Chain Drive Tensioner material

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Rallyho
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Chain Drive Tensioner material

Postby Rallyho » Tue Sep 13, 2016 3:28 pm

While I'm trying to find a short term replacement for the tensioner foot, has anyone else seen high wear on these? Has anyone looked at using a different material and skinning the "foot" with it to combat this? McMaster Carr has alll sorts of project plastic...some of which would survive 200+ degree tranny fluid...and a couple that aren't stupid expensive. "Kevlar filled nylon" sounds cool. Thoughts?
Rallyho

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Geoff
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Re: Chain Drive Tensioner material

Postby Geoff » Fri Sep 16, 2016 12:00 pm

I looked around for a spare 30:31 chain tensioner for you but didn't find any. You may need to build new 'feet'(?). I would suggest sticking with a normal chain tensioner/guide material. You don't know how some interesting-sounding material may behave. (i.e. kevlar filled nylon might hold up well but will it wear the chain? glass-filled plastics typically have fairly long strands of fiberglass - 6-10mm I think?- so would the Kevlar strands end up wrapping up in the chain eventually?)

Typically chain tensioners are made from graphite filled or molybdenum disulfide (MDS) filled nylon 6.6. Nylon 6.6 is relatively strong and heat resistant and the graphite or MDS filler helps add extra lubrication.

The original tensioner that broke down on you is probably graphite-filled nylon 6.6. But it's also more than 35 years old and has been soaking in oil so it's not surprising that it broke under heavy abuse. I wouldn't fear replacing it with the same material.
The kind of dirty that doesn't wash off :eyebrows:

Rallyho
Posts: 368
Joined: Thu Nov 16, 2006 12:31 am
Nickname: El Blanco
Number of Saabs currently owned: 6
Location: Camden, Maine
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Re: Chain Drive Tensioner material

Postby Rallyho » Mon Sep 19, 2016 2:13 pm

Thanks Geoff. That's good guidance. When ya gonna get yer rig out there and spank it wicked hawd?
Rallyho


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