A frequent source of frustration for Triumph owners is the stripping of the threads holding the rear hub to the Trailing Arms (TA). The TAs are made of cast aluminum which is both soft and porous and the six studs on each side are threaded at 5/16-24, which Triumph only rated at 14-16 foot pounds of torque. Anything more then that and you can strip the threads in the aluminum. Some people just drill and re-tap at 3/8, but youre still threading a steel stud into aluminum. The better solution is to use a threaded steel insert in the TA that the stud can screw in to, but the problem with doing that is drilling and tapping 12 holes that remain on center and perpendicular to the TA. If you have even one misaligned, the brake back plate and the rear hub wont fit properly or not at all.
More information below.
A Drill /Tap guide for doing both HeliCoils AND Keenserts
HeliCoil replacement text under the Heading additional Information
Trailing Arm Repair Kit for use with
Heli-Coils is Part# TARK-HC
The difference between kits -KS & -HC are the insert type you plan on using i.e KeenSerts or Heli-Coils. While the jig plate is the same for both kits, the drill & tap insert guides are different so make sure you
use the correct inserts
with the jig that you are ordering.
These kits DO NOT INCLUDE the drill, bottoming tap or inserts. You will also need a good quality tap lubricant for use in aluminum for both drilling and tapping. WD40 is an OK substitute.
Heli-Coils
are also available from many sources but as a former NAPA store owner Id just recommend you order NAPA part # BK 770-3082. This kit contains 12 inserts, the insertion tool and the tap. It DOES NOT INCLUDE a 21/64 drill bit or tap lubricant. Additional inserts can be ordered under NAPA part #BK 770-3132.
Please specify the kit based on the threaded inserts that you will be using.
Trailing Arm Repair Kit for use with
Heli-Coils is Part# TARK-HC
KeenSerts
Trailing Arm Repair Kit for use with KeenSerts is Part# TARK-KS
KeenSerts
also known as key-lock inserts these can be sourced at many places, Ill use
www.McMaster.com
and their part numbers as these were used for our testing.
HoweverMcMaster only ships parts domestically, so anyone outside of the United States may want to order Heli-coils which are more readily available worldwide or substitute Recoil brand key lock inserts (very similar to KeenSerts) Recoil brand is available worldwide.
Please note that KeenSerts require an X drill size and 7/16-14 bottoming tap. Theres some confusion here because a 7/16-14 tap is labeled to use a U drill size,
BUT the KeenSerts instructions specify the larger X drill size
. So dont make the mistake of using a U drill. The KeenSerts directions also call for a countersink but you wont need one when you use this set-up. If you were free-handing the tap, the countersink helps to line you up and get you started. The tap guide used here does all of that for you.
McMaster Part# Description
https://www.mcmaster.com/
92070A337
7 PIECE KIT with TOOL
BLACK-PHOSPHATE STEEL KEY-LOCK THREAD INSERT, 7-PC THIN WALL REPAIR KT,5/16-24 INT,7/16-14 EXT T
92070A250
PACKAGE OF 7 ADDITIONAL INSERTS
BLACK-PHOSPHATE STEEL KEY-LOCK THREAD INSERT, THIN WALL, 5/16-24 INT THRD, 7/16-14 EXT, 7/16L,
1413K42
TAP MAGIC CUTTING AND TAPPING FLUID, FOR ALUMINUM, 4-OUNCE CONTAINER (can use WD40)
2521A644
GENERAL PURPOSE HIGH-SPEED STEEL HAND TAP, BOTTOMING, 7/16-14, H3 PITCH DIAMETER, 4 FLUTE
2901A168
X SIZE DRILL BIT
Please specify
the kit based on the threaded inserts that you will be using.
Thread Repair
Helicoils
Heli-Coils
are also available from many sources but as a former NAPA store owner Id just recommend you order NAPA part # BK 770-3082. This kit contains 12 inserts, the insertion tool and the tap. It DOES NOT INCLUDE a 21/64 drill bit or tap lubricant. Additional inserts can be ordered under NAPA part #BK 770-3132.
Please specify
the kit based on the threaded inserts that you will be using.
key lock KeenSerts
Contents
One (1) Alignment Jig
One (1) Tap guide Helicoil
One (1) Drill guide Helicoil
One (1) Tap guide Keenserts
One (1) Drill guide Keenserts
Installation
Detailed documents, videos and downloads on installation can be found in
Product Support
under the Trailing Arm Kit section.
Also see:
Trailing Arm Repair Kit Set-Up
|
Trailing Arm Repair Kit (TAK) Contents
.
Download:
the Installation Tip pdf for use with Inserts