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#846 - Cummins Swap
Author: andy1canada (Show all albums)

Howdy Folks!

Going to give this another try as my first attempt didn't go so well on the 'Diner-conversion' thread (Will update/edit that soon).

Started my Cummins swap by pulling off the bumper; only took better part of an hour. That sucker is HEAVY! Better part of a 100 lbs I bet. Will be looking to knock substantial weight off that baby while still retaining a 5000 lb towing standard.

This will take a while as it will unfold as time and resources permit, so please be patient.

More pics and hopefully some videos (FMC-TV) to follow.

Show Newest Photos First | Show Oldest Photos First238 Photos - Page : [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20]

Added two 5/16" small gussets to the angle bracket to beef it up some. Drilled 3 x 11/16" holes for the 3 x 5/8" (gr.#8)bolts that will secure the air-spring mount arm to the mount. Note: I made the bolt holes 1/16" larger for two reasons (1)I'm not a machinist and only have a simple drill press to drill these holes in correct alignment and knew I'd be off a bit so this would provide some wiggle room. (2)slightly larger holes would also provide useful horizontal adjustment to help correctly align the lower spring mount with the upper one on the chassis. The following pics show the mount in place and the welding tracks where it's attached to the trailing arm.

Prep work on the trailing arm/torsion bar tube mount bracket footprint.

As Frank and Lenny and no doubt others have, I decided to mount the air-spring support on the trailing arm somehow. The road I took relies entirely on this 5/16" pc of angle iron being securely welded to the upper end of the trailing arm and to the outer torsion bar tube. This needed to be done right, so I hired a professional welder to do this particular job. All other parts I welded myself and as I am a woodworker by trade, I make no apologies for how sloppy many of the welds are.

Disclaimer: This is a sketch of the general idea of the direction I've gone with on this air-spring mod on my coach. Any sketches and all related pictures I'm sharing here on this subject are simply to provide my fellow coach owners with another perspective on an air-spring install on an FMC motorcoach. I am not in any way endorsing/suggesting/advising that this method will work, or, is safe to copy or use on other coaches. Anyone who does so, does so at their own risk.

Air spring trailing arm mounts completed. As I cobbled these together from some gifted steel, they're rather patchworked together. They're about 36" long and the 6" round lower disc is tilted about 10 degrees upwards off the plane of the beam. If they prove not able to do the job, I'll simply make new ones out of heavier box channel steel.

Included this pic to illustrate the close proximity of the bottom shock-mount to the edge of the air-spring mount beam. Got to thinking it might be a good idea to fab a simple bracket to provide an additional support-connection between the trailing arm and the air-bag arm while still providing the shock mount in the same position. Plan to look closer at this.

Now... to make it all out of steel!

Good 4" or so clearance from bag to tire.

Some simple brake-line re-routing will be in order here to keep stuff away from chaffing the bag.

Again, good access for another weld along the entire bottom edge.

This pic shows that with the 3 1/2" x 5" angle mount bracket in play, there actually may be enough room to get at it with a mig to weld it to the trailing arm.

Here ya' go Lenny! I actually took your advise and did a mock-up out of some crap plywood I had kicking around. Used a laser under the coach to spec out the sketch to make sure all clearances were considered and accounted for. The primary material will be 3 1/2" X 5" X 5/16" angle iron. Most of the 3-ft. main-beam section and the 12" long mount section that will be welded to the trailing arm will be made from this; additionally, this mount will be bored for three 1/2" bolts so the main beam can be bolted to it and easily removed if required. So far it's looking good but I've yet to confirm the correct angle to mount/weld the mounting plate at.
Show Newest Photos First | Show Oldest Photos First238 Photos - Page : [1] [2] [3] [4] [5] [6] [7] [8] [9] [10] [11] [12] [13] [14] [15] [16] [17] [18] [19] [20]

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