Dirty Job But Somebody has to do it!

[dalej]

I called four places around our home and couldn't find the parts so I called Prevost Expar. The replacement parts are as follows...

Steer/Tag seal #610754/$23.89
Drive seal #621069/$36.88

Steer/Tag gasket #610755/$2.69
Drive gasket #620923/$2.88

note: Out bus is a 1986 w/o disk brakes

[Orren Zook]

Jon Wehrenberg;This may bring some criticism, but I was able to install all my seals using a wide board that completely covered the seal and by careful tapping with a hammer. So far I have not had any failures of seals I installed that way.

Well Jon, now the secret is out we all know the special tool MR. Z. was speaking of. Just because it wasn't made by some commercial manufacturer doesn't mean it isn't any good!

Kinda like tomatoes, home made is often better. JIM

I have a lot of customers that also use a block of wood to install their wheel seals, some successful and some not so. The design of the classic version of the scotseal is such that it will allow the top portion of the seal to bell or compress if struck after the seal has seated against the bearing race. This bending of the seal housing then causes either the sealing surface not to contact the inner wall of the seal or worst case result locks the movable inner seal member to the outer housing causing a groove to wear on the axle spindle that might require a speedi-sleeve or the axle surgeon to repair. When the installation tool is used you will hear a different metallic ring as the seal seats against the bearing race when you use the seal driver.

I scanned four pages of a CR installation for reference, but its too big to upload even page by page, if anyone's interested in this PM me and I'll send it to you.

[JIM CHALOUPKA]

Thanks for the professional insight Orren! JIM

[dalej]

Man...this is a job for the big dogs! I think I will let Jan do it and I will polish wheels.

PS...What is the best poor-mans way to put these seals in?

[Jon Wehrenberg]

Dale,

Just a few comments...separate the hub and brake drum. I suggest that so you do not add any leverage on the seal as it slides into position. Much easier to slide on the hub. The screws holding the drum to the hub may be hard to get out. I made a "screwdriver" tip from a cold chisel and was able to nurse all the screws out carefully using short bursts from the 1/2 impact wrench. Use Never-Seez when you replace the screws with new ones. I never have figured out why the screws are there. The drum isn't going anywhere.

Orren provided sage advice. I have been dodging bullets by gently tapping on a board that is on the seal, after I position the seal on the hub. The key is to not get the seal cockeyed. Patience.

The inner portion of the seal that contacts the spindle must rotate freely within the seal. Critical. If you damage the seal installing it and the inner portion does not freely turn, junk it and start again.

A final note of caution, and this is important. When you replace the hub the oil reservoirs for the bearings are going to be dry. Make sure they have been refilled, either by tipping the differential, or by pumping or pouring rear end oil in there.

[dalej]

Jon, those were the right numbers for the hub wheel seals. I ordered the parts from Prevost so the numbers are different, posted earlier.

Drive: Chicago Rawhide 48690
Steer and Tag: Chicago Rawhide 40086

Thanks for all the info guys. I'm waiting for the parts now. The cost was about what it would have been thru NAPA.

[JIM CHALOUPKA]

For removing the screws holding the hub assembly together, I would suggest an impact screwdriver. It is usually about 1.5" in dia. and about 8" long with a 3/8" square drive. The tool body is knurled for a secure hand hold. Select the correct square drive tip( flat blade or whatever is reqd.) for the job and insert the blade into the screw slot and apply a counter clockwise force on the handle. Hold the tool perpendicular to the screw and apply sharp hammer blows to the end of the tool. This is a good tool for this application, you get a sharp impact of torque turning the fastener along with a linear force driving the blade into the slot.
This tool is especially useful in an application that an experienced mechanic knows at a glance will be troublesome.
I recommend this method above the customary impact wrench because it has the linear force combined with the twisting action. Screws and bolts in blind cavities usually only need the tool for initial loosening, after which a conventional screwdriver or wrench may be used.
The conventional impact wrench is too powerful and abusive to the fastener. It is difficult to hold the tool unto the work and often damages it. Forcing one to drill it out and retap the hole. JIM

[Jon Wehrenberg]

Jim,

Been there and done that and have the Tee shirt.

Trust me, that tool will not work on 1/2" screws. A tight fitting screwdriver tip that cannot move or damage the screw head is required unless you want to get out the old torch and start heating parts.

The impact wrench is not to over power the screw, but to kiss it with just enough force to break the corrosion and whatever else it holding it.

These are slotted, FH screws and some idiot that has never worked on a coach specified them. Later coaches have phillips screws which are not much better, but are an improvement.

[Joe Cannarozzi]

The way your removing the hubs is the hardest in terms of weight.

When I replaced a seal on the drive axle I did not remove the tires seperatly. I simply pulled the axle and then jacked the rear end housing so the tires were right at the point of leaving the ground, then just slid everything off on a smooth slippery piece of metal. I usually get stuck with no help and by doing it this way I had to lift nothing.

Removing it as you are with the brake drum still attatched to the hub makes for a very heavy assembly.

Here, once again, prevo adds another step to a process that in most other cases does not exzist. The brake drums are screwed to the hubs with large flat head tapered screws. I might add that they are also not easy to loosten and or remove. I'll bet you tried but couldn't.

It will not be easy for you to reinstall with the new seal with the drum still attatched to the hub. To be safe you might get some help lifting that back up so as not to nick that new seal going back in. Either that or get those tapered flat head screws loose and out and seperate the drum from the hub.

OOPS, sorry, better late than never.

[dalej]

I haven't had to nor want to try and lift this assembly, as the photos shows I'm using a floor jack to lift and carry the assembly away to work on.

I was going to ask if anyone has had to pay someone to replace the seals. Jan says that the money I haved saved on labor, she could spend on cloths! She wants a dollar amount!