• Hi Guest!
    You can help ensure that British Car Forum (BCF) continues to provide a great place to engage in the British car hobby! If you find BCF a beneficial community, please consider supporting our efforts with a subscription.

    There are some perks with a member upgrade!
    **Upgrade Now**
    (PS: Subscribers don't see this gawd-aweful banner
Tips
Tips

Stripped Threads

SteveHall64Healey

Jedi Trainee
Offline
On my BJ8, the lower bolt on the clutch slave cylinder stripped it’s hole in the bell housing. Any suggestions on how to deal with this - ideally without hauling the gearbox out?
 
Last edited by a moderator:
Re: Stripped thread - any advice?

To fix properly, I'd be thinking heli-coil.

Wonder if this would work in lieu of pulling the trans: take an 8mm bolt and cut a couple of lengthwise notches with a grinder to make it into a self-tapping screw, then run it in with maybe blue or orange loctite.
 
Steve, before you give up, try a slightly longer bolt. I thought one of mine had stripped but discovered the bolt wasn't reaching good threads.
 
I agree with Steve. Heli coil ought to do it.
 
great suggestions everyone - thanks. I will try the longer bolt first, then try chasing the thread. If that fails resort to thread repair. What would be the advantage of a thread repair kit over drilling out the hole and starting a slightly large threaded hole - presumably with the next closest larger size?
 
great suggestions everyone - thanks. I will try the longer bolt first, then try chasing the thread. If that fails resort to thread repair.

Not a big issue, but you would have two different fasteners holding the cylinder in place. Now might be a good time to modify one of them by cutting off the head and making it into a pin to allow for easier removal/bleeding as while you need two to locate the cylinder on the housing you only need one to hold it in place.
 
Last edited:
All good suggestions above! To add to the list, my choice of threaded insert is called a Keensert. Basically, it's a steel threaded insert that has wedges that are driven home to lock the insert in. Here's a short video.
 
I rethreaded my BJ8's bellhousing last time I had it out; previously, I'd made do with some 'make-a-thread' goop that worked well enough (those bolts aren't particularly stressed). IIRC, I used 'ThreadSert,' not 'HeliCoil' brand, which are equivalent. 3/8" 'fine'--24tpi if I'm not mistaken--bolts are used all over on Big Healeys, so it pays to have a kit handy (in particular, they're used for the front shock mounts, which are easy enough to strip). I use red (strongest) threadlocker on inserts, and I've never had one come out. Unfortunately, I don't think it's possible to drill and tap for inserts in situ.
 
There are four ideas given. Chase threads, longer bolt, thread insert, and making is a stud by cutting the bolt head and red threadlock it in. Access is the key I would make both the same. As a rule fine threads tend to strip in Alum. easley so having both the same and studs this can not happen again. Madflyer
 
These are all great ideas. However, I got lucky and a fresh bolt with blue threadlocker is holding well. Next time I have to service the slave cylinder, I plan to attempt to replace the thread with heli-coil or the like.

Steve
 
All the Healey gearboxes I rebuilt got this upgrade. Keeps the factory-spec'd fasteners too.

IMG_7439.jpg
 
Back
Top