View Full Version : TR2/3/3A TR3 Timing Chain

12-21-2008, 07:50 PM
Initially I had planned to go ahead and replace the timing chain, sprockets, and tensioner on the 59 TR3 while I had the front end apart, figuring I'd rather spend an extra $100 now rather than have to take everything apart in the future. However, reading though the various threads here leads me to believe the quality of the replacement parts is not all that great, and I might be better off with the stock parts if they're in decent condition. Is that still the general concensus?


A visual inspection of the sprockets seems to show them to be in good shape, to my eye at least. They aren't "sharktoothed" or hooked. I added several thumbnails to my TR3 page -- www.woundedduc.net/TR3 (https://www.woundedduc.net/TR3) -- that you can click on to see much larger, more detailed photos.

The manual details measuring the chain by placing a straightedge between the timing gears and measuring the "deflection", noting it should be less than .4". What exactly are they measuring? Are they talking deflection as in pushing and pulling the chain fore and aft (towards the engine block and away from it)?

Thanks in advance.

12-21-2008, 09:15 PM

I'm doing the same, at least for the sprockets. No reason I can see to change them. The chain & tensioner though are getting replaced. Not positive, but I believe the deflection is what you see taken up by the tensioner, it would be the measured sag from the straight edge.


Don Elliott
12-21-2008, 09:53 PM
In 1990 I replaced the timing chain (I can't say if it needed to be changed) with 80,250 miles on it from new. This new timing chain has now been driven a little more than another 100,000 miles in 18 years. My sprockets and cam + can bearings are all the original ones from 1958.

But I had to change the timing tensioner about every 40,000 miles. So change that now and about 40,000 miles from now, change it again and have a look at your sprockets and chain again at that time.

01-31-2020, 12:49 PM
Has anyone tried the Timing Set from TRF. Moss each component sold separately.
Thanks John

01-31-2020, 09:25 PM
The deflection would be left and right at the mid point between the sprockets...not for and aft.

I don't have an opinion on keeping old parts. I replaced my sprockets, chain and tensioner 3 years ago and will let you know if they act up. So far they are behaving as they are supposed to.

02-07-2020, 01:37 AM
I found the new timing components to be pretty good, in contrast to most of the new stuff. I got everything from BP Northwest; used the slightly more expensive AE chain, but it's a really nice part. The chain I removed was totally worn out, and the gears had visible corrosion in the valleys and sides of the teeth, so in any case they had to be replaced.

02-07-2020, 02:13 AM
I ordered the set from TRF. Got crank gear and chain; cam gear on back order. Two pieces received are of good quality; I am satisfied with them.

02-07-2020, 03:15 AM
An important step for installing the chain on a TR is to polish the chain links on the outer side, so there are no sharp edges to cut into the tensioner. The links are stamped at the factory, so come with some sharp edges that will eat into the tensioner prematurely if not removed.

02-07-2020, 05:32 AM
Didn’t think of that. I will check it prior to install. Thanks

02-07-2020, 09:38 AM
Check the inside of the timing chain cover where the tensioner pushes against the cover. On mine there was a lot of wear from the end of the tensioner. I welded up what was shortly going to be a hole.


02-07-2020, 02:27 PM
Has anyone tried the Timing Set from TRF. Moss each component sold separately.
Thanks John
I have TRF parts ( including timing chains and gears) in my rebuilt TR4 engines. One engine has roughly 20,000 miles while the other has about 10,000 miles. Both are doing just fine.

02-07-2020, 11:32 PM
When I did my first engine on a TR4a engine I neglected the whole timing chain area. A hole appeared in the cover similar to the picture shown. Got a used cover from Fred Petroske (sp?, anybody remember him?) in New York, and a new chain and tensioner from the Roadster Factory and got many trouble free miles after that. If the teeth aren't pointy or showing signs of wear I would leave them but I am very much a if it ain't broke type.

02-08-2020, 02:34 PM
A number of years ago I bought a TR4A as a parts car. The previous owner had started working on the engine and quit. The body was in very rough shape as it was previously located in Buffalo, New York ( bad rust). I wanted the wire wheel hubs and knock offs, so bought the car. Eventually I tore the engine down to potentially use the block. I had no information as to why the car was parked and work started on the engine ( head removed).
The one thing that I did find when I dismantled the engine was that the timing chain tensioner was in pieces in the bottom of the cover. There were also a few pieces in the oil sump. My suspicion is that the tensioner broke and that the car was running erratically. The owner was likely looking for the cause and never found it before he quit and parked the car. If that is true then a little thing like that tensioner can cause a whole lot of problems that are hard to diagnose.

02-08-2020, 07:45 PM
If the tensioner goes the chain rattles against the sheet metal cover...makes a banshee of a racket like everything’s about to come apart!