9" rear end question

[geoffkd]

OK...so I'm having some trouble with the rear brakes on my bronco. It's in the shop now, but apparantly it's not the stock rear end (big surprise %) ). So my question to the experts is this: How can I (or my mechanic) figure out where this rear end came from? (I need this info so we can get the right parts). TIA for any help.

P.S. BTW the problem I'm having is that the drums installed by the previous owner are too deep and are wearing out the bearing seals.

 

[ebroncoman]

Hmmm, sounds a little fishy. Make sure the shop isn't trying to take you for a ride. Ask a few more questiond about what they've found. There aren't too many rear end configurations that ford has stuffed underneath EB's, ie: large bearing, bigger drums, or whatever. Did a previous owner install a different 9" assembly under your bronco? Mustang, maveric, etc. Just don't want to see a fellow EB'er get screwed

 

[TJK74]

Your drums should have no effect on your axle seals leaking. Can you explain more about the problem with the drums

 

[PPiazza]

If its a 9inch it should not make much of a difference, unless it has disk breaks. Even then if its leaking then it still should not make too much difference. Sounds fishy explain more!!!

 

[geoffkd]

Thanks...the shop is good though, the guy's not an expert on 4x4's, but he does good work, doesn't do extra stuff I don't need, and doesn't charge an arm and a leg. He called me about 30 mins after I dropped it off to tell me that something wasn't kosher. I'm pretty sure the guy I bought it from threw something under there...could have come from anywhere. So I'm wondering is there any way to tell where this axle came from/what the right brake parts are?

On the other hand...I guess I could convert to rear disks...I don't really need to know much to do that do I? My poor wallet though :'( ....

 

[TJK74]

The drums that should be on there should be either 10" x 2-1/2" or
11 x 1-3/4" the only thing i can think of is that at some time the drums were replaced from being worn and they were replaced with the wrong size. the only other size that they could be is and 11" x 2-1/4" which is speced for the 76-77 unless they tried throwing on a set of front which are 11" x 2".
I'd say have him measure what you got to see what the problem might be.

 

[geoffkd]

OK...thanks for the interest...What I know: Oil is leaking into the brake drum from the axle casing and gunking it all up and there's a disturbing clanky sound kind of like if you put a penny in the dryer by itself and let it run when I drive (not quite that bad, but irregular like that would be, more high pitched too), that goes away when the brakes are applied.

What I was told: The leak is being caused by the drums that are installed being too deep and are rubbing/putting pressure on the wheel bearing/seals. At least that's what I think I was told...I might be mixing up which bearings/seals are having the problem. My ignorance is frustrating. ?:? I'm learning though.

I called my mechanic, but he was on a parts run...does that description make sense? I'll clarify more when he calls me back. Thanks again.

 

[SaddleUp]

OK...thanks for the interest...What I know: Oil is leaking into the brake drum from the axle casing and gunking it all up and there's a disturbing clanky sound kind of like if you put a penny in the dryer by itself and let it run when I drive (not quite that bad, but irregular like that would be, more high pitched too), that goes away when the brakes are applied.

What I was told: The leak is being caused by the drums that are installed being too deep and are rubbing/putting pressure on the wheel bearing/seals. At least that's what I think I was told...I might be mixing up which bearings/seals are having the problem. My ignorance is frustrating. ?:? I'm learning though.

I called my mechanic, but he was on a parts run...does that description make sense? I'll clarify more when he calls me back. Thanks again.

Still sounds fishy. Assuming the axle is a Ford 9" then if the drums were to deep they would rub on the backing plate which would show up as a severe problem long before the seals started leaking. If the axle even turned it would make a horrendous scraping sound. Even if it pulled outward on the axle it would cause bearing failure before it wouldn't cause the seal to leak. I.E. To cause the seal to leak the bearing would first need to fail.

 

[geoffkd]

Well here's another question, while I'm waiting to be called back.

I brought my mechanic a pair of complete rear brake assemblies. The whole thing that slides on those 4 bolts behind the axle, plus the drums. These came off a '73 I think and I got them free from one of the other great people on this forum. (and they are in fact significantly different from what is currently installed, the drum is much shallower, and the backing plate (is that the piece the drum fits in?) has a lip about 3/4" deep on it.

