Fixing loose JX bottom pulley

Not sure how many people stress out at the prospect that there beloved diesel engine is total scrap because their bottom pulley has worked loose and mashed up the crank.
If you stopped driving before the pistons said hello to your valves then you may be able to save your engine.
This is what I did.
Remove the necessary parts to give access to the lower pulley.
You may find that the bottom bolt is already loose which makes things easier for stripping down.
If the crank and pulley look like this you may be able to save them.




The three machined holes were done by a local machine shop. They are drilled then reamed to 3/16.

They also made me this tool, which when screwed into the end of the crank will hold the pulley square as it is a very snug fit on the inside of the pulley.


Screw it into the end of the crank as shown here.


Slide pulley onto shaft. The pulley and crank on my engine were only damaged on one edge. Refer to the earlier photos.
Turn the pulley clockwise to but the 2 good surfaces of the keyway together.
Then drill the end of the crank to about 5mm, the depth that the silver steel pin will need to recess into.
Then fit the first dowel to hold the pulley in place.
Now drill the 2 remaining holes into the end of the crank using the pulley as a guide.


A little tip to gauge the depth of the hole you need to drill.




With this done, pull off the pulley. clean, degrease, remove any burrs of the crank and use bearing lock on pin before you reassemble.

I'm not saying this will last forever, but if you do a good job and take your time to get it right you will get your van back on the road. You can then start saving for that 1z tdi conversion.

Its not all dome and gloom and you have little to lose, so give it a go.

pm me for more details if needed.

are diesel cranks not hardened in some way?

did you have trouble drilling it?

idea

Good bit of work there. Using a new pulley and drilling that would sort that side of the keyway issue (they are about 26 quid), and you really should use the NEW type crank bolt, they put a modded one in later motors to cure this problem (the new type is a stretch bolt and it`s tightened up differently to the first type, it`s got a small "pip" on its head so you can tell `em apart) I Loctited it as well for good measure.

Edited by Joker_Club - 17 Oct 08 at 20:37

That's a tidy job Tim!  We need a good T3 mechanic in Bristol...

With a high-reving aircooled motor you would go for 8 dowels for the extra strength.  Is there scope for 7 dowels on the aaz?  I guess the success of this type of repair has a lot to do with how carefully the crank holes have been drilled. 

The engine which I repaired was a 16 td. I guess that the problem here is just VW's inbuilt obsolescence on their belt driven ohc engines.

The crank is not broken yet and should easily last the length of the rest of the engine. This is a very strong repair.

check the crank bolt, if it's got a nipple it's the newer style and shouldn't undo when torqued

http://www.brickwerks.co.uk/shop?page=shop.product_details&flypage=flypage.tpl&product_id=575&category_id=109

Best of luck with your repair. Take your time and make sure that the dowels are a good fit into reamed holes. Then make sure that you torque up the new bolt to keep all parts in place.