Leveling revisited for MCI 102

[someguy]

https://www.mcicoach.com/service-support/serinfo/serinfo12B.htm

It might be possible to talk to this controller with CAN messages and get it to set the height of each corner individually.

[Jim Blackwood]

Maybe that could be made to work for the newer buses, I don't think mine has the CAN bus.

If I have time I'll try to get out the jack and jack stands today. I need to decide which end to work on, as the front leaks down. So, do I work on making the front end airtight, or do I work on the rear controls? Hard to decide.

Jim

[someguy]

How do you make that work with the existing leveling valves ?

[Jim Blackwood]

Read the thread, it's a work in progress.

Jim

[Jim Blackwood]

I've changed my mind about how to do this because a mechanical system will have no issues with leak-down ever. Semi landing gear are pretty good jacks with 4 times the needed lifting capacity so I am installing a set of three 17" travel Jost gear in a tripod arrangement, located at the front and rearmost bay bulkheads and anchored to the axle subframes. The front one is now installed except for the trim. I should be able to test it this week sometime.

In operation I expect to use the air ride suspension to drop the bus onto the bump stops and bring it up nearly level, then extend the jacks, take up the load, and finish leveling. The return to ride height at departure should eliminate any risk of driving away with jacks down, as well as making retraction an unloaded operation and therefore easier. I think it should be pretty easy to add limit switches for powered operation.

Jim

[windtrader]

The front one is now installed except for the trim. I should be able to test it this week sometime.

Looking forward about this. Those things are expensive new and something likely to be available in the used market. Personally, I have not had any trouble leveling bus sufficiently to our likings. Some may need zero degrees flat, we aren't so particular. I use the multi-level wood ramps for leveling and it has worked for us. Some desire push button, fine with me. Still interested in learning repurposing the truck jacks.

[Jim Blackwood]

Thanks Don, glad there is some interest. I put the cushion foot on today, it had to be removed to avoid cutting a larger hole in the floor and I modded it so it would bolt on with ten 1/4" serrated head bolts. They don't see any of the load, just secure the retaining collar to the foot. Also finished the motor adapter for the gear reducer and I'll slip that on the shaft when I go back out and look for a simple way to tie down the motor. After the electrical check and adding oil. Next I have a little mig welding to do which I hope to get done today and then I have the trim work on the bottom of the bus which includes reattaching the end of the center stringer around the jack. I'm putting off photos until after that's done.

I like these Jost gear. At just under $300 each they are cheap. Well, not compared to wood blocks but compared to other landing gear. The gearmotor to drive one will run into some money of course but there's no reason not to crank them down manually or as was suggested, with a battery impact until they touch. And there are surplus gearmotors out there if you know where to look. After my test I'll know more about what can work and I'll go shopping. You can chain drive 'em if needed, and there are also taper hub sprockets that will work on a keyless shaft. So a lot of possible options if you can do a little rough fabricating.

You could probably find something used, but watch the travel and overall height. You might save anywhere up to $700 that way if you find a real deal. But sometimes it's better to just buy something new that will work correctly than trying to adapt something that may be worn out. And it's also nice to work with clean parts.

Jim

[buswarrior]

Keep all the greasing points either accessible, or run hose to a centralized location.

They get real nasty as the lube dries out in 'em...

Happy coaching!
Buswarrior

[Jim Blackwood]

I've had the caps off and these have about a pound of very sticky grease in the gearbox. That should come close to lasting the lifetime for my use. It has 2 zerks, top one to the gearbox, lower one to the slide. Both should be fairly easy to get to. Might need a longer hose on the grease gun but otherwise I think that'll be OK. I'll pay attention to that when I mount the gearmotors though.

I got most of the welding done yesterday except the bottom trim. Gearmotor is tested and hung on the shaft and the cushion foot is installed. Used stainless wire to weld the angle brace to the bulkhead and standard MIG wire to weld it to the subframe. One more bulkhead weld to do and then sealant and paint.

Well, off to work.
Jim

[chessie4905]

if in the future you intend to grease, make sure it is compatible with what is already in there.

[Jim Blackwood]

Pictures!
I still have to apply seam sealer, I'm using Permatex Ultra Black gasket maker which is fairly serious overkill but at least it'll stay put. Also I'm looking at how to best install limit switches.

Ops check: N/G
The speed is acceptable if somewhat slow at 3.4 seconds per crank rotation but the 1/2 hp motor isn't nearly ballsy enough. Which means that gearbox isn't either. Time to go scrapyardin' for a suitable replacement. Probably something in the 2hp range would be my guess. Which means I can forget about using my surplus inverters here. Oh well.

Jim

Oh, and thanks for the advice on the grease. I figure any good EP grease is probably good enough. I made up the shortage in one unit with some black lithium grease which I've had forever and needed to use up.

[richard5933]

Does that landing gear have a two-speed crank? If so, are you sure it's in the low gear? If it's in the high gear it might be the cause of the problem the motor is having.

[buswarrior]

Oh baby, what Richard asks...

If there's any lifting at all, as opposed to running them down and then dumping the suspension to load them...

You'll be wanting low gear, or a way to readily click it between high and low.

Happy coaching!
Buswarrior

[lovetofix]

You just need to get the gearbox that semi trailer jacks use to give the Motor more mechanical advantage.
You only have the bare jack, typically they come mounted on a trailer with a two speed gear box that drives both jacks and the hand crank is attached to that gearbox. (Richard eluded to this)
The handle does NOT drive the jack directly like you are trying to do with that gear motor. There is no way you could lift a loaded trailer with the handle direct on the jack. That is why they have two speed gearboxes, high gets the jack to the ground and then low gear had better be working to do the lifting or you have to dump your air suspension to get your truck out from under a loaded trailer.

[richard5933]

Oh baby, what Richard asks...
Buswarrior

Not sure if I asked it correctly...

But I know that trying to crank up a trailer that is stuck in high gear is a losing proposition. Not easy for a driver, certainly not easy for a 1/2hp motor.