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Little end bearing noise

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Hi All

I rebuilt my TR4A engine introducing a lip seal at the rear main and all went well apart from a persistent tink tink tink

So I went in search of the cause : looking first at rocker clearance, could a rocker be touching the rocker cover

The noise started with the engine and was more noticeable at low revs when the engine made less noise

Anyway with covid-19 restrictions I went the whole hog and took the engine and box out and strip the thing down again

The lip seal was still there, the camshaft was smooth and not clicking , the cam followers and cam shaft were unmarked

The only thing I could find was loose little end bearings

According to an engine building friend the gudgeon pin should just slide out of the conrod little end under its own weight: well mine just fell out and were clearly loose in the bearings

I could waggle the pin in the rod

The conrods were ones that I had ground smooth as in Kastner competition black book years ago when the 4A was a race car so they didn't owe me anything

My question to the forum is: who has replaced little end bearings as there is a Churchill tool according to the Workshop manual but more importantly once in the little bearings need to be honed exactly square.

Has the forum addressed this in the past as I can't find anything on it (I do have a "Can't find it Gene" according to my wife)

Thank you in anticipation of your general advice

Michael Hunter

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Interested in replies to this, as I think one or more of my small ends are rattling.


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Hi Michael, give Nick Bonham a call, I don't know if he is still working but his firm do a grand job of it and will hone them square to the big end diameters also. Failing that even Lenton Engineering in Nottingham (Radford I think from memory) can press in your supplied little ends and hone them for you.

Mick Richards

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Hi Michael

I too had a rattle when warm and on tick over went with a little more revs thought it was cam followers so removed and replaced , cam lobes looked ok 

no change so removed cam for better look found cam bearings badly scored so out with engine to replace which turned into rebuild. I too had a loose

little end which I believe to be the cause of the original noise so had the con rods sent away for new little ends to be fitted which needs to be done on a 

jig to keep the rod square. Engine rebuilt and running fine although not yet run in


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Thanks Guys

In the present situation I have found at set of old conrods which have tighter little ends which I can use with this engine (road use only these days)

But your comments push me to drag out the cams shaft bearings and check them, I have a home made tool to push the thru although it does mean that I have to take that round plate out of the gearbox end



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1 hour ago, Rob Salisbury said:

It's a job for a well equipped and Triumph friendly workshop, in the past Sutton Rebore have done both 4 pot and 6 pot rods for me, it's not expensive but you need someone who knows what they are doing.

Cheers Rob

Sutton Rebore is no more, but SRS Engineering (also in Sutton) are recommended to me for such jobs. I was going there anyway to get my head skimmed, & hard valve seats put in. I can see this job growing !


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