My thought was that these would just replace whatever was on there now and it would be good and easy. (I would have done it myself, but I would've had to disconnect the brake lines and I don't know much about what kind of mess that would make, and 7pm in the rain in front of my apt. didn't really seem like a fun time to learn.) So I thought my mechanic would be able to do it for me pretty easily. He says there's no way it will work. Am I missing something? He may not understand what I wanted, but does that seem like a reasonable solution? (assuming that the problem really is having the wrong size rear brakes).

 

[TJK74]

those new brake assemblies should work for you. It would require pulling the axle and while you do that its the perfect time to replace the leaking seals. Not sure why he says it won't work. The drums on these thing are really pretty basic and simple. So,i'm not sure what he is refering to. I'd throw some more questions at him and see what he says.

 

[SaddleUp]

Well here's another question, while I'm waiting to be called back.

I brought my mechanic a pair of complete rear brake assemblies. The whole thing that slides on those 4 bolts behind the axle, plus the drums. These came off a '73 I think and I got them free from one of the other great people on this forum. (and they are in fact significantly different from what is currently installed, the drum is much shallower, and the backing plate (is that the piece the drum fits in?) has a lip about 3/4" deep on it.

My thought was that these would just replace whatever was on there now and it would be good and easy. (I would have done it myself, but I would've had to disconnect the brake lines and I don't know much about what kind of mess that would make, and 7pm in the rain in front of my apt. didn't really seem like a fun time to learn.) So I thought my mechanic would be able to do it for me pretty easily. He says there's no way it will work. Am I missing something? He may not understand what I wanted, but does that seem like a reasonable solution? (assuming that the problem really is having the wrong size rear brakes).

Unless you also change the axles it will not work. They have a different backspacing between the flange and the bearing. The exception would be if they happened to be the right ones if your drums are not.

 

[geoffkd]

Well...I've got my baby back from the doctor now, but she's still sick.

To his credit though, my mechanic didn't charge me for any of his work since he wasn't able to fix the problem.

So now I'm back to square one. Here's what I was told: The drums currently installed are 11" x 2-1/2" What could that be from? Mustang maybe (I was told that the engine was swapped from a mustang by the prev. owner's prev. owner) Also, on the driver side there are washers between the drum and the axle to keep the drum from grinding (this was the fix a year ago when the wheel bearing failed). Apparantly the passenger side is not as bad and has no washers, but the seal is leaking and needs to be fixed. (I'll do this when I figure out what the final solution will be). So I guess the sound I've been hearing is the drum "gently" rubbing against the backing plate.

So what has caused this? Where did these brakes come from? Why would one side be different from the other? (the brake hardware is the same). Are the axles not correct? How do I figure out what I've got so I can then determine what I need to fix the situation?

Should I just go with a disk conversion? Will I run into problems if I have some funky set-up on the rear end?

Thank you bronco gods! Your help is appreciated.

 

[evil69]

Just asking, but you don't have a 8.8 rear do you? Sounds like somebody lost the drums or lost a tire and axle combo and ruined the backing plates and drums. Prev owner...."hey, I have these drums that seem to fit kind of, so slap 'em on! I'm selling the thing anyways"

You will need to find out what you have before you can get the correct parts for a disk conversion. The bearing size and stud size will tell you what you have. You may also want to measure the total width of the housing and post here as well.

 

[geoffkd]

OK...I don't know if it's an 8.8" rear end. that's all I need to measure? The bearing and the stud? What's the stud? %) I'll figure this out yet!

 

[ORVP]

When you give up I have a small bearing 9 housing.

Its a small bearing 1973 Ford 9" housing.
Things aren't quite right under there. Finding it hard to have the brakes make the seals leak considering they are behind the bearings. It really sounds like a frankenstein rear end. You know bolts rods and electrodes but you never know where it all came from.

 

[SaddleUp]

It sounds like the drums were worn out by a previous owner and they grabbed whatever they could get their hands on. I think you need 2 1/4" drums to correct that part. You will still need to replace the axle seals but the drums being incorrect doesn't have anything to do with them leaking. It sound like you have a 76/77 axle which was when they would be 11" diameter by 2 1/4" deep.
http://broncograveyard.com/bronco/i-12398B_drum__11__x_2_25___1976_-_77_only.htm
The rearend swap was probably done to put a large bearing axle under it since that is what it would be if it is a 76/77 housing. You can verify this by measuring the bearing retainer plate and checking it against the measurements at this link.
http://www.wildhorses4x4.com/20.asp

Note: If I'm correct then you may have tapered bearings which use a different type of seal that goes outside of the bearing. To replace the seal in that case requires removing the bearing from the axle.

