I’m ready to assemble timing chains onto the block on my '64 OTS with 3.8L. The manual states oil is introduced to the lower tensioner, through the locating spigot (need to order one of those) and passes through a small hole in the slipper head. However, I only have a fake hole. It looks real, but it goes nowhere. I can’t blow through it, spray through it, or even poke a small pin through it. Did anyone else notice this? I think it’s a bad idea to drill it out, because it would likely release the spring trigger prematurely. Thanks.
What make/brand is this tensioner? There should be a thru-hole, and the spring tensioner can be easily reset if it comes loose. There has been a HUGE amount of discussion on these tensioners over the last several monts. The bottom line is if your tensioner doesn’t say Reynold Renold on it as the manufacturer don’t use it and find one that does!
Read through this recent thread on the topic. In one of the later posts I included photos of all the components of a Renold tensioner, including the tiny hole in the metal face of the slipper.
-David
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Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
6
Well, that isn’t what I garnered from the discussions. There are zillions of companies making these same tensioners for use on everything from Ferguson tractors to Nissan automobiles. Many of them make quality tensioners – but one does not, and that’s the Rolon brand offered by many Jaguar parts houses.
The root cause of my engine failure was a plugged “gauze” filter (conical filter), which wore the (dry) slipper foot out as the chains stretched. It took 25 years to fail. During the course of the rebuild, I encountered other problems (naturally!), but it feels good to be putting parts back together after 2 years.
BE CAREFUL!!! I remember maybe 20 years ago when I rebuilt my engine the spacers didn’t have a hole. Once I built the engine it sounded like a sewing machine. Turns out that the XK engine was supposed to have a hole in order to provide oil pressure to operate the chain tensioner. I had to tear down the front of the engine to fix the issue.
Mike
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
9
Y’know, in the discussions of how lousy the Rolon tensioners are, I don’t recall anyone mentioning before that they didn’t even have a real hole for lubing the chain. Is that actually how they’re made, or did someone forget to drill the hole on this particular one?
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
11
I remember that being mentioned. How does this make it “better”? I presume that hole points straight down, so the oil is squirted directly onto the timing chain just before it gets to the slipper?
I understand this same tensioner is used in scads of engines. Is it likely that having the hole in the side of the piston is a great idea for the Jaguar XK but might be a disaster in some other engine – say, one in which the tensioner is oriented differently so oil coming out that hole doesn’t get to the chain?
Others here have found the hole in the slipper plugged with debris.
I bought this from Terry’s and it’s supposed to be the ones they use in their racing engines. That was good enough for me. I started a thread discussing this.
Kirbert
(Author of the Book, former owner of an '83 XJ-S H.E.)
13
I wonder what that means. Were they plugged with debris from the inside, meaning debris that was in the oil? Better filters needed, obviously, but also I’d presume the hole in the side would be as likely to get plugged as the hole in the top. And the idea that a gauze screen could get totally plugged up is also disconcerting.
OTOH, perhaps they were plugged with debris from the chain – which also shouldn’t happen, but I guess the chain could pick up some sludge from the sump and drag it around. Still, you’re shoving stuff into the hole against the oil pressure, so you’d think the oil would just blow it back out.
So, it turns out my unbranded tensioner has a small hole in the piston, so it would probably have worked fine. Still, I’m glad I picked up an “original” Renold on Ebay.
I’ve attached a photo of the box the tensioner came in, for reference. I call it unbranded because there are no identifying marks, be it Rolon or Renold or Made In Great Britain.
A side view of the rubber shoe may indicate if it’s a good one, or not: the “good” ones have the rubber bonded around the end sides, the others are just bonded on the flat foot of the metal shoe…
The last Renold I bought was marked Renold Made in France, so not necessarily GB made these days. Good quality though, much better than the new Rolon I binned…
