I went and did it:

[javadog]

That's weird. What's the explanation for that?

[speeder]

Originally Posted by javadog

That's weird. What's the explanation for that?

I don’t know. Never seen it before.

Anyone else seen this before?

[javadog]

Focus, man, focus.

[speeder]

Originally Posted by Tim Hancock

Here are a couple of my tire date codes to show you what to look for... A 2007 tire and a 2012 tire.

Wow, the 2012 looks a lot worse than the 2007, at least in that photo.

[speeder]

Originally Posted by javadog

Focus, man, focus.

?? I can read the date code just fine, not sure if it’s coming through in photo but it looks like someone chunked-out the code and re-stamped it. Not a good sign.

[javadog]

I see some flash around the number area, which isn't unusual and I think I can read the number 3411 but the photo is too blurry to see much of anything.

Tires are toast, so it doesn't matter.

[speeder]

Originally Posted by Zeke

When it come to tires you have to consider that is your only connection to the road. Not being facetious. I realize the GM motorcoach was ahead of it's time in many ways and the fact that it uses air bags is great. But, they were engineered in the 70's and we know a lot more now. Someone with a shock absorber (damper, if you prefer) like Paragon Products can dial in the shock rate based on the existing parameters.

So you're nearly perfect WRT the ride and handling. However, to complete the package you wouldn't want to use poor tire design. In the world of street use pick ups Michelin is recognized as the best riding tire you can buy. It's a truck tire designed for trucks know as an LT.

The state of the art Michelins may be hard to come by in a 16.5" wheel. If the year of the GMMC was one of the years they shipped with non-radial tire rims, they must ube replaced. A great upgrade would be the Alcoa AL rim in a more standard size.

Not any tire will work given that the tire pressures used on a GMMC will be around 60 psi front and a little less in the rear, but they must be adjusted on each trip for the overall load at each axle. So 4 people with their siht and a full tank of fuel requires upping the pressures. People who constantly tow or overload the GMMC should buy E rated tires and use 80 lbs. That is not going to give you the limo ride.

The first thing to do is get the #'s off the rims and determine if they are the 2 year only radial tire style rims. Otherwise any tire dealer should refuse to mount radials and you're stuck with bias-ply steel belted tires.

Solid advice and I appreciate it but this is a GM P32 chassis and the tires are 19.5” F-load rated 12-ply. The GVWR is 14.5k lbs, if not mistaken. My PU truck uses E load tires, (9k GVWR?).

[speeder]

Originally Posted by javadog

I see some flash around the number area, which isn't unusual and I think I can read the number 3411 but the photo is too blurry to see much of anything.

Tires are toast, so it doesn't matter.

Yep, 3411 and agreed, they’re toast.

[Tim Hancock]

The date code looks official to me.... They obviously have to change the date code in the mold for when the tires are made. Just looks like the date insert was not fully flush in the mold.

[tevake]

I gave you my suggestion on the tires a while ago. First the front tires, then the inner tries on the rear axel, then the outer rear tires last. The inner rear tires are pretty hard to check out while on the vehicle.

So how is the engine working in the coach and transmission and the other running gear, are they doing well? You could drain each to see how the oils are doing.

I had to take the drive shafts out to get them all gone thru. That was a major improvement in the comfort underway. The center strut Bering was done for. And the u joints were Pretty bad to.
Getting that system sorted out was so good in the feel on the road.

I think the rear hubs are not easy to find. So check your bearings on the wheels in the rear axel.
They did rear drum brakes till the mid 80s I think. Are the ones on your coach still original?

You sure do seem to be going thru it pretty well, well done!

Cheers Richard

[speeder]

Originally Posted by tevake

I gave you my suggestion on the tires a while ago. First the front tires, then the inner tries on the rear axel, then the outer rear tires last. The inner rear tires are pretty hard to check out while on the vehicle.

So how is the engine working in the coach and transmission and the other running gear, are they doing well? You could drain each to see how the oils are doing.

I had to take the drive shafts out to get them all gone thru. That was a major improvement in the comfort underway. The center strut Bering was done for. And the u joints were Pretty bad to.
Getting that system sorted out was so good in the feel on the road.

I think the rear hubs are not easy to find. So check your bearings on the wheels in the rear axel.
They did rear drum brakes till the mid 80s I think. Are the ones on your coach still original?

You sure do seem to be going thru it pretty well, well done!

Cheers Richard

My drivetrain is in good shape, including driveshafts, as far as I can tell. It goes smoothly down the road. No fluid leaks present at this time, which is impressive considering how long it has sat. I do plan on changing the differential oil and changing all rubber brake hoses, I already replaced the brake MC and front hoses plus fluid. Radiator will get fresh coolant and distilled water plus diesel additive to coolant when radiator comes back.

I have no idea how to check wheel bearings on this thing. I'm feeling pretty good about the roadworthyness of it, once I replace some tires. My RV has disc brakes front and rear, definitely original.

[speeder]

Since I've got some smart guys on this thread, I have a question about chassis grease. I picked up a grease gun today but the selection of grease at Autozone was frankly confusing...they really had a lot of options. This is normally a good thing but I had no idea which one is best?

Here are some pics I took, I can go back and get the one I need:

[speeder]

[RWebb]

Valvoline - IIRC, it is SynPower is good - Sherwood uses it I think

get something you can use (nearly*) everywhere - wheel bearings, driveshafts & chassis


* I use Wurth HHS clear spray grease for seat tracks, doors, etc.

[speeder]

New tires ordered and will be mounted on front when they come in next week. Small town Goodyear truck tire dealer beat every online price on some Bridgestones, some by hundreds of dollars.

I’m on rust patrol now, lots of surface rust on sheet metal parts under the rig. I go after it with my spinning wire wheel after a good cleaning w soap and water, then treat w red oxide primer. I should have taken a *before* pic of the battery compartment but it was nasty, it sits under the floor right where you step into the coach and is exposed to the outdoors. The entire thing was so filthy and rusty that the red cables were basically black, Rainman can’t abide that.

[speeder]

Sorry, photos coming.

[javadog]

Red oxide primer isn’t going to be enough to prevent further rust, primer is almost useless in that regard. You need to lay down some decent paint on top of it.

[speeder]

Originally Posted by javadog

Red oxide primer isn’t going to be enough to prevent further rust, primer is almost useless in that regard. You need to lay down some decent paint on top of it.

I generally put a top coat on but the primer alone definitely arrests further corrosion the times I’ve used it alone.

[javadog]

For bare metal I prefer a self etching primer, besides, what’s one more rattle can cost?

FWIW

[Seahawk]

Originally Posted by speeder

Since I've got some smart guys on this thread, I have a question about chassis grease.

Ask the local tractor dealers. I use MF stuff on my tractors and equipment because the MF dealer stocks it and backs it. Perfect for chassis uses.

This is a great thread.

Thanks, Denis!