Help with Ford 9" and LS1 brakes

[67rstbkt]

Posted this on PT and here, hoping someone can help me:

Hoping you guys can help me out of this mess I think I created. I narrowed a 9" Ford I had and used Moser 7900 housing ends. These maintain the Ford bearing size while using the GM pattern for the brakes. My plan was to use LS1 Camaro/Firebird brakes. While talking with QT performance about ordering axles, he said:

"I hate to inform you but the ends you need for those brakes are Part # 7900FM. The difference between these ends and the ones you have is the 7900FM are called "flush mount" as they let the axle bearing sit flush in the housing end. The bearing bore is deeper. The ends you have will leave the bearing sticking out 1/8", which is common for the 9" style bolt in axles. The factory 93-02 Camaro backing plate will need to sit flush against the housing end to work properly. One might be able to carefully machine the bearing bore deeper to allow the bearing to fully seat."

I've put way more work into this rearend than I want to admit at this point, all the points for my 4 link are welded on, housing is completed. Any suggestions on how I can salvage this? Can I remove the 1/8" from the brake backing plate? Has anyone else run into this issue? Any advice appreciated

[AmKenpo1]

It is acceptable to remove the material from the Caliper mounting bracket.
0.145 deep and 3.155 dia. should get you what you need and allow for bearing preload. This is what we have done in the past for our customer's that ordered complete assemblies with the Big Bearing/3.150 style housing ends.

Wil.

[Rhino]

I'm running these brakes on a 12 bolt with 9" flush mount ends. I wouldn't machine it out of the backing plate. Remember, this part was engineered to only attach the brakes. We're asking it do do even more in this situation since the C-clip rear it didn't do any axle retention. Machining out for the bearing will only leave the "retainer" weaker.

Another option to machining the caliper bracket would be cutting a spacer out of 1/8" plate. Quick, simple, cheap.

[BBPanel]

A couple of other things to ponder. When I did this on my Nova (9" w/GM flange), the rearend had been shortened 1" per side too much. The LS1 calipers are pretty wide (including the brake line connnection, etc) to the extent that they now interferred with the frame. So I went with S10 brakes - the rotors are 1/2" smaller but I didn't consider that an issue for my application. The calipers are much narrower and an added bonus, the e-brake bracket is integral to the backing plate. May not be what you are looking to do but wanted to pass on my experience. -Bob

http://img.photobucket.com/albums/v203/BBPanel/66Nova/IMG_0166.jpg

[67rstbkt]

It is acceptable to remove the material from the Caliper mounting bracket.
0.145 deep and 3.155 dia. should get you what you need and allow for bearing preload. This is what we have done in the past for our customer's that ordered complete assemblies with the Big Bearing/3.150 style housing ends.

Wil.

Thanks for the input
So what your saying is to remove the 1/8" of material from the center of the backing plate? Would this change the alignment of the rotors to the abutement bracket/caliper?

[67rstbkt]

I'm running these brakes on a 12 bolt with 9" flush mount ends. I wouldn't machine it out of the backing plate. Remember, this part was engineered to only attach the brakes. We're asking it do do even more in this situation since the C-clip rear it didn't do any axle retention. Machining out for the bearing will only leave the "retainer" weaker.

Another option to machining the caliper bracket would be cutting a spacer out of 1/8" plate. Quick, simple, cheap.

So basically what your saying is to use a 1/8" piece with a bore to match the housing ends (3.150, I believe?) before I slide the backing plate on? Won't that affect the spacing needed? The stock axles I have right now (for mockup only) are the 2-3/8" offset version. I believe I can get a different offset when I order my axles.

[67rstbkt]

A couple of other things to ponder. When I did this on my Nova (9" w/GM flange), the rearend had been shortened 1" per side too much. The LS1 calipers are pretty wide (including the brake line connnection, etc) to the extent that they now interferred with the frame. So I went with S10 brakes - the rotors are 1/2" smaller but I didn't consider that an issue for my application. The calipers are much narrower and an added bonus, the e-brake bracket is integral to the backing plate. May not be what you are looking to do but wanted to pass on my experience. -Bob



Thanks, that's something to consider if I can't get this to work. I already have all the parts, really want to use them if I can.

[BBPanel]

Thanks, that's something to consider if I can't get this to work. I already have all the parts, really want to use them if I can.
What I did won't solve your backing plate/bearing issue - you would have the same issue w/S10 backing plate - I was just pointing it out as a solution if you have LS1 caliper clearance issues. Also, I'll see if I took some pics but as I recall my bearing protruded just a little even with the flush mount ends, but nowhere 1/8". -Bob

[67rstbkt]

What I did won't solve your backing plate/bearing issue - you would have the same issue w/S10 backing plate - I was just pointing it out as a solution if you have LS1 caliper clearance issues. Also, I'll see if I took some pics but as I recall my bearing protruded just a little even with the flush mount ends, but nowhere 1/8". -Bob

Thanks, I got that; If you can post a pic of that so I can compare what mine looks like, that would be greatly appreciated.

