Guys, I know we have several good ford 9 inch diff threads out there, but could we extend it to cover all the different drum brakes & backing plates which is mostly what I am interested in. each time I end up with a diff I am surprised to find small variations in the brakes. I assume there was only 10 and 11 drums, but this may prove me wrong.
The big block Mustangs and Rancheros had 9" rears with small bearings and 10" drums something like 67-69.
My recent experience with the big bearing 9" has been: 1 3/4" wide linings, 11" drums on the 62 F100 housing used on my 31. 2 1/4" wide linings, 11" drums on a similar looking housing used on my 32. Drums for the 2 1/4" linings were easy to find at the time - about 14 years back. We were told by the parts house guy at the time, that the new drums were Dodge and they could be due to the extra five holes like you find on ChryCo. Even so, they could be drums that fit either end and the extra holes are for the front hub rivets. Along with that I've been told by a knowledgeable guy that the Ford hub register hole and the Dodge are different. So take all that with a grain or two of salt. The 1 3/4" wide linings have an easy to obtain drum with the 5 x 5 1/2" bolt pattern. Things got a little confusing since I'm running aftermarket alloy axles with the 5 x 4 1/2" pattern. I understand that the 57 Ford brake drums with their 4 1/2" pattern are a drop-on fit with no alterations required. But, they are expensive new and it's tough to find decent ones at the junkyard. I ordered new drums for the 62 F100 and cost was about 1/3 -1/2 the cost of the 57 drums . . . depending on who you talk to. The 62 F100 drums have ten holes, five for the 5 x 5 1/2" pattern drilled 9/16" fwiw. There are also five more holes on a smaller pattern with three being approx 3/8" and two being 1/2". Not sure why the difference there, it looks like the drum was made that way so it could go front or rear. There was plenty of room to drill for the 5 x 4 1/2" pattern. A small fwiw that probably won't impact the stock axle user was that we had to bore the drum register hole out .010 to match the register flange on the axle. Other than that, not too much trouble. ~~~~~~~~~~~~~~~~~ If someone can correlate the data and make a tech article for these brakes it would be a big help to many. One piece of information that would help is to find out how many different backing plates there are.
Exactly, that is why I started this Thread, it would be nice for matching drums and also to know what is out there and what to look for. Previously the 9" diff thread covered all the different size width and bearing for diffs and I hope this will do the same for brake backing plates.
If i recall right, there are 5 different bearing offsets for the ford 9", the bearing offset is the distance from the backing plate retainor to the axle flange. So there are at least that many different brake combinations.
Be nice to have some kind of chart with it all laid out with off sets and diameters and models of car etc.
good luck with this. ford LOOOVED to change brake drum specs for some reason. Maverick 5 lug rears use 3 different drums over the span of like 6 years. best best would be to start a list of all the applications that had 9 inch rears. then cross the PN to the specs in a Bendix catalog, etc. I've got the bendix catalog if someone wants to compile an application list..
The register size is different for cars and trucks, learned that the hard way trying to put car drums on truck axles....anybody want some car drums send me a pm.
I am going to put some more info here in a format that can hoefully be useful using the stuff posted. I am not all that knowledgeable in this department that is why I asked the question in the 1st place, but in more recent times, I've seen a variety of 9 inch brakes stuff so I will keep you posted. Any additional info any HAMBers have is welcome and can be added now.
The main thing you need to know which rear you have. There are small bearing, large bearing Old style and large bearing new style. As long as you get the right bearing style you got half the battle won. The next thing is make sure you get the backing plate and drum from the same car. Like they said before there are a lot of differnent offsets with the brakes. I have found 11 inch drums on some of the full size car from the 60's and 70's Just watch out for the 5 on 5 bolt pattern. most cars are 5 on 4 1/2 pattern and most truck and broncos are 5 on 5 1/2 pattern You may find some vans with the 4 1/2 pattern I just found a early bronco rear with 11 X 2 1/2 on it. Now thats a oddball.
I had a hard time trying to locate brake parts for my 9" (78 mercury marquis) think they were 11.5 vented rotors x 1.5-2 offset and caliper mounted to the bearing retainer
I've used 2-1/4 and 2-1/2 X 10" drums on 1-3/4 X 10 brakes, just part of the drum was unused by the brakes. Pickup and Bronco axles are shorter from the bearing to the flange than big car axles to reduce flex under load, so the backing plates (11" brakes)are different to accommodate that. Not sure if the drums are different. This may apply to van axles also.
