Brake Drum/Hub advice

drjmetz · Post by **drjmetz** » Tue Jun 24, 2014 9:51 am

Hello all,

I need some advice and wisdom regarding Porkchop's brakes. This process has gone on so long I think my eyes are starting to bleed (I've had other projects to work on but this needs to get done ASAP).

The problem: When removing the brake drum from the wheel I damaged the hub because I had to remove the counter-sunk screws with a drill. See: http://jmetz.com/2014/04/19/willys-jeep ... the-storm/

I just couldn't get the drum off any other way. However, when I called up Kaiser Willys to see about getting a replacement hub, I started getting all kinds of questions about whether the hub was mounted on the inside or the outside of the drum (I thought the questions were really odd, as I sent the URL to the tech on the phone and it showed precisely what it looked like before, during, and after).

The parts manager told me that someone had tried to retrofit an old-style drum to the M38A1, but when he showed me what the "old style" looked like it seemed like nothing that was on either my civilian or the military Jeep. He told me that what was supposed to happen was that the hub and drum were to be pressed together using a hydraulic press, and then mounted onto the wheel. However, I have no idea how that would actually work, as I can't figure out how you would take it off to maintain the brakes that way (the hub does not look like it is supposed to be removed at all). Not only that, but none of the restoration manuals or repair manuals say anything like this (as far as I could see).

Generally speaking, I feel like I'm getting confusing (if not bad) advice here). Right now the drum wobbles as it's not actually attached to the hub directly. I'm really not sure what is or is not required, or even recommended. I just know that what's there is wrong, and I want to do it right.

Any advice? Thanks so much in advance!

Best,
J

Post by **wesk** » Tue Jun 24, 2014 10:56 am

There's nothing odd about your hub, wheels or your situation.

For want of the correct tool you have painted yourself into a corner, so to speak.

Those wheel to hub retaining screws come in three flavors. Coin slot, straight flat slot and phillips head. There are screw bits designed for each of the three head styles. A bit of penetrating oil, a bit of patience to soak them a few days and the correct bit would have you sitting sweet and done right now. Before you booger up any more screw heads buy the tool.

This is a coin slot bit or Hi-Torque bit.
http://www.amazon.com/Hi-Torque%C2%AE-I ... B0040C2YRG

These are drag link sockets, the smallest of which will usually fit your flat slot screw heads.

This is a large flat slot bit
http://www.toolsource.com/screwdriver-l ... 69650.html

This is the large #4 phillips bit.
http://apexbits.com/440-4X-Apex-1-4-Phi ... -Bits.aspx

When you have tough screws that have been in there a while and the penetrating fluid is slow working the other tool you need is a hand impact driver. It, the correct bit and hammer will break loose the stubborn ones.

http://www.summitracing.com/parts/lil-3 ... MgodBS4AWg

Now back to your current problem. Hopefully your heavy duty drilling has not wiped out the threads in the hub. If you haven't destroyed the hub threads then spend a couple of hours carefully driving and picking the remains of the drilled screws out of the hub. Using a 1/4"x20 tap clean the threads up. Now buy the needed quatity of new 1/4"x20NC-2x3/8" flat head counter sunk screws at your auto parts store. Install the new screws with just a dab of locktite on each screw.

If you have already destroyed the threads in the hubs you have two choices. replace the hubs or take them to a machine shop and have hat type threaded inserts installed in them from the inboard side to fit the 1/4"x20 screws.

Carquest lists a 3/4" long screw but you should be able to find a 3/8" length or shorten a longer one.

http://www.carquest.com/webapp/wcs/stor ... ?acesApp=0

skyjeep50 · Post by **skyjeep50** » Tue Jun 24, 2014 11:00 am

You're getting bad advice. Go to the downloads section of this website and go through the maintenance and parts sections and you will see how things are put together. Yes, the drum is held to the hub with screws and yes, they need to be there to center the drum on the hub. I bought replacements for my M38 at ACE Hardware - the originals didn't appear to be hardened or special screws. Remember that when talking to civvy parts houses, they may not be fluent in "M series" talk, they get quickly confused. Call some of the reliable military jeep parts suppliers - they are more in tune with what you need.

