Bobbed M931 almost done, Pics soon! A few questions please...

[joesco]

Just back from one of the largest Spring Shops in New England and I think I am going to jump out my first floor window! My entire suspension has to ripped-out in order to correctly size the suspension for the truck and obtain a NH vehicle inspection sticker. $1800 - $2200 for parts and labor. I am totally flabbergasted! The Spring Shop tech (35 years experience) said along with all the other issues I listed earlier in this thread, the springs themselves are to narrow for the truck. The tech was amazed I was able to make the 10 mile one-way trip without the suspension, literally falling off the truck!

I was going to leave it there and bit the bullet, but just don't have the funds right now. I was scared to death driving him home. Just glad the schools were closed today and traffic was much lighter than usual!

My only course of action left is to purchase a 5-ton Front spring set as suggested by many on this forum. Then to have it installed is my next challenge as the Spring Shop wasn't to enthusiastic in installing them. HOLY C R A P!

 

[Vintage iron]

That is a good price on new springs installed.

 

[joesco]

I would agree Matt, but added to cost of the original bobbed project, costs exceed $4k!

 

[Vintage iron]

Sorry to see this was a result of a "friends " poor workmanship I hope he will do the right thing and refund to the money to cover the rework.

 

[MO MV man]

Why not just get a set of 5 ton front springs and all their hardware?

That's what I'm going to do.
Maybe the ride quality won't be "smooth" but it is better than my bobtail M931A2's present rear suspension unloaded! LOL

And you'd think the inspector would be tickled to death with how beefy that hardware is!

 

[wheelspinner]

Thanks twinturbo90 for the correction, sounds like wheelSpinner might have been referring to the PCB. Thanks all!

yes! My eyes read fail safe but my brain heard PCB. Sorry! I have replaced both and certainly knew the difference. Doh!

 

[joesco]

So 5 ton Springs are an option, some Pro's, some Con's , airbags, but cost prohibited, what about a deuce spring set? After all the Military trucks that I have owned over the last 20 years, I am now beating a dead horse!

Why not just get a set of 5 ton front springs and all their hardware?

That's what I'm going to do.
Maybe the ride quality won't be "smooth" but it is better than my bobtail M931A2's present rear suspension unloaded! LOL

And you'd think the inspector would be tickled to death with how beefy that hardware is!

 

[MO MV man]

There is a ton of info on all of your listed choices.

I'd LOVE to do airbags on my truck but that just ain't gonna happen.

I used front deuce springs on my bobbed deuce and they worked fantastic.
That's why I'm doing what I'm doing-famliarity.

 

[Csm Davis]

There is a ton of info on all of your listed choices.

I'd LOVE to do airbags on my truck but that just ain't gonna happen.

I used front deuce springs on my bobbed deuce and they worked fantastic.
That's why I'm doing what I'm doing-famliarity.

I don't understand why all of you guys keep fussing about how much air ride cost. A good set of OTR truck bags are around 250 and the junk yards are full of control arms and bag supports it should not be a lot more to use air.

 

[jesusgatos]

Think the engineering and fabrication required scares a lot of people, which is not a bad thing. At least they know enough to know that they probably shouldn't be designing and building/adapting custom suspension setups to these massive trucks. The guys who know just enough to be dangerous and aren't afraid to go for it are the ones that scare me.

 

[mopar]

Joe
Hadn't followed your build in a while sounds like it has been a headache and a half. Good Luck with the springs.
Sean

 

[joesco]

Well my donor 5-ton front springs arrived today. I am hoping to have the existing suspension removed and replaced over the next few weekends. Those of you folks whom have used this spring set, 2 questions....

1) Did you use the existing hangers or use outboard hangers?

2) It appears that if we use the existing hangers, I have read the air cans will need to be re-positioned. It this a difficult process?

In the meantime, tomorrow I hope to install my new fail-safe module and troubleshoot as to why my Park lights aren't working.

Thanks.

 

[Vintage iron]

I am bobbing a M931 for a customer. He wants me too use 5 ton front springs. It should be interesting. I think front springs are designed for the front of a truck under a engine. But the customer insists and it is his truck.

 

[CBR Metalworks]

5-ton front springs and hangers work perfectly fine. You need to rotate air brake cans slightly, a 1" lift block and new u-bolts makes everything have plenty of clearance.

 

[joesco]

Thanks guys, hopefully my spring guy will get to it this weekend!

 

[jcappeljr]

I have bobbed 6- m939 trucks.The 5 ton front springs work great,all you need to do is spin the brake cans a little.And repipe the air lines.

 

[CBR Metalworks]

I have bobbed 6- m939 trucks.The 5 ton front springs work great,all you need to do is spin the brake cans a little.And repipe the air lines.

I don't know how you get by without running a spacer of some sort. I rotate the air cans but best I remember it was still too close for comfort between the spring and brake cans. I have noticed there are different thickness leaf spring pads, I have seen some that are probably 1/2" thick, and others probably 1" or a little thicker (guessing, been awhile since I looked at them). The difference may be as simple as pads off a winch truck or non winch truck, wrecker truck, etc.

 

[jcappeljr]

I have done it with and with out a small spacer.

 

[joesco]

Thanks all! Can't wait to get this done, inspected and on the road. Appreciate all the input.

 

[joesco]

New 5 Ton Front Springs, replacing the 1 Ton rear set is finally done. The installation went very smooth, we just needed two 1" spacers to clear the air cans on each side. $400.00 for the donor springs and $150.00 for (16) chassis bolts / nuts, (4) new u-bolts, (4) 1" spacers and two spring bolts / nuts. Just need to add several grease fittings and tighten everything up. I am picking it up tomorrow and hope to obtain my NH State Inspection next week.

Thanks for all the advice folks. Can't wait to start driving him now!!!!