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
.
Trailing Arm Repair Kit for use with
KeenSerts, Helicoils, or 3/8 studs is Part number TARK-Master, that includes one Master Guide Plate and three sets of a drill and tap guides.
This kit is ideal for shops or clubs covering all the versions of trailing arm studs.
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.
3/8 studs
This kit, TARK-3/8 is for installing 3/8 studs directly into the aluminum rear hub housing, often required for upgrades to rear CV shafts
TARK 3/8 Kit for tapping to 3/8-16 for use with larger studs.
This kit does not use inserts. This kit can be used when fitting some CV axles and does not use threaded inserts
.
Studs can be purchased from your local auto parts store or from goodparts.com in various lengths
.
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
One (1) Tap guide 3/8 Studs
One (1) Drill guide 3/8 Studs
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
Download:
the Installation Tip pdf for use
without
Inserts