wishthisMackwouldwork Posted January 14 Share Posted January 14 Hi everyone, thanks for all the info in the forum. So I decided to go through and paint my 1986 RM6864X over the winter, but when i got into the rear axle to fix a seal, there was evidence of a bearing failure, and the previous owner tried to put it back together without replacing the hub. The hub bearing is cracked, and the seal face on the axle housing was pretty damaged. All I can find out about this axle is that its a 6.14 meritor according to old notes on my parts manual No tags anywhere giving the model. Getting a new hub is near impossible, but I would love to figure out if there’s a replacement that fits Pilot wheels instead of Budd. All the part numbers in my book are obsolete. I guess the main thing is retaining the axle with a speedi-sleeve (anybody use one?) and finding the hub. The local dealer can get the bearings and seal. The front of the spindle is about 3 1/16” in diameter. Any idea about what’s out there that fits these axles? Or perhaps the axle model? Or contact the Mack museum? Thank you! Tristan 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/ Share on other sites More sharing options...
mrsmackpaul Posted January 14 Share Posted January 14 Get some photos of the offending axle and axle housing Measure the hub, I can see the bearing is busted but can't see the hub damage Can clearly see the axle damage A seal like this will probably work fine here as the rubber bit doesn't spin Paul 1 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566366 Share on other sites More sharing options...
The Heinz Posted January 14 Share Posted January 14 I've seen someone order those old type hubs here, very recently in fact. The dealer couldn't do anything for you? Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566402 Share on other sites More sharing options...
wishthisMackwouldwork Posted January 14 Author Share Posted January 14 No the local dealer can not find the hub from the parts numbers, as they have been discontinued. I wish I had a part number off of it. Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566421 Share on other sites More sharing options...
Geoff Weeks Posted January 14 Share Posted January 14 Ok, start with the bearing numbers, both inner and outer cup and cone. Get the seal bore and part where the seal rides diameters. Unless it has a real odd bearing spacing or brake spider placement, I suspect a newer outboard drum type hub could be fit. My guess is it will be a typical 20K/40K hub. Hub used on 20K single or 40K tandem axles. If you can get the aprox bearing spacing that will also be helpful. I am assuming std 16.5x 7 rear shoes? Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566423 Share on other sites More sharing options...
Joey Mack Posted January 14 Share Posted January 14 Isnt the hub number cast into the hub? Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566426 Share on other sites More sharing options...
Geoff Weeks Posted January 14 Share Posted January 14 (edited) They are on spokes, but not so sure about Disk. The next thing you need to know is the bolt circle for the axle studs and count and the diameter of the studs. 7" B/C and 5/8" dia studs 8 count are common, but 3/4" and other sizes are used. 580 outer bearing cone space a little over 4" apart are common on the spindle if in the range I mentioned. If it falls into the common hub, then you could replace with outboard drums and common hubs. https://www.webbwheel.com/online_catalog_hubdetail.php?hn=26431--MLT Edited January 14 by Geoff Weeks 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566428 Share on other sites More sharing options...
Mark T Posted January 14 Share Posted January 14 That housing is probably a more popular 23,000 pound Meritor or Rockwell piece than the mystery hub is making you think. Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566433 Share on other sites More sharing options...
Geoff Weeks Posted January 14 Share Posted January 14 https://graphicvillage.org/meritor/pb2006.pdf Another catalog. You aren't likely to find inboard drum hubs, but have a good chance of finding out board. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566434 Share on other sites More sharing options...
Geoff Weeks Posted January 14 Share Posted January 14 I just realized I mis-read the 1st post, It isn't the hub that is cracked, but the bearing race. Knock out the race and inspect where the bearing goes. Get a new set of bearings, or at least an outer race, and see if it will press firmly into the hub. If so, you are good to go, if not you can look to replace the hub or have it built up and re-machined to hold the bearing. Building up and re-machining will cost a few bucks, but everything you have can be re-used. New hub means new drum and may be new wheels. If your lucky it will hold a new race and can go back together. Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566440 Share on other sites More sharing options...
