noise from rear under braking

[mazdarotary]

Hey guys I just noticed yesterday while driving home that when I got on the brakes the pedal felt a bit strange. I put down the window ,and also noticed a sort of grinding noise from the rear end. I am guessing it is the brakes,but what do you guys think?It is only heard under braking,but the emergency brake still works fine. Could I have worn the shoes down and am now hearing them grind on the drum?Is replacing the shoes easy?Also same question about the drums?Do I need any special tools to remove any of the stuff?Thanks in advance.



Oh yeah didn't i read somewhere that there was some way of upgrading the size of the brake shoes in the rear?



Chris

92 D250 CC

83 RX-7

74 Mazda REPU

 

[JLEONARD]

Chris,

I had a Chevy that had a big chunk of the pad material seperate from the shoe and get wedged ... . made a funny grinding/squealy noise for a few miles then stopped. Took it apart later in the day and saw what happened. Luckily no damage to the drum.

When I bought my Dodge and looked at the brakes the first week I had it the L rear drum was toast... looks like the same or similar thing happened there at one point in time but worse.

Jay

 

[mazdarotary]

I just got off the phone with autozone. The guy was asking me a bunch of questions as far as what size shoes the truck had on it and what size ring gear I had in the rear end. I am at work today without the truck so I have no way of going out to look at it. Could you guys tell me what I need to order as far as brake shoes,and drums if the drums are even in bad shape?I am used to ordering stuf for my Mazda's which is pretty straight forward. They eiter have disk or drum in the rear,and the rear ends are all the same size just some have limited slips and others don't.



I actually didn't have a chance to look at the brakes yesterday. For one I had the baby all evening,and two I am not sure how to remove the drums. Do I need any special tools?



Thanks,Chris

 

[JLEONARD]

Chris,

Can't help you there... .

When I did my rears the first set of parts that I ordered using the door jamb numbers that I was asked for didn't even come close to looking like what I had.

So my son ordered and received every combination of drums, shoes and cylinders that was available thru Acme Auto parts.

We used what fit which was the largest shoes, cylinders, and extruded hub style drums..... and returned what we didn't use.

Hope you don't have that much trouble.

BTW... . I had to buy a 2 9/16 wheel nut socket to do the job.

I think if you search the archives there's quite a bit of info about how to R&R the drums.

Jay

 

[mazdarotary]

Jay does this nut have to be removed to take off the drum or for some other reason. Someone said the axles have to come out. Is this true?I really don't feel comfortable removing the axles. Maybe the person was speaking of a 4X4. My truck is a 2WD.



Chris

 

[cerberusiam]

Yes and yes. The nut is what preloads the bearings and holds the drum and hub on the spindle. The axles then bolt to the hub and spline into the third member. That row of bolts around the center hub of your rear wheel is what holds the axle in. Just remove the bolts and the axle slides straight out. After the axle is out you can see the big nut that holds the hub on. Remove it and the hub and drum slides off the spindle just like the front. Back your brakes off before trying to remove the hub. If you have a lip in the drum and shoes are adjusted out the hub/will not come off easily. The axles generally have a taper shim that the bolts go thru for centering and holding. When you take the bolts off the axle may not be loose right away. Whack it a couple times with a mallet and it will loosen up. Its a pretty simple operation so don't worry too much. Every time I do the rears I have to measure the shoes cuz these trucks came with about 3 different sets. Good luck.

 

[AlK]

Chris,

I would take the wheels off before you remove the hubs. Those puppies are quite heavy. Be careful when you take the hubs off or when you reinstall them on the axle or you will damage the oil seals. In addition you may have to add some fluid to the rear end. Since the rear axle bearings are lubed by the oil in the rear end, a little trick that I use after the hubs and wheels are back on, is to jack up the opposite wheel to allow some oil to flow down the axle tube to the bearings.

---

Al

 

[paccool]

Before pulling anything off, take a look at the inside of the drums and the backing plate to see if there is any oil on them. If so, the seals are probably gone and you may need to put "speedy sleeves" on. These are metal sleeves that install on the stub housing to give the seal a new sealing surface to ride on.



You will see this area when you pull the hubs. Make sure you have a oil catch pan under the hubs cause there WILL be oil running out when you pull em!



My 93 has 3" shoes with 1 1/8" wheel cylinders. Some people say the trucks came with 2 1/2" shoes and 1" cylinders but the Napa guy said mine should have the 3" set up and it did when I pulled it apart.

 

[JLEONARD]

My truck had the 1 1/8 cylinders as stock. Don't know what the shoes are... I never measured them ... just replaced with whatever was on there.

 

[BCaldwell]

Chris, There is also a little "u " shaped keeper? that is wedged into the nylock nut. It is reccomended that you replace it when you do a re and re of the hubs. Bill

 

[mazdarotary]

Well all thanks for the input. I succesfully repaired the rear brakes on Saturday. I did so with some guidance from a friend and the FSM. It wasn't nearly as scary as I thought it would be. The only thing I still need to do is get some new amsoil for the rear end. When we removed the axles some lube came out but not much. When I re-installed the wheel bearings I filled them up some with a synthetic gear oil(not amsoil),and gave a few shots into the axle housing. The PO had Amsoil in the rear,and I know I should have removed it all when I was in the axle anyway but I didn't have the oil so it will have to wait a few days. I didn't use a rounded nut socket like the FSM called for but just a really big regular socket(it pays to have a friend with a MAC tools truck). The axle didn't have the nylock nuts that I have heard so much about. It just had a regular big nut and a wedge shaped thing that tapped into the threaded shaft the nut went on. I suppose that is to keep it from coming out,but I am not sure how well it would work. I set the torque wrench to 130 ftlbs and tightened the nut while spinning the drum,and then backed it off 1/3 of a rotation like the FSM said. Is this the proper procedure?The brake drums looked ok so I didn't replace them. I wanted to have them turned down but there was no place to do it on saturday so I just put them back on. Probably not the best idea but i was under a time limit. I also did replace the inner wheel bearing seals which didn't seem to need replacing but I figured it was a good idea. I also didn't replace the wheel cylinders because they looked fine. Was that a bad idea not doing this?Thanks again.





