I am on the road having an issue throwing fan belts. I have a 1967 MCI 5a with an 8v71 with a spring loaded pulley which is making a gravely noise. I do not think it is the bearings as the seem good and everything seems to rotate quietly with belt off. I will see if I can post a photo of the pulley it does not seem to be separating evenly while the belt is spinning which I believe it should. I am not familiar with this type of pulley system so any advice would be appreciated. I am currently at a rest area west of FT Stockton Texas.
Does your MCI still have the air belt tension intact if so make sure the handle is in the right postion my 8 would throw the belt when that happen.
There are several large tractor and supply places in Ft Stockton if you need parts the Napa store is a outlet for bearing.
I know the rest area I stop there take a nap and use their free WIFI
good luck
not sure if it ever had a air tensioner or not but, I have attached the instruction from the fan bay. Which I have done several times today I might add. At least it was not too hot and I should count my blessings.
Jamie, redo your heading to include MCI 5 and the guys that own the 5 will be all over it like white on rice.
good luck
Thank you I will luvrbus.
Jamie, have you checked the bolts in pulley coming off the engine it may be loose.
good luck
Removed
He has the early style tensioner( No air cylinder) Try spraying penetrating oil into the spring/pulley mechanism. it could be frozen and not allowing the pulley to open evenly.
I haven't ever had problems with mine, but i was told that the spring is what usually breaks on these. From what i have heard they are near impossible to find, so most people go to a solid pulley as a replacement. Good luck with this and let us know what happens.
Thank you again luvrbus I have checked the bolts on the crank pulley and they look fine and are tight. Thanks Now Just Dallas I just checked all allen screws in front and on the back and they are tight as well. Thanks James77MCI8 I will try the penetrating fluid as a side note I just left the Corpus Christi area I was parked by the Gulf. While I was there my AC fan quit working and the fix was to apply some penetrating oil. Gotta luv that salt air.I am attaching a photo of the pulley assembly from the parts manual, hope that alright.
I have heard the same thing Ed Hackenbruch I have examined the spring and can not find a break. I have lubricated the pulley assembly James77MCI8 but it appears to be lifting uneven which is producing a lager space at the top and a smaller at the bottum. If some one has one of these is it supposed to be even all around? I will try to see if I can capture that via photo.
I wish you were closer to Abilene, I would try to help you out. Even though I'm not much of an MCI guy, two heads are better than one.
Good Luck and hope you are able to get back on the road.
Paul
About the only other thing i can suggest is that it might be the bushing coming apart, no. 4 in the picture. Try taking the belt off and grab the pulley and see if it has any front to back play while you turn it. Could be the reason you are hearing a gravelly noise. Or it could be the insert drive segments falling apart. no. 3 in the pics. You will probably have to take it apart to see.
Ed Hackenbruch thanks for the reply the penetrating oil that Thanks James77MCI8 suggested seem to have done it. I have been on the road for about 80 miles to the next rest stop on it is running OK I still heard the gravely sound but it is not as bad I am not sure it is the only issue When I get home I will disassemble and see if I can determain the issue.
Oh and Dreamscape I am from San Antonio, TX originally and I must say I do know how far it is to Abilene, thanks for the offer hopfully we are good now.
I was having the same problem on my 5 and found that one of the rear bolts (closest to the pulley) that hold the gear box to the mounting plate was missing and the gear box seemed to be bouncing up and down throwing the belt. Replaced the bolt and worked better but then the belt would turn on its side. I figured the spring was getting weak so I removed the pulley and welded the two halves together in the bottom of the v groove. You could also bolt them together. Worked like a charm. No belt problems since. You just need to check the belt tension more often. You can also replace it with a solid pulley.
Bob, i don't suppose that you saved the spring?
Damn Yankee, I have checked all the bolts except I do not seem to have number 1 in the below diagram. The diagram is for a 1966 MCI 5 I have a 1967. are those the bolts you mentioned? I have never had them I might need to get them.
If alignment and tension are acceptable might be worth removing the belt to inspect it for damage or extreme warping, including the pulleys. Might try reinstalling the belt backwards to help prevent it from jumping. However proper tension and alignment are key.
My MCI 5a has a solid pulley bracket, most likely made by the prior owner, possibly for the same reason. I run the belt tight enough to prevent major chaffing on the tension side on the blower box "floor". Greased the pulley with high-grade synthetic to be safe.
It's possible the engine has a failed motor mount and caused enough movement to change pulley alignment/tension (?).
Good luck!
Thanks for the reply Garymci5 I will check the motor mounts, but it looks like the issue was resolved by the penetrating fluid. of course time will tell and it does seem that folks have eliminated this pulley system from their rigs and I may want to do the same.
Ed: I left the spring on just in case the welds failed.
Jamie: I never knew there was a #1 to loosen. I just adjusted it with # 2 & 3. To check the blower drive mounting bolts you need to get a flash light and look down over the top of the pulley or just reach in and feel for them (1 on each corner) and check if their tight with a socket. If your rubber mounting bushings have been oil soaked they will get very mushy over time and will need to be replaced.
Jaime, if you do change over to a solid pulley i would be interested in the old one. ;D
Ed Hackenbruch I will keep your request in mind. I am planning on arriving home tomarrow night and then I plan on tearing it down to clean and examine all the parts in the next few weeks. it is a mess in the fan bay right now lots of rubber dust from the belt when it was not riding correctly. I have also replaced the belt with a new one.
Quote from: Jaime on May 20, 2010, 01:24:28 PM
Thanks for the reply Garymci5 I will check the motor mounts, but it looks like the issue was resolved by the penetrating fluid. of course time will tell and it does seem that folks have eliminated this pulley system from their rigs and I may want to do the same.
Curious as to what was actually done with that penaltratin' fluid! Sounds like something was stuck....?
Garymci5 I don't understand it myself I looked at the way this works and it does not make a lot of sense to me that it would ever work, but it does work the pulley separates against spring pressure vs centrifugal force(gyroscopic effect) and the pressure should keep it evenly spaced and according to the book dynamically balanced. The issue I appeared to have is that the pulley was separating unevenly, so I suppose it was binding but for the life of me I do not know were. it appears that half of the pulley free floats against the pressure of the spring. if some does know I would be interested in the answer myself. it worked so well when I head out tomarrow from El Paso I will be heading to ALBQ NM instead of home as long as I have no issues on the way From I 10 to I 25