Iron Duke Timing Gears

[nickinau]

Hi Guys,

This winter I took the engine out of my 1986 Notchback to do some maintenance. Basically I'll be driving the car out to Alberta this coming spring, so wanted to change any of the things that would leave me stranded on the side of the road, that can't be easily fixed. One of these issues that worried me the most was the fibre timing gears that came in the car from the factory. It didn't sit well with me that at any point these gear could go out and leave you pretty much dead for good. So anyways I decided to replace the factory original gears which miraculously lasted 207,000km with an aluminum/steel set that would last pretty much until I do a rebuild in the future worry free.

Overall it wasn't as bad of a job as most people said it would be probably because of the easy access with the engine out of the car.

I took a few pictures of the process that will hopefully help somebody if they're planning on doing this job.

1. So the old gear is pressed onto the camshaft pretty damn tight. So in order to remove the old gears, we tapped two holes into the metal ring of the gear, and tapped the same size of the screws that came with the puller. I think they were 1/4 in holes or something. As long as you have some of the tap in the metal to give more grip the size doesn't really matter.

2. Pulling off the gear was not too bad. We broke one cheap power fist puller on our first attempt, and needed a big breaker bar to "crack" the gear free of the 29 year sitting position. After it initially cracked the pull was pretty easy. The metal gear that is on the crankshaft comes off by hand easily as it is not pressed on to the crank.

3. Picture of the gear and the puller assembly. The damage on the gear is from when the gear was being pulled off.

4. In order to press the new gear on, a lot of the guys online said that you have to drill and tap the camshaft, then use a threaded rod to press the new gear on. I was kind of sketched out by this method, so decided to use Ottawa's frigid February to get the cam icy cold. After leaving the garage cracked open to let everything nice and frosty, I put the new aluminium gear in a toaster oven and heated it to 450 degrees F. After an hour baking in the oven, to my surprise the new one slid on with absolutely no fuss, and I had my buddy standing by with the 0.0030" feeler guage to ensure proper clearance between the gear and the camshaft retainer plate. After about 30 second, the new gear was on rock solid like it was pressed on normally. After cooling off, I slid the new crank gear onto the crank and lined up the timing marks.

All in all it only took about 2 hours to complete the job, not including removing the engine etc. But since the engine was out for new clutch, mounts and exhaust, it was totally worth now having the piece in mind that this critical part won't fail unexpected.

Hope this helps someone,

Nick

[GT_Gulf]

I hope she doesn't let you down on the long haul to Alberta

[aaron88]

Love the use of heat and cold.  I use this method all the time and it's usually overlooked by most.  Good job.

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