Chris

 

[dpuckett]

Chris,

You're probably ok without turning the drums. They arent quite as critical as the rotors on the front. The 3/4 and 1 ton DOdge pickups have what's known as a full floating rear axle- the axle only transfers torque; it doesnt carry any weight or do any sealing, hence the floating designation.



You really should have packed the bearings with grease. I know, it will get diluted eventually with the gear oil, but it will keep a thin film of grease on the surfaces for the most part. I wouldnt take it apart just for that, though. It is good that you lubed it with gear oil, anyway.



If the seals are more than a year old, I'd replace them anyway. They are what, $4. 99 a piece?



For future referrence- you SHOULD have (print this out and file with truck stuff; it is IMPORTANT info; same to the rest of you thinking about brake work in the near future)



Dana 70HD/ 71 rear axle with 10. 25" ring gear, 12x3 brakes, REGARDLESS of whether the shoes are actually 2-1/2 or 3". Look and you will see some buffer zone, so to speak, on the outer edges of the drum with 2. 5" brakes. ALL the drums are 3". You dont have the D-60/61, or the 9. 5 ring gear. Not sure why they list that in a 1 ton. Basically, you have a 1 ton with SRW, and lighter springs. WHeel cylinders all bolt up the same. I went from 7/8 to 1-1/8 WCs in a 92 W250, and what a difference that makes.



You DID flush out all the old fluid, didnt you? Hook up the bleeder hose, and crack the screw, and you'll see why I ask that. If it is more than a year or two old, it will be brown.



-DP

 

[mazdarotary]

Thanks for the input DP. My truck did have the 2. 5" shoes in it so that is what I replaced it with. I thought of packing the bearings with grease but my friends father who was a dodge tech for over 20 years said it wasn't required. He was the one who told me to put some gear oil in them though. I didn't crack the bleeders but maybe I will later today. I flushed the whole brake system with new fluid about 6 months ago so I am guessing the fluid is in good shape. Oh yeah I did use some gasket maker on the axle flange where it bolts to the hub. It seemed liuke there was some there before. Was this right to do?Thanks again.



Chris

 

[mazdarotary]

Hey guys also I have noticed the rear brakes making a squeling noise since I replaced the brakes saturday. It only seems to be audible at low speeds with a meduim amount of pedal pressure. Should I have used some sort of anti squel substance like on a disk brake setup?ALso could I have mis-adjusted the brakes with the adjuster?I adjusted the wheel thing in the drum until there was a slight drag on the wheel. But also I am thinking that because I use the E-brake all the time it is adjusting them even more whenever I use it. ANy help would be appreciated. Thanks





Chris

92 D250 CC

74 Mazda REPU

83 Mazda RX-7

 

[paccool]

That noise you are talking about could be the new shoes seating on the old drums. Since you didn't turn them, the surface is probably uneven and the shoes will need some time to seat.



There is still a metal gasket where the axle flange bolts on, right? Should be one there. I used a little RTV on mine when I put it back together with new gaskets. No leaks in almost 2 years now.

 

[mazdarotary]

I don't remember seeing a metal gasket where the axle flange bolts on just some RTV,and I put some new RTV on it when I re-assembled it. Maybe it wasn't there to begin with. Thanks for the reply.





Chris

 

[Tim1]

Kriss!!! I'm concerned what you mean by just a regular nut not nylok and torq to 130lbs. If you don't use the nylok procedure, then you use the zero preload procedure with a 2 nut system. The wedge you speak of is supposed to stake the nylon, will do nothing to steel. Did I miss something? Tim

 

[dpuckett]

Tim1- if you dont look real closely, it doesnt look like a nylon inside on the nut. But, you are right, since the wdge goes into it, it has to be something relaitvely soft.



mazdarotary- you DID scrape off the old RTV before putting on the new stuff, didnt you? Sometimes, the metal ring sticks to the hub or axle shaft, and you dont notice if you dont know to look for it.



-DP

 

[mazdarotary]

I am not sure Tim1. I didn't notice nylon on the nut but maybe I missed somethingI adjusted the preload as per the FSM i have. Maybe I should get back in there and check it out. To be honest with you now that i think of it the nut did seem to get tight before i ever reached any torque limits so maybe that was the nylock i was feeling wedge itself into the threads. Maybe I just didn't see the typical white nylon that i associate with a nylock nut because it was dirty with gear lube?Does the procedure i used sound ok with a nylock nut setup?



Chris

 

[mazdarotary]

dp I did not scrape anything off but what i did see was some old RTV on the flange that i just sorta picked off with my fingernails. It looked like it was pretty clean to me. I even wiped it all down with a solvent before putting on new RTV gasket material. I have yet to put the hub caps and trim rings back on and have not noticed any fluid leaking on the wheel/tire combo(aside from what leaked when doing the job)yet. would I be able to get these metal seals at any parts place?or are they a dealer only thing?You guys have me worried now that my axles will be leaking.



Chris