Hi all, Purchased my coach in January/08. It is a 87 102A3 with a 6v92 5 spd fuller. I have been struggling with trying to figure out this clutch. It is very hard to depress.
The seller gave me a folder full of paperwork, some of which says the engine was replaced approx. 50,000 miles ago. While the engine was out, the DD Dealer changed the cross shaft. It doesn't look like the clutch assy. itself was changed. They replaced the clutch cable. I have disconnected the cable and it seems free. The clutch seems to work normally with the exception that it is what I call "strong". I can't keep the clutch depressed at a red light without my leg starting to shake. Is this normal.
I have heard that when a clutch pressure plate gets "old" it gets harder to depress, is this true?
Thanks in advance Gerry.
Gerry,
On my MC-5 with 4 speed spicer, the pedal was very difficult to push as well. I tried adjusting the clutch and it just started to slip. Then I tried messing with the air assist and that didn't help. Then I took it to the local bus garage, C&J and they looked inside and said the fingers are way too far in which means the clutch is worn beyond adjustment.
So I pulled the engine, replaced the clutch, adjusted everything back to what the book said and put it back together. Now the clutch can be adjusted, the air assist works and my leg doesn't shake anymore.
I pondered putting an auto in it while i had the engine out, but it was a little expensive for me and there were some cooling and fabrication issues that I was not comfortable tackling. I wish I would have put an auto in it.
FWIW- Fred
Gerry,
Two weeks ago I purchased an 86 102A3 with an 8V92 and a Fuller 5 speed. At the time I was worried that I may not like the 5 speed, in fact, I would have preferred an automatic. The bus was delivered to me on 9-30 and since that time I have driven the bus approximately 45 miles, all in town. I have found pretty much the same thing, the clutch pedal is fairly hard to depress. The fellow that I bought the bus from told me that he had recently replace the clutch cable. I'm not sure my bus has an air assist? Maybe someone can explain to me how I might check for this and how it operates? This is my first bus and although I have been around hot rods and airplanes all my life I have never been subjected to the bus world.
Please let me know if you find a resolution to the stiff clutch problem as possibly I might have the same problem. Maybe this is just the way these clutches operate?
On another note, shifting the 5 speed takes a little practice also. I have no problem shifting up but I definitely have a way to go with down shifting.
Good luck and let me know what you learn.
Doug High
Vancouver, Wa.
Go to a truck wrecking yard and buy the master cylinder and slave off a truck about all of your Japanese made trucks had a hydraulic clutch and some American made have it also Have a Great Day
I have looked at mine and don't see an air assist, do they put them on all MCI's and was mine removed? I like the idea of a hydraulic clutch. Has Anyone done this? If so I would love to find out how.
Gerry
Probably have to run the bus up on blocks; then look at the clutch linkage right along side the bell housing. There is an air cylinder with a single air line attached to it oriented horizontally, front to back. It is pressurized at all times and as the clutch pedal is depressed the cylinder starts to move upward. As it moves upward, the air pressure causes the cylinder to assist the clutch action. The further the pedal is depressed, the more assist the cylinder provides. Hard to understand, but it works and its simple. The cylinder is easy to see.
Fred
Hi Fred, I have a four foot retaining wall in my back yard and I back the bus up to it. I can see the clutch assy well. There is no air cyl. does'nt even look like there was an air line there. There is a brace that has an adjustment stop attached to it. and a rather large spring that looks like it helps return the cable. I'l try to get some pictures tomorrow.
Gerry
It never hurts to grease the clutch shaft bushings and clutch fork shafts. You may have some fittings on the linkage up front also. Boat trailer wheel bearing grease stays in a long time. Its my favorite for all chassis uses.
I have driven a 102A with 8V92 and 5 speed still in commercial service that had a clutch in it that was lighter than a car. An absolute dream to shift!!! And it was over 10 years old at the time!
That is NOT the norm, most bus clutches are found to be somewhat heavier than one in a car.
That being said, it's your bus, make it behave the way you want it to!
Check the maintenance book for missing or inoperative parts. Remember, the previous owner just fooled the paid driver into driving it like that to save the money on repairing it properly, or in the misguided belief that it saves clutches, since the driver can rest their foot on the pedal between shifts without a partial release burning it out.
happy coaching!
buswarrior
Hargreaves,I know 2 people that have have converted to a hydraulic clutches on MCI's they got the parts off wrecked Prevost buses with manuals transmissions, the master cylinder and the clutch cylinder Prevost has been using the hydraulic setup for years if you need the Prevost parts # I can get it for you good luck
1) If everything is working correctly, the clutch should not be much harder to depress than a pickup truck clutch. Yep, same answers; lubrication, alignment, wear, mismatched repair parts, etc., all can make a difference. Could something have been changed?
2) My RTO 910 Roadranger was kinda hard to shift when I first got my Crown. Hard to move the lever. Boogiethecat recommended lubing all the zerts on the shift rod and it made a big difference. Only took 3 pounds of effort and about 1 inch of movement.
Fuller 5 speeds like the T905M and T1105M (a likely tranny) usually are very easy to shift. Don't know if yours employees a rod or cable. Maybe some lubrication will help. Gary's recommendation helped me greatly. Good luck. :) :) :)
The geometry of all the linkage,arms,etc must be in correct position too.
Another thing to check while you're there.
This info will be found in the maintenance manual.
Best of luck with your repair.
Gee, a maintenance manual would help quite a bit right now!! I will try to post some pictures tonight.
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Sammy , thanks very much for the info. it was great. I've come to the conclusion that the pressure plate is old and stiff. I went through all the adjustments that Sammy sent me. I get the required 1 3/4 in cable travel at the pedal and when the cable is disconnected at the trans. I get the same travel, but when I hook it all up and depress the clutch pedal I only get 1 1/4 in. travel. This is not enough travel to apply the clutch brake.
The pressure plate that is in the coach has a bolt that you depress and turn clockwise to get more freeplay, counterclockwise to decrease the freeplay. Mine seems to be stuck as When I tryed to adjust it I stripped the teeth off the adjuster, thats the kind of day I've been having LOL. There were enough teeth left to put it back together and lock it in place.
I
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Sammy , thanks very much for the info. it was great. I've come to the conclusion that the pressure plate is old and stiff. I went through all the adjustments that Sammy sent me. I get the required 1 3/4 in cable travel at the pedal and when the cable is disconnected at the trans. I get the same travel, but when I hook it all up and depress the clutch pedal I only get 1 1/4 in. travel. This is not enough travel to apply the clutch brake.
The pressure plate that is in the coach has a bolt that you depress and turn clockwise to get more freeplay, counterclockwise to decrease the freeplay. Mine seems to be stuck as When I tryed to adjust it I stripped the teeth off the adjuster, thats the kind of day I've been having LOL. There were enough teeth left to put it back together and lock it in place.