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TR2/3/3A Timing Chain Tensioner - 1959 TR3

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https://s1275.photobucket.com/user/mt10flyer/media/tensioner001_zps2dcaae8d.jpg.html

There is the link to pics. I bought a tensioner from TRF and one from Moss for comparison purposes.

The failure of the Moss tensioner occurred at the location of a kink on the bottom side also found in the new Moss tensioner. Also, after only 500 miles the broken Moss tensioner has surface pitting and had a generally terrible overall appearance. The new TRF tensioner has no kink, but does have strange surface markings (which pleases me NOT). Also, at the location the Moss tensioner contacted the inside of the timing chain cover, significant damage occurred in that 500 miles. I am an engineer but not a materials guy, however, I believe the old Moss tensioner metallurgy is too hard and brittle. It therefore, rubbed that damage area in the timing cover and failed quickly. The kink did not help any.

I ran the TRF tensioner because this is the third failure I have had with the Moss supplied one. If I have another failure, I will customize and run a roller bearing...but I hope not.
 
Something to mention...it's a good idea to polish the chain links on the outside, just to make sure you have no burrs or sharp edges to cut the tensioner.
 
Wow yea you never know about those aftermarket parts. It lookslike the piece got real hot. Almost like there was an oil issue? Could there besomething wrong with the oil flinger dealie?
 
The one that looks like it got hot has not been run yet. That is the TRF part which looks like it was annealed weird, but it "feels" OK. I'm NOT liking its appearance, but I'm going to run it.
 
That was my thinking; what you are seeing is the burned oil from the tempering bath. It needs to be hardened and tempered (which looks like it was not done properly to the Moss part); so they only skipped the final step of polishing the surface.

Might not hurt to try to polish it up; but the chain should do it quickly enough and the oil film might act as a startup lubricant.
 
Well sun on the beach. Another timing chain tensioner failure. Once again, the tensioner broke and was driven through the timing chain cover...again. I had installed a good used cover, new post, etc and here I am again. Fourth time? I've lost track now. FYI the timing chain was brand new when I rebuilt the engine. It looks a little stretched?

I am tempted to fashion something else. The MGB has a good one but I haven't looked yet. I am tired of this for sure.

Pic-1 is overview before clean up
Pic-2 shows the tensioner almost worked through the front plate - wonderful
Pic-3 shows hole - I should charge the DOT for resealing their roads. Oil leak = Exxon Valdez.
Pic-4 shows where the tensioner "rests" against the cover
Pic-5 is the tensioner remnants
 

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Don’t discard that cover. That can be welded . I can’t believe after all these years no one has come up with a different tensioner system. My tensioner broke shortly after I bought the car. The tensioner split lengthwise in two places and then broke off at the bend. Like the chain wore grooves in it before it failed . The small pieces were in the bottom drain hole under the sprocket and I found smaller fragments in the sump when I torn my engine down for rebuild this winter.
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Hello From Fernley NV RBCC member. I replaced my chain seal and tensioner TRF the old one was 25 years TR 6 looks the same I did not have as much wear as yours. It seams like time and time again problems come from Moss. Cover may have deep grove in cover. Madflyer
 
This is the tensioner in a MGB. I never had as issue with it and am thinking along these lines. Any other ideas are welcome for sure!
460-560_1_1.jpg
 
Yes a Saab 4 cylinder use a spring loaded ratcheting plunger type.as the belt wears the tensioner moves out on click about 1/32 or; it threads right from the side with the plunger running right on the chain.

Anyways I have been driving these cars awhile and only one went bad and what it was doing was making a grinding gravelly noise. There must be something else incorrect; is the oil slinger for the chain correct? I believe they can go 2 ways and look right and fit fine. The oil gets thrown it different patterns. Perhaps the chain is not getting the correct amount of oil because the slinger is turned around. The slinger would probably work either way around, but one will be better.

Oh and I would keep it stock.
 
Oil slinger is correct and it is getting plenty of oil - or was before the broken shards poked a hole in the timing cover which let out expansive amounts of oil. I've had the car since 1994 and this is the fourth time. Either I accept that every 6 years or so I get to replace the slinger, or I fashion a better solution and take my chances. I had the MGB for fifteen years with an engine rebuild at the start and never had this issue...so I'm thinking (which can be a bad thing).
 
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