Shock Absorbers

[VanTare]

Gerald I have never used the Road King shock but have saw the prices at the RV stores and will not be buying any soon 

David

[belfert]

How many years and/or miles does a typical bus shock last?

I asked about the shocks when I had my brakes and everything else done and was told the shocks were still good 12,000 miles ago.  I would be very surprised if the previous owner replaced the shocks as they neglected the brakes and most everything else.

[JohnEd]

Lin,

Talking to Luke is a superb idea.

Tokico is a really good shock.  Japans best, I think.

Belfert,

Do the speed bump test at low speeds.  It shouldn't bounce more than 2 cycles and coming off the bump it shouldn't hit bottom.  Start at a very slow speed cause if they are worn it will be a hammering experience.  With fresh Koni's or equal it will seem controlled and not like you might break something.

John

[JohnEd]

Lin,

With the buses weight on the tires AND the thing blocked so it won't kill you....do the following.

Have it started and get a buddy in the drive seat.  Go under and look at all the steering stuff while Bud rocks the wheel back and forth.  Steering box and it's mount should be rock solid without any movement whatsoever.  If the ball joints are not apparently moving between the halves, wrap your hand around the joint covering the gap and see if you can "sense" any slop.  It is going to be moving around a little but there should NOT be any relative movement between the top half and the bottom.  These things need to be "solid" or you get a lot of behaviors that make driving a chore.  This won't check bushings but they can be checked by apearance.  Jack up a corner and slide the very end of a 2X4 under the tire.  Lift on the wood and you should NOT hear or feel any clunking....loose bearing.

If it is all tight as far as you can tell, install the integrated power steer.  Then get it aligned and inspected by a shop.  With new shocks at that point you should be set for life as far as this part goes.

It should go down the road like it was in a groove and when cornering you should have to "set" the wheel once and have it carry thru the curve/offramp.

Let us know what you discover,

John

[steve5B]

     After reading all of these post about the shocks absorbers I know one way they use to test them at Flying J (service centers)

     they would use an infared gun to see what the difference of the heat coming from each one.   Has anyone tried this?

     Also the ones on buses the same on trucks?


   Steve 5B.......

[JohnEd]

Shocks expend energy as "heat" and a proper shock will generate a lot of heat on a rough road.  All the shocks in the front should be the same temp and the same for the rear.  Fly in this ointment is that quality shocks will fail at the same rate and will fail gracefully.  There will be no difference in their temps even at the end of their useful life.  If there is, your cool one is shot but they should all probably be changed.  who would ever change just one?

2 cents,

John

[Lin]

I live on a mile long dirt road.  Maybe I will go up and down it to give the shocks a workout and see if there is any temp difference.  I normally drive my car at about 30 mph or so on that road.  I only drive the bus at 15 or less or it gets very bumpy.

[Airbag]

Lin
I have had my MC-5A on the dirt a few times and the dust the cooling fans produce is amazing. I think the trick is to keep RPM low?

[Lin]

Airbag,

I leave a huge trail of dust, but it is from the exhaust kicking it up.  If I rev the engine here, the exhaust will dig a hole.  It's not really a dirt road, it's packed sand.

[Sojourner]

To test shock absorber reaction on large heavy vehicle...either both front or rear drive wheel go squarely over speed bump at 5 mph or less. If it bounces more than 1 1/2 times you need to take a closer look at the shocks. However one side may try to rebound more than opposite side. Jack up & safety block to check tire tread completely around the tire and from inside to outside.  Cupping or unusual wear in any area indicates the shocks may not be holding the tires on the road.  Look for broken mounts, damaged bushings, and oil on the shock absorber barrel. If all appearance is good but more than 1 ½ times rebound...too weak or internal leaking valve or dry.

If your bus has tag wheel...you need to raise and chain up so that it isolate from front & rear dual reaction test.

If tag wheel bounce while partial or full brake locking...leaking or bad check valve or worn rubber grommet...replace shock with new rubber.

The bottom-line to test any shock absorber...you need drive 5 mph or less over speed bump of 3 to 4 inch and no more than one bump at a time to see the result. If you can rebound the bus by hands like we do on cars, the power to you.

Sojourn for Christ, Gerald

[Sojourner]

     After reading all of these post about the shocks absorbers I know one way they use to test them at Flying J (service centers)

     they would use an infared gun to see what the difference of the heat coming from each one.   Has anyone tried this?

     Also the ones on buses the same on trucks?
   Steve 5B.......

Good shock will produce heat after and after several reactions. It only a partial of the shock test and selling point to sell shocks to a confuse customers.

Buses shock ratings are not the same as truck unless the mass of that portion is the same weight, axle load rating and suspension travel distance.


Sojourn for Christ, Gerald

[JohnEd]

Lin,

I think you have proved that you bus shocks are bad.  I don't think there should be that much disparity in the speeds down the road.  The difference in the performance of the vehicle between good and bad shocks is profound.  Stated here it was "you could really tell the difference right away".  Replace your shocks with the very best you can afford.  #1 Koni and #2 Gabriels.  Do Sojourner's, Gerald's test.

John

[Lin]

I spoke to Master Luke today and wanted to pass on the conversation.  He said they have always used Gabriel shocks and found them adequate.  He did not put down Koni, but said that they could not justify the cost.  I checked the price and it was close to $200. each.  At six shocks, I probably would not take that plunge.  I also asked about symptoms of radial arm bushing failure.  He said to look for areas that have been cleaned by rubbing.  When I mentioned that a couple of mine were cracked, he said that can happen even when you first put them on due to the pressure.  Looking for signs of wear and rubbing seems to be the test.

[OneLapper]

Lin, did Luke give you a price on shocks he can sell you?  I bought shocks from US Coach not long ago and I think they were only $100 each.  Maybe expensive?  He had them in stock and I had them the next day, and it took only a few hours to install.  The ride difference was night and day!  I don't, however, have a clue as to what brand they were.

Mark

[Lin]

Mark,

I did not ask him for a price since I am not done with my research.  He said that he uses Gabriel and did so even when they were running buses.  I guess it is a good chance that that is what you got.