Rear caliper bracket bolt torque spec
Thread Starter
Le Mans Master
Joined: May 2005
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From: Central Maryland
Rear caliper bracket bolt torque spec
I'm heading out to swap a rear hub on my LT4 car. FSM says torque for rear caliper mounting bracket bolts is 116 lb-ft (+/-15 lb-ft). Is this correct? Seems mighty heavy.
FSM also calls for some adhesives on some bolts. Do y'all use any?
TIA.
Live well,
SJW
FSM also calls for some adhesives on some bolts. Do y'all use any?
TIA.
Live well,
SJW
Race Director
Joined: Jun 2004
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From: WI
My '88 FSM lists 70 ft lbs for the rear bracket bolts. Always use thread locker.
It's possible they have the torque so high because the FSM says to always use new bolts. Torque them once and they stretch then get throw out. I've been reusing mine at 70.
It's possible they have the torque so high because the FSM says to always use new bolts. Torque them once and they stretch then get throw out. I've been reusing mine at 70.
Last edited by Aardwolf; Mar 9, 2010 at 10:25 AM.
Team Owner
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From: Lacey WA RVN 68-69
NCM Sinkhole Donor
The bracket bolts are torqued to 70 or 75 ft-lbs depending on the year.
You can re-use the existing bolts but apply new "blue" threadlocker. Clean the bolt threads of the old threadlocker using a wire brush. Do the same with the bolt holes. Use something like Loctite Blue on the threads and torque to spec. Don't use the Red threadlocker as that stuff requires heat to release.
The two small bolts that hold the caliper have two different torque specs Upper to 23 ft-lbs and lower to 16. Don't know why that is as the front caliper bolts are 23 ft-lbs for both upper and lower.
It would be a good idea to clean, inspect, and re-lube the guide pins to make sure the caliper body moves freely.
You can re-use the existing bolts but apply new "blue" threadlocker. Clean the bolt threads of the old threadlocker using a wire brush. Do the same with the bolt holes. Use something like Loctite Blue on the threads and torque to spec. Don't use the Red threadlocker as that stuff requires heat to release.
The two small bolts that hold the caliper have two different torque specs Upper to 23 ft-lbs and lower to 16. Don't know why that is as the front caliper bolts are 23 ft-lbs for both upper and lower.
It would be a good idea to clean, inspect, and re-lube the guide pins to make sure the caliper body moves freely.
Thread Starter
Le Mans Master
Joined: May 2005
Posts: 7,355
Likes: 2,279
From: Central Maryland
Thanks for the replies, everyone. The idea that those bolts should be torqued to 166 lb-ft, as called for by the FSM, seemed insane to me (I just noticed that in my original post, I mis-typed it as 116 lb-ft), as 166 lb-ft is two lb-ft more than is specified for the huge spindle nut!
Truth is, with the access so confined back there, it wasn't easy applying the 80 lb-ft that I decided to go with. I can't imagine how I could have gotten anywhere near 166 lb-ft on the upper bolt, as I had to use an ancient Snap-On Torque-O-Meter that I haven't used in decades because my click-type wrench was too long to fit inside of the wheel well, and that old Snap-On wrench just didn't give the leverage I'd have needed to go much above 100 lb-ft.
I'm happy to say that the job's done, and the car's down off the lift. It's time to tackle some other chores now.
Live well,
SJW
Truth is, with the access so confined back there, it wasn't easy applying the 80 lb-ft that I decided to go with. I can't imagine how I could have gotten anywhere near 166 lb-ft on the upper bolt, as I had to use an ancient Snap-On Torque-O-Meter that I haven't used in decades because my click-type wrench was too long to fit inside of the wheel well, and that old Snap-On wrench just didn't give the leverage I'd have needed to go much above 100 lb-ft.
I'm happy to say that the job's done, and the car's down off the lift. It's time to tackle some other chores now.
Live well,
SJW
Last edited by SJW; Mar 9, 2010 at 11:59 PM.
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From: WI
If it was on the brakes it's because it vibrated loose. I had a caliper bolt fall out at an event last summer. It had thread locker on it. Prep also plays a big role, the threads must be cleaned. Locktite makes a prep compound too.
For the front you can turn the wheel and the angle provides a much better swing for the torque wrench.
For the front you can turn the wheel and the angle provides a much better swing for the torque wrench.
Thread Starter
Le Mans Master
Joined: May 2005
Posts: 7,355
Likes: 2,279
From: Central Maryland
Beats me. But I'm betting it's an error in the '96 FSM.
Live well,
SJW
