View Full Version : Trailing Arm Studs

06-18-2006, 09:04 PM
The rear trailing arm studs are stripped. It seems like I read they should be drilled out & helicoiled with coarse threads 5/16-18. Is this correct? The studs I have found are coarse on both ends I don't think this should be a problem. Should I replace them all or just the bad ones? If I just replace the bad ones I'll just have fine threads on some & coarse on the others. Should I use loctite on the studs going into the helicoil?

06-19-2006, 07:08 AM
I would use a Keensert for the repair. They are similar to a Helicoil but are a permanent fix. They will not budge once set in place. They are more expensive and harder to find, but in my opinion, are worth it.
As far as replacing all or some, that is an area that isn't worked on with much frequency. If it ain't broke.... But that decision is yours.

06-19-2006, 01:19 PM

Time-Serts are another option, also stronger and a more permanent fix than Helicoils. Also more expensive and harder to find. Motorcylce repair shops love em and use them alot to repair stripped threads in aluminum parts.


06-19-2006, 01:39 PM
I was just on the Time-Serts web page. They look like a great way to repair such an important area. Looks like it would be better than new.

They had a list of dists also.

06-19-2006, 01:48 PM
Do you have to drill out the hole in the trailing arm and use a different size stud?

06-19-2006, 04:42 PM
The keen sert would be similar to the time sert except it doesn't have a top flange. It does have two or four tines that get driven down through the threads, making it a permanent fix. They can be removed by drilling out the insert, tapping the tines toward the inside of the hole and screwing the insert out.
The hole must be drilled and tapped as it does with all of the threaded inserts.

06-19-2006, 06:53 PM
Here's another option people have used successfully:

EZ-lock inserts (https://www.use-enco.com/CGI/INPDFF?PMPAGE=593)

You can get it in either 5/16" fine or coarse thread internal. External thread is 1/2-13 coarse, which I think is where you want to be coarse going back into the aluminum, and you potentially could still stick with NF studs. Supposedly you can find studs coarse on one end, fine on the other, but I don't know an easy source.


06-19-2006, 08:39 PM
If you are going to HeliCoil one, you might as well do them all. This area is one of the major weak points on the TR6 (and 250 and 4A-IRS) where Triumph put fine thread into a soft metal, aluminum. I HeliCoiled all mine and did use Locktite. It is a permanent fix as far as I am concerned. This is an area that every TR owner should check out, you would be amazed how many are bad. The PO of my car had actually stuck a couple of mine back in with JBWeld. That's scary.
Plus, IMHO, I feel that HeliCoil is better in aluminum because they get tighter as you tighten the bolt.


06-20-2006, 07:55 AM
Do you happen to recall what size you used?


06-20-2006, 04:29 PM
It's been a while but I believe the bolt size is the same as the original. Frankly can't remember if the thread inside the Helicoil is fine or course, the gripping part of the Helicoil is for sure course. That is why the bolt failed, soft metal and fine thread. I know the bolt size is the same, actually, just don't remember what the threads were. Go to any NAPA and see what they have in stock. Comes as a whole kit, really simple to install.


06-20-2006, 04:45 PM
Recoil is Alcoa's version of Helicoil and is usually less money. I have found them to be equal quality.