Horseshoe Cam Tensioner bolts - not happy with the threads question.

[McCabe-Thiele (Ted)]

Today I went to put back the horsehoe tensioner bolts I am less than happy with one of the bolts as I began to tighten them up (I was aware of this previously but it seems worse). One bolt went to an initial 4 N-M but the second was not tightening up as it should so I am pretty sure the thread is worn and starting to strip.

I put some Locktite on both threads and all was clean before assembly. What are the forces at play on the tensioner is it possible that it could come adrift with just the one decent bolt?

I suspect either the PO has had it off before or the threads have been worn by the vibration through the seized  horseshoe?

Question is what can be done to the casing threads to fix the problem are there any best options?

[Bryanj]

Helicoil both of them

[TrickyMicky]

Just a salient thought to throw in, if you are going to purchase a helicoil set, shop carefully. I have been buying a lot of bits and pieces from White Rose Tools, and have been 100% satisfied. They stock a thread repair kit by Sealey at £135. They also stock EXACTLY the same kit under the Blue Spot brand at £36!!! Haven't used mine as yet, but it looks the business.

[Bryanj]

Depends on fuel cost but you can brig it to me in Glos and i will do it for you

[McCabe-Thiele (Ted)]

Depends on fuel cost but you can brig it to me in Glos and i will do it for you

Thanks for the offer but you are a tad too distant - I will go to the engineers who did my tensioner screw insert and have it helicoiled. I have read on here somewhere of another brand / type of insert but can't bring the name to mind.

[Bryanj]

Timesert but i dont think there is enough metal around the bolt hole to fit those, they are tapped out to 10mm

[AshimotoK0]

Depends on fuel cost but you can brig it to me in Glos and i will do it for you

Thanks for the offer but you are a tad too distant - I will go to the engineers who did my tensioner screw insert and have it helicoiled. I have read on here somewhere of another brand / type of insert but can't bring the name to mind.

After all of the issues you have had Ted ... a trip to Bryan's would be beneficial for other reasons as he could cast an eye over you parts and give you his opinion & do your threads. Just a thought.

[McCabe-Thiele (Ted)]

Timesert but i dont think there is enough metal around the bolt hole to fit those, they are tapped out to 10mm

In that case I will stick with a couple of Helicoils - tbh my experience of Helicoils was way back in the late 1960's when they used to be poorly thought they would sometimes come out with the bolt! Like most things the technology has improved and they are dependent also on the fitter.

 

[McCabe-Thiele (Ted)]

After a pretty long wait (17 days but who's counting) I collected my upper crankcase today - despite engineers being careful there were clearly fine bits of alluminium turnings in the casing groan.........

So removed the bits I had left in place - gear selector forks, slector shaft & gear selection tumbler to re-clean the casing. 
Thank goodness I had removed both gear clusters safely stored in oiled zip lock bags.

Probably as it took so long I was given a pair of new set bolts as the threads were badly worn on the originals.

Only thing I have left in place is the starter gear that I have thoroughly cleaned with petrol, dried then squirted with WD40, dried again, cleaned the crank oil ways (again) and cleaned out all the thread holes with cotton buds after jetting with WD40.

I plan to have a long weekend off with a view to rebuilding the crankcases next week unless..................

[smoothoperator]

Well hopefully the helicoils are all good and you have a squeaky clean engine! It's all progress Ted.

[McCabe-Thiele (Ted)]

Well hopefully the helicoils are all good and you have a squeaky clean engine! It's all progress Ted.

They have done a superb job of the Helicoils with some neat replacement set bolts - not cheap £30 inclusive but happy - I can now get on with the engine work next week.

[Bryanj]

That is cheap, we charged £6 per helicoil(£10 for spark plugs) back in mid 70's. The special taps are not cheap and i would expect engineers to be at least £60 per hour

[McCabe-Thiele (Ted)]

That is cheap, we charged £6 per helicoil(£10 for spark plugs) back in mid 70's. The special taps are not cheap and i would expect engineers to be at least £60 per hour

Apparently they charged me for three quarters of an hours work so it was a good price.