2 helicoil or not 2 helicoil, that is the question

[Guest]

OK, latest problem. On the LHS front hub, one of the 4 bolts where the rotor attaches is totally stripped. I tried new bolts, thinking it was just the thread on the bolt but no joy. I have it back on the car with 3 new bolts in right now (stupid I know, but I was sick of it on stands).

Can I get it helicoiled - is that the term you use here? - with any success (and if so what should it be costing me?), or am I facing dropping the 300ish for a new hub? /ubbthreads/images/graemlins/pukeface.gif

I wish I'd never started this job...
TIA as always, Alan
/ubbthreads/images/graemlins/england.gif

Edit - I just saw TRF have rebuilt hubs for $160. That's a little more palatable. I'd still prefer to go cheap though...

 

[dklawson]

I've only worked on Spitfire and GT6 front hubs. From your avatar I assume your car is a TR6. I don't know how your front brakes differ from mine, but I would assume they have to share some similarity. The rotor itself should be secured to the hub by the lug bolts. If one of these is what's stripped, you could TRY a replacement stud in the hopes that new ones have slightly larger splines to secure them. Some of my other cars have had "secondary" fasteners to hold the rotor to the hub when the wheels are removed. These have typically been nothing more than small 1/4-28 flat head screws. If your hub has something like that which is stripped, you could certainly have it HeliCoiled.

As for the cost, the process isn't long or involved. I think AutoZone sells small kits if you want to try this yourself. The kits have a drill bit, special tap, a few inserts, and the installation tool. For special sizes I've paid upwards of $50/kit from sources like McMaster-Carr. If you don't want to do this yourself, call around to shops (automotive AND machine shops) and see if you can find one that already has the kit. If they already have the kit they will only charge you for the labor and the insert itself... perhaps 1/2 hour's work if you bring the part into them.

 

[Guest]

It's a 73 TR6.

It has the rotor attached to the rear of the hub by 4 bolts. I'd need to helicoil one of these.

This is just the latest in an ever increasing series of problems caused by me having the bright idea of upgrading my brakes and thinking (ha ha) that the parts would be easy to swap on a 32 year old car.

 

[frankenstang57]

/ubbthreads/images/graemlins/tongue.gifYou could always tap out the hole the next biggest size and go that route. It's alot easier than a heli-coil, and your going to be drilling it out for the coil anyway. I've used them with success in the past but they can be a bit of a pain when the come back out when removing the bolt. /ubbthreads/images/graemlins/devilgrin.gif

 

[piman]

Re: 2 helicoil or not 2 helicoil, that is the ques

Hello Alan,
another option is a second hand hub. Stripping the brake disc securing thread is uncommon, I think, so that is probably a good route to take.

Alec

 

[Alan_Myers]

Re: 2 helicoil or not 2 helicoil, that is the ques

Hi,

I'm not a big fan of Helicoil and similar. There is a much better alternative if you can find it. It's called a Time-sert. These are complete sleeves that thread into an enlarged hole, rather than that silly coil that sometimes works, sometimes doesn't. For a critical thing like a brake rotor, I don't think I'd trust a Helicoil.

A replacement hub would be the best solution, if possible.

It could probably also be welded, drilled and re-tapped to the original size. But, a used replacement would probably be cheaper.

Alan Myers
San Jose, Calif.
'62 TR4 CT17602L

 

[dklawson]

Re: 2 helicoil or not 2 helicoil, that is the ques

I've never used TimeSerts but have only heard good things about them. Alan, do TimeSerts have the same potential "back out" problem that Frankenstang mentioned? I use HeliCoils at work with the caveat that you never use Loctite on HeliCoils. Do similar limitations apply to TimeSerts?

 

[martx-5]

Re: 2 helicoil or not 2 helicoil, that is the ques

Time-serts are good, but the procedure to install them is essentially the same as a Heli-Coil. There is nothing wrong with a properly installed Heli-Coil. If it's going into cast iron or aluminium, the threads produced are superior to the original material. That is why the aircraft industry uses them on virtually every threaded fastener that goes into aluminium. I have installed literally thousands of these here at work, and have yet to see one fail. If you're reluctant to do the job yourself, bring the rotor to a local machine shop and have them install it.

 

[vettedog72]

The disks seem to last for ever on a TR6(if you don't road race a lot) so rather than the "new" part at $300 I would drill and tap a new hole for a larger bolt (be sure to get the correct grade). I bet a used spindle, when you don't need one /ubbthreads/images/graemlins/wink.gif, will be as cheap as dirt. KEEP UP THE UPGRADES, BTW, were you doing the Toyota 4X4 upgrade?

 

[Guest]

I've decided to just buy a remanufactured hub from TRF. By the time I'm done it's going to be the path of least resistance, and with the amount of time I've spent on this, least resistance is the way to go...

And yes it is the Toyota conversion - I'm adding drilled rotors and doing the Morgan cylinders at the rear at the same time. Or trying to. It seems though that at the rate I'm going I'll have a new car when I'm finished...

 

[vettedog72]

That is not a bad feeling; I get that feeling when I put new spark plugs in! /ubbthreads/images/graemlins/smile.gif

 

[Guest]

Don't - the last time I took mine out (to do a compression test) I found out I'm about due for an engine rebuild.

I'm still trying to 'adjust' to the price of having it done over the winter, mentioning spark plugs hits a nerve...

 

[vettedog72]

I mean wash it and clean the tires! /ubbthreads/images/graemlins/grin.gif