s cams

Yes you will need to replace the seals. Never ever reuse a seal. Bearings are fine to reuse unless there is a problem with them. Also you may need to replace the s cams themselves, if the bushings have been shot for a while there will be wear on the scam shaft. As far as cost, only thing I can add to that part of the discussion is about 7 years ago I replaced the scams, bushings, drums, brake shoes(with new spring kit and rollers) slack adjusters and seals on my reefer and I think it was just over a grand for all the parts. No labor cause I did it myself. For what it's worth its a fairly simple job requiring no special tools except for the axle nut socket(about thirty bucks at any parts store). Removing the tires is the physically hardest part. A good breaker bar and a six foot pipe starts to get pretty #### heavy by the time you get to 80 lugnuts and studs.

 

Any truck parts store. Napa, truck pro, fleetpride are the big chains, but plenty of smaller regional or independent stores out there. If buying from a independent store, make sure it isn't generic junk, stay with a known brand such as meritor or bendix. While there are much tighter import restrictions today, I don't trust the cheap knock off China brands due to the Crap they used to pull such as brake linings made from pressed grass clippings.

As for torque, depends if you have the budd style or the newer hub piloted wheels. (Double check these numbers cause I'm just going off memory so could be wrong) budd style inner at 175 to 200 ft lbs, outer at 350. Newer style that has the single 33mm nut is 450 to 500. When dealing with torque in that high range you just get it f'n tight. A six foot pipe on your breaker bar will do the trick. But do not do this with the old style budd wheels. Those inner studs can snap if offer tightened, and it's a bear to get that wheel back off. If this happens you can use a torch to cut it out if you are good, if not you can get a too for about forty bucks to remove the outer from the broken inner. I wouldn't worry about that happening tho cause it's usually caused by an idiot tire guy that just wants to lay on it with a great big air gun.

 

I don't pull the hub off to do S-cams most of the time. I made a tool from a piece of pipe cut in 1/2 to knock the bushings out. The pipe has to be a little smaller than the bore and a little thinner than the bushing. Once you get the slack off, you can pull the cam out until it hits the hub. The take out the bolts holding the cam tube on and slide it out of the way. The you can get the outer seal out of the bore and use the tool, stick it in there and hit the cam back in to push the bushing out. Once the bushing is out, there is enough play to get the cam tube off and the cam out without removing the hub.

Going back together, you just have to put the outer washer or plate, seal and bushing on the cam, line it up and use a soft drift punch to drive it all in as an assembly. Remember that both seal lips face toward the center of the truck. The inner seal must allow grease to pass, if you put both lips facing each other, one of the seals will push out when you grease it. The inner one is the one that lets grease out to keep grease off of the brake shoes.

If you remove the brake chamber from the cam tube, it's a little easier. After you do a few, it's easier to leave it on. If it's a trailer axle with no cam tube, it's a really easy job. Drives and steers with cam tubes are a little tougher, but much easier and quicker than pulling the hubs. I only pull hubs if it needs a seal or bearings.

Here's a link to the tool. I made mine and didn't put a fancy handle on it. It's not worth $68 if you can make it.
http://www.uniquetruck.com/p-14540-striver-tool-s-cam-bushing-driver.aspx

 

IF you are asking about torque on the lug nuts or if you can replace the seals, don't bother doing the work but have someone who knows what they are doing do the repairs.

 

That's the spirit! Go on and perform the repairs. Follow grapeApe's instructions and you shall be fine. Only time I ever remove hubs is if oil seals are leaking. Them drums are heavy though.

 

In that case, I'd pull the hub to check the bearings and replace the seal. The S-cam is easier to do while the hub is off, but if there is nothing wrong in the hub, it's mire work to pull the hub than to work around it.