| Author |
Message |
T. (Bluegrass)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 7:44 am: | |
I have a vibration In my MCI-7, It starts about 65 MPH and goes up to about 82 MPH.
Can someone tell me what might be causing this vibration. I have changed the Tires and wheels thanking that might be the problem but It Is not.
Thanks
Tony |
Stan
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 8:17 am: | |
My next check would be the entire driveline. Have the driveshaft checked on a dynamic balancer and also check for wear in the U-joint yokes. Tell the balance shop about the vibration and the speed so they know where to check. The bearing cups have to be a snug fit in the yoke.
I went through this problem and had the driveshaft out twice before I replaced the yoke and cross on both the transmission and differential. My vibration only occured between 65 and 72 MPH (right where I wanted to drive). |
TWO DOGS
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 8:41 am: | |
flywheel bolts ??? |
John that newguy
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 9:16 am: | |
Not at RPM, but at speed?
Why don't you have a friend drive alongside, behind, and around
your bus as you cruise down the highway with it vibrating? It'd
be cheaper to do that, than spend $$$ for a "technician" to
try to figure it out. It could be an out of alignment tag... a defective
tire... Some kid on the roof.... |
dOUG wOTRING
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 11:14 am: | |
tIRES OUT OF ROUND |
Richard Bowyer (Drivingmisslazy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 11:34 am: | |
You say you changed the tires and wheels. Did you have them checked for balance. I had a bogie tire cause this same problem on my Eagle. After having it balanced, the problem went away. I then had all wheels balanced and it did improve the ride quality.
Richard |
Doug Wotring
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 11:58 am: | |
A ballance wheel/tire does not mean it is round........tire may need to be trued. most tires are not round |
Richard Bowyer (Drivingmisslazy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 12:41 pm: | |
Yes, and many have flat spots where it has skidded.
Richard |
T. (Bluegrass)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 2:53 pm: | |
Richard
I put all new Tires and wheels on the coach to try and get away from this, when I grease the Drive shaft ( U Joints ) It don't seem to be as bad as It was. what have you guys done with the lights on trailers that are 12 Volt and the lights on the coach are 24 Volts. I know that you run them through Relays but with the running lights on one and the brake lights on one and the turn signels are on one, seems like a lot of confuesion.
Tony |
TWO DOGS
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 3:13 pm: | |
sounds like you need new u-joints if greaseing will temp. fix it... |
TWO DOGS
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 3:19 pm: | |
get magnetic mount taillights ,use 24 volt bulbs..stick them on whatever toad you are pulling |
John that newguy
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 4:04 pm: | |
put a 12v bulb in series with whatever 24v bulb circuit you want to light.
And whazzamatta with a friend doing a visual inspection of the bus as it's rolling?
(man, the way we complicate things) |
pete hyser (4501pete)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 4:32 pm: | |
i have a shudder at those speeds until about 67 or 68 then it evens out..i think like all my trucks that there is a spot where its just going to shudder..then even out..anything more drastic..then you would feel it in some way at lower speeds..but im used to it now
pete |
Doug Wotring
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 4:57 pm: | |
it is a oout of roound tire.
get them trued ( on the wheel) |
T. (Bluegrass)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 6:45 pm: | |
Hey Guys
I am going to try all the things that has been put on this board as soon as I get It out of the snow bank probably this weekend, I will get the Eagle out of the shop and go get Fuel In the MCI, we just got back from Branson MO. and all the snow fell on us I guess I should have stayed there, will be going to Florida about the 15 of Jan. hope I can get the lights figured out there Is an excellent article here. someone put this on the BNO.
( http://odyssey.smugmug.com/gallery/131040 )
I hope that It Is warm there these 10 degree nights are killing me, maybe I should go to Texas where two dogs Is but I heard that Its cold down there and I cant stand cold anymore,( he probably wouldn't let me park that MCI next to his Eagle anyway,( grin ).
