Hi, this is somewhat of a new problem for us. Tonight, for the 3rd time this season we've lost a Brake Caliper off the rear end which generally results in snapping the ear off the Caliper and taking part of the Rear End Case with it. We've never had this problem before and we've used Wilwood calipers for the past 7 years. I torque them 65ft/lbs with Red Loctite before each race.

Has anybody else had this problem? I'm thinking about investing in those LRB mounts to see if it helps this.

[TQ29m]

How long has it been, since you've had the rear gone thru? Most of the time it's caused by the rear being too loose, has too much end play, you can do it, or have it done, but you need it tight enough, that when the side bells are all torqued correctly, it's almost impossible to turn the axle by hand, it needs to be preloaded, so when it gets to operating temps, it isn't moving side to side, if you'll call the manufacturer, they will tell you what the preload should be. The caliper mount, that uses the side bell bolts is the hot ticket, but the preload still needs to be ck'd, often, that's what I found out. Bob!

Thanks. The first time it happened our Rear End was 12 races from fresh. The last few have had about 20 shows on them since being overhauled. I'll definitely check out the new mounts that bolt to the side bell.

This is for a sprint car, by the way.

[Tim]

Originally Posted by 10_Racing Hi, this is somewhat of a new problem for us. Tonight, for the 3rd time this season we've lost a Brake Caliper off the rear end which generally results in snapping the ear off the Caliper and taking part of the Rear End Case with it. We've never had this problem before and we've used Wilwood calipers for the past 7 years. I torque them 65ft/lbs with Red Loctite before each race. Has anybody else had this problem? I'm thinking about investing in those LRB mounts to see if it helps this.

Are the caliper mounting bolts breaking, or is there just nothing left? I've had a little trouble with the bolts coming loose, which prompted me to safety wire the bolts after torquing. Haven't had a problem since. Also, the Winters rear end site give you the values for pre-load and bolt torques. I think it's in the rear end section of the catalog near the end.

Tim Simmons

It seems to be stretching the mounting holes out which leads me to believe they may be coming lose and slowly working themselves out in the course of a race. Instead of a circle they are stretched out to more of an oval shape.

Here are a few pictures of the rear end after last night. Pardon the dirty car, I've been in a rush to get a new rear end in and haven't got it cleaned up yet.

[TQ29m]

2 things appear in the picture to me, one, that looks like a grade 5 bolt, which would stretch under heat, second, it also looks like the axle doesn't have much if any preload, and as it warms up, the end play increases, allowing the axle to move against the brake pads, creating more than necessary heat, possibly stretching the bolts, letting the caliper loose, then it's just a matter of time! That's my story, and I'm sticking to it! I fought this issue for years, even went to putting a tether on the caliper, so I wouldn't have to hunt it, cause I knew it was coming off, when wasn't an issue, but it would be coming off. I musta planted a couple dozen brake pad trees across the country. If you can easily roll the axle, by hand, with it cool, better order a pkg of shims, and the other mount, but it still needs to be shimmed. Bob!

[Go Fast]

Had this same problem on the Epperson 2E in 2010. Bolts kept coming loose and letting the caliper rattle around, safety wire kept them as tight as safety wire can. Snapped the bolts off flush and lost the Brakeman caliper at the L-burg Kiss race that year. Bought a new rear end while waiting for the old one to be fixed. No more problems until now.

Friday night in the SKM at Bloomington the bolts snapped off after the last restart and the caliper left the car after smacking Shane in the butt. Finished the race with no brakes. That rear end had two shows on it after being freshened by a very very good rebuilder. It also has a floating rotor mount, so axle end play cannot be the cause. The bolts were brand new grade 8's and were safety wired.

I am at a loss and looking for a different style mount that does not use just the two side bell bolts. I was looking at the Wilwood radial mounts, but it looks like the radial mount just bolts to the same two side cover mounts. Anyone have experience with some other mount that bolts to the actual side bell studs? Building a brand new car for Sprint Week and cannot afford another failure.

[red33]

Yes shims and better grade bolts plus safety wire

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Thank you for the responses! We've had ti bolts there in the past but we broke a few sets of those and decided to just put regular steel bolts in. We have a bin full of Grade 8 bolts so it's my fault for grabbing a Grade 5. I'll take some of the suggestions mentioned above and let you guys know if we have some better luck.

Thanks,
Kyle Miller

[TQ29m]

I also tried the floater, to no success, seems it binds on the splines, and I actually felt it made it worse. I have a midget rear, and I finally made a steel mount, that used 4 of the side bell bolts, and welded 1" steel spuds to that ring, to mount the caliper back in the same location, and haven't looked back, that seems to have fixed it. I saw someone was making a billet aluminum one for the big rears, that was all one piece, and also used 4 of the side bell bolts, looked really nice, but don't recall who was selling them, wish I could, I wouldn't keep it a secret! Bob!