Bobbed M925

[wehring]

more pics

More pics.

Justin Wehring
979 997 3112

 

[wehring]

eldgen

Eldgen,

Thank you for the post. I always appreciate the opportunity to learning from someone. I am using separate legs for each bag. Manual inflation and deflation via schrader valve at the rear crossmember. No auto level system.

I understand that I have a lot of range of motion with the BAG but the limiting factors are the angles of the DRIVESHAFT. What I was not sure of that came clear today was how will the axle sit on the springs at height X and what will be the orientation of the shaft flange angles. A driveshaft is basically a slight "Z" shape (except with CV shafts) and this should be considered when you change the geometry of a driveline. Each joint should be a mirror of the other. As it sits now, I am back to the factory pitch. I can easily go up several inches in the bag's range of motion but as the leaf springs swing down and pivot about the front hangar then the lower shaft flange angle transitions from a slight negative (which is equal to the top joint) to 0* then into a positive pitch. It is not good practice to transition across a + to - angle with the lower joint. When your lower joint crosses over the neg to pos angle thedrive shaft Z shape becomes a U shape and you get vibrations and other drama.

I am not sure if I hit on what you were asking. If not I am here to talk more about this.

Justin Wehring
979 997 3112

 

[eldgenb]

you hit it on the head. I always have to be careful posting certain tid bits just for the sake of people not seeing the good intention of things. There are many things I still do not know and it has been by the graciousness of others taking the time with me to get me up to speed that has made it possible to do some of the things that I am now doing.
Great build, following your progress intently.

 

[housemover]

Justin I think you will find if you don't plumb the bags so they can release and take on new air the ride will suck. Air can only compress so far. Call me and I'll try to explain better.

 

[mktopside]

Justin I think you will find if you don't plumb the bags so they can release and take on new air the ride will suck. Air can only compress so far. Call me and I'll try to explain better.

Hey now!

I know this is his project, but he's not the only one interested in learning things!!!

Air suspension fascinates me, please elaborate if you have the time.

 

[hemichallenger]

Air bag pictures

 

[eldgenb]

Justin I think you will find if you don't plumb the bags so they can release and take on new air the ride will suck. Air can only compress so far. Call me and I'll try to explain better.

that is exactly the other half of what I was thinking especially when articualtion comes into play or an uneven load. Someone who is not constantly thinking about the road conditions and there load balance can end up in a bad spot. If you put a leveling valve on each bag it would constantly keep the driveline angle the same and the truck level whether the load shifts, terrain changes or anything. I bought mine from CC equipment for $120 a piece iirc and those were dump valves as well for easier loading/unloading and better angle for a dump bed if necessary. I have also found it handy for those pesky garage doors that are just a hair too short. I plumbed them for in cab control using a deuce air shift front axle switch. Just my .02

 

[wehring]

hitch

Picked the hitch up from the machine shop. They drilled and tapped the insert for a ball then turned the ball shank down and threaded it the full length of the shaft (to the flange) for strength. I will weld the ball into place tonight.

Justin Wehring
979 997 3112

 

[wehring]

Thanks Ted

Thank you Ted. I will spread the leafs apart when I clamp them to the axle. It looks like the bottom bolt for the bag should be centered on the frame.

Justin Wehring
979 997 3112

 

[hemichallenger]

Thank you Ted. I will spread the leafs apart when I clamp them to the axle. It looks like the bottom bolt for the bag should be centered on the frame.

Justin Wehring
979 997 3112

Glad to help. You are doing fine job. Wish it was mine.

 

[bigjuice69]

whats the load capacity of that ball? looking good keep it up!!!!

 

[wehring]

ball

It was a 30K before the machine shop turned it down. The previous diameter was to the shiny area on the flange. I lost a lot of capacity when the od was reduced but I will get a lot of it back when it is welded.

I have sent the pics and dimensions to a stress engineer at work (NASA) for review to see what the new rating of the asssembly will be. I will have more hard data next week.

Justin Wehring
979 997 3112

 

[wehring]

missed the deadline

Well tomorrow I depart with the M923E3 ESP to pick up an M113 and attend a machinegun shoot... sadly the bobbed M925 will not make the trip. I simply could not complete it in time without cutting corners. This next week I am out of the state with work so it will be 2 weeks before it will be completed.



Justin Wehring
979 997 3112

 

[eldgenb]

Well tomorrow I depart with the M923E3 ESP to pick up an M113 and attend a machinegun shoot... sadly the bobbed M925 will not make the trip. I simply could not complete it in time without cutting corners. This next week I am out of the state with work so it will be 2 weeks before it will be completed.



Justin Wehring
979 997 3112

Thats what you call in the movie biz... A Cliffhanger. Well done on the hitch setup, nice looking piece of work.

 

[chess]

im really liking the suspension set up! didnt really know how it was going to go at 1st but its looking great!!!!

 

[DKELONE]

I do not mean to pirate your thread but I figured this was the way to reach most bobbed 5 ton guys. I am looking at doing a data plate for the bobbed 5 ton & have no idea how many of these have been done. Anyone have a feel for this? Please record your comments on bobbed 5ton data plate thread. Thanks, David

DAVID P. KELONE
MVDATAPLATES.COM
6401 NORTH SHERIDAN ROAD
PEORIA, IL 61614
DKELONE@AOL.COM
309-696-7080​

 

[wehring]

8.3 cummins

There is nothing to do in the Yuma desert but work and think. This is a bad idea since I left at the tail end of a project.

I talked with a good friend that bought my M931A2 with an 8.3 Cummins. There is a chance he will not take the engine and tranny when he picks up the truck so I am kicking around the idea of transplanting the 6CTA into this M925 bobber project. Safe numbers are 400 hp and 960 ft/lbs of torque in a lighter package than the current 250 N/A Cummins.

What say ye?

I will be home on Friday and this weekend is devoted to some family time first then I WILL have this truck driving by Monday morning. I have all of the intake and exhaust components to complete the 8.3 conversion so it should only take a weekend to transplant if he makes the final decision to let it stay.

Justin Wehring
979 997 3112

 

[chess]

i have water trucks with the 250 and 8.3 although there both great i have a problem with the 250 with the sleeves cracking due to the electrolysys. theres one with the 8.3 with well over 15000 hours pedal to the metal and it running great still. to me the 8.3 is lighter, more powerful. and less prone to problems. if it were me its a no brainer.

 

[eldgenb]

Hey Justin, is this rig for you or for a customer, if its for a customer make sure they pay dearly for it because I think the 8.3 is a huge upgrade for that truck. What will you have to do to the tranny to run those kind of #'s?

 

[cjtroutt]

Looking good more photos.