Tony |
TWO DOGS
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 7:21 pm: | |
It was 78 degrees today...almost had to turn on the A/C ...but,the fan pulled me thru...bring that MCI on down.... |
DAVID HEAD (Chuck)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, December 28, 2004 - 7:45 pm: | |
MORE THAN LIKELY THE U JOINTS.THE PROBLEM USUALLY HAPPENS ABOUT THAT SPEED;USUALLY HARD TO DETECT AT WHAT END OF THE SHAFT THEY ARE GONE BUT BETTER OFF CHANGING THEM ALL WHILE YOUR AT IT . BETTER TO DO IT SOMEWHERE THAT YOU KNOW THE MECHANIC THAN SOME GUY BETWEEN YOUR PLACE AND FLORIDA . |
Ben Miller
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, December 29, 2004 - 5:50 pm: | |
I just had the same problem on my way home from Alaska in august last 200 miles. When I got home I got under the bus and could not find anything, so I removed a couple of caps from the u-joint and sure enough one of them was worn pretty bad. Took the whole thing and replaced both u-joints. Problem fixed. Ben |
T. (Bluegrass)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, December 29, 2004 - 6:47 pm: | |
Les
I am sorry I deleted your email, this Is the place that I ordered the Relays and sockets from.
Tony
http://web5.automationdirect.com/adc/Shopping/Catalog/Relays_-z-_Timers/15A_Electro-Mechan ical_Cube_Relays
782-2C-24D - RELAY24VDC 2PDT 15A -- 4 shipped.
782-2C-SKT - RELAY SOCKET 782/AD-70S2 -- 4 shipped |
Phil Dumpster
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 31, 2004 - 1:59 am: | |
If the vibration is constant at a certain speed range and does not change with throttle position, then your U joints aren't the cause of the problem.
Out of round tires and out of balance wheels will cause a vibration at much lower speeds, and the frequency of the vibration will increase with speed, but it won't go away.
Carefully inspect all of the bushings and ball joints (tie rod ends, kingpins, suspension bushings) in the front end. You will most likely find a worn pivoting joint which is allowing the toe of the front wheels to be altered from spec. As the toe varies, other aspects of the front end geometry will come into play to counteract and correct the anomaly, resulting in oscillation. From outside the coach, it will appear as one or both front wheels "wiggling" on their steering axis.
If all of this sounds like a foreign language to you, then get yourself and your bus to a good truck shop that specializes in front end alignment. Tell them what the problem is and they'll know where to look. |
T. (Bluegrass)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 31, 2004 - 6:35 am: | |
Phil
I don't guess that the front end Is out very much as I just took off some Tires that had 90,000 miles on them and they still looked like I just put them on the Coach I have inspected all of the bushings and ball joints tie rod ends, kingpins, suspension bushings on the front end and the bushings on the rear. and as of yet I have not found anything, I thought I checked the u-joints but I didn't dig deep enough I don't guess, but the vibration Is definitely coming from the rear end and It don't do It until I get up to about 65 MPH to about 80 MPH then I will say It as someone did on this board (It Is In the range that I really like to drive in ) so I will do what two dogs, David, and Ben suggested and pull some caps off the u-joints and see If I can find anything wrong. If not I will see If there Is a tire out of Balance and or out of round.
Many thanks Guys
Tony |
TWO DOGS
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 31, 2004 - 7:22 am: | |
BET...it's the u-joints |
Stan
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 31, 2004 - 8:18 am: | |
As I pointed out in my first post, when you check the U-joints make sure that the yoke is not worn where the bearing cup is seated. |
John that newguy
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 31, 2004 - 8:46 am: | |
The max rpm of the drive shaft at 80 mph, is the same as the
max rpm in a lower gear and consequential speed. Why is he
feeling vibration at X speed, rather than X rpm range, if it's
the drive shaft?
I've had out of true, out of balance tires bring forth vibration at
certain speed ranges. Hell, I think we all have had that experience.
(One of our cars had a vibration only between 50-60 mph due
to a defective tire.)
