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TIMING CHAIN TENSIONER FAILURE and Alternate Part -- CS-103A
ROLON Brand, replacement for factory part numbers:
17H343 Tensioner - chain (with Allen key)
17H6680 Tensioner assembly
17H31 Slipper head

A report for FAULTY REPLACEMENT PARTS is listed in article FT-089

On 19 Feb 2017, Thomas Aczel in Australia wrote:
"My newly and meticulously built engine started to make an increasingly loud whine from the front end of the engine within 1200 miles of being fitted. The motor still ran perfectly well. Removing the fan belt made no difference. The timing cover came off. We discovered that the rubber pad on the (brand new) Rolon timing chain tensioner had separated from the tensioner blade body".
Failed Rolon Chain Tensioner Failed Rolon Chain Tensioner Failed Rolon Chain Tensioner
"My mechanic noticed that the tensioner blade from a Jaguar item fitted straight in to the MG item. The Jaguar equivalent seemed to have the pad much more securely united to the blade than the Rolon "original".
Chain Tensioner, Jaguar Chain Tensioner, Jaguar
"A subsequent search suggests the Rolon failure is moderately common, so if this occurs again I'll replace it with the Jaguar item. I'd not be the first to do this it would seem:
www.mgexp.com/phorum/read.php?41,2502263 -- Regards, Tom

More failures reported by:
Austin Blanch in Raymond Terrace, Australia, Oct 23, 2013
Thomas Aczel in Australia
Shaun Holmes in Norwich, Norfolk, UK
Basil Adams near Sears Point, CA, USA
Heath Racing in Tennessee, USA
Dick Russ in Oklahoma City, Oklahoma, USA
Scott Brown in Redwood City, California, USA
Hap Waldrop in Greenville, SC, USA
Eric Russell in Mebane, North Carolina, USA - Mar 5, 2015

On Oct 23, 2013, Basil Adams wrote:
"I've seen many. That's why I stock the French tensioners made for Jaguar. They go right in an MGB with no modification. The only difference is the initial release mechanism for installation". -- Basil

On Mar 3, 2015, Dick Russ wrote:
"In My E-Type, shortly after the engine was back together, I was hearing chain noise on start-up. I found the Rolon Tensioner contact shoe in the bottom of pan. I decided to go with the Jaguar tensioner which has a lip on each end of the shoe for reinforcement (made in France)".

On Mar 5, 2015, Hap Waldrop wrote:
"The deal is you need to get it from the Jag dealership, this is OEM part. If you order a Jag tensioner from most of the aftermarket vendors, you get a Rolon brand with the same rubber pad we have on the MGB tensioner. The body of the tensioner bolts on to the B series block, just like the MGB one, but you don't have access to the loaded spring, and few other small items, so what I do is use the pad/plunger of the Jag unit with the body of the Rolon tensioner from the MG (not 100% necessary, but if you do this you get the best of both worlds)".

On Mar 5, 2015, Eric Russell wrote:
"I had a Rolon failure. I bought the 'Jaguar' version. It bolts onto the B-series block Failed Rolon Chain Tensioner `exactly the same as the other. The spring mechanism is simple - leave the red plastic spacer in place until the tensioner & chain are in place. Then pull the spacer out & push the rub block 'in' - away from the chain - and the spring is released.

Attached is a photo of the failed tensioner. The rubber block is (was) only glued to the metal part. The Jag version's rubber block wraps around the metal piece so it seems much less dependent on the glue's strength".

On February 26, 2017, Tom Aczel in Australia wrote:
"My mechanic (who has vast Jaguar experience) had two catastrophic engine failures with the Jaguar tensioners in 6 cylinder Jag XK engines. He points out that in an MG the timing chain is short and fairly tight, and in his words, 'The tensioner just stops the chain flapping about a bit'. In the DOHC Jaguar engine, the chain is much longer and the tensioner more vital. The valves also can potentially cross over and clash if the cam timing is off, as well as hitting a piston. The two failures were where the rubber had worn down far enough for the tensioner blade to completely fall out of the tensioner body.
Massey Ferguson TEA20 tractor Timing Chain Tensioner 826113M1
My mechanic's solution was to fit the tensioner out of a Massey Ferguson TEA20 tractor! This apparently fits neatly but has a longer shaft, overcoming the ability of the tensioner blade to fall out of the tensioner body with wear. I asked therefore if this was also a Triumph TR engine part, but apparently it is not". --
Massey-Ferguson part no. 826113M1, made by Reynold (France).

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