The 'E' Type Forum

We are struggling to remove the Crankshaft sludge plugs on a 3.8 Jaguar engine which has the smaller Allen key drive plugs, (C4283).

We have drilled out the various peened areas to try to relieve the plugs, but still no joy. Can we apply any form of localised heat to the plugs to try to loosen them before using an impact driver or is any form of heat to the crankshaft a no-go?

regards,

Dave

I would not advocate the use of heat.

When taking out mine (albeit on a 4.2) I used a "proper" allen / unbrako 1/2" socket and a long breaker / extension, around 2 foot length, and even then I had to put a lot of grunt to get them moving. I'd started to chew up one of the hex holes with a less than perfect fitting unbrako socket, and managed to find a socket that I had to slightly hammer into position, a real nice tight fit.

They are very tough to remove! I wouldn't use heat on the crank though. I got them out of my 3.8 crank using a high torque air impact gun. Took just a few seconds on each one :-)

The key to help removal though is to use a brand new, good quality allen bit. The impact gun/hammer will give better results than just a big breaker bar.

If all else fails, just leave them in and get your machine shop to remove them.

Cheers.

Thanks for your super quick responses !

We were very reluctant to consider any form of heat, but as Simon says, these little bug#ers are becoming pretty annoying. We have already order a high quality - very expensive high impact allen bit and have used the high torque air impact gun to good success in the past.

No heat it is then - many thanks !!

regards,

Dave

...you have a PM.

Carsten

Dave : this is one of the worst jobs on any XK engine , but it is absolutely essential , as you will see when you get them out. I would not use heat . I'm afraid that you are probably going to have to drill them out until there is an annulus of about 2 or 3 mm left when they should be capable of being rotated with a chisel

Very, very carefully drill them out if they wont move using the usual methods. Thats what we did, bugger of a job and best done using a proper pillar drill set up to get the angles spot on.

As above. Good job for the machine shop.

Be sure to run a tap down the threads once they are out. I use Loctite on them when I reinstall them.

One tip I was given by an engineering shop is to tighten them up slightly before unscrewing them as it breaks the seal.

I was also told that a little heat on the plug not the crank was fine and failing all else, find a washer with the hole just slightly larger than the allen key recess and MIG weld it through the hole to the plug, then weld a nut to the washer.
The heat helps to break the seal and the nut can be used to turn it out.

Used this method on several cranks and it made the job easy.

Paul