Key or pin cam gears?

Elementaltoad · **Joined:** Wed Jul 27, 2022 12:06 pm **Posts:** 14

While I have my CRD apart, I am debating trying to pin or key the cam gears to prevent them from any possibility of slipping. The "press fit" makes me a little paranoid if a cam gear slipping and getting the cams out of sync.

Has anyone done this or is there any reason not to?

My66dodge · **Posted:** Thu Aug 18, 2022 9:38 pm

If you torque them properly they will not have a problem, I have done 50+ timing jobs on them plus all the countless other vehicle like vw without pinned timing gears and never yet had a problem, that’s why there is a torque spec

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WWDiesel · **Posted:** Thu Aug 18, 2022 11:15 pm

The answer is: NO you do not need to add pins or keyways to the camshaft gears on this engine....

The VM engineers designed the cam gear sprockets fitmit to the cams on tapers with NO keyways or dowel pins for a valid reason.
You pin both cams to the intake/valve cover in the proper position using the two screw in alignment pins while leaving the two cam gear sprockets slightly loose which allows them to freely rotate on the camshafts tapers as you set the correct tension on the cam belt using the spring loaded tensioner pulley.

This allows infinite adjustment of the cam gear sprockets on the camshafts to get perfect timing relationships between the crankshaft and the two camshafts.
Once you have the rubber cam belt tensioned correctly, you then tighten the the two cam gear sprockets to the proper torque while holding the cam gear sprockets stationary with one of the special tools designed for this task.

Timing it this way gives you perfect timing!

If the camshaft gear sprockets were pinned (dowels) or had keyways, you would be forced to set the camshafts in relationship to the teeth on the rubber belt. This could cause the intake & exhaust cams to be OUT OF TIME with the crankshaft by several degrees and that would have a negative effect on engine performance and economy.

:rockon:

Elementaltoad · **Joined:** Wed Jul 27, 2022 12:06 pm **Posts:** 14

Makes sense, I guess there is no guarantee once you key them that another brand or version of belt would ever match up next time. I did buy some Loctite meant to add a bit of security on pressfit sprockets as well, so the chances of a cam bolt or sprocket ever coming loose once cured should be pretty low. Thanks for the explanation!

PZKW108 · **Joined:** Sun Apr 06, 2014 5:23 pm **Posts:** 461

Elementaltoad wrote:

Makes sense, I guess there is no guarantee once you key them that another brand or version of belt would ever match up next time. I did buy some Loctite meant to add a bit of security on pressfit sprockets as well, so the chances of a cam bolt or sprocket ever coming loose once cured should be pretty low. Thanks for the explanation!

Loctite not needed !

Get the proper timing belt tools, follow the procedure/ torque specs. Nothing more, nothing less !

WWDiesel · **Posted:** Wed Aug 24, 2022 10:33 pm

PZKW108 wrote:

Get the proper timing belt tools, follow the procedure/ torque specs. Nothing more, nothing less ! :BINGO:

Very good advice! :rockon:

There is no need to reinvent the wheel.

Elementaltoad · **Joined:** Wed Jul 27, 2022 12:06 pm **Posts:** 14

Will do, I decided to replace the exhaust valves while I'm in here. I just got the broken glow plug out, the valves will be here Saturday and will start putting it back together this weekend.

Key or pin cam gears?

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