that the front axle isn't turning and thus be engaged, leading to the excessive wear scenario.

Agreed.

If we flat tow I would also reinstall the front driveshaft so this should not be a problem.... unless.... there has already been damage done to the sprag and/or transfer case. <sigh>

 

[Valence]

Correct! M809 Series are air-assisted hydraulic brakes, just like the deuce. I have an M816 wrecker in my driveway to prove it.
No caging of brakes needed (or possible). Also, yes, I believe air supplied from the lead vehicle would be used to APPLY the brakes on the unoccupied, towed M818.

I just felt I needed to write and acknowledge my lack of knowledge as I don't want to mislead anyone. I honestly do not know if the above highlighted sentence is true and I don't want to mislead anyone! Sorry.

 

[USAFSS-ColdWarrior]

Thanks, Valence.
It's pretty much agreed that the statements are correct and our understanding of the system functionality is correct.

I sure have gotten an accelerated education on the SPRAG. It's a rather ingeniously designed "on demand" engagement mechanism. From this newfound knowledge I now believe that the reason the S.O. folks pulled the front driveshaft MAY HAVE BEEN because in towing the truck with the front axle lifted the SPRAG engaged and they were trying to get the front axle to stop spinning its wheels - thanks to their lack of understanding of the SPRAG engagement geometry. The good thing in that seems to be that with the wheels off the ground the 8% differential between front and back drive gearing became a moot point without any traction/resistance between the speeds of the drives. Hopefully there is no damage to the SPRAG if this was indeed the case.

Thanks to all the contributors hereto.
John

 

[Tow4]

If the front drive shaft on the M818 is not installed, how can there be any excess wear on the sprag? If it stays engaged the whole time it doesn't matter since there is no load other than spinning the flange. BTW, oddball007 has been driving his M818 without the front drive shaft for years. It was removed when he got the truck.

With the M818, you can hook up the glad hands on the front bumper to the towing vehicle and it can operate the brakes.