Tires and tires accessories...

[Geom]

Hey guys,

We've been shopping around for our bus for the last few months. As we close in on the bus we're about to buy, I wanted to get your thoughts on a couple of things; with more to come I'm sure...

It is a GM 4107

The tires on it are a bit long in the tooth and I want to replace them. Any advice on brand, type, etc of tires? We're not looking for "million mile" tires as we'll most likely be putting only a few thousand miles on it a year. We plan on living in it fulltime; so predictable, reliable and safe are obviously high on our list. I'm willing to consider used tires if I can understand a bit more on how to buy good ones. I will probably only do used tires on the drive tires and new for the steer. Any other advice on buying tires and having them installed? If there's a particular shop you prefer, also please share (it's in the Sacramento area).


The current owners mentioned these wheel balancer things that can be installed on the tires(wheels). After talking with the owners and reading about them online, I'm very interested in having them installed on the bus. Anyone using those now? Any experience/thoughts on them? I see two brands that seem to come up, Centramatic and Balance Masters. Any preference towards one or the other? Is so, why?

While talking with the owners they'd also mentioned a safety item that can be installed on the steer axle to "assist" in case of a steer tire blowout. Although we'll be installing new tires on it, s**t does happen and the more I can increase the time window to react to something like this the better. We're pretty new to buses and driving a vehicle this large, so we're choosing to err on the side of caution. From my understanding, this device is basically a shock absorber that dampens the initial shock/adverse steering with a steer tire blowout. It sounds simple enough. I've tried to do some research online for it and have come up rather empty handed with lots of vague info. So I'm hoping some of you folks have seen these things, preferably are using them, and have some thoughts to share. One concern I have is having another thing, possibly interfering, between turning the steering wheel and actual steering. Plus I'm not sure how this thing would respond if I actually needed to make a significant steering correction (obviously in an emergency) on purpose.


As always, thanks a lot in advance for any help or advice you can share.

Thanks
George

[akroyaleagle]

George,

Welcome to the board!

Click the word search in the blue line above, type in tires, I think it will answer your questions.

Good Luck,

[TomC]

Most buses used 12R-22.5 16ply tires. But once you're converted with all your junk inside, you probably won't need the weight carrying of the 12R-22.5. Reducing to a 11R-22.5 16ply will be a much more popular tire-even though you go from 485rpm to 497rpm-which means if your turning 1800 at 65mph, you'll be turning 1845rpm with the 11R's. Get the bus weighed by axle to find out what tire you can run. Then run that tire at the tire manufactures tire pressure to get the best ride and tire wear.
I suggest using what is called a regional tire. They are usually rated to 75mph, but have a stronger side wall and with stand scrubbing-like around town driving.
Use new tires in front-always! And used tires can be mounted on the drive axles. Unless you're anticipating going off road, or doing winter driving, all position tires can be used on the drive. They will typically get better fuel mileage then traction tires.
When I drove truck, I tried all of the tire balancing methods-Equal which is a sand like stuff installed inside the tire; balance masters use mercury as the balancing. Both these don't work worth a hoot. What I found works best-when buying a tire, have it spun balanced, then run Centramatics-which is a balancing ring that mounts behind the wheel with ball bearins in automatic transmission fluid. There's enough weight in the ball bearings to make a difference.
If you have integral power steering (in the steering box-like Sheppard) you don't need any other assistance on the steer axle. You'll be surprised how fast a bus can react to a jerked steering wheel in a emergency.
Run a name brand (non Chineve)timer and you'll be fine. Good Luck, TomC

[chessie4905]

   Just for our info....standard or automatic and manual or power steering?You could consider Bandag Recaps in steer tread on the back.

[gus]

You don't need any type of steering assist if you have either the original hyd boost steering or a Sheppard full time PS conversion.

Manual - maybe, but the manual system is geared so low that you probably don't.

This is a very, very low bus, if you change to 11:00s it will probably be another inch lower. I would stick to 12:00s.

[trucktramp]

If you keep good rubber on the steer axle, you shouldn't have to worry about blowouts, just keep an eye on the age and weather checking

[RJ]

George -

Welcome aboard!  Always willing to help a new busnut!

Besides what Chessie asked (stick or auto trans, manual or power steering), what size tires are on the coach now?

Also, if the coach has an automatic, which one?  A VS, VH or V-730?  Makes a difference.

We'll bombard you with info once you fill in the blanks, as this topic has been beaten to death over and over and over here and over on the BNO (www.busnut.com) board.

And if you really want to start a firestorm, ask about oil for the Detroit 8V71!

