Question regarding camshaft removal

[lopena]

I need to remove the camshafts on my 1964 OTS 3.8 liter to adjust the valve clearances (this will be my first time doing this).

My question is as follows:

Is it necessary to go through the additional step of slackening the timing chain tension (using special tool JD2B) before removing the camshafts? Shouldn’t the cams simply lift out once the two (safety-wired) sprocket bolts are removed?

Most YouTube tutorials say ‘yes’…loosen the chain tension, but the official Jaguar Service Manual makes no mention of releasing the chain tension before removing the camshafts (page B.33).

Thanks in advance for your assistance!

Alan
N.J.

[christopher storey]

You can in fact probably get the shafts off without loosening the tension, but it is very undesirable because it may strain the chain links, and it will be virtually impossible to get the sprockets back on when reassembling. Slackening is only a two minute job anyway

[mgcjag]

Hi Alan...as Christopher mentions above. .....also once youve set your clearances you will need to reset your valve timing so will have to slacken/tighten the chain anyway so you will need the tool anyway....although you can just use a pair of long nose pliers....so slakening the chain to remove the cams makse the job a bit easier.....Steve

[lopena]

Christopher, Steve:

Okay, I did as you both suggested and loosened the chain with the special tool and *presto!* the camshafts slid right out. Hopefully they will go back in as easily as they came out!

Thanks for your help!

Alan
N.J.

[lopena]

One follow-up question, if you please: when I re-install the camshafts should I slather some re-assembly lube into the cam bearings, or is motor oil sufficient?

Thanks again!
Alan
N.J.

[christopher storey]

If you have graphogen or similar , it will do no harm, but if you have not renewed the cam bearings, there is no need for it : oil will be sufficient

[mgcjag]

Alan.....do not expect your tappet gaps to be correct the first time you refit your camshafts. ....as this is your first time you will be very lucky if they are correct.....often taking 2 or 3 attempts to get them spot on.....personally i would replace the cam bearings they arnt very expensive and a very thin smear of oil( if graphogen then very thin) and torque the bearing caps correctly as this will affect the gap if you just tighten by hand...torqing gives consistency....Steve