V12 HE Distributor shaft replacement

My 88 XJS needs a new distributor gear shaft. Does the engine have to come out of the car?

No Joe the distributor drive shaft is simply removed from the engine. Why do you think it needs a new driven gear?

I’m not sure if he’s talking about the shaft on the distributor itself, or the lay shaft in the engine. The distributor can be pulled from the top, but not the layshaft.

1 Like

Thanks for the comments…
I’m referring to the drive shaft in the valley of the engine, also called the jack shaft, auxiliary shaft, and distributer drive shaft.
For whatever reason a distributer advance weight jammed the distributer, stopped it from spinning, completely stripping the internal shaft’s teeth. Hence, a new shaft is needed along with a new distributer.
I was told the engine must be removed. So my question is: Can the radiator be removed along with the front of the engine, and the shaft replaced “in situ”?

Interesting. AFAIK the Distributer is designed so the gear’s shear pin should break before the jack shaft gears are compromised.
Replacing the jack shaft is theoretically possible without removing the engine. However for a repair facility it’s easier and more cost effective to remove the engine.

I found a jack shaft in Canada whose owner claims will fit my engine. What the bearings for this shaft? Does it have any or what is used on the 3 bearing surfaces I see?
BTW, nice website… Will need to discuss some modifications you’ve made for my cars.

There are bearings for the shaft. To get it out, the timing chain cover would have to come off, which means everything on the front of the engine needs to come off. Removing the timing chain cover is not trivial. Releasing the timing chain tensioner without breaking it is also non-trivial, and they are hundreds of dollars, if you can find one. Obviously you need to remove whatever is necessary such as the radiator, etc, to pull the shaft out of the front of the engine.

Camp Chaos Chronicles on Youtube has many engine assembly and disassembly videos. I highly recommend watching his engine videos to see what you are in for.

If all of the teeth were stripped off the shaft, you also have all off that metal floating around the crankcase. That means you likely need to pull the oil pan, sandwich plate, etc, to get the chunks out.

Thanks to all for your comments and recommendations.
NO ONE, I mean, no one would remove and replace the jack shaft! Seems no one had the proper special Jaguar tools to do the job nor the people able to do the job.
I found a replacement engine and made the swap. Interestingly enough though, I had to rebuild the distributor first. New engine runs fine but I now have an electrical issue. Will post that under new topic.
Thanks, again, everyone.

2 Likes