FWIW & HTH. . .

[Geom]

Excellent! Thanks for the great info so far guys.
Duhhh, I should've included some additional info on the steering  and trans.

It does have (full time) power steering, I think it's a Sheppard, but I'm not certain of that.
It's also an auto trans running a V730 (with lockup if that makes much difference).

The tires on it now are 12Rx22.5 and I think I'll stick with 12s. Not that I'm going to be doing a lot of off roading in this , but I think it's low enough to the ground that an inch will make a difference in some places. Would there be any particular advantage to 11s?

Thanks again all!
George

[RJ]

George -

Thanks for filling in the blanks.  Now we can give you more intelligent answers!

With power steering on a coach, don't waste your $$ on a "Steer-Safe" unit.  Those are designed for the S&S market.  Best thing to do if you have a front blow-out is to STAY OFF THE BRAKES until you gain control, then start slowing to a stop. Run new tires on the front axle, and maintain the correct air pressure to reduce the risk.  Most tire failures are from UNDER inflation, so monitor the duals, too.

This next is a little techie, so bear with:

GM designed the 35-foot coach's powertrain around tires that turned 495 revs per mile using the stock 4.125:1 rear axle ratio.

With the manual 4-spd, the bevel gear ratio is 0.808:1, which, when multiplied by the rear axle ratio of 4.125:1 gives an OVERALL rear axle ratio of 3.333:1.

With the V-730, the bevel gear ratio is 0.875:1, resulting in an OVERALL rear axle ratio of 3.609:1, approximately an 8% reduction.

Translation:  Better acceleration with the automatic, but lower top speed, more engine revs per mile and greater fuel consumption.  (Based on the 495 revs/mile OEM tire.)

Ideally, keep as close as possible to the 495 number when buying drive tires.  If you want to recapture some of that lost percentage because of the automatic, then buy tires that turn roughly 470 revs/mile.

The only tires that I've found in the 470 range are 11R24.5s, which would mean new wheels as well on your coach.  Maybe not an issue if it currently has steel wheels, but if they're aluminum, you may not want to replace them.

Your choice, but this is background info to help you make an informed decision.

FWIW & HTH. . .

[TomC]

12R-22.5=485rpm. 11R-22.5=495rpm. 11R-24.5=476rpm.
Of these three tires, the 12R will be the hardest (and probably the most expensive) of the three. Then the next hardest is the 11R-24.5. The 11R-22.5 will be the easiest to find, although most all over the road trucks are now using low profile tires. Most buses now use the metric 315/80R-22.5 (real expensive) along with most trucks in Europe. Good Luck, TomC

[Dave5Cs]

George In West Sacramento there are quit a few Commercial tire dealers just across the river from Sacramento. Goodyear Heavy Truck for one.
49er Truck Plaza is another and they have a bus wash there also!...
G & S Commercial Tires and wheels, in Roseville, CA off PFE Road.
Dave

[chessie4905]

   So, if someone had 3:70 or 3:90 ratio gears manufactured for the GM's, there could be a fair amount of interest in getting them if the price wasn't exorbitant?

[uncle ned]

Listen to RJ. 

The best thing I have done to HUGGY is to replace a set of 315 24.5 low profile with a set of 11r24.5 tires. Bought Hankook because of the price and available
and getting rid of Michelin 5 year old that I had two blowouts with. both on the inside rear.

Makes cruising down the inter-state a lot easier and the fuel mileage is noticeable better.  about 12 mpg  6 going and 6 coming back makes 12 in my book.


uncle ned

4104 with 6v92 and v730 and the tall gear for a 4106 rear end.

[muldoonman]

Makes cruising down the inter-state a lot easier and the fuel mileage is noticeable better.  about 12 mpg  6 going and 6 coming back makes 12 in my book.


uncle ned

4104 with 6v92 and v730 and the tall gear for a 4106 rear end.

Like your mileage calculator, Uncle Ned. I get about 10 MPG with that math. Feel better already.
Glen S.

[qayqayt]

We have a PD-4108, very similar to your PD-4107.  We bought a set of six new 12R22.5 tires.  What a difference in handling!  The former tires had lots of tread left but were between 7 and 10 years old and mis-matched brands.

Don't forget the spare tire.  Hopefully you'll have the tool in the bus for the front bumper.  It hinges downward to expose the spare tire compartment.  Our spare was on an old split rim so we got rid of it and picked up a used 12R22.5 tire and rim.  Watch how the old spare comes out.  The replacement has to go in with the same side down.

Bryan