Hi - I’m building an XK engine from a '72 XJ6 and I very recently got a new, reproduction version of the Oil pump/Distributor Drive shaft (C8646). Several companies sell that repro part. Mine had a serious problem that is not visible to the eye - it’s only when tested that you see the problem. I don’t know if it’s a one-off defect or what but better safe than sorry.

The issue is that the offset slot that engages the drive-dog teeth is too close to the center by a few thousandths. Thank goodness I was messing around at the bench and tried to engage the bottom of my original, low mileage 22d6 distributor with it - it would not go without forcing!

That prompted me to drop it in the block without the bronze gear and try to mesh the distributor. Not happening. I also found after some more messing around that the ‘head’ of the shaft that meshes with the dist drive dog is too thick by a few thousandths so that if you do get the dizzy in it has no clearance and may push the head against the bronze bushing and cause excess friction until it wears the bushing down - all of this is a great way to break a bronze gear among other things.

I will spare you the details of my attempts to modify it to make it work and various adventures in measuring… just please, to anyone building an XK motor with that reproduction part (Oil pump/Distributor Drive shaft C8646)- save yourself ALOT of potential cursing and extra work/money/aggravation: Try to fit it to a distributor out of the car first. If it works, drop the shaft into the block and test fit the distributor and bolt the dizzy down. It should fit easily and rotate perfectly with no appreciable friction…

5 minutes of test-fitting will save your sanity.

~Mike
72 XJ6 (x2)
73 XJ6
85 XJ6
84 XJS

 

Sadly, your experience is becoming rather too common with repro parts for classic cars. Our club for MG Midgets and AH SPrites has also had many problems too. There is no longer a car manufacturer there with a quality control and warranty claims department checking out what is coming in and what is failing.

 

Amen to that. I've gotten to the point where I scour the internet for NOS OEM parts for stuff that is critical. For example, I got a new timing chain set that contains the infamous Roloc timing chain tensioner. Known to fail occasionally because of the way the slipper is molded to the metal piston. Found a NOS Renold version which is what is in the motor now.

Also, I'm now gun-shy of this stuff so I didn't really trust the critical middle timing chain guide that came with the set. It's under tension from the tensioner pushing the chain against it. Had to find a NOS Metalastic part on ebay. I drive my cars fairly hard and all over creation, they ain't trailer queens so they gotta be right. Glad I bought a 'set'

It's sad how the aftermarket doesn't support Jags very well. Even new, green-box Lucas stuff can't always be trusted. I see that they put their name on the terrible, round-riveted, black distributor rotor that can leave you mysteriously stranded. Not a wive's tale - it happened to me after 2000 trouble free miles with the thing. Luckily I always carry a spare rotor because I was aware of the problem so I was up in running in 5 minutes... but I was about to head up the mountain I live on. Could've been much worse.