Timing chain adjuster threads size?

[miked]

Can anyone help me with this?
Whilst checking the valve timing and tappet settings I found that some of the threads on the chain adjuster holder (in the water pump cover) are pulled. Yes, as coarse as they are.
Even through it will nip up, I don?t want to risk it, nor do I want to pull the motor apart. I would like to make repair with the engine on the bench. Helicoil, or an adapter. I think I may be able to do this without causing any grief if I take the wedge and tension sprocket out (and block the hole) to prevent any debris entering with the plunger out.

I have tried to match up with a thread gauge and book but can not find anything like it. I thought it might be UNC. To be honest my eyes are not what they were. Too long in the dark in my early days. The motor was just put back together by the PO after lots of work, so I don't really want split it.

Anybody any idea what this thread is.

Mike

[types26/36]

Mike, a few years ago I repaired one, I had it welded up then I drilled and retapped it. From memory and (I could be wrong) I seem to remember it was 5/8 11 UNC.
I also seem to remember it was the same thread as the old BMC Mini sump plug.....the one that had the magnet in it if you know or remember those
Happy to be shot down in flames if someone knows better

[miked]

Brian,

Thanks for the reply. I was struggling to decide around that area. I think you are right. Instead of the outer being 625 thou, I was only getting about 608. I will have an other check. I think I am going to leave it until I have to split the motor and just make a secure bodge. A proper alloy repair can be done when it is off the engine, in the future

Mike

[alan.barker]

the thread is a little special. it's G1/4 bspf( bsp fine). you can buy this helicoil kit from <www.hillclif-tools.com> . you need the helicoil to be 1.5 x dia long. the kits not cheap but the end result is super. stronger than original.
when you reassemble DO NOT USE LOCTITE . this is what someone did on my car and thats why the thread strpped when i dismantled the engine
i hope this helps
Alan B

[miked]

Thanks Alan,

I just inquired about a price.

regards Mike

[mark030358]

Mike PM me ...

I think I can help