Hello, I was wondering if there was a way to tell if the cam chain tensioner has been changed to gears. I just picked up the bike but it came with a little build cheat sheet. The line in question is "Gear drive Andrew Cams". I am new to the platform and not 100% sure if this means if this has been switched over to gear drive.. I am guessing the only way to be 100% is to open her up, is there a way to do this (just to see whats in there) without taking the cover off (more worried about the exhaust)?

By the list i think it was built in 2004, was it a thing back then to be changing over to gear drives? Any history on this would be appreciated, thanks.

 

[QUOTE=Tunafish389;20899932]Hello, . I am guessing the only way to be 100% is to open her up, is there a way to do this (just to see whats in there) without taking the cover off ?

No,

 

pull the cover if you want to confirm gear drives are in it.
Don't know how close Thunder Header exhaust is, but I was able to get my cover off with exhaust on by cutting a hex wrench a little shorter for the bottom bolts


..L.T.A.

 

Here's the history on gear drive cams...

The 88" twin cams came OEM with spring cam tensioners and Morse silent link cam chains. These could be problematic. The combo of high spring tensioner, inferior tensioner pad material, and link chains could quickly wear out the tensioners. If the pads wore out, it could lead to a very large repair bill.

It was routine, and some (I'm one of them) consider upgrading the OEM spring tensioners between 20K & 30K miles. Today, with time and heat cycles, I've seen on my bikes and others of that vintage, that even if they had low wear, the tensioner pads were very pitted. That suggests they are getting brittle and more readily able to break up.

There were several upgrades going from $$ to $$$$$$. The top of the list in cost and quality was adding gear drive cams, removing the cam chains and tensioners from the equation altogether...

Two caveats to the gear drive cam upgrade.

1) You need to measure engine run-out at the cam plate. If run-out is over .003", the gear drive mechanism will wear quickly and could fail. That would be as costly as letting the spring tensioners fail..

2) You need to check/set the lash on the gear drive cams. If not that can lead to very noisy gears, but more importantly rapid gear wear and eventual failure.

However, if installed correctly on a bike with acceptable run-out measurements, they are virtually bullet proof and will last well over 100K miles.... They are used on high performance builds as they hold the cam timing better than the chain drive sets up. I have a set in my 124" crate engine @ 135/151.

The gear sets are made by S&S Performance. There are several cams available from S&S, Andrews, etc that can use the gear drives....

 

Don’t remove the cover unless you unload the valve train first.
You should be able to hear the difference between gear and chain driven cams.
Find someone familiar with them and let them have a listen.

I would assume if they’re on the build sheet, they’re more than likely in the bike.

 

Thanks for the info everyone, looking at it, I might be able to pull the cover enough to take a peak inside with exhaust on.. I will have to look into unloading the valve train also.

 

Anyone with an experienced ear can tell you if it has the gear drive in it, gear sets have slight whine the chain cams do not. Find an old school shop with a few grey beards, they'll know

 

Screwdriver to the ear and listen is no wives tale

 

Outer cover on a T/C supports nothing