OK - my last post was clutch got really easy to operate. I made the adjustment to the travel adjustment wheel and it was normal for the next few days.
We left Utah and headed for vegas. everything was normal then downshifting to pull into camp the clutch was easy again. I parked, dumped, filled water. Went to leave and experienced the following.
-Clutch is really easy to depress, transmission doesnt slow down enough for me to shift into gear
-Checked the adjustment and it was right (one clockwise turn to "tight")
-Let bus air down (0 psi) aired back up and same - cant shift into gear
I had everything greased before leaving WI 2 months ago by an operator running MCI 9's
Does this sound like a clutch spring issue?
Anyone know a place near Vegas to get good service?
You have a cracked/broken middle clutch disc, that does cause dragging, I would stop engine, put in gear and restart, you can shift gears without the clutch if your savey. Stop when need to get the R gear and restart.
Been there, Why I converted to the RTO910 10 speed and the truck HD Pull clutch.
That is when I found the SAE 1 bell housing andSAE 2 flywheel, and the fun began, what a mess until I got a SAE 1 bell housing for the SAE 1 flywheel, then things started making sense.
The origional MCI setup uses a push clutch, junk in my book.
Take to a bus shop that does MCI, it will cost in the $2,000.00 area, new pressure plate, new moveable disc, two new clutch discs, throw out bearing and a new clutch facing insert, labor. When done, it is still a poor clutch setup, my opinion, I am too much HD Truck setup.
Good luch
Dave
Gary Bennett at B&B Coach 702-873-4415 he can help or send you in the right direction
good lucl
Most mornings, you can find him there at 7:30 am. good luck
Since you mentioned that the pedal pressure got light at times, could be an issue with the air assist unit not pushing lever in far enough? If it continues to stay light, could be broken spring,s in pressure plate. Just other possibilities. Have you checked the clutch lever travel while someone pushes the pedal clear down? Push type clutches have been used in these coaches for years with few problems, except from excessive slippage by operator. Not saying that pull type systems aren't better.
I did observe the operation but didnt measure ill make the measurements tomorrow morning as my son opperates the clitch pedal.
If that all checks out I will be there waiting for Gary tomorrow.
Thanks guys.
Dave, where are you located now? Lvmci...
On lake mead at the Echo Bay campground. Right at the dump station. In the lake mead national recreation area.
Well...that's where the bus is. I'm stocking up on food in Vegas right now. I'll be back there in a couple hours.
Dave, do you know how to find Gary's place, B&B? Its a block behind the Palms hotel, Flamingo & Arville, lvmci...
I know where it is now thanks.
I was going to call in the morning but now I can just get over there.
I'm hoping it is (magically) drivable tomorrow morning and I can get over there without a tow.
Assuming it isn't an issue with linkage, adjustment...
Can't wait for the sun to rise and check it all out.
With pressure getting lighter, you probably broke one or more of the "fingers" that release the clutch. With those fingers broken, it is easier to push in since you're no longer pushing on the whole clutch, and it is dragging since that broken part of the clutch can no longer get released. It will not fix itself-have to tear into it. Advise having it towed over to B&B. Las Vegas Freightliner works on buses also. Good Luck, TomC
It would be a good time to change to an automatic, as cheep as they are now you could change for about the same price as replacing the clutch.
Jack
It would be possible to disconnect everything on the engine as if you were doing an engine removal, support the gearbox, slide the engine forward a foot on the cradle, gain access to the clutch to re&re it, and slide it all back together, but I wouldn't try it. The main issue is the gearbox is totally supported by hanging off the back of the engine so keeping it in place would be very hard, but you might do it with a proper transmission jack. The engine really needs to come out, then it's very easy. Don't forget to inspect/change the pilot bearing in the flywheel and the throw-out bearing - there will never be an easier time. The springs for the clutch cover are "blue" coded, I got mine from Luke when I rebuilt my clutch.
Really sorry to hear of your troubles.
Brian
Just spoke to Gary. He suggested checking the connection to the transmission at the end of the linkage.
Getting into my coveralls now
Dave, sent you a pm ;)
Hi, get of I15 south to LA, turn west on Flamingo towards Rio/Palms hotels, at end of Palms hotel is Arville stoplite, turn left, south, just past hotel is apartments on left, school district bus yard on right, then a industrial center on left, 1st entrance on left, look for Garys marroon Dodge dually, if you get to Orleans hotel at Tropicana you've gone to far, if you need it, Gary may have used tranmissions available, sometimes he does, tom, lvmci...
I heard a big air leak while under the bus. It's coming from the rear end of the clutch air assist cylinder. There is a petcock supplying the cylinder. Wih it off the air leak stops.
I'm taking off the cylinder, inspecting and bringing it to Gary.