IIRC, '66 Bronco (maybe '67) had the 10" drum, the 1967/8-77 bronco's had the 11" drum. Offsets between the various models isn't all that well known to me. However, Moser's catalog gives bearing retainer dimensions for the 3 different sizes. I could type them in, but my head hurts, lol.
Actually, the Bronco rears came with either the 10 inch brake drum ( small axle bearing ) or the 11 inch ... like the F-100 ( large axle bearing ) ... the year model has nothing to do with it. The small bearing axle was called the 2700# axle and the large bearing axle was called the 3300# axle.
Now we are getting some where with all this good info from you guys sharing your experiences. I had a project going where I installed 1960 Galaxy rear wide 11" drum brakes onto my 1960 F100 which had the narrow 11" drums. What a job got new Galaxy drums, redrilled axle flanges to car pattern & the backing plates to the large bearing and machined the center hole larger for the large bearing got it all done and when the drums were fitted the brakes locked up. Seems the drum was locking onto the metal edge of the brake shoe. I gound the metal edge down even with the width of the shoe, removed the gasket between the housing and backing plate and machined about 3/32" off the lip on the inside of the drum where the contact was being made. Once that was done the drum was locking onto the lip of the backing plate which has required a temporary additional 3/32" spacer. Works OK now. No fun and boy I wish this post had been on here earlier Now after reading this post I know why since the off sets are about 1/4" shorter on the F100 axle to housing flange each side compared to the car brakes. Any ways not to worry I hot rodded it and now it fits fine...
Road test report, well with the gear ratio change from 3.89 to 3.56:1 there is a definite improvement on the flat and unloaded which is how it is driven most of the time. It seems it is better fitted to its torque range for around town use. Boy are those big back brakes nice. The truck pulls up real good with less effort and a more positive feel. The brake system is not boosted but still feels nice to use, not so much heavy effort required.
Here some information.. Early Bronco Axle Specifications Rear Axle Specifications '66-'75, 28 spline, big bearing short side: 26 15/16" long side: 29 1/4" '66-'75 28 spline, small bearing short side: 27 1/8" long side: 29 5/8" '74-'75 28 spline, big bearing/small brakes short side: 27 1/4" long side: 29 3/4" '76- '77 28 spline, big bearing/big brakes short side: 27 3/16" long side: 29 11/16" Brake Specifications 66-75 small bearing 10 x 2.5 74-75 medium duty 10 x 2.5 66-77 large bearing 11 x 1.75 76-77 11 x 2.25 Rear Axle Bearings Application *Seal Bearing I.D. O.D. 69-78 Bronco 2780 and 2900lb 9568 rw-207-ccra 1.3780 2.8346 69-78 Bronco 2780 and 2900lb 9568 rw-207-ccra 1.3780 2.8346 69-77 Bronco 3300lb 51098 514003 1.5312 3.1496 Tapered Roller Bearing 3195 a-20 1.5625 3.1483 Axle Shaft Seals 71-77 Bronco 5131 66-71 Bronco (from 3/18) 480570 66 Bronco (to 3/17) 40652s EB rear axle info: ALSO............................................................................................. Types of 9" Housings For one thing, housings come with various brake shoe widths 1 ¾", 2.00" and 2 ¼ " as well as different spline counts and bearing sizes. '67-73 Mustang/Cougar - are light duty, with the thinnest housing material, and a 3" diameter housing at U-bolts. They include small axle bearings, 28 and 31 splines. '57-68 passenger car and 1/2 ton truck - are medium duty, stronger than Mustang type, 28 and 31 splines Ranchero/Torino have a heavy duty thick wall housing, 3 ¼ inch diameter axle tubes with flat tops. '69-77 Galaxies (coils), Lincolns (coils), and late pickups (leaf)- are 3 ¼ inch in diameter all the way to the backing plate, coil housings have upper control arm mount. ------------------------------------------------------------------------------------------------------------- How To Recognize 9" Housing Centers They do NOT have a removable rear inspection cover. '57 - no dimples, flat center band up the center of the rear cover, bottom drain plug. '58-59 - two dimples on back of housing, flat center band, some had drain holes. '60-67 have two dimples, flat center band, oil level hole in back cover. '63-77 Lincoln, LTD, and Thunderbirds had 9 3/8 inch centers, housings were cut away at the gasket surface for ring gear clearance, one curved rib at the front top portion of differential, strong but poor selection of axle ratios. ------------------------------------------------------------------------------------------------------------- Types of 9" Axles 28 spline axles cannot be shortened and re-splined (they're tapered). '72 and earlier 31 spline axles have the ability to be shortened . '73 and later 9" (cars) have a 5 X 5 ½ " bolt circle and the axles cannot be shortened . '67-73 Mustang axles are identified by wheel flange center, with oval hole/recess - 28 splines, with two large holes/recesses and a counter sunk center - 31 splines Given a choice of 28 or 31 spine axles, you want the stronger 31spline versions. ------------------------------------------------------------------------------------------------------------- More Facts 5 X 5 ½ " lug pattern is a "truck" bolt pattern, 5 X 4 ½ " is a "car" bolt pattern. A 9" complete rear axle is approximately 35 pounds heavier than an 8.8" rear axle with approximately the same components. It is common to find a 9" in a old Falcon or Comet that has had a HIPO SMALL block with 31 splines and a locker. If the case has two vertical ribs from the top to middle of the case it is a good IRON type. If, in the very center of this case, there is the letter "N" then this is a NODULAR CASE. This is the strongest factory case made by Ford. ------------------------------------------------------------------------------------------------------------- 9" Rear Axle Width Information Axle Widths quoted below are axle flange to axle flange (roughly equates to rear track) '65-66 Mustang 57¼" 57-59 Ranchero and station wagon 57¼" (narrowest 9" housing) '66-77 Bronco 58 inches but has 5 X 5 ½" diameter bolt circle 67-70 Mustang 59¼" "77-81 Lincoln Versailles 58 ½" (probably has disc brakes) 57-59 Ranchero and station wagon rears, 57¼" '66-77 Bronco 9", 58 inches '77-81 Granada 58 inches '67-71 Comet, Cougar, Fairlane, 59¼" 64 Falcon 58 inches 57-72 F-100 measures 61¼" (5 X 5 ½ " bolt pattern) 71-73 Mustang- measures 60 - 61¼" (Not all are 9", some are 8") (5 X 4 ½" bolt pattern) 67-73 Torino, Ranchero, Fairlane- 9" 59¼"to 61¼" 67 Cougar- 60 inches 89-01 - Ford Explorer 8.8" 59¼" 59 ½ " (5 X 4 ½ "car" bolt pattern) 89 Lincoln Mark VII- (per F100Connection.com) (width unknown) 67 Fairlane- 63 ½" (coil springs) '72 Ford Van 3/4 ton- 68 inches '73-86 Ford Vans- 65 ¼" The rationale for providing information on rear ends deemed too narrow or too wide is two-fold 1. It saves you the trouble of measuring them to see if we missed them. 2. You may want something normally considered too narrow or too wide due to the offset of your wheels.
Nice work Schiltz, this will go down as some of the best info we have received all round. Much appreciated indeed. Russ.
--------------------------------------------------------------------------------------------------- I'm running into this problem now with a 66' Bronco rear-end, it's brake shoe is locking up. I'm running 10" brakes (2-1/2" wide) and the metal end of the shoe is scraping, The left side is OK because it as a Moser axle but the right side is getting hung-up and locking on the metal part of the shoe. Adding to the matter that when I went to disassemble the brakes the anchor pin for the return springs broke off! I had an extra backing plate hanging around (2") and tried to remove the anchor plate... Forget about it! My next plan was to drill out the center of the broken anchor and thread the hole and use a bolt as a retainer, that really screwed me when the Tap broke off (On the car). I ground down the area to make the anchor hole flush an managed to remove the broken 1/4" tap. I then decided to drill out the hole to 5/16" and had a hell of a time, even with a new drill bit (It ruined 3 bits, must be hardened anchor plate)! I finally was able to drill through and then "Very-very" slowly, I ran a 3/8" tap fully through. I'm going to A/zone later, they show a backing plate assembly for 75'-81 Camaro for $16.00 which includes a screw on anchor, this is anchor is all I need to adapt (#13867). As far as the shoe scraping, instead of using 2-1/2" shoes, I'll be looking for 2-1/4" shoes... Maybe that will work!
I ran into an interesting problem today. I am installing spring over axle. Model a spring over a 66 bronco 9 inch. So I put the spring perches at desired model a width and noticed the backing plates are gonna hit the perches. I dont know if I can run different backing plates and drums to gain some room. Any ideas or help would be appreciated. I probab need half and inch on each side
Redirecting this, hoping for some help. I need to narrow my banjo rear, but the backing plates are going to be to close to the frame for the brake lines to not hit the frame. I’m thinking if I can get a narrower brake on there, it would move the backing plate away from the frame giving the brake line room. it’s a 40 rear with stock brakes. The stock drum is about 2 inches deep, but only used 1.5 wide shoes, so if I can find a 1.5 wide rear brake setup that uses 9 inch bearings( the axle will run 9 inch shafts) that will give me 1/2 inch each side to clear brake lines, is there anything this size?
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