But at that high speed in a vehicle that's causing that much wind
disturbance, the vibration may be due to aerodynamic problems,
and not due to drive train deficiencies. It's not a "stock bus" anymore,
but one adorned with a bunch of stuff on it's exterior. An awning
wobbling at 70 mph will shake the entire vehicle.
And again, someone driving behind and alongside should be able
to determine at a glance, the nature of the vibration. |
Richard Bowyer (Drivingmisslazy)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 31, 2004 - 8:54 am: | |
I had exact same problem and it was a bogie tire with a flat spot on it.
Richard |
Philris
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 31, 2004 - 9:27 am: | |
JTNG,
The drive shaft speed is related to road speed, not engine RPM or transmission gear. The only time that is not true is if the bus has a two speed axle. |
Gary McFarland (Gearheadgary)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 31, 2004 - 9:51 am: | |
Tony, does the vibration ease up if you ease up on the throttle?
Gary |
John that newguy
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 31, 2004 - 1:46 pm: | |
Philris-
Aaaaaackkk.... where was my head...?
Yeah.. could be the shaft. Anything's possible. But in absence
of a clunk and vibration at any other speed? Tires or some
other aerodynamic problem would be my consideration. |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Friday, December 31, 2004 - 10:08 pm: | |
We've had a similar shaking around those speeds and I recently discovered one adjustment anchor on the engine was missing its pin and the wishbone at its after end has between 1/8" and 1/4" clearance in the hangers. It looks as though the bolts were never tightened down enough.
When I get a chance this next trip, I expect I will be doing something about those items, and if I remember it, I will post the results here.
For what it's worth.
Tom Caffrey PD4106-2576
Suncatcher |
T. (Bluegrass)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 01, 2005 - 3:13 pm: | |
Gary
It does ease up when I get down below about 68 and when I am at 65 It completely goes away.
Tony |
Gary McFarland (Gearheadgary)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 01, 2005 - 4:17 pm: | |
But if you are loading the driveline, having the vibration and you lift on the throttle, unloading the driveline, does the noise instantly go away? This is one indication of a driveline problem, at least in my experience.
Gary |
T. (Bluegrass)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Saturday, January 01, 2005 - 7:56 pm: | |
Thanks Gary
I will try that monday and see If unloading the driveline does that. |
Jim-Bob (Pd41044039)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, January 05, 2005 - 11:18 pm: | |
I recently had a wheel balance problem that might apply. I had a front wheel out of balance which I couldn't solve even with a new, balanced tire.
While working on the bus I noticed that the front wheel was far enough out of balance that when I jacked up the wheel, it would rotate back to the same point all the time.
Turns out that there are balanced & non balanced brake drums available. The guy at the truck brake & wheel co scoffed & said it didn't make any difference.
Well, I insisted on "wasting" $10 each extra for balancing on new front drums. Sure enough, the new ones had big chunks of steel bar welded on the O.D..
I put 'em on & couldn't get the wheel to rotate around at all. Went on a trip & Voila!, no more wheel bounce. (Used to be at about 60 & over.)
If I were you, I'd lift up the front wheels & check for them turning on their own from any position.
Jim-Bob |
Marc Bourget
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 06, 2005 - 2:53 am: | |
Jim-Bob,
Previous posts related that there are 3 "levels" of drums, Premium, So-so and Junk.
There are actually technical names for the grades but I forget.
The big criticism of "junk" was the balance issue.
Onward and Upward
Marc Bourget |
Jim-Bob (Pd41044039)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Thursday, January 06, 2005 - 3:31 pm: | |
Well I have only recently become aquainted with two. I found it fascinating that the "Expert", (the 25 year guy at the spring & brake shop) didn't think there WERE balanced drums, and when he found them in the catalog, insisted that "over 50MPH it didn't make any difference"!
Moral of the Story: Use your own brain, the "experts" are sometimes wrong.
Most of the non wear problems on my buses were CREATED by "professional" mechanics. |