Driveline Vibration Issue Solved

[60Vette]

Folks:

I had a high frequency vibration at highway speeds that came and went depending on power settings and road conditions. I changed the u-joints and it seemed to slightly improve however it was probably wishful thinking.

I caved in and dropped it off to Freightliner. They determined the rear air bags were set 3 inches too high causing the pinion angle to be out of spec. They adjusted the valve and problem solved. A tough lesson for $600. The price reflected them pulling out the driveshaft and checking the phasing. I had re-assembled the driveshaft on a surface plate after installing the new joints so I know it was not out of phase.

But anyway, the lesson here is if you are chasing a hi-freq vibration you might want to look at your ride height.

Now as I leave for the Keys in Feb I won't be sweating that damned vibration.

2002 Freightliner XC chassis 300 HP 5.7 ISB turbo-charged

[palehorse89]

Hello, glad you fixed the problem, it is an interesting story. Thanks

[Petro]

60Vette;

Thanks for posting of finding a solution to your vibration. That is valuable information for any of us trying to deal with a vibration issue now or in the future.

Don

[Triker56]

Gaffiney adjusted my ride height for $35 a few years ago when having other work done.

[60Vette]

Originally Posted by Triker56

Gaffiney adjusted my ride height for $35 a few years ago when having other work done.

Just hurt me!

[wb7auk]

Been there and done that. Problem corrected after many attempts of get shop to
take care of the problem and ended up going down there and instructing them how
and where and how much before it was done right. Still a lot of money was stent
before I discovered they did not have a clue.

[60Vette]

Originally Posted by wb7auk

Been there and done that. Problem corrected after many attempts of get shop to
take care of the problem and ended up going down there and instructing them how
and where and how much before it was done right. Still a lot of money was stent
before I discovered they did not have a clue.

I know what you mean. I purchased the Freightliner manuals, Cummings Manual and Onan manual. I'm into the Tech manuals for $400 and learning a lot. I also downloaded the wiring schematic which by the way was designed by a mentally ill person.

It really is amazing what I have learned from owning this rig. I'm a retired aircraft mechanic so I have a rudimentary understanding of systems which seems to help.

Actually, wb7auk, I have been thoroughly impressed with my Freightliner techs (Patriot Freightliner, Westfield, MA) and amazed at their youth.

And by the way impressed with you guys on this forum who take the time to throw in your thoughts regarding various issues.

60Vette

[Craig_R]

Originally Posted by 60Vette

I know what you mean. I purchased the Freightliner manuals, Cummings Manual and Onan manual. I'm into the Tech manuals for $400 and learning a lot. I also downloaded the wiring schematic which by the way was designed by a mentally ill person.

It really is amazing what I have learned from owning this rig. I'm a retired aircraft mechanic so I have a rudimentary understanding of systems which seems to help.

Actually, wb7auk, I have been thoroughly impressed with my Freightliner techs (Patriot Freightliner, Westfield, MA) and amazed at their youth.

And by the way impressed with you guys on this forum who take the time to throw in your thoughts regarding various issues.

60Vette

My younger brother used to take his Freightliner into Patriot Frieghtliner and always had good things to say about them. I'm not sure how you feel about doing service reviews, but if you are so inclined you could do a review on Patriot Frieghtliner at RV Service Reviews. I couldn't help but notice that they are conspicuously absent form the list.

[wb7auk]

Originally Posted by 60Vette

I know what you mean. I purchased the Freightliner manuals, Cummings Manual and Onan manual. I'm into the Tech manuals for $400 and learning a lot. I also downloaded the wiring schematic which by the way was designed by a mentally ill person.

It really is amazing what I have learned from owning this rig. I'm a retired aircraft mechanic so I have a rudimentary understanding of systems which seems to help.

Actually, wb7auk, I have been thoroughly impressed with my Freightliner techs (Patriot Freightliner, Westfield, MA) and amazed at their youth.

And by the way impressed with you guys on this forum who take the time to throw in your thoughts regarding various issues.

60Vette

I was not talking about Freightliner repair but another large truck/ RV
repair shop.
My back ground in past years allows for my own repairs but due to health
issues a little limited now.
I still look for the shop that is up front and does not take advantage of
you, sadly they are few and far between.
Most operate under the mind set that almost all owners of RV's have little
or no knowledge and therefor can be told anything.

[powerboatr]

3" to high
did your coach sit high out back
mine to me is low for the long overhang but its within specs

[60Vette]

Craig_R:
Great idea. I will pass on my kudos for Patriot on that site.

Art:
Absolutely! Especially if you are on the road and they know they'll never see you again.

By the way, one of the young techs has the largest Snap-On box I have ever seen. It looks like a condo and I can't reach the top of it. I thought I heard music coming from within. I suspect he might have illegals living inside.

He had to show me his latest addition which was an inductive coil on the end of what looked like a timing light. It would heat up a rusty frozen nut so you could remove it eliminating the need for an oxy/acet torch. Worked amazingly well but can you really ever replace the torch for immediate and soaking applied heat?

Powerboater:

Yes it sat too high in the back causing an extreme angle from the back of the transmission to the pinion on the rear end. Side to side was fine and the front bags were in spec. (Can I say front bags here?)

60Vette

[wb7auk]

I have seen all sorts of reasons why someone raised the ride height from the mud
flap hits the ground to the trailer hitch is to low.
I have also see the same number of where to measure the ride height and almost
all are wrong.(One of the problems seen in a lot of shops)
The simple fact is there is a correct place and height and should never be adjusted
out of those spec's.

[Rich-n-Linda]

We have the same issue in our '06 Mandalay 40E. A light, high frequency vibration at 65mph.

I'm headed to Camp Freightliner in February. Going to have the ride height checked there, along with a few other preventive maintenance items.

[Rich-n-Linda]

A 4-wheel alignment and the correct pressure in the tires (I was running too much at 110 psi) and the driveline vibration is gone. The coach also handles better now. Tended to oversteer in the corners just a little. It doesn't do that now.