It's the same cylinder as the original belt tightener cylinder on the old OTR A/C compressor if you still have that. Parts to rebuild the cylinders are available (I carry a spare set aboard) and Luke has them. Good Luck
NCbob
The air cylinder is a 2" diameter single action cylinder, and can be easily rebuilt by changing the O-rings. There is a sponge inside that is soaked in oil, to keep it lubricated. It has two rod end joints, mine where totally seized but they are common 1/2" rod ends. The petcock is there so if the cylinder leaks you have the option of shutting off air to it - I just removed mine, because it had failed, and direct-connected the supply to the air cylinder.
There, I feel better now that I managed to get that off my chest!
Brian
I checked the tensioner for the old compressor, it didnt have similar Orings. Ordered the rebuild kit for delivery Monday. The tech on the phone mentioned the rebuild kit is also for the air cylinder that locks the front door shut. Mine is disabled, tonight I will disassemble and see.
It is leaking due to the wear in the Oring. It is shaped more like a D (wore flat against the piston).
Many thanks to Gary at B&B coachworks for helping me out
How does a leaking clutch assist cylinder make the clutch easier to operate.
Tony-It shouldn't it should make it harder. If it works it should be easier. I think it started working (maybe it was seized up or slow leak)
The problem-
--bus can't move, can't get into gear
--when I press the clutch pedal the transmission doesn't slow down to allow me to shift into 1st
History
--I don't think air assist Was working when I got the bus (a year ago). My first bus ...I thought it was just really hard and that's how it is.
--last 3500 miles clutch was hard to press
--gassed up (bus was warmed up) and I SLAMED the clutch down because I was expecting it to be hard to press
--clutch worked but was easy to operate
--I adjusted the free play dial as there was a lot of free travel and it was nice and easy to shift (bonus)
--I drove about 15 miles from camp to the dump station and noticed the clutch kind of bumped and I pressed and released it
--I did my business at the dump station, started bus and can't get into gear
Notes
--it didnt have a noticeable air leak here before
--it still won't go into gear with air shutoff to the cylinder
--it is possible that I am fixing an unrelated issue (proper air assist may not get me rolling)
--It seems to be an issue with the distance of travel
--I checked the connection at the transmission and the clutch seemed good and tight
Thanks all for being so helpfully and responsive.
Dave -
Just because you cannot put the coach into gear with the engine running doesn't mean you cannot drive the thing.
That's what every friggin' 4905 driver had to deal with, due to GM's use of a wet clutch.
As long as you've got a straight shot in front of you, simply shut off the engine, put it in gear and restart the beast with the clutch in.
You may bump along a bit until the engine's fully running, but at least you're no longer stranded.
You should be able to upshift w/o using the clutch, just the throttle.
Simply pop it out of gear as you roll to a stop, then repeat the process when it's time to get rolling again.
OTOH, enjoy the view where you're staying until the parts come in. . .
FWIW & HTH. . .
;)
What view RJ I bet he is shocked they call that area the Lake Mead Rec Area he won't be looking out over the lake lol
Cant see much of the lake but it is a good view. I mean nothing bad of "stranded".
Btw-bus is pointed uphill and wont roll starting it in first. If i needed to i could probably roll it backwards down the hill and turn it around. Ill excersize my patience.
Probably not waiting on parts to find out if this air cylinder repair gets me going. Im pulling an "ok" Oring from the door claw and will put a heavy oil in there to get a seal and see if this gets her going.
From a "whats changed" troubleshooting perspective its logical that thia may work. When i look at the diagram and think about the symptoms I worry that thia air cylinder issue isnt the end of it.
Stranded in good weather with the people I love...not a bad gig
Adjust the linkage so there is no free play and try again. hold the clutch down for a minute, the input shaft brake may not be working. if it works slowly adjust so you get some freeplay back.
cheers Gerry
That setup doesn't have an input shaft brake, unfortunately. It's a very simple clutch, just a mechanical lever on the outside of the bellhousing, two fingers hold the throw-out bearing which presses the fingers. The cover plate has about 25 1" diameter springs maybe 2" tall, there is a plate - disc - floating plate - disc - flywheel. The fingers ride in adjustable trunnions.
Brian
Still feel it is a broken center disc plate draging, had same experience on my MCI7, was able to put in gear, start engine, use clutch to get moving (draging heavy) and shift w/o clutch. Also, the big MCI shop used a carriage w/wheels that rolled on the frame rails to move transmission back, look for rails inside on bottom of frame rails.
Agree, good time for a 740.
Good luck
Dave
I can't see how the assist cylinder is going to help in this situation. On my MC 7, near as I can tell, the assist is only there to make the pedal easier to push in. It does not make any difference to what is going on inside the bell housing.
Sounds more like your not getting enough travel somewhere. Broken fingers, worn out throw out bearing, clutch center broken out, etc.
Time will tell. Hard to say if driving it would cause any more damage. Just depends on what's broken.
John M.
If i go with a 740 ill probably have to get jakes too for coming down the hills...right?
