front vibration

[mwf]

Hi guys,
back with another question.
I took the bus out for a test run today, being that I need to take it to Tampa next Friday.  I have not used the bus since June 10th.
All seemed good 'till I got about 50 mph.  I then got a real bad vibration.  Slowed down, pulled into a lot and looked things over.  All tires seemed OK (I had checked the pressures all 8 were 100, during pre-trip), little more wear on the outside of the passenger side steer.  Took back on the road, did not get a lot of vibration.  I took on interstate and got just a little around 68 mph.

Any ideas....

[Cary and Don]

I could be real wrong on this, but our bus will do the same thing if it sets a long time.  The wheels get flat on the bottom, and until they warm up, it will vibrate. More like a thumping actually.

Don and Cary
GMC4107
Neoplan AN340

[letz4wheel]

I would tend to agree with Cary...you had square tires. What you should see is that the vibrations lesson as they warm up. When I really notice the vibration gone is when I warm the tires up then stop for a bit...the heat soak does them good!
Doug

[mwf]

Update:
One of the front tires was cupped bad.  Both the steering tires were 10 years old.  I put two new ones on.  Cost was $460.00 each.  Also had a take off put on one of the tags (other tag replaced last spring), also had a tear off put on the spare.  Lanning tire in Sarasota really treated me well.  Total bill was 1,200.00.  That was four all four tires, stems mounting and disposal fee's and tax.
Got back to the school to find out one of the headlights burned out, and one marker light out.  Replaced them, only to find that the marker wiring was all rotten and had to replace the whole fixture.  Good thing I got some Fred last spring  

Next up, try to find out why I leak so much oil.  Oh the joys never end.

Then maybe find some more time to teach my class and coach the team

Thanks for all the advice I get on this board!

[JohnEd]

mwf,

The cupping would concern me.  $460 each, now.  Isn't that incentive?  Did you get one of the air/over/hydraulic 12 ton jacks at Harbor Freight?  You NEED one.  I recently read a smattering of steps to follow to make certain ALL your front end components are OK.  Sounded interesting...to me at least.  You may interest some young mech that would be interested in working on you bus for cheap just out of curiosity.  If he isn't qualified then it is up to you to monitor all the testing but use his muscle and braun.  Not suggesting you rip anyone off...please hear me on that.  Symbiotic?

Good luck, 

John