Hi everyone :) HELP PLEASE

 

Ive got a drama with my starter motor mounting and wanted to see if anyone had any advice or has had the same fault.

 

The thread for the lower starter motor has been ripped out of the g/box and due to this not being strong the actual starter motor mounting face has sheared at the top leaving the other mounting nut in place.

 

Its a pretty big drama and ive already got a new starter motor on the way but need to look at sorting the thread on the gearbox so that the mounting stud will go back in secure.

 

There is a few ideas i have had as i am a mechanic myself just wanted opinons from people. I can either retap the hole to accept a larger stud or retap it and insert a wire thread insert to take the same stud but not sure if this will be strong enough. The only part of the thread that is still there is right inside and its only about 2 threads anyway so not enough to hold the stud.

 

Thanks in advance for any advice or ideas :)

 

Marty

i'd say re tap with a larger stud....

I would re tap to the next size up.... Carefully!!

i'd say re tap with a larger stud....

Snap!!

snapped :D

re tap! next size up.

Thanks for the advice guys :)

Hi Marty, This is a very common issue and have dealt with it many times, most times caused by the wrong bolt been fitted and then overtightened and as alloy is soft pulls the thread out, or the bolt not tightened up enough so the starter rattles the bolt about.

 

Depending on the exact level of damage there are different ways to repair the thread, in your case get a larger bolt of same length and match this to a tap of the correct size, been soft you will easily re-thread the hole after drilling it out slightly to get the hole round again.

 

As far as the repair been strong enough, when you have repaired the thread and refitting the bolt and nut fixing use thread lock to prevent any chance of the fixings coming undone from vibration and all will be ok.

 

Jeff TT

I had the same problem when a Zed garage replaced my gearbox and bodged it, retapped the bolt thread and a new stud and nut at the top, been fine since.

TBH I have used "Helicoils" in the past to good effect as well.

Ah good stuff sounds like a plan. Also do you know what is the standard thread and whatyou retaped it to??? if i go one size up will the starter motor mount still go on no problem or will i have to drill that slighty. Is there anywhere on the net as well to source the stud to use. Cheers

 

Marty

m10 x 1.75 iirc.Its also worth bearing in mind that the hole can be made deeper and the thread tapped further down.Just use a longer bolt after.

I actually araldite epoxy'd the broken ear bit back on the starter motor again with some small metal struts in the epoxy to brace the edges and wrap over the corner where the hole is. The starter motor was then put back on the car to get it going temporarily. Another starter motor was then bought ready to replace it when the araldited bit would surely break again. That was more than 3 years ago. It is still working fine and the spare is in the garage!

 

The nuts work loose and the starter motor breaks its mounting flange when it tries to start the engine while it is half hanging off.

Job done :) retapped out to M12 and seems to be doin fine had to get a really good set of taps from halfords for 30 quid but no problem in the end but did have to modify the starter motor flange to get it on which was a bit tricky. Finally my Zed is back on the road just gotta sort the running dramas now.

Job done :) retapped out to M12 and seems to be doin fine had to get a really good set of taps from halfords for 30 quid sort.

 

You should have gone to and engineering supplier and got a HSS tap set. Would have been been cheeper and better.

 

Allan

Yep the set i got from halfords are HSS and got taper and plug type plus a set of dies as well so able to do any re-tapping in the future now :)