MFI Cam Pulley - a slight problem

davidppp · Post by **davidppp** » Wed Aug 23, 2006 11:38 pm

\\hello again.

These are the type I like best:
http://buy1.snapon.com/catalog/tools.as ... 2&store=uk

Kind regards
David

tanick · Post by **tanick** » Thu Aug 24, 2006 10:46 pm

Cheers David, I appreciate your advice.

Ordered up 3 of them from Snap on (the two smaller sizes plus a larger one for when an 8mm stud gives way) and a set of LH cobalt drills (out of stock

)

Also ordered a few bits from pelican such as the hex extension to get the barrel nuts off the heat exchangers etc.

I loooooove buying tools. I found a Draper catalogue on one of my engineer's desks this afternoon - spent about 30 mins trawling through making a mental list.

Now all I need is a car to perform surgery on, as of yesterday it was still where I left it

veryporky · Post by **veryporky** » Tue Aug 29, 2006 12:40 pm

Watch that Draper stuff. In my experience it's made of poor metal. Any Draper stud extraction technology IMO will shear off in the end of the cam!!!!

tanick · Post by **tanick** » Tue Aug 29, 2006 8:34 pm

Don't worry Keith. I might use a draper hammer to hit something with but for this job (if my car ever comes back) I'm only using good stuff. In fact, I made a decision a while ago that I wouldn't buy rubbish tools. I've bought a set of Snap-on left hand cobalt drills and 3 of the splined extractors that Davidppp recommended (2 small ones and a larger one for when something bigger goes at a later date - they're only £3 each). I'm impressed with Snap-on, I finish work at 2pm on Fridays and used to pop in to see my car at Bodytech as it was being restored. The Snap on truck used to turn up while I was there and I always checked the deals. I got a full 3/8 metric socket set for £100 a few months ago. A bargain as it should last me the rest of my life.

hot66 · Post by **hot66** » Tue Aug 29, 2006 8:53 pm

but ... the only screwdriver I have ever broken was a snap-on one. The blade sheared under torsion. They did honour their warrenty though & replaced the blade straight away

I'm quite a fan of Teng tools

tanick · Post by **tanick** » Wed Aug 30, 2006 10:52 pm

Doorbell rang at 9pm tonight and a heavily pierced dutch bloke delivered my car.

Here are the pics of the problem:

This is the end of the cam. I can see the remains of the two sheared screws in there still.

The broken screw:

And here you can see the damage done to the pulley, probably after the first screw broke and evidence of the fact that the cover kept the pulley on the cam, probably just friction keeping it turning.

So I've soaked the heat exchanger nuts in Plus Gas. Thankfully there's loads of room to get a drill in between the body and the engine. I'm really hoping I don't have to drop the engine for this one.

Lesson - If your engine is old and out of the car, change these two screws. It may save you a world of pain.

Barry · Post by **Barry** » Thu Aug 31, 2006 9:34 am

As a general freeing off nuts/bolts tip: someone recently gave me a can of Wurth Rost-Off Ice.

It works be using differential contraction, cools the parts down, this then opens up micro cracks between the two componants. When they are not looking, the rust-breaking element of the fluid goes down the cracks and attacks the rust.

Tres good!! With patience I've not failed to get anything apart with it yet.

Commision please, Mr Wurth

.

Barry · Post by **Barry** » Thu Aug 31, 2006 9:36 am

BTW, have you come up with why the 1st one sheared in the first place Nick? Or do you think it was the actual bolt/screw rather than the level of work it was being asked to do?

Being about to start an 2.4 E resto, I'd be interested to hear your conclusions ....

tanick · Post by **tanick** » Thu Aug 31, 2006 12:14 pm

It doesn't have to do much work so I'm guessing corrosion. We'll never know but if I were you i'd change the fasteners for new ones.

Barry · Post by **Barry** » Thu Aug 31, 2006 5:02 pm

Yes, I think you're right Nick: a bit like Luke's flywheel: a whole heap of aggro for a few pounds-worth of bits.

Hope you get it back together O.K.

912uk · Post by **912uk** » Thu Aug 31, 2006 5:18 pm

Arr man that sounds like a whole load of trouble you didn't need..sorry tohear the greif I hope now the car is back you can get it sorted..

I second Teng Tools as well

Most of mine are Brittle Tools but I have a great 3/4" Teng Socket set for all those BIG jobs...

davidppp · Post by **davidppp** » Thu Aug 31, 2006 5:44 pm

I would be very surprised if this is a simple corrosion failure:

I would favour either they were loose, or they were too long and bottomed in the holes so that the pulley wobble fatigued them..
We should place bets!

Kind regards
David

Barry · Post by **Barry** » Thu Aug 31, 2006 6:59 pm

Certainly the picture of the 'head' end looks like a stress failure of some sort: I'll go for 'fixings fretted slightly loose, allowing wheel to fret, causing fatiguing of bolt' please

.

I suppose if it's corrosion, or bolts bottoming out, they should be tricky to come out, if on the other hand they practically fall out, then either as above or overloaded by the pump. I wonder how much power one of those pumps takes at full load ....

tanick · Post by **tanick** » Thu Aug 31, 2006 10:50 pm

They haven't fallen out. Removing one has cracked the cam The screws aren't too long either as I've drilled through one and there is 8mm space behind it..

P'd off now. CraP german camshafts

sorry about lack of focus.

[/img]

davidppp · Post by **davidppp** » Fri Sep 01, 2006 7:46 am

Bugger!

The seal is the only crucial think for this purpose:there is every chance it can be repared good enough to still seal.

The seal will have to come out..good to change anyway while working there.

Then clean up the cam and fragment thouroughly any check they fit together accurately..if not fettle till they do.

Then glue it with a decent epoxy after very very thorough degreasing, and hold in place with a cable tie while it sets..

Then emery cloth the joint to remove any roughness.

I'd now resort to tapping out the rollpin holes..IIRC they are slightly smaller than the allen bolts and may need a pilot drill run thro of the correct size before tapping..check on the tap charts..you will probably need to buy the correct size ..

If the pulley is well fixed, maybe adding some loktite to the face, I see no reason to make new rollpin holes..the loads are not high at all..

Good Luck!
David