There have been a lot of TC88's sold over the years, have any companies come up with replacement for the plastic pads that won't shear off? Like maybe ...a wheel?

And since its small pieces that get jammed up in the oil pump, does anyone make a pre-filter to catch debris before it gets into the pump?



There's certainly a market for this stuff

 

They do make a wheel, it's called gear drive. Cyco makes a replacement pad and Harley redesigned them in 2006 to eliminate the issue.

 

They did. It's called "hydraulic tensioners". Use a SE cam plate and the later tensioners.

There is a design issue with spring loaded tensioners. They need to be tight to keep from bouncing. When the roller tappets slide off the top of the lobe they want to momentarily turn the cam forward which places a load on the tensioner. forcing it to move. They increased spring pressure until the closing ramp would not move. This additional load caused the tensioner to wear.

Hydraulic tensioners are better in that oil does not compress and overall tension on the chain is less to maintain proper chain tension. The only time the tensioner has any load is on the lifter off the ramp and oil supplies just enough force to keep the tensioner from moving. The rest of the time the load is light and the tensioner shoe lasts much longer.

The old spring tensioner doesn't know how to deal with the change in force so it has to supply maximum force 100% of the time.

 

As far as oil pumps go.. The SnS pump has inlet screens on it.. If using it, the SnS plate is the way to go since the slots are wider for the bigger gerotors.

 

Gear Drives.
Scott

 

Gear drive?

 

From what I've heard, the gear drives only work if a crankshaft has a minimal run out, .003", but factory spec is +-.012". I was talking about using the spring or hydraulic cct, but instead of a plastic shoe pressing on the chain, use a wheel so the friction would be insignificant.

Good to know there's an aftermarket oil pump with a screen out there, thanks I'll look into it

And I appreciate the explanation of why the cct' s failed to begin with, extra pressure. I've read the advice to check the wear on the shoe every 15k-20k mi, how much mileage can I expect to get from a hydraulic cct before I should check for wear?

 

Me thinks the plastic wheel, would need a bearing, and would still be subject to wear.
The chains had burrs on the links, and once polished smooth from either buffing, or running operation, very little chain shoe wear after that.
Yes, no more than .003" TIR, is what is wanted for gear drive installation.
Scott

 

Why no wheel? Additional complexity and cost with questionable returns... the wheel may last longer than a plastic tensioner, but what of the rest of the system required to use a wheel?

The hydraulic tensioners seem to last pretty well, and they clearly work well enough for stock.

 

Not enough room for a wheel unless you make it really small. Then it would like wear out quickly.