Joey Mack Posted January 14 Share Posted January 14 I saw the cracked race, also curious about the hub. I really dont think its cracked.. Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566441 Share on other sites More sharing options...
mrsmackpaul Posted January 15 Share Posted January 15 Geoff and Joey your both right, the bearing is only cracked My mistake as I miss read it and I guess I mucked it up for others following me So I am thinking the hub is damaged for the bearing to open up that far Paul Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566467 Share on other sites More sharing options...
Joey Mack Posted January 15 Share Posted January 15 Thats quite possible. He will just have to fit a hood race in there to see. It may have spun a groove inside the bore, we dont know yet. Im still surprised a replacement hub cant be found in the parts lookup system . Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566468 Share on other sites More sharing options...
wishthisMackwouldwork Posted Saturday at 01:18 AM Author Share Posted Saturday at 01:18 AM Sorry for the late reply, I’ve been really busy with the paint job. I ordered new bearings, just to see if the race and seal will fit in there snug. Yes, like Geoff said, i can only fine outboard hubs (I assume that means the hub slides over the lug studs) compared to bolt on. If that race is loose, how bad would it be to weld in the race haha? I bet the heat might make it crack again. JB weld? I will look into machining as well, that makes good sense. I would love to be able to fit super single 13” wheels, which are really rare for Budds, so the back wheels and tires match the front. But that may be asking for too much. I will see what’s out there for a 23k Meritor axle. I will measure the outer spindle tomorrow to see if they are common hubs. Thank you guys for all your help. The Mack dealer just says good luck, and they cant even get a built sheet for my truck because its too old. Cat can rebuilt a 1975 dozer at the dealership, but Mack could care less about anything over 15 years old. Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566769 Share on other sites More sharing options...
wishthisMackwouldwork Posted Saturday at 01:22 AM Author Share Posted Saturday at 01:22 AM On 1/14/2025 at 2:36 PM, Mark T said: That housing is probably a more popular 23,000 pound Meritor or Rockwell piece than the mystery hub is making you think. Yes it is a Rockwell. Don’t know about weight rating. Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566771 Share on other sites More sharing options...
Geoff Weeks Posted Saturday at 01:29 AM Share Posted Saturday at 01:29 AM Knock the old race out, buy a new race (cheap) and see if it is snug in the hub, if it is, your good to go, if isn't you have several options. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566773 Share on other sites More sharing options...
Joey Mack Posted Saturday at 01:37 AM Share Posted Saturday at 01:37 AM Welding the race in place wont guarantee a straight fit, and you will have bigger issues. Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566775 Share on other sites More sharing options...
Mark T Posted Saturday at 01:48 AM Share Posted Saturday at 01:48 AM It's too bad you can't find a better parts guy. But like Geoff said, try a new bearing. It just might work. By bearing I mean the outer race and all . 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566777 Share on other sites More sharing options...
Joseph Cummings Posted Saturday at 03:33 AM Share Posted Saturday at 03:33 AM Find a more common version of that rear, and bolt your pumpkin in it. Be nice if you could find one out of a Mack. Although it sounds like a lot less work to just have that bore welded up and re-machined Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566785 Share on other sites More sharing options...
mrsmackpaul Posted Saturday at 08:30 AM Share Posted Saturday at 08:30 AM The cone part of the bearing and the roller part are available in lots of combinations generally So if the outer cone is loose dont dispare as usually different cones of greater out side diameter are available to match the inner bearing You will need a decent bearing retailer that actually knows what they are doing to do this Then get the hub machined out to suit the new cone Or you can weld the hub up and machine it back out to suit, it will be I, imagine cast steel, not cast iron, if it's cast iron machine it out and shrink a sleeve with liquid nitrogen and drop it in, then machine it out to correct size, it will be as good as new No matter which way you choose this isn't a big problem to solve Paul 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566790 Share on other sites More sharing options...
Geoff Weeks Posted Saturday at 12:54 PM Share Posted Saturday at 12:54 PM I had hubs "spray welded" and re-machined before with good results. Often the amount of metal needed make a sleeve difficult and over-boreing effects the seal area also, so sleeve would have to extend out to there.Hub is thin at that area. If you have go with machine work talk to a few machine shops to see what they recommend. 1 Quote Link to comment https://www.bigmacktrucks.com/topic/74995-rear-hub-disaster-in-1986-rm-with-meritor-axle/#findComment-566793 Share on other sites More sharing options...
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