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Elite Veteran
 
Location: Victoria, BC. Canada | Wanted to share my latest triumph with getting #846's shifting issues back to spec. http://www.fmcowners.com/mbbs22/images/emoticons/cool.gif
I've owned this coach 7 yrs or so and haven't put that many miles on it ( < 500 ) and its never really seemed to shift properly, ie. I could hardly feel it shift and the kickdown has never worked.
Be it wanting to drop a gear to pass a Winnebago - an obligatory action in my view - or trying to pick up or hold speed to climb a hill, I've always had to manually downshift to find second and more revs.
Not any more.
First I have to send out special thanks to Billy Sitton for all the help and direction he provided to get me ( and my carpenter-brain ) looking in the right places to solve this.
If you open another browser and then this page from FMC Motorcoach.com: http://www.fmcmotorcoach.com/files/Parts_manual/11_Fuel_System.pdf (see: figure 11-6 on pg. 11-13 ) you'll have a handy reference to what I'm about to talk about.
Also, you can get a good enough visual of the trans shift cable assembly and trans shift lever, here: http://www.fmcmotorcoach.com/files/Parts_manual/16_Transmission.pdf (fig. 16-1)
I was going to go out and climb under the coach to take a pic of the two trans-control levers in play here, but it's pissing out real hard and that's not going to happen right now.
Based on the symptoms I had shared about the issues with my trans - the forecast was basically imminent doom for my 80,000 mile 727 - and considering I plan to roll to the Oregon Rally in a few days, I thought I'd start with a fluid & filter change. I have to say it was not nearly as challenging as I'd imagined. I warmed up the engine then used my Pela-6000 vacuum pump - these things rock! ( https://www.youtube.com/watch?v=wawzok1uzdE ) - to suck just over 3 quarts of fluid out of the trans dip-stik tube then - with all wheels still on the ground - I slid a big catchment pan under the trans pan and began loosening pan bolts. I left a bolt in each end mostly loosened off so the pan wouldn't let loose with fluid all over Terry's waiting head after gently prying the pan loose with a big screwdriver.
My little vacuum pump got all but about 1/2 pint out of the trans so there was little to deal with once it came away.
Inspection of the pan contents left me relieved there were no significant metal chunks/fragments/flecs. Only some soft granular particles that Billy thought would likely be band material (organic).
Cleaned up the pan and trans mating surface then installed the new filter - torque to 72-inch pounds - then fitted the new cork gasket to the trans pan. * here's a trick: after contemplating using some kind of 'goop' to hold the pan gasket in place so it could be bolted back on, I flashed on the idea to use the pan-bolts themselves, hand-threaded though each hole into the cork gasket aligned on the other side. Just 4 or 5 turns leaving each bolt sticking 1/4" or so out from the gasket held the gasket perfectly and made starting each bolt back in - a breeze!
Torque on the pan bolts from what I gathered was 150 in/lbs. Since my inch-pound torque wrench only went to 100, I torqued each one there, then gave em' another 1/8th turn.
Pumped about 3 1/2 quarts of fresh trans fluid back into her then flashed her up and let it run for a minute till I could kick-down the high idle and checked the fluid level; down below 'ADD' by about 1 pint or more. Threw another 1/2 pint at it then took her for a spin.
No significant improvement. Still wouldn't kick-down when I tromped the pedal to the floor and was still 'flaring' (revving up) during my manual 2-3 upshift. I was getting depressed now.
Back to the service manual, back to the Youtube video's... back to whining at Billy.
Billy stressed again the importance of double-checking for any clearance/obstruction issues with the throttle rod and lever assembly. I told him that I'd already checked it over (with my wife at the helm pounding the gas pedal like a big base-drum) and had confirmed the trans throttle-lever had full forward movement. He said - "...check again!"
So I did.
What I discovered blew me away. With the trans in 'Park' the shifter lever was running no interference with the throttle lever assembly. BUT, as soon as you put it in gear and the shift lever moved rearward it then became squarely in the path of the throttle lever; more so, as you moved the lever lower into 2nd and 1st gears.
Well I broke down and went out and took a pic to clarify things some. Second page of my album: http://www.fmcowners.com/mbbs22/photos/photo-thumbnails.asp?albumid ...
I bent the upper throttle lever on the trans upwards about 3/8" or so, enough to completely clear the lower shifter lever and PRESTO - I had full travel regardless of what gear it was in!