Post by **wesk** » Tue Jun 24, 2014 11:03 am

I believe Skyjeep is saying you were getting bad advice from the vendor you were talking too and not me. I only offer good advice here.

drjmetz · Post by **drjmetz** » Tue Jun 24, 2014 11:08 am

Hi Wes,

As always, your responses are extremely valuable, well thought out, and more useful than 99% of anything else I've been able to find in print. Thank you so much for your patient explanation.

I should state that the passenger's side brake drums were done after I did the driver's side. With that one, the impact driver worked like a champ. The hub came off so easily I thought I was in a dream (compared with everything else that takes forever).

In this case, I was putting penetrating fluid on these screws for months with no progress. Did the whole "heat up and cool down" expansion thing too. That blog entry was in April, but I started that drum back in September! After trying and trying (and getting a friend to try as well), I broke down and took the drill to the screws.

Again, I thank you for the extremely detailed instructions - especially the exact measurements. I honestly don't know if I can find the words to express how appreciative I am. What are your thoughts about the advice to press the hub to the brake drum? Does this sound like normal procedure, or even a good idea?

J

drjmetz · Post by **drjmetz** » Tue Jun 24, 2014 11:09 am

wesk wrote:I believe Skyjeep is saying you were getting bad advice from the vendor you were talking too and not me. I only offer good advice here.

Absolutely!

drjmetz · Post by **drjmetz** » Tue Jun 24, 2014 11:11 am

skyjeep50 wrote:You're getting bad advice. Go to the downloads section of this website and go through the maintenance and parts sections and you will see how things are put together. Yes, the drum is held to the hub with screws and yes, they need to be there to center the drum on the hub. I bought replacements for my M38 at ACE Hardware - the originals didn't appear to be hardened or special screws. Remember that when talking to civvy parts houses, they may not be fluent in "M series" talk, they get quickly confused. Call some of the reliable military jeep parts suppliers - they are more in tune with what you need.

Thanks. That's what I was thinking too. It just didn't make sense with what I experienced (or read about; I've got all kinds of repair manuals, including the valuable ones from here too. It just didn't jive). The 9" brakes - from what I can tell - in 1952 were exactly the same for the CJ-3A and M38A1, so I'm not really buying the "someone tried to retrofit old-style hubs" claim.

Thanks for the comment!

skyjeep50 · Post by **skyjeep50** » Tue Jun 24, 2014 11:16 am

When I first looked at your post, Wesk had not answered yet - we were both crafting our answers at the same time but I hit the "submit" button after he did. NO! - I did not mean Wesk's advice was bad! I was referring to the other people you mentioned. Sorry for the confusion.

Post by **wesk** » Tue Jun 24, 2014 10:40 pm

Why press a brake drum onto a hub on which it fits loosely and uses the three screws to position it correctly. Makes absolutely no sense. I think your advisor was thinking about an entirely different make/model axle.

drjmetz · Post by **drjmetz** » Tue Jun 24, 2014 10:43 pm

wesk wrote:Why press a brake drum onto a hub on which it fits loosely and uses the three screws to position it correctly. Makes absolutely no sense. I think your advisor was thinking about an entirely different make/model axle.

I don't get it either. I sent him the pictures and then the link, which he said that he looked at, but what he was saying wasn't making sense. I'm glad that I have some additional 'eyes' to back that feeling up.

jaycee · Post by **jaycee** » Thu Jun 26, 2014 3:15 am

the man was probably thinking of the ww2 jeep or maybe the early cj2a which has the drum retained by the wheel studs inboard

drjmetz · Post by **drjmetz** » Thu Jun 26, 2014 8:20 am

jaycee wrote:the man was probably thinking of the ww2 jeep or maybe the early cj2a which has the drum retained by the wheel studs inboard

That makes sense, and I suppose it's possible, but what gets me is that they wouldn't look through the link that has the pictures of *exactly* what I'm talking about (but said that they did). I mean, it shows the process of taking off the drum to expose the hub in a pictorial. You don' even have to read all those pesky words and could see what was going on just by scrolling through the pics.

Even after saying they looked through it, they still asked if the drum was mounted on the "inside or outside." So it's really just a case of lazy customer service, IMHO...