I went to put the air assist cylinder back in this morning.
Easier to get out than in. Pickjng up a ja k and stands / blocks now.
I worked the clutch more to see if i could find slippage.
The bus wasnt running or aired up and the clutch pedal was real easy to operate (without air assist as its disconnected). Does this support the broken disk idea? What provides the resistance i usually feel?
It's pretty much impossible to check by yourself. You need someone operating the clutch pedal while you look at whats happening in the back.
I am not an expert on this, and my only experience is with something similar happening my Spicer. However, the difference was that I could get it into first and shifted without the clutch from there on. I found shifting without the clutch a pleasure compared to double clutching. If you have a tach, it is very easy to do; actually easier than shifting with the clutch. On mine, there was no getting around the fact that the clutch needed to be rebuilt, and since it is a 5a, the engine had to come out. After all the research, we did replace it with an Allison. It came to more than a clutch rebuild but was certainly worth doing. It changes the whole experience.
We did install Jakes at the same time, which is certainly also a wonderful thing, but it is not essential. You can and will downshift your Allison quite a bit anyway to stay at the rpm's you want. Yes, it will shift automatically, but you can do it better. Again, if the engine is coming out, that is a good time to put the Jakes on. It will be a lot easier on the ground. It is also a good time to go through a bunch of other engine stuff like injector size, advance timing, hoses, etc. This all ups the price, but will save you in the long run.
I hope you find an easy fix but have my doubts.
Dave, despite all that has happened I hope you were able to enjoy a little of the thanksgiving day, happy thanksgiving to you & yours, tom, lvmci...
Another small note, IF considering the 740, you will face an issue with the flywheel SAE2 size and Bell Housing SAE1 size, would make sure who ever does the changeout, fully understands what the situation is, I am sure they have a torque converter disc plate for the SAE2 flywheel bolt up and a SAE1 for bell housing, burt I found a .5 to .625 slacer needed to space the trans back. What a cluster f%@k, it all worked out in the end.
If I faced that again, I would change the bell housing to work with the SAE 1 flywheel, then all goes smooth.
Just saying, be ware.
Dave
Quote--bus can't move, can't get into gear
--when I press the clutch pedal the transmission doesn't slow down to allow me to shift into 1st
I guess you know that this rotating gears issue is pretty much standard in a lot of our buses and the only way to get it into gear is to depress the clutch and force the gears to stop by forcing it into gear. Lots of noise but doesn't seem to do any harm. Some get around it by forcing it into second first to get the gearbox to stop rotating and then changing into first. Seems to vary with oil temperature and is often worse when you start off in the morning.
Have you tried putting it into first gear with the engine stopped. Fully depress the clutch and start the engine.
If the clutch is faulty and is genuinely not disengaging, the bus will want to move off, but if it is just the normal rotating gearbox problem, the bus will sit there until you want to move off.
Some have such problems with the gearbox continuing to rotate that they resort to slipping it into first just before coming to a stop but of course that gets a bit trying on the old knees if you have to sit there for minutes waiting for the traffic to clear.
I was able to move the bus!
I rolled it backwards and around a corner to point the nose downhill.
Got it eolling forward and slipped it into first then shifted without the clutch. Worked great as there were no stops.
I used to do exactly what you say Tony...slip into 1st as i approach a stop and hokd that clutch down (i have young knees).
i will try starting it with the clutch down and in 1st next time.
for now were happilly broke down and having a good time.
Hi Dave, howzit goin? Are you in a safe harbor? Did you figure out what's wrong? Had dead batteries last night, was supposed to bring the Italian Greyhound down to LA today, will check water level on the 2 yearold batteries, have to go to Alaska wed, don't want to be on I15 Sunday. Maybe the planets are aligning up early and they're sapping all the energy from the old girls already! Lvmci...
Hi Dave, I hope all is well, did some maintainence on the 8D batteries, water down low after almost 2 years in the desert, should have known, the gods are just remindng me to do maintainence, fired right up, off to LA, backb tonite, lvmci...
Cool, glad thay got you going. Your welcome to come hang with us when you get back. Were between Government wash and the road to Boxcar cove.
Im gping to call Gary to arrange things for the week. May be staying at RV villagr where Tony is.
Right now im pretty sure it is a clutch issue and i happen to knoe where a scrap mc7 is in AZ. Im calling them to see if it has the same clutch transmission setup.
FWIW the clutch is the easy part, I got all the parts I needed to rebuild mine from Luke pretty much overnight. While having a press to take it apart is nice, you don't need one, you can do it with bolts to relieve the spring pressure and pull it together again. Or about any truck transmission shop should be able to rebuild it for you in about a day. The hard part is getting to the clutch in the first place...
Brian
Hi Dave, got to I15, from Jean to Primm (stateline) about 25 miles, stop & go bumper to bumper, came back home will wait for Monday, looked to be the same all the way up thru mt. Pass, lvmci...