 

[geoffkd]

So, can I conclude that whatever backing plate is currently installed is correct for the axle/axle housing? Is it possible to install the wrong backing plate? Axle? From the pictures on the wild horses site (VERY helpful BTW, Thank you very much ;D ) I think it's the 76/77 like you guessed. But that's from memory, I'll make sure when it stops raining.

Assuming that's the case though, I should just need to get the correct drums (11"x2-1/4") and then redo the seals. Right? How do I tell if I have the tapered bearings? Will it be really obvious if I remove the axle? Is there any chance the wrong axle is installed? Or would that just not work?

I'm starting to think I just might be able to fix this thing! (Without completely emptying my wallet)

 

[SaddleUp]

So, can I conclude that whatever backing plate is currently installed is correct for the axle/axle housing? Is it possible to install the wrong backing plate? Axle? From the pictures on the wild horses site (VERY helpful BTW, Thank you very much ;D ) I think it's the 76/77 like you guessed. But that's from memory, I'll make sure when it stops raining.

Assuming that's the case though, I should just need to get the correct drums (11"x2-1/4") and then redo the seals. Right? How do I tell if I have the tapered bearings? Will it be really obvious if I remove the axle? Is there any chance the wrong axle is installed? Or would that just not work?

I'm starting to think I just might be able to fix this thing! (Without completely emptying my wallet)

I would guess the backing plates and axles are correct. I am also guessing you can probably just get drums and seals but be sure to check over the brakes while your at it. I personally would get a minimum of brake shoes, wheel cylinders, and drums. The tapered bearings are pretty obvious once the axle is removed. Tapered will have the seal on the outside between the bearing and flange and the bearing race may stay in the housing when the axle is pulled. The other type of bearing has the seal in the housing itself. You might consider putting tapered bearings in anyway if you don't already have them. If you do be sure to remove the seals in the housing if they are there because they need gear oil to reach them. The assumption here is that this is a 76/77 big bearing axle. They don't make tapered bearings for small bearing axles. When you pull the axles see if they are 28 or 31 spline. It is possible that they have already been upgraded to 31 spline which would be a big plus. I would be tempted to upgrade to them while you have it apart if it hasn't been done but that would cost a bit of money that you may not want to spend right now. You would need to get a new carrier (or at least side gears) and new axles. Figure at least $400 extra but it could go upwards of $1000 or more if you decided to put an ARB Air Locker in at the same time with several in between options depending upon what you plan to use it for.

 

[Skuzzlebutt]

As long as you're puylling it all apart anyways, pull the shafts out and measure their lengths. having that info will tell you what size drums you need to be using. Also measure the whole hosing end to end, and contact Currie or Duffs. They will know what you need from what you have.

 

[geoffkd]

OK...thanks again for everyone's input...Here's what I know now, after pulling the whole thing apart. It's a large bearing - good. The bolt pattern is 3-1/2" x 2" That seemed weird...the studs are 3/8" So I guess it could be 3-9/16", but it sure didn't look like it...I was using a tape measure though, so I guess it could be. but that would mean it should have a 10" brake drum, and it's an 11" drum, no doubt. Just when I think I've got this figured out... ?:? . Also the axles are 28 spline, and 25" long on the driver side, and 27-1/2" on the passenger side, measured from the end to the outside of the bearing.

So then I notice that the holes on the bearing retainer plate look like they were drilled out cuz now they have oval holes...so maybe it used to be 3-1/2" x 2-3/8" bolt pattern and had 1/2" studs and someone converted it. So what would that mean? They took a 74-75 medium duty housing and used 76-77 axles and brakes?? Is there another simpler solution to how my truck ended up with this odd set-up on the rear end?

Anyway...that doesn't really matter...I think the brakes are from a 76-77...11" x 2-1/4". And that's all I really need to know to put it all together. Well, except for the axle seals...but I think I've got that figured out...they're the kind that are inside the bearing...so that means ball bearings not roller bearings then, right?

Well, I need new wheel cylinders, so maybe if can track some down on Sunday, I can get this thing wrapped up this weekend. Thanks again for everyone's help.