That done, I also discovered that the lever - with its new-found full travel - was rubbing against a nearby braided hose which had to bent up out of the way. Satisfied with the bottom end of things, I checked for any new obstructions up top around the carb and firewall and found that since I'd bent the lever on the trans upwards slightly, it caused the hollow rod to rub on a hose in front of the carb. A quick zap-strap hung it up clear and all moved freely.
The next test-drive was like a religious experience... okay, almost.
Suffice to say, now when I'm doing 50 or so I can matt the pedal and she instantly drops a gear and holds 2nd till she hits 60 then shifts back into 3rd with an audible 'chirp' from the duallies.
Okay, I made up the 'chirp' part. Just trying to get Lenny rattled.
It's like driving an entirely different machine now. I'm proud of what I was able to do with my simple carpenter-hands and brain.
In closing. There is one other adjustment in the throttle pressure rod (kickdown) assembly that needs to be confirmed. See the above link from the Group 11 Fuel system; Fig. 11-6 Pg.11-13
This adjustment involves the slotted Link (pt #13) that connects the rod to the carb. It is adjusted by loosening off the bolt (pt #8) and making sure ( with engine hot and off choke high-idle) that the pin from the carb that rides in that slot is set all the way forward in the slot with NO play anywhere between the carb or linkage and the trans lever below. After I rectified things down below I discovered that the pin in my slot was sitting about 1/4" back from the forward end of the long slot.
Note: if you want to get to what I'm referring to here quickly, go to about 6.5 mins in this cool old Chrysler video (I love these old retro tutorials).
https://www.youtube.com/watch?v=FY9WTWayCC8
Hope this helps someone someday... somewhere.
Terry
#846 | |
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Expert
Location: Cottage Grove, OR | Good post! | |
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Elite Veteran
Location: Oceanside, CA | Add that turbo charger and you may just chirp those duallies! | |
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Elite Veteran
Location: Victoria, BC. Canada | Ha-a-a-a-a-a-a! Knew I could draw you out.
The only issue I have with a turbo is when stuff more air in you also need to stuff more FUEL in which is counter productive to the power & economy equation. Maybe if a guy could keep his foot out of it mostly. Maybe... mostly?
Terry
#846 | |
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Veteran
Location: Oslo Norway | Great post. Thank you! | |
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Elite Veteran
Location: Medford, OR | That's funny you just had this experience Terry (im not really laughing)I had the same issue on 850. I think the kick down shift lever arms are suffering from SAG. Old SAG. Lol. I wasn't happy with 850's shifting, so after doing some investigative work, I found my kick down arm hitting a metal bracket on the firewall when the throttle was held wide open. I was able to "relieve" this metal bracket to allow for full forward movement of the kick down linkage. Yay fixed! Nope. Still had shifting issues I wasn't happy with. It wasn't until I was checking the fluid level in the tranny after I serviced it. After i shut off the engine, I was looking things over and I thought why not check the movement of the kick down linkage? Well, it was still in neutral (after checking tranny fluid), and the linkage would hit the park,drive shift arm!! Mystery shift issues over. I just reached down and bent the arm back up some because I'm strong like that. For the life of me I couldn't figure out 'why' that arm was bent down? I havent done any work in that immediate area? So I think they just suffer from SAG!
Dan #850 | |
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Elite Veteran
Location: Victoria, BC. Canada | Wow, sounds like you had the same issue and same resolution. This is good.
A word about trans-fluid levels in the 440': I thought I knew what the 'Full' and 'Add' marks meant, along with the 'Check with engine HOT in Neutral' advisory. I didn't really, and was having trouble verifying if I'd got it right.
During my correspondence with Mr. Sitton while he was helping me sort out my kickdown issues, I asked about the correct way to check trans fluid levels?
My problem, as it turned out, was that I didn't understand the difference between a WARM ENGINE and a HOT ENGINE. Says right on there - CHECK WITH ENGINE 'HOT'!
Bill told me to only fill the trans to, or, just below the ADD mark when it was still cool/warm because when it runs a while - way off and over the valleys yonder - it will get MUCH HOTTER and the fluid will EXPAND to the 'FULL' mark.
I've learned that my trans needs to read about 1/2 pint below the ADD mark when cold/warm to rise perfectly to the FULL mark when she's hot enough to bake-bread back there.
Terry
#846 | |
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727 Throttle presure (kickdown) rod/linkage set up