I reported on an aftermarket timing chain damper (aka “chain guide”) failing in my rebuild after 5,000 miles, now more than six years on. Conclusion was a rare 1/1200 defective part.
It was part of a timing chain kit that included the four chain dampers, upper and lower chains, lock tabs and Rolon tensioner (more on that below). The part itself is around $13. It keeps the chain from lashing too much and so long as the chain’s tensioned properly is not absolutely critical to function … and a big job to fix. The vendor’s advice was to drive the car till I got around to fixing it but to not exceed 4000 rpm, which is what I did for another 8,000 miles. Procrastination.
I finally bit the bullet these past several days. Pulled the head, sump and timing cover, removed the broken remnant and replaced it and the other aftermarket upper chain damper with the originals, which are still in excellent condition. This is the remnant with the piece I extracted six years ago:
The engine had a 1-2 second rattle sometimes on startup. Without the benefit of the damper the lashing upper chain gradually wore away a small bit of the piece left in the engine, obviously putting fine steel particles in the oil but I changed it and filter six times over the course of those 8,000 miles. No wear on the chain itself.
On a positive note, after 13,000 miles the other replacement upper chain guide and two replacement lower guides were all in like new condition, the lower chain tensioner the same. This is the notorious Rolon tensioner that anecdotally has a high failure rate, specifically the rubber shoe detatching. There’s no evidence of that here, and very little wear.I have a new Reynolds tensioner to replace it - still deciding if the need is indicated. If it ain’t broke, and all that …
Going to get the head redone now that it’s off. Updated valve guides with oil seals will be nice. Will finally get around to replacing the scalloped camshaft sprocket retainers. Replacing the weeping teflon front seal with the standard item. Decarbonised the combustion chambers. Cleaning up 10 years of accumulated oil film will pretty up the engine bay. Silver lining.
Looks like a nice clean break on that guide. I’ll bet you could weld it
Does the shoe look any different on the new tensioner? The prevailing wisdom (might just be an old wives’ tale) is that the issue with Rolon is that there is not enough rubber wrapped around the metal piston. This allows hot oil to reach the bonding layer and eventually delaminate it.
It actually looks like the Rolon shoe is les securely mounted than the Renolds. The Rolon plunger looks to be a sort of three sided thin steel box into which the shoe is bonded, while the Reynolds plunger is a more robust piece of steel that the shoe is wrapped around …
Yep that looks about right. I’d be inclined to use it. Tough call though because in theory, yours has thus far passed the test. You can try what I’ve heard Rob Beere does to triage the guides, and that is to soak on hot oil for some days and see if anything loosens. Where’d you locate the Renolds one? Had it sitting on the shelf?
Rather than trashing the part maybe it could be modified by putting a couple of solid alum aircraft rivets in to secure the rubber . Ahhh maybe not that part failing could cause damage
Fabricate a part from 4130 x 050 steel and research a glue ?
Just some ideas
Merry Xmas J-L
Well, that was a quick fix. However, when I removed the replacement lower chain damper (on the left, original on the right) it exposed damage that was covered by the chain. The witness marks are quite deep after 14K miles while 65K mile original has little wear.
The longer lower damper is showing no real wear and the shoe is still hard.
The oil delivery arrangements between the Rolon and the Renold are dfferent. The Renold has a larger oriface and it actually recesses within the block. The backing plates are also different - the original Renold has an extra channel while the Rolon is a larger circle only - one might expect the Renold’s oil delivery would be somewhat better?
That is horrible, really really awful. I’m so glad I found NOS ones
This drove me crazy. I’ve seen every permutation of these, some with no oil feed hole at all (how’s that supposed to work?) I’ve seen others with a tiny hole and no larger recess for the locating dowel, and with recess but with a tiny hole. Your Renowled looks right to me though. I don’t know the purpose for the extra slot in the shim. I really don’t like the full length backing plate. I received one where, when pinched tight, the piston shoe was wide enough to drag on the backing plate, garbage
I don’t think the base plate matters much, but the rubber/ shoe attachment does.
When I rebuilt the Rover a few years back I replaced both tensioners (upper/lower) with Renolds, that I got from J. R. Wadhams, a Brit Rover parts place, largely because of the failures reported on here of the Rolons.
But to the same degree referring the Manchester as Mancheter isn’t any better. 
