Diagram of Air Assist Clutch for a MCI 5....

OneLapper · November 29, 2015, 04:09:29 PM

Clifford sent me an air assist control and air cylinder from a MCI 5. Does anyone have a diagram of the setup used on a 5? I'm planning on installing it on my 4106.

Thanks!

bevans6 · November 30, 2015, 06:07:53 AM

Sorry, wrong manual. I thought I had a picture, but don't...

Brian

OneLapper · November 30, 2015, 11:30:52 AM

Thanks for look for it, Brian! With some luck, someone will have easy access to one.

I spent the long weekend in the bus with the kids. I practiced slip shifting which worked fine under light load and low rpms. It was very difficult to get the timing right at higher rpms and loads. Besides, the 4106 just doesn't seem to like shifting without the clutch. I've driven several 4104s that slip shifted just as smoothly as a tractor trailer. Maybe it's my transmission.

On that note, I'm considering this winter pulling the engine and tranny, as well as the rear axle. I have a nice tranny and axle ready to install. I'll make sure to clean and lube with graphite the shift rods which are now getting stiff to move, something I didn't think of doing the last time I pulled the engine out.

bevans6 · December 01, 2015, 04:28:44 AM

While some people who maybe don't do transmission rebuilds don't agree with me, that old spicer is in no way designed to be "slip shifted". The design of the gear dogs that lock the change gears to the main shaft is wrong for anything but double clutching. I am charging the battery for my camera, and I should have a picture of the MC-5C clutch linkage including the air assist cylinder for you in a half hour or so. If you can, can you send me a picture of the clutch linkage as it goes into the bellhousing of your gearbox?

Brian

OneLapper · December 01, 2015, 03:41:41 PM

Thank you Brian!

Ok, so that setup is completely different than the air assist system on the 4106. Where, exactly, is the air diverter valve in that diagram? Is it near the pedal or the transmission?

I'll post a picture of the linkage tom'w night when I'm close to the bus.

Thanks again, Brian. I really appreciate it!

Mark

bevans6 · December 01, 2015, 10:36:09 PM

There is no air diverter valve, or air valve of any kind. The cylinder is always under system air pressure. It always presses outward at full power. When it is in line with the clutch arm, there is no assisting force vector. When the clutch arm tilts upward as the clutch pedal is pressed, the force helps press the clutch arm upwards with a force of SIN times angle times total cylinder force, or some trigonometric thing like that. This is the setup on my 5C, I don't know if earlier MC-5's were different. I don't see how you would make that work on a GM unless there is a clutch arm you could mount the cylinder to in a similar manner. It's a 2" ID cylinder so it develops between around 300 and 375 lbs of force at normal air system pressure. It's no miracle assist, my leg still aches after parking the bus.

Brian

luvrbus · December 02, 2015, 12:36:16 AM

Mark,the one I sent you is from a Eagle it's about the same but uses a lot less linkage,ask the guys here for a drawing on a 05 Eagle it is a simple install and works.Sorry but I gave my Eagle manual to someone so no help from me

OneLapper · December 02, 2015, 01:19:33 PM

Quote from: luvrbus on December 02, 2015, 12:36:16 AM
Mark,the one I sent you is from a Eagle it's about the same but uses a lot less linkage,ask the guys here for a drawing on a 05 Eagle it is a simple install and works.Sorry but I gave my Eagle manual to someone so no help from me

Ah! Thanks! I had the number right, just the wrong bus....

I'll try a new thread.

Thanks

OneLapper · December 02, 2015, 01:20:56 PM

Quote from: bevans6 on December 01, 2015, 10:36:09 PM
There is no air diverter valve, or air valve of any kind. The cylinder is always under system air pressure. It always presses outward at full power. When it is in line with the clutch arm, there is no assisting force vector. When the clutch arm tilts upward as the clutch pedal is pressed, the force helps press the clutch arm upwards with a force of SIN times angle times total cylinder force, or some trigonometric thing like that. This is the setup on my 5C, I don't know if earlier MC-5's were different. I don't see how you would make that work on a GM unless there is a clutch arm you could mount the cylinder to in a similar manner. It's a 2" ID cylinder so it develops between around 300 and 375 lbs of force at normal air system pressure. It's no miracle assist, my leg still aches after parking the bus.

Brian

And thank you for taking the time to post a diagram and write a lengthy repair, Brian! I really appreciate it.

RJ · December 02, 2015, 03:40:42 PM

Mark -

Do you not have a "mousetrap" on your clutch linkage?

RJ