MRAP tire differences for the Deuce Bobber

[3dAngus]

Yesterday, I recovered my two sets of 395/85R20 MRAP tires for my Deuce bob project. It turns out there was a surprise in the two lots I purchased. There were two different sets of wheels with the new Michelin X’s mounted, one set of 4 had 12 bolt and the other set had 24 bolt. This being my first experience with MRAP tires, I never knew they had different styles, much like the HMWVV does. At 650 miles round trip, it’s not like I’m going to do a preview on new tires. No complaints here. Just wanted to share.
So, I do some research. It’s not complete, nor perfect, but the best educated guess I can get out of it from using multiple sources including tech manuals is this. Feel free to correct if there is a known deficiency.
Set number one is NSN 2530-01-537-3979. This set is for the JERRV 6X6 and earlier contracts and is the 24 bolt version. It can also be used in the Cougar, and is used for CAT II operations.

Set number two is NSN 2530-01-555-5033 and for the Cougar rear ASL and PSL 4X4. It is the 12 bolt version and used for CAT I operations. Category of operations listed by Navy TMs as follows:

The MRAP vehicles consists of three categories: Category I (CAT I) vehicles support operations in an urban environment and other restricted/confined spaces; including mounted patrol, reconnaissance, communications, and command and control. Category II (CAT II) vehicles provide a reconfigurable vehicle which is capable of supporting multi-mission operations such as convoy lead, troop transport, explosive ordnance disposal, ambulance, and combat engineering. Category III (CAT III) vehicles are capable of performing mine/ IED clearance operations. The Navy will not procure any CAT III vehicles.

Below is an example of MRAP wheels and Michelin X tires of different series. Hub and ten bolt holes remain the same. I have reason to believe any adapter plates would be the same, and am trying to obtain one now for verification/validation. Two piece steel plates bolted together are different, and NOT just in the number of bolts. The 24 bolt has a lip where when sitting on its side, water can accumulate between the lip and create a rust condition. This should not be a problem in actual use however, where the tires remain vertical and should drain properly.

 

[gringeltaube]

........... The 24 bolt has a lip where when sitting on its side, water can accumulate between the lip and create a rust condition.....

Those look to be aluminum wheels...?????

G.

 

[3dAngus]

Those look to be aluminum wheels...?????

G.

Great catch!

Magnet tests indicate the 24bolt are aluminum. The 12 bolt are steel.

 

[gringeltaube]

Ah, OK... it simply looked too massive to be steel.

Nice wheels, BTW!!
It seems to me that (in both cases, Al and Fe) it should be very easy to recenter them for the Deuce: i. e., a 1/2"-plate machined to the 6 on 8-3/4" pattern, turned/ milled down to 3/8" only where it bolts to the (inner wheel side) mounting surface, and using the shoulder to ensure that the assembly remains perfectly centered.
Just throwing ideas out...

G.

 

[Heath_h49008]

Hutchinson Industries - Tactical Wheels


How much do they weigh?

 

[3dAngus]

I cannot say. I have seen two GL weights, of 400 pounds on one site, and 500 pounds on another, but that doesn't mean anything. I don't think I want to lift them, but got a good feel for it loading, where I worked with the GL forklift loader to reduce the height from 4 stacked high on a pallet to two stacked high without the crushed pallet for transportation purposes.

THEY ARE HEAVY!!! Nice link by the way.

 

[buzzinhalfdozzen]

I have a 12 bolt version. Was wondering what it came off of. Guy said it was a hemmtt wheel when he sold it to me.

 

[3dAngus]

Here is some pics of the 12 bolt and the 24 bolt MRAP hosted on a cougar 4X4. I'm no expert, but I believe the 6X6 Cougar variant of the MRAP vehicles all have 24bolt wheels.
I hope these come out OK. I just copied and pasted, instead of downloaded.

 

[Artisan]

I realize this is a tad bit of an old thread but perhaps someone could help me, me the tire ignoramus!

I have an M925A1 w/ 14:00 R 20 tires.

I would like all new tires.

I see a bunch of the 2530-01-555-5033 wheel assemblies for sale.

Is this tire the same as a 14:00 R20 ? If not what is the dimensional difference?

If I grabbed some of these assemblies would I run into any problems if I trashed the rims
and swapped the tires onto my M925a1 rims ?



TIA!

 

[eodcoduto]

This might have been hashed out but here is some info on the MRAP wheels. As an EOD Tech I saw the evolution of the Cougar (MRAP CAT I and II) and it was a logistical nightmare. The first Cougars were 4x4 with huge spring packs that rode horrible, so they went to the single leaf front axle, and they changed the axle/bolt pattern. If you have a new and old version Cougar in the Convoy you needed both types of wheels. Some of the 6x6s had this problem as well, with one truck having a swapped axle so we needed both types of wheels for one truck! It looks like most of the wheels being sold now are the Gen II Cougar rims. The newer style truck had the Budd style with a small reverse dish and the single front leaf spring. Those axles should be coming up for auction soon I hope.