Timing Chain Rattle

[MB]

I'd agree with NickA that front chain adjuster seem to be at its loosest setting

adjustment.jpg

[flying farmer]

I had this problem on the engine in the TR. The solution was to carefully build up the end of the chain guide with weld (slowly so it doesn't get hot), then redrill the hole closer to the edge of the guide giving a bit more movement.

IIRC I moved the hole outwards by about the width of the bolt thread.

Neil

[Westfaling]

I'd agree with NickA that front chain adjuster seem to be at its loosest setting

[ATTACH=CONFIG]27234[/ATTACH]

i think that's the tightest setting but I'll pull it apart tomorrow to confirm - I might be able file it to get a bit more movement or resort to Neil's suggestion.
Nick

[milothedog]

i think that's the tightest setting but I'll pull it apart tomorrow to confirm - I might be able file it to get a bit more movement or resort to Neil's suggestion.
Nick

If you look at this, I'd say your right Nick .GRID005156.gif

[MB]

Yep your probably right I think I have my pivot point and slot orientation Vicky verky. I thought the hand was levering up not pushing down and I did mine a long time ago!

scan0001.jpg

[Westfaling]

Well I pulled off the tensioner and guide tonight. Alarming findings
The guide on the top is the one that came off with less than 1600 miles on it. Deep wear groves and rubber breaking up. (The lower one is my old one)

TC wear.jpg
The tensioner had quite deep grooves too (the one on the right) The one on the left is the old one that I've just put back on.
TC wear2.jpg
I did file the adjustment hole as suggested by Neil. I maybe added 3mm to the adjustment range leaving enough metal -IMO.
NB For the record it was adjusted all the way in.
TC filing.jpg
The top (straight) guide had no visible wear.
Once re-assembled as per the ROM the chain stayed tight to the top guide when turning the engine in either direction.

I should probably have pulled the LH chain too but it seems tight and I'm on a deadline for a road trip to the North Island next week.
My biggest concern is that the rubber appears to be crap! Anyone else come across this??
I forsee another strip down to replace the guides/tensioners if I can be assured I'm buying quality products?
Nick

[milothedog]

have you checked the Oil spray holes are clear

[Westfaling]

That's a good point perhaps it was overheating due to lack of oil feed. I've put a different tensioner back on but I should check that before I button it all up.

Nick

[staginhiding]

At least you've found the problem..its when you dont know what it is it becomes frustrating..
This goes back to the question we all seem to be asking about the quality of new parts,critical when its in a major mechanical unit..

Sam

[Westfaling]

Sam
Yes quite satisfying - I wasn't imagining the noise and it was getting worse. Feet up with a Cognac right now. If it was an oil supply problem it may not have been a problem with the rubber.
Nick

[NickA]

My biggest concern is that the rubber appears to be crap! Anyone else come across this??
I forsee another strip down to replace the guides/tensioners if I can be assured I'm buying quality products?
Nick

I seem to remember there was an issue with the guide rubber quality that was raised quite a while ago. Can't find a reference to it anywhere though.

I'd have put the old guide back in again

Fancy running your engine for test of the tensioner oil spray like this?

http://www.youtube.com/watch?v=rfcLGNo1wx8

[Bob Heritage]

The original oil feed was in the centre of the pad and lubricated as the chain passed over it, the later ones have the oil feed to the side to lubricate before the chain passes over it. I know of one garage that drills the centre of the pad on the new ones also.

[Ian Durrant]

The original oil feed was in the centre of the pad and lubricated as the chain passed over it, the later ones have the oil feed to the side to lubricate before the chain passes over it. I know of one garage that drills the centre of the pad on the new ones also.

That's interesting. My Stag has the newer type and if I remove the oil filler cap at tickover you can see there is a little oil on the chain. However on SWMBO's TR7 (half a stag lump), if I do the same thing, oil is flung from the chain up and out of the filler. Its a 1982 so you would expect the later type tensioner (and history file has no mention of new chains). As the chain is still fine I guess it will be a while before I can find out (I hope!).

[MB]

I seem to remember there was an issue with the guide rubber quality that was raised quite a while ago. Can't find a reference to it anywhere though.

I'd have put the old guide back in again

Fancy running your engine for test of the tensioner oil spray like this?

http://www.youtube.com/watch?v=rfcLGNo1wx8

I remember this as well, must of been about 20 years ago BF (before forum) There was a bad batch of guides where the rubber wore through too quickly. Cant find it in the old technical reprints on the main site but they may have thought it was an issue that was resolved so not worth including or happened after this doc was edited.
Unlikely you have chain guides from this batch unless you had them stored for about 20 years, so probably another example of poor quality reproduction parts.
I recall Tony Hart identified the issue with the original bad batch so you could email him or has someone got a collection of old club mags neatly stored in chronological order and lots of time to search through them.

I suspect your Stag paranoia and ears have saved you a bigger bill.

[Guest]

Good one Nick,
What a bugger but at least you have that problem sorted out.Hope that this time next week the weather is fine and we have a good trip north!!!!!
Anthony