Stripped thread on clutch slave cylinder mount. Options?

[CanberraBJ8]

I've just replaced the dust boot on the clutch fork and noticed while doing it that one of the bolts securing the slave cylinder to the gearbox housing was loose. When I tightened it, I found why - its stripped.

I'm supposing the solution is a heli-coil, but this looks like a gearbox out option, as there is no room around the hole to repair it that way in place. Are there any other options?

 

[British_Recovery]

Not a correct method, but one I used in an emergency, was to try a coarse thread bolt or a slightly larger (metric) bolt. My temporary solution was done in 1965 on my BN6 and worked without a problem. Use a tap if you can, so you don't crack the bell housing. Bob

 

[healeyblue]

How about try a longer bolt to see if there are any better threads further in? Check first with the bolt out and a bent piece of wire to see if it is a through hole or a bottomed hole, so you don't run into the bottom with the new bolt.

 

[CanberraBJ8]

Thanks, those are both ideas that i'll try out. Either way I can then go on and re-tap with the g'box out if they don't work i guess.

Thanks

 

[Bob_Spidell]

I had the same problem and used some of the 'liquid thread repair' stuff. Took a couple tries, but was able to get good torque on the bolt. This is a sort of glue--cyanoacrylate probably--that forms new threads using a bolt and some release fluid. It's held for maybe 8 years and 30K miles. I'll put a helicoil in next time I get access.

This isn't what I used, but Locktite products are usually credible: https://www.amazon.com/Loctite-Form-A-Thread-repair-kit-grey/dp/B000WSEUII

 

[Randy Forbes]

Whenever I rebuild a <<Healey>> trans, I install thread inserts for the slave__I mean, what bone-headed engineer decided to use a fine-thread bolt in aluminum?

Healey Blue won't have that problem...

 

[CanberraBJ8]

Just did a search on the re-coil product. Its more expensive here ($64) than in the UK despite the label stating made in Australia - go figure!

Anyway, saved the online shop to favourites for when the gearbox is out next and will look for the thread repair from Loctite or similar for the mean time. Thanks everyone for the help.

 

[Bob_Spidell]

Some (most) of the ****coil kits don't come with the proper drill bit, and it's usually an oddball (eg. 25/64"). I put red locktite on the coils; not necessary but I figure it can't hurt.

 

[Bob_Spidell]

re: "what bone-headed engineer decided to use a fine-thread bolt in aluminum?"

I always figured it was a cost saving decision--3/8" fine bolts are used in several places (bumper brackets come to mind).

 

[Randy Forbes]

re: "what bone-headed engineer decided to use a fine-thread bolt in aluminum?"

I always figured it was a cost saving decision--3/8" fine bolts are used in several places (bumper brackets come to mind).

Yes, but it's a standard engineering practice to use a coarse thread in a softer (than the fastener) material; notice the cylinder head studs: coarse threads on the end screwed into the cylinder block and fine threads for the nuts to go on.

For something so simple as "writing a spec" it has caused a lot of people trouble__my own slave cylinder "fell off" driving around Lafayette, Louisiana sometime in the early 80s, and I then resorted to "mega-stick" (2-part epoxy roll sourced through the Dyna distributors) to form some temporary threads. That held for years until the xmsn was out for a rebuild. Shakes head...