I’ve seen two recent failures on this forum of the ‘Rolon’ brand tensioner. I have one for my rebuild and just got a price for a ‘Jaguar original tensioner’ from XK’s.
Should I go with this original(?) unit or install my old one? It has little wear. No one seems to stock the ‘Renold’ brand unit that was recommended.
Thanks folks.
Bob
So long as they assure you it is NOT a Rolon, which are marketed as “OE Jaguar parts.”
If so, a semi-worn original is better than the new Rolon.
Rob Beere seems to offer the Renold on his website. I found one on eBay not to long ago. That’s what’s going into mine.
1 Like
Or you can use a genuine Land Rover Series 3 petrol engine one. Or one for an MGB or just about any BMC “B” series engine. They are all the same part.
I have used Land Rover ones for the last few engines as I bought half a dozen, but have run out.
I got one for my Mk2 through our local Jaguar dealer (Purnell’s at Blakehurst) under the Jaguar Land Rover Classic association. It has the wrap around rubber foot and the dealer overnighted it from Melbourne warehouse. Came in Jaguar box and was made in France.
This is what I did when I re-re-re-re-re built my engine, actually it was the last ‘re’ and I found one on ebay.
Cheers,
LLynn
Hello Bent-Bob:
FYI, Jaguar Classic Parts supplies the correct lower chain tensioner as Part # EAC3629 through your local Jaguar dealer, ie. Jaguar Classic Parts - EAC3629 is pictured and discussed in this thread in the last few months (courtesy bora492)
The thread shows the part as supplied by Jaguar (and likely some others). Coincidentally, in the past couple of days I emailed jaguarclassicparts.com in the UK with a question specifically about EAC3629. My question: “Could you please confirm the manufacturer of this part? The original genuine part was made by Renold in France. The commonly available replacement item carried by many suppliers today is made by Rolon and is marked as such on the body of the tensioner. Is your part made in France by Renold?”.
Their email response from yesterday says this: “Jaguar Land Rover do not share supplier information with external parties but I can confirm that the manufacturer is located in France.”
It seems to me that Jaguar # EAC3629, as supplied by Jaguar, is the best available part matching the original specs supplied today - and is made in France so it’s not the Rolon tensioner. The trick is to make absolutely certain when you order the part ascertaining what it is and what it isn’t. Price point should be a good indicator but make sure you question the supplier first. I’ve noticed some major parts suppliers (one of the usuals) carries both brands - Part# EAC3629 @ $34 and “special order”; and Part# EAC3629* (note asterisk) @$18 as aftermarket reproduction and “in stock”. That stresses the need for us to do our due diligence when placing our parts orders because it can be quite confusing, no doubt.
Suggest you contact an authorized Jaguar dealer and share what they have to say - we’re all ears! Good luck. 
1 Like
If I gotta ask…!!!
The block alone is nearly $15k…
It’s Ally… think of how much you’d save on shipping! Not to mention not needing a heavier engine stand to assemble it.
Guys
You can add me to the list of people experiencing failure of the Rolon tensioner on my 3.4 ltr. A previous owner had fitted this unit.
The bonding on these tensioners is nowhere near the original specification, and it is doubtful if the shore hardness of the rubber block comes anywhere near the original requirement.
In my days on the workshop floor as an automotive technician we were taught strictly never to turn any engine, with a timing chain camshaft drive, backwards. In fact it was almost a sacking offence. In all those days and later in life in various countries I never saw a Renolds tensioner failure even on heavy high mileage diesel engines.
It seems some of the lessons of old have been forgotten………….
Somewhere on this site someone mentioned a Nissan equivalent, but wasn’t too specific. I would certainly trust a Japanese manufactured part.
I believe that was me. The Nissan L16, 18, 20, 24, 26, and 28 engines (Datsun 510, 610, and 240-280Z, etc) use a tensioner that is virtually identical to the BMC/Land Rover/Jaguar tensioner. I’ve found NOS Nissan tensioners on eBay without difficulty, and knowing Nissan, there’s a good chance they still produce them.
Be careful buying an MG tensioner as mentioned above, as most MG parts suppliers are just supplying the Rolon parts also…they are a known failure point in the MG world also.
The one you want is the Renold (sp?) part that is made in France. Even going to to your local Jaguar dealer won’t ensure that you get the French one, as I believe they have two sources.
There is also an MG parts supplier in the Bay Area names Basil Adams who keeps the French ones in stock for reasonable money…I believe his come in Land Rover packaging. His email address is basiladams@yahoo.com
1 Like
It does look substantially similar, odd coincidence. But the oil pickup port doesn’t have a built in collar to help seal that passageway. If the piston is the same exact size though I’d guess it could be used in the proper part’s body.
It’s actually not an odd coincidence. 1950’s and 1960’s Nissan engine design was so similar to BMC products of the time that Nissan cylinder heads and camshafts literally swap over onto their BMC cousins.
Yes, I don’t know which tensioner body the Nissan design replicates, but the plunger and rubber shoe should swap over to any of them. That’s is the failure point with the Rolon parts, so that’s the part where you’re looking for OE quality.
Here’s a vendor that claims to have OE Nissan parts.
Just a small note of caution: Does anyone have practical experience of using this Nissan tensioner in the XK engine over a significant period of time? I notice in the photo that the rubber pad does not wrap around the steel “shoe” as it does in the supposedly better Renold part. Some have suggested that this is why the Rolon part fails. I don’t have the engineering data to say whether the loading on the part is higher on the XK engine than an MGB, but I’d be a little wary of extrapolating too much with such a critical engine part.
They work: unless there’s been a change, in the years since I wrenched, they are a direct replacement.
If it were a genuine Nissan part, I’d use it unreservedly.
Also, all the A series Nissan engines used the same tensioner.