I am trying to adjust the upper timing chain on my 77 xjc. I loosened the nut, pushed in the locking pin and tried to turn the adjuster. does not move in either direction. looks to me like something is seized. any advice is greatly appreciated.

 

The upper chain 'eccentric' adjuster is seized with carbon buildup.
You might try a solvent like 'carb cleaner' dripped in the cup-like area above the adjuster.
Then work the shaft back and forth.
I have seen 'punch-marks' in the holes for the factory adjusting tool by a previous owner.

The worst one I worked on was a 1952 MK VII (3 and a half liter).

I had to remove all the components and soak them in solvent.
The parts finally came apart for re-installation and adjustment.

bob

 

Welcome to the forums ferdy,

I've moved your question and another you posted earlier from General Tech Help to XJ6 & XJ12 Series I, II & III forum. This is the place to post technical questions about your 1977 XJC.

Please follow this link New Member Area - Intro a MUST - Jaguar Forums - Jaguar Enthusiasts Forum to the New Member Area - Intro a MUST forum and post some information about yourself and your vehicle for all members to see. In return you'll get a proper welcome and some useful advice about posting to the forum.

Graham

 

I agree with Bob,

I have had a few jammed up, and I use a "brew" of 50/50 ATF and Diesel Fuel, fill that cup thingy, dribble it around the general area, keep an eye on it and fill as required, and after a day or 2, sweet as a nut. Adjustment possible.

Drain and refill the engine oil with a good quality oil and new filter.

Lack of use, and poor oil changes is the root cause here.

 

Thanks to all of your advice. I will soak it overnight and check.
Tony.
________________________
Calgary ,Alberta, Canada.
1977 xjc.