Starter bolts thread and size

[sixor8]

It's concerning my 1999 Griffith but these starters were used on several cars. I've discovered that the last 'person' butchered one of the Allen bolt heads. The upper one, probably getting it out, and re-used it.

A quick search says it's M8 but my micrometer has it with a shank diameter of 9.45mm so that can't be right. I intend to use 'normal' bolts so are they M10 UNC or something imperial?

[Penelope Stopit]

Found here https://landroverforums.com/forum/general-tech-hel...

[GreenV8S]

sixor8 said:

are they M10 UNC or something imperial?

UNC metric threads are not a thing. I expect you'll find it is imperial, almost certainly UNC. I don't have one in front of me, but if you measure the thread OD and thread pitch it should be obvious what they are.

[sixor8]

Of course, I was running off a the keyboard without thinking, UNC is NOT metric, doh.....

3/8 makes absolute sense, thanks. I don't know why some of the thread about starters on here suggest they are M8... Think I'll get some proper hex bolts, it's not as if they need to be cap head Allen bolts.

[sixor8]

Update on this: I replaced the chewed up allen cap headed bolts with 2 x stainless steel hex items (I recommend one at a time, to avoid having the awkward lining up again...), £2.43 delivered.

[Ozzie Dave]

Just be careful if using SS bolts, if not going into stainless steel they can very quickly suffer galvanic or bi-metalic corrosion, use something on the threads and under the head to stop this happening (not a steel washer).

[JohnMcL]

Also, A2 Stainless is hardly high tensile, more like soft cheese. If it must be stainless, at least use A4-80.

[sixor8]

I put copper grease on the threads of almost everything I take on and off any car. Since there is no flexing or movement such as in suspension where stainless would be a no-no, I just bought the cheapest non-basic bolts available. It's not a boat...

I kept the non-chewed up Allen cap-headed one in case anyway.

[Ozzie Dave]

Hi Sixor8, its not a put down, just having seen how fast this can take place, more worried about any damage to the bellhousing that could be expensive for you later on. And yes I also like to use SS bolts on the stuff we build when its non loadbearing, its just so much 'cleaner' however we tend to work with plastics.