Discussion in 'Early CJ5 and CJ6 Tech' started by ODBuffalo, Jan 30, 2015.
if the differential cover has ever been removed for any reason, that tag probably went bye-bye.
I haven't had the time to physically monkey with the drum for the last few days but my brain is still working on it.
Just weighing out my options. If I CAN get the rear drums off, Ill definitely need to replace the shoes, cylinders and most likely replace or at least have the drums turned.
Or, I can take 1960willyscj5s advice and source a replacement axle. CJDrive has a rolling chassis for sale here with all new brakes. Need to find out if the gears are the same.
I have found another near Toledo and he says he can set it up with new brake parts. His price seems a little high for me.
The hardest part for me (besides the extra cash) is retrieving the parts or chassis with no truck or trailer.
Trying to figure out my ratio. So I counted the number of turns on the driveshaft for one full rotation of the drum.
One drum rotation = approx. 2.75 turns on the drive shaft. So 2 full drum turns was about 5.3.
So I must have the 5.38 ratio right?
A '62 probably would had a 5:38 as stock.
Any new to me Jeeps I drain all fluids and pull the covers off of anything I can just to check out what's inside as far a ratios and gear condition.
A tale, years ago I worked in a tire shop, one of my jobs was doing brakes. A guy with an older Plymouth pulled in. It took me about 20 mins. to get the rear drum off, installed all of the new parts and the drum is nowhere close to fitting. Oh, the emergency brake is still pulled out.
That is true if both rear wheels are turning equally. If only one wheel is turning, the differential gear action will double the rotations.
i.e. - For an accurate reading, jack one wheel, rotate it twice, count the number of driveshaft turns.
The gear ratio is stamped on the ring gear. Drain the oil, take off the cover, get a rag and you will see all the info you need stamped into the ring gear.
This is what yours is going to look like, pretty much exactly.
If you cannot get the drum off you're going to have a bad time with any other portion of your rebuild process. I do not suggest you get another axle as you WILL have the same issues you have here. 50 year old plus stuff will need new brakes and seals and maybe bearings. If you think the drum is above your pay grade the hub/bearing and seal while pulling axles will definitely be something you may see as very difficult.
I think the next best thing is post your location and see if any near by members are willing to come over that have done it before and help you out in person.
It's bad to see you are having that much of a problem with that drum. In my 40+ years of wrenching I've never had that much trouble with one. It might be time to get the BFH out, break it and source a new drum.
Well, I finally got the drum off. After a couple hours or so trying to get it to come loose, I sacrificed the drum by drilling 4 holes in it and pried it off. I'm still not sure what was holding it on. It almost seemed like the hub was slightly over lapping the drum, the shoes may have been original and the pads where actually partially separated from the shoes. The inside was packed with solid goo, like tar. I can't believe how much was in there. It didn't look like the shoes had made grooves in the drum. The hard part about these drums is that there is no where to grab it.
I'll be needing at least one drum.
Thanks for everyone's help, I appriciate all the insight and encouragement.
I have 8 of them,with the cost of shipping and turning them to clean up you are probably better off to buy a new drum.
The overlap was likely from someones early advice to beat it with a hammer. I mentioned i thought I saw that in the photo.
As for the tar, that's what I was describing and why I mentioned filling it with brakleen from behind.
Glad you were able to get the drum off.
I dissagree. The brake drum is cast iron and is not malleable enough to allow deformation to the extent that it would peen over and prevent the drum for separating from the hub. Even if it did, the hub is beneath the drum. Before that were to happen to the extent you propose, the drum itself would crack. This is why others tried to dissuade the OP from hammering on the outer portion of the drum. Cast iron is brittle. What has happened is the drum and the hub with the lugs are all iron bearing substances. When the iron oxidizes, rust, the iron oxide molecule that is formed, is much larger than the original iron molecule. This causes parts that were initially a tight tolerance to become lightly chemically bonded throughout the new iron oxide molecule and reduce the already small tolerances to zero.http://www.metalwebnews.com/howto/rust/rust.html This new molecule is very weak and brittle, so a quick strike can shatter the iron oxide and allow release of the part. The lugs also rusted and contributed to the lack of an acceptable tolerance surrounding both the lugs and the holes in the drums. The tar substance is years of people greasing the zerk fitting and allowing the grease to go into the drum.
TLDR: rust makes things stick together and space between parts get smaller or non existent. Thermal or mechanical shock can shatter the rust.
Good points - with a couple small observations.
I think the potential "peening" would have been theoretically possible if a mis-strike hit the hub center, and expanded the hub metal over the drum. But it would take a lot of mis-strikes to have any significant effect. The BFH technique is time honored and effective.
The Tar is more likely to be escaped brake fluid or differential oil leaking past the axle seal. I suspect very few owners ever grease the bearing zerks at all.
"The brake drum is cast iron and is not malleable enough to allow deformation to the extent that it would peen over and prevent the drum for separating from the hub. Even if it did, the hub is beneath the drum."
Um, I don't think so. The hub protrudes from the hole in the center of the drum (as seen in the photo), and it is common for a ring of rust to form there.
In this case, it looks to me that the lip of the hub was repeatedly hit with a hammer between more than one set of studs.
I do understand what you are saying about cast iron.
Well, I think both of you may be right. Yes, I have poor aim with a hammer and hit the hub maybe once or twice but I dont think thats what was holding the drum on so tight. In one of my earlier post I asked if the drum fit over the hub and everyone confirmed that it did. But Im telling you by looking at it up close it sure looked as if the center hub was slightly overlapping the drum, I couldn't see the inside edge of the drum. Im no chemist, but it seemed like the hub/rust expanded a little.
Anyways, I hope the other 3 don't give me such a hassle.
get a gear puller put on the drum and put some pressure (use common sense here) then hit the drum with a hammer(hit it like a man not like a little kid or gorilla ) the drum will move out a little bit. then put more pressure on the puller. hit the drum all around. Will time some time but it come out.
Good possibility of warping the drum by pulling on it's rim, unless done VERY gently.
Im going to replace all the drums, shoes, cylinders and all the hardware. The Jeeps on a tight budget but should I go ahead and replace the lines while Im doing it? Im just concerned with all the cylinders the lines are going to give up. Master too?
New brake parts is always money well spent.
x2.....brake lines are cheap and a new MC is a must
Separate names with a comma.