Tensioner rebuild

fourteener · Post by **fourteener** » Tue Oct 09, 2007 12:24 am

I found bits and pieces on rebuilding the chain tensioners but not a comprehensive how to. I took some pictures whilst rebuilding one in case anyone else wants info on the same thing.
It's a pretty straight forward job but because it's such an important engine part it's not one of those things you want to cock up.
(...If anyone spots any boy scout errors please tell me before my engine grenades

)

Tensioner rebuild

louis356 · Post by **louis356** » Tue Oct 09, 2007 9:38 am

Fantastic!!
Thank you for doing this. Need more items like this

Top marks for the presentation too!!

One day I'll make use of this.

912uk · Post by **912uk** » Tue Oct 09, 2007 10:57 am

this is perfect I never have done one of these ( as a non 911 owner ) but I am now starting to learn some 911 stuff we need more articles like this from all of us and what a super asset that would be..

would the 911 mod save this as a sticky in the 911 side

great work

58A - 71E · Post by **58A - 71E** » Tue Oct 09, 2007 11:55 am

Fantastic thread

If I'd seen this I might have considered rebuilding my 901s instead of buying new 930s, definitely a cheaper option!

impmad2000 · Post by **impmad2000** » Tue Oct 09, 2007 12:52 pm

58A - 71E wrote:If I'd seen this I might have considered rebuilding my 901s instead of buying new 930s

I didn't believe rebuilding 901 tensioners was ever a good idea, or was that just the really early ones ?

Perhaps someone can clarify.
I know Mike Bainbridge had a little tool that he used to set the fill level, perhaps this is the tool that you were looking for.
I reckon that whatever you have done to the tensioners, the safety collars that Pelican sell are a great backup

Great and very useful write up.
Thanks
Tim

58A - 71E · Post by **58A - 71E** » Tue Oct 09, 2007 1:08 pm

impmad2000 wrote: I reckon that whatever you have done to the tensioners, the safety collars that Pelican sell are a great backup :)Tim

Agreed Tim

(Fourteener) James, do you intend to use the collars?

hot66 · Post by **hot66** » Tue Oct 09, 2007 1:43 pm

I have the safety collars ( although not fitted yet )

I thought I'd post on this thread to see how many more James's we could get

Derek · Post by **Derek** » Tue Oct 09, 2007 3:01 pm

Great write up.

And my middle name is James

Derek

fourteener · Post by **fourteener** » Tue Oct 09, 2007 8:05 pm

Safety collars are for chickens

I'm not sure if they would support a collapsed tensioner anyway, they're pretty flimsy. I wonder how much clamping force on the shaft they can generate from 2 tiny 4mm bolts. The collars have been designed to fit tensioners supporting chains in varying stages of wear (stretch) meaning there could be a little stub or 15mm of plunger shaft to clamp to.
I know they're only a temporary defence against total collapse but I would have though a tubular design allowing a few mm of free play at the top would be more robust. But then you haven't got one design fits all.

It's the very early 901 tensioners (shown at the bottom of my page) that are suspect. I can see compared to the later 901 type how the oil could bypass the ball valve and lead to failure.