Fred,
The problem is the oil tensioner doesn't build up pressure fast enough at
start-up and therefore lets the tensioner move all the way in ( you probably
already know this but other's may not), thus no tension on the chain until
oil pressure does it's job. I fixed this by buying a stiff spring at PEP
boys to replace the weaker ineffective stock spring (inside the tensioner).
I had to shorten it to size but, it's thicker design prevents the tensioner
from moving back so far at start-up.
Another easier fix that a Roadster specialist shared with me was to snug
"nylon" wire wrap straps around the shaft of the tensioner as spacers, to
basically, do the same thing; prevent it from moving back so far. I did
something similar on my first attempt but the rubber spacer didn't hold up
to the oil and high temperatures and eventually disintegrated. However, he
said the nylon did the trick. One can add more straps to increase the
desired space. Plus, it's a 5 minute install...nice.
Either manner will keep the tensioner from losing all affect at start-up.
Marshall
> From: Roadster <roadster@texoma.net>
> Reply-To: Roadster <roadster@texoma.net>
> Date: Mon, 29 Oct 2001 00:51:44 -0600
> To: Datsun Roadster List <datsun-roadsters@autox.team.net>
> Subject: U20 Timing chain
>
> Howdy All,
>
> The upper timing chain has just started to buzz. The head has never
> been off and it has 70k miles so I assume that it is just the usual
> chain stretch/gear wear. I have a new set of chains/gears but don't
> want to use them until I go through the engine next spring (I hope!)
>
> Didn't I read somewhere (Gordon?) that the upper tensioner can be
> shimmed to get a bit more life from the chain? It is only driven
> occasionally but I don't want it to commit suicide.
>
> I once knew a fellow who did away with the oil pressure aspect of the
> upper tensioner. He drilled a hole in the side of the head and
> installed a screw in the tensioner so he could adjust it manually. A
> bit extreme I think!
>
> --
> Best regards,
>
> Fred Schroeder
> '70 2000
> SRL311-13359
> TDROC
> Home page http://home.texoma.net/~sitsinwest/
> Regular e-mail Sitsinwest@texoma.net
>
> ///
> /// datsun-roadsters@autox.team.net mailing list
> /// Send admin requests to majordomo@autox.team.net or go to
> /// http://www.team.net/cgi-bin/majorcool
> /// Send list postings to datsun-roadsters@autox.team.net
> ///
///
/// datsun-roadsters@autox.team.net mailing list
///
|