I can't get this bastard sprocket off the crank. Any tips or tricks I should know?

I'm stuck!



I can't get this sprocket/whatever it's called off the crank.

I've read in the tech section that a guy had to drill and tap it and use a puller. I'd rather not have to do this if at all possible.
Apparently it should be fairly easy, just wanted to check if i'm missing something (or doing something stupid) :thumbup:

Cheers
Ben

 

Don't think it was ever meant to be easy Ben, that's why a new sprocket comes with the 100K service kit.

I got mine off by drilling a hole through the sprocket close to the crank shaft and then with a hammer and cold chissel gave it a love tap over the hole which essentially split the cog and it slides straight off. Just make sure you drill the hole under a groove, not a under peak of a tooth otherwise you don't have a place to place the chissel.

 

Is the end of the crank there just a straight shaft, or is the similarly colored metal on the inner edge of the sprocket also a step on the crank shaft?

Just concerned which part to drill.

This part wont bother me for quite a while yet but, if it's so hard to get off, how hard is it to fit the new one?

Ta
Ben

 

99 out of 100 have to be drilled and split. Not sure why Karl calls it a 'love tap' .... ?

 

i must be that lucky one of 100.
spray heaps freezer/lubrication, then pry it out with a screw driver.....that's what i did, seriously.

 

Ditto

And the Nissan part is surprisingly cheap @ about $30

 

I personally do not condone beating of any kind whatsoever on the Crank Snout. There are precision bearings that do not take kindly to this type of abuse.


This is a situation that you have to put a little bit of thought into though. The Woodruff Key that is used to align the Crank Gear is usually wedged in there a bit. So with a small punch in the Keyway you can tap the Key just a touch. This will sometimes loosen the Crank Gear up a little bit. I have NEVER had to cut or beat on ANY Crank Gear that I have ever removed. I use this stuff...


AeroKroil...


http://www.kanolabs.com/google/


It is very good stuff. I will spray it into the Keyway repeatedly and let it soak for hours. This usually works.


If all else has failed... Instead of beating the crap out of the Gear I will drill 2 holes 180 degrees from each other into the Gear itself. Tap the holes with a Tap and Die set. Thread bolts into the tapped holes and use a "Steering Wheel" type puller.


I do not recommend EVER beating on the Crank in any was shape or form with a hammer or other object.



However you can get somewhere sometimes by wedging a small screwdriver behind the Crank Gear and actually lightly tapping on the gear towards the Engine. Yes...Towards the Engine. This will sometimes break loose the Gear which allows it to be removed.


I also do not condone Prying on the Oil Pump to get the Gear loose. One wrong "Bull in a china shop" will render you pulling your Oil Pan to replace the Oil Pump.



And...Judging from the picture you do not have your Crank or any other timing components lined up for the job. *VERY IMPORTANT* Before you pull anything apart the mark on the Crank Gear MUST line up with the mark on the Oil Pump housing. I.E. Top Dead Center on the compression stroke of cylinder #1. ALWAYS!!!



This will also put the Keyway at the 12 o'clock position and will help your penetrating oil do its job by actually getting in where it needs to be.