[BBPanel]

Thanks, I got that; If you can post a pic of that so I can compare what mine looks like, that would be greatly appreciated.
Ok, just wanted to be sure I didn't lead you down a path to the same problem. I'll take a look but as I recall it was on the order of 0.030" or so.

[67rstbkt]

Ok, just wanted to be sure I didn't lead you down a path to the same problem. I'll take a look but as I recall it was on the order of 0.030" or so.

I appreciate that. How did you deal with the bearing protusion, btw?

[BBPanel]

I appreciate that. How did you deal with the bearing protusion, btw?
As I recall, I spoke w/Moser and they weren't concerned about it so I bolted it up and never looked back!
May not be as elegant but I suppose you could use washers on the t-bolts to mock up everything before having a 1/8" shim made or machine the backing plate. You could verify the axle offset needs that way too if you choose to user the spacer.

[67rstbkt]

As I recall, I spoke w/Moser and they weren't concerned about it so I bolted it up and never looked back!
May not be as elegant but I suppose you could use washers on the t-bolts to mock up everything before having a 1/8" shim made or machine the backing plate. You could verify the axle offset needs that way too if you choose to user the spacer.

I started mocking it up, I see what you mean about the calipers. It's a tight fit. I'm wondering what would happen if I mounted them to the rear (clocked 180* from stock)?

I have not taken exact measurements yet, but it looks like my new axle would need to extend out (increased offset?) from the housing an additional 3/8" for this to work. I measured some washers I had and found some that were really close to 1/8" to space out the backing plate.

I based my measurements on a 98 Camaro I have access to; I figured that if I match those measurements, the brakes should be correct.

[BBPanel]

I started mocking it up, I see what you mean about the calipers. It's a tight fit. I'm wondering what would happen if I mounted them to the rear (clocked 180* from stock)?
In my case it was an issue regardless of which side the caliper was on. Just depends on the shape of the frame.

[67rstbkt]

In my case it was an issue regardless of which side the caliper was on. Just depends on the shape of the frame.

Thanks, I'll take some pics as I get further into this mock-up. I'm pretty certain I have a little more space compared to a Nova, so I may be able to pull it off. We'll see I guess. I'm assuming the S-10 brakes you used mount the same way, correct?

I'm thinking my plan at this point should be do what I need to do to get the LS1 brakes to work and as a last resort, switch over to the brakes you used.

[67rstbkt]

One more question on this regarding some other parameters:

1: the size of the axle flange (surface that the rotor will mate too) - The stock LS1 rotor appears to mount to a surface that is approximately 6 3/8" measured across, not diameter. Does the new axle need to be the same or can it be smaller? The axles I'm looking at are 5 3/4" across

2: the register - middle of the flange or hole in the center of the rotor. The rotor looks to be 2.775, the axle is 2.770. Is this ok being slightly smaller?

I know these two specs would fit since they are smaller than the full dimensions, just wondering if there is any reason why this would be a problem?

[67rstbkt]

Just want to say thanks for all the help, I've measured about a million times (at least it feels like that) and ordered my axles today. I have two ways I can go; first is to use the Camaro rotor, the second is to use the Corvette rotor. The Camaro rotor looks like it should work with my setup, but I may need to have that .105 machined out of the backing plate to make it perfect. With the Corvette rotor, I would have to space the backing plate out towards the rotor, so no machining. I'll decide when I get the axles and let you guys know what I went with.

[67rstbkt]

Just wanted to take a minute to update this with my solution. I ended up using the full Camaro setup (aka LS1 brakes) with the corvette caliper.

I ordered my new axles with a 2.5" offset, which worked out well with the new brakes.

To solve the problem of the Ford style bearing hanging out of the housing end, I took the backing plates to a machine shop and had them remove .105
They made a perfect cut and I like that the seal sits inside a recess rather than a plate sit flat against it.

If someone else decides to run this style brake on a Ford 9" with GM ends, I would suggest getting the flush mount housing ends so you do not have to worry about getting the backing plates machined.

I also reversed the sides so that the calipers are located towards the rear instead of the foward side of the wheel. There is a little more space for the large caliper clocking it this way. Also, this will change the e-brake cable configuration to a forward pull.

The rubber boots on the backside were very well worn and I could not find just rubber boots, so I used the rubber from my old B&M shifter to make new ones. I just cut a slit for the lever, slid over the new rubber, re-attached the factory cover, then trimmed off the excess (I don't have a picture of it).