Just scored some 90 fin drums will 47 merc back plates work?

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Golddredger

Active member
Joined
Dec 15, 2014
Messages
44
Hey guys,
I just picked up a nice set of buick 90 drums. I been reading for days on guys doing the conversion. I have the correct hubs and spindles already but need to know if a set of 47 Mercury 8 backing plates will work out. I already own them. Still on the car so I cannot check the fit yet. Is there anything more modern that will work? Plenty of 70's rigs at the picnpull. I see that 56 f250 but how about a 76 f250? No info out there on alternatives. Seems guys are not trying anything else and of course turning to ebay for the backing plates you will pay a premium due to that is what everyone else thinks they need for parts. I would rather walk out of picnpull with a loaded set of backing plates on half price day for $20. Can't be a pipe dream there has to be an alternative. Below is some pictures of the 47 merc backing plates. I snagged the pics online but they are the same as mine. Think they would work?
 

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Last edited:
Got my fingers crossed. Soon as it dries out a bit outside I will pull them and mock things up for a solid confirmation. Was hoping someone would sy oh yes I used those!
 
47 Merc brakes are just the same as 47 Ford brakes. To do the conversion, you will need to mate the Buick drums to the Ford hubs. A machine shop can do the work, or, you can buy a drilling template from Wilson Welding in Texas and do it yourself on your drill press.

To get the Ford lug nut studs pressed out of the Ford hubs you will need to cut the retaining ring off the base of each stud. If you look at where the stud comes through the stock Ford drum, there is a little ring there that keeps the stud in place. If you take a small hole saw, with the center drill bit removed, you can run it down over the studs and cut that ring away, then the stud can be pressed out.

After you drill the 5 new holes in the Buick drums you can go to NAPA and buy new studs and press them in. A tack weld on the back side of each stud will keep them from turning or pushing out.

You will probably have to machine a little metal off the backside of each Buick drum, where it contacts the Ford backing plate. They will usually rub and need about an 1/8 of an inch or so machined off so they can turn freely.

Don
 
Thanks Don I will get that pattern coming from Wilson and get this project going. Going to be awesome on the car. Can't wait! Thanks
 
Here is some info from Bob Wilson's site on the subject:

WILSON WELDING HUB INSTALLATION FACT SHEET



The hubs you have received have a five-lug bolt pattern of YOUR choice. Before installation, your drums must also be drilled with the same pattern. You have three choices: 1) Ship them to us and we will drill them for $25 per hub plus shipping. 2) Have them drilled by a local machine shop, 3) Follow the steps below and do it yourself. You will need a Wilson Welding drill bushing bolt guide ($5.95 plus $3.00 packing, shipping), a good drill press (not a hand held drill), a ¼ inch, 3/8 inch and ½ inch drill bits.



DO IT YOURSELF DRILLING YOUR DRUMS

Step 1 – Remove the Buick hub from the finned Buick drum.

Step 2 – Lay the drum, outer side up, on a flat surface. Temporarily insert fully the new hub, small bearing hole upward, into the hole of the Buick drum. Hand thread the drill bushing bolt into any one of the threaded holes of the new hub until it lightly touches the drum surface. Locate the hub in the drum to insure maximum distance from the already existing stock holes present in the drum. Drill a single ¼ inch hole in the drum using the drill-bushing bolt as a guide. This needs to be done with a drill press, not a hand held drill.

Step 3 – Remove bolt from the hub. Remove the hub from the drum. Again, using a good drill press, enlarge the ¼ inch hole to ½ inch. Step drilling is the best approach. Graduate from ¼ to 3/8 to ½ inch.

Step 4 – Reinsert the hub into the drum as before and insert a ½-20 X 2 inch grade 8 socket head cap screw from the inside of the drum, through the drum, into one of the threaded hub holes. Tighten lightly. This grade 8 bolt will stabilize the hub in the drum and will allow you to drill the last four holes into the drum. One at a time, insert the drill-bushing bolt into each of the four remaining drilled holes in the hub and drill a ¼ inch hole.

Step 5 – Remove the grade 8 bolt. Remove the hub from the drum. Enlarge the four – ¼ inch holes to ½ inch with your drill press. Again, step drilling is the best approach. Note: NEVER ATTEMPT TO USE THE NEW HUB AS A DRILLING GUIDE WITHOUT THE DRILL BUSHING BOLT. THE ½ INCH DRILL BIT WILL RUIN THE MACHINED THREADS IN YOUR NEW HUB.



INSTALLATION OF THE HUB TO YOUR DRILLED DRUMS

With your drums drilled, you need five grade 8 socket head cap screws, ½-20 X 2 inches long, the included round flange with five holes, your drums and your new hubs. With the new hub on the outside of the Buick brake drum, the five bolts are inserted from the inside of the drum. First place the included round flange inside the brake drum. Insert the five bolts through the flange / through the drum surface and threaded into the hub from the back side. After all five bolts are threaded and tightened for the final assembly, tack weld the grade 8 bolt heads onto the flange. This is critical for your safety. If you do not secure the bolt head to the flange, you are asking for trouble. (Be certain that all your painting, polishing, detailing has been finished before final welding) Grade 8 bolts MUST be used. A grade 8 Bolt has 5 marks on the head surface. After FINAL hub/drum assembly, the drum brake surface must be trued on a brake lathe before mounting. The bearing races must be installed before the hub/drum assembly can be trued.



WHEEL BEARING INSTALLATION

Before mounting your wheels to the drums, you have to CORRECTLY install your bearing races, bearings and dust seals. If you think a lot is riding on your tires, you have just as much riding on your wheel bearings. If you are not sure how to pack your bearings, how to install the bearing races and know when to stop tightening the spindle nut, have a pro do it. YOU MEAN THE BEARINGS DO NOT COME GREASED FROM THE FACTORY ?????? To install the dust cap, place a short length of 2 inch pipe on the outer lip of the dust cap. Hammer on the pipe, not directly on the dust cap.



BOB WILSON: 214-662-9483


I would call Bob and tell him what you have and he can steer you. Bob is a super nice guy and has a lot of parts on his website that might make the job easier for you.

Don
 
Here is some info from Bob Wilson's site on the subject:

WILSON WELDING HUB INSTALLATION FACT SHEET



The hubs you have received have a five-lug bolt pattern of YOUR choice. Before installation, your drums must also be drilled with the same pattern. You have three choices: 1) Ship them to us and we will drill them for $25 per hub plus shipping. 2) Have them drilled by a local machine shop, 3) Follow the steps below and do it yourself. You will need a Wilson Welding drill bushing bolt guide ($5.95 plus $3.00 packing, shipping), a good drill press (not a hand held drill), a ¼ inch, 3/8 inch and ½ inch drill bits.



DO IT YOURSELF DRILLING YOUR DRUMS

Step 1 – Remove the Buick hub from the finned Buick drum.

Step 2 – Lay the drum, outer side up, on a flat surface. Temporarily insert fully the new hub, small bearing hole upward, into the hole of the Buick drum. Hand thread the drill bushing bolt into any one of the threaded holes of the new hub until it lightly touches the drum surface. Locate the hub in the drum to insure maximum distance from the already existing stock holes present in the drum. Drill a single ¼ inch hole in the drum using the drill-bushing bolt as a guide. This needs to be done with a drill press, not a hand held drill.

Step 3 – Remove bolt from the hub. Remove the hub from the drum. Again, using a good drill press, enlarge the ¼ inch hole to ½ inch. Step drilling is the best approach. Graduate from ¼ to 3/8 to ½ inch.

Step 4 – Reinsert the hub into the drum as before and insert a ½-20 X 2 inch grade 8 socket head cap screw from the inside of the drum, through the drum, into one of the threaded hub holes. Tighten lightly. This grade 8 bolt will stabilize the hub in the drum and will allow you to drill the last four holes into the drum. One at a time, insert the drill-bushing bolt into each of the four remaining drilled holes in the hub and drill a ¼ inch hole.

Step 5 – Remove the grade 8 bolt. Remove the hub from the drum. Enlarge the four – ¼ inch holes to ½ inch with your drill press. Again, step drilling is the best approach. Note: NEVER ATTEMPT TO USE THE NEW HUB AS A DRILLING GUIDE WITHOUT THE DRILL BUSHING BOLT. THE ½ INCH DRILL BIT WILL RUIN THE MACHINED THREADS IN YOUR NEW HUB.



INSTALLATION OF THE HUB TO YOUR DRILLED DRUMS

With your drums drilled, you need five grade 8 socket head cap screws, ½-20 X 2 inches long, the included round flange with five holes, your drums and your new hubs. With the new hub on the outside of the Buick brake drum, the five bolts are inserted from the inside of the drum. First place the included round flange inside the brake drum. Insert the five bolts through the flange / through the drum surface and threaded into the hub from the back side. After all five bolts are threaded and tightened for the final assembly, tack weld the grade 8 bolt heads onto the flange. This is critical for your safety. If you do not secure the bolt head to the flange, you are asking for trouble. (Be certain that all your painting, polishing, detailing has been finished before final welding) Grade 8 bolts MUST be used. A grade 8 Bolt has 5 marks on the head surface. After FINAL hub/drum assembly, the drum brake surface must be trued on a brake lathe before mounting. The bearing races must be installed before the hub/drum assembly can be trued.



WHEEL BEARING INSTALLATION

Before mounting your wheels to the drums, you have to CORRECTLY install your bearing races, bearings and dust seals. If you think a lot is riding on your tires, you have just as much riding on your wheel bearings. If you are not sure how to pack your bearings, how to install the bearing races and know when to stop tightening the spindle nut, have a pro do it. YOU MEAN THE BEARINGS DO NOT COME GREASED FROM THE FACTORY ?????? To install the dust cap, place a short length of 2 inch pipe on the outer lip of the dust cap. Hammer on the pipe, not directly on the dust cap.



BOB WILSON: 214-662-9483


I would call Bob and tell him what you have and he can steer you. Bob is a super nice guy and has a lot of parts on his website that might make the job easier for you.

Don





Awesome! Will give him a call and get rocking on this. Thanks!
 
Oh, sometimes Bob is in the back making parts and can't hear the phone (two man operation) so you might have to leave a message or keep trying.

Don
 
That's right.
Boy those drums are a bit hard to come up with and to have even one pair let alone two, be ruined is a shame.
 

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