DIY fix for screwed up crank noses

[lord_verminaard]

Damn, Rob- looks nice.  

Any detail of the pins you used to tap into the crank?  Are they snug with the holes in the pulley?  (aka no "tenth of one degree" play in them?

That serp.  pulley is really pretty too.  

Brendan

[GoKraut]

Guess I missed them. :oops:

 :wink:  :lol:

[GoKraut]

Damn, Rob- looks nice.  

Any detail of the pins you used to tap into the crank?  Are they snug with the holes in the pulley?  (aka no "tenth of one degree" play in them?

That serp.  pulley is really pretty too.  

Brendan

Brendan,

I purchased 5mm hardened dowel pins from Fastenal.com. There is no play. The holes in the crank are 4.95mm (5mm drill bit) and the pins themselves are 5.01mm so a few very light taps of the hammer do get them in.  Initially I ordered 5x14mm pins and realized I was being absent minded.

The depth of the cog itself is 19.35mm from where I drilled at the top of the cog to where the face of the crank nose is.  So if you go and do the math.  I drilled the crank nose by just just over 5mm.  I think it was about 5.2mm for each hole.  19.35+5.2 = 24.55mm pins.  Just under a standard inch (25.4mm).

So what I decided to do to correct this little difference is order pins that were longer. I'm going to cut them where they need to be cut and then grind them down so they are a snug fit and so the sleeve of the crank bolt presses the pins into the nose.  So snug side to side on the nose and pressed down with the crank bolt.  Will absolutely have some pictures for you guys when I get that all done. Right now I'm simply waiting on Fastenal's latest shipment (since I had to reorder the right size)  :roll:

[RabbitJockey]

brilliant, i wonder how this would work on the older 22mm hub cranks.  my 11mm 1.6 has this issue, i did fix it with a new crank sprocket and stuff, but u am sure this problem will return.

[jtanguay]

brilliant, i wonder how this would work on the older 22mm hub cranks.  my 11mm 1.6 has this issue, i did fix it with a new crank sprocket and stuff, but u am sure this problem will return.

did you put the red loctite on the bolt and give it a good yank?

[RabbitJockey]

yep, i filled the slightly chewed up part in with jb weld... u know what else can you do haha, aside from what this thread is showing.

[jtanguay]

yep, i filled the slightly chewed up part in with jb weld... u know what else can you do haha, aside from what this thread is showing.

do you use a/c a lot? i was thinking of having some kind of a/c disengage switch i could use to turn it off when i feel the need for some 'spirited' driving  :twisted:

[RabbitJockey]

yeah my ac i think is what made the problem way worse since it didn't get bad until it started getting warm out haha.  ac disengages when u have it turned off.

[jtanguay]

yeah my ac i think is what made the problem way worse since it didn't get bad until it started getting warm out haha.  ac disengages when u have it turned off.

yea but having a button to press instead of moving the selector is much more convenient as that hand is usually shifting gears  :twisted:

[gigaz2]

easy to do, the magnetic clutch can be disengaged anytime. you could even fit a switch on the pump to disengage AC when going full throttle.

even my 1993 Renault ECU has that feature

you can also disable the alternator and ICE automatically ( if the battery has enough charge to keep everything else going )

any of these systems must have a delay, so if you blip the throttle the AC doesn't get affected, alternator also sends huge spikes if disconnected when supplying power.


EDIT: sorry for the offtopic, great work on the jig!

[gldgti]

just re-reading all this for myself, and i got to thinking - i reckon using a lighter drive pulley isnt necessarily a good thing -

sure, all the load is driven by the crank sproket and associated pulley - BUT, the total inertia of hte system is what reacts when the loads change. so, say your driving along and switch on the a/c, putting a sudden load on the pulley- the less inertia the pulley has, the more quickly it will want to decelerate. so, in theory, the heavier the drive pulley is, the better, because its in the inertia transfer when turning on a load, there is less associated reduction in rpm....

i think...

[lloydbiker]

Has anyone ever had to replace a crank gear, once it's been pinned?

[R.O.R-2.0]

i believe maybe one user pinned his crank..

all the others went with the more socially accepted method of TDI crank sprocket.

[commuter boy]

Has anyone on this board ever even pinned a crank sprocket?

Moi.  My dad's done a couple in Eastern Canada as well.

[Rabbit79]

http://www.vwdiesel.net/forum/index.php?topic=25424.0

I've pinned a 22mm crank. The above link shows my trials and tribulations on that. Unfortunately I don't have the engine back together yet so I can't report any results.