TR4/4A TR4 Timing Chain Maintenance

[TR4]

Is there regular maintenance needed for the timing chain on my TR4? Lately, after about 200 miles, there is a slight noise coming from around the lower timing gear and with a shot of WD40 it goes away for another 200 miles. Should I be looking at replacing the chain or simply removing the cover, checking the tension and greasing it up? Advise is appreciated.

 

[Don Elliott]

Usually, the noise from a timing chain will not go away with a squirt of oil. So I don't think it's your timing chain. The noise you get from the chain (if you have a noise problem) only occurs when you rev (blip) the engine when parked and the chain will "rattle" or "clatter" as the RPM drops after you take your foot off the gas pedal. If this is the case, it's still not the chain, but you would need to change the timing chain tensioner, a $3.00 leaf-spring item that wears out because, to tighten the chain, it always rubs on the chain edges. The expected life of a tensioner is about 40,000 miles. There is no grease inside here. It's all oiled by the engine oil.

 

[TR4]

Thanks Don, maybe I have something rubbing and hitting it with the WD40 keeps it quiet for a while. I'll take a closer look.

 

[Darrell_Walker]

Excatly where do you squirt the WD40? The "lower timing gear" is on the crankshaft, are you lubing the front crank seal (where it comes out of the timing cover)?

 

[tomshobby]

If WD40 is helping when squirted on the outside the crank pulley might be loose.

 

[TR4]

Excatly where do you squirt the WD40? The "lower timing gear" is on the crankshaft, are you lubing the front crank seal (where it comes out of the timing cover)?

Yes, that is exactly where I am squirting the WD40, right where the crank comes out of the timing cover.

 

[Darrell_Walker]

Excatly where do you squirt the WD40? The "lower timing gear" is on the crankshaft, are you lubing the front crank seal (where it comes out of the timing cover)?

Yes, that is exactly where I am squirting the WD40, right where the crank comes out of the timing cover.

Ok. It seems unlikely that the WD40 is doing anything to the internals of the timing chain, since the chain should be well oiled from the internals of the engine. It could be that the seal is going bad. It is basically a rubber ring, held against the crankshaft with an internal spring. In any case, it would require pulling the timing chain cover off to replace it.

 

[TR4]

Thanks Darrell, so if I pull the timing cover to replace the seal, I guess I should replace the tensioner too. Anything else to replace while I'm in there?

 

[Darrell_Walker]

Thanks Darrell, so if I pull the timing cover to replace the seal, I guess I should replace the tensioner too. Anything else to replace while I'm in there?

The cover gasket, of course. And check out the crank where the seal rides. If the crank is scored, there is a "speedi-sleeve" that you can put on to give the seal a good surface to run over. If you still have the mechanical fan, it is probably worth installing new rubber mounts on it.

 

[TR4]

Thanks again Darrell. I'll let you know how this goes. Maybe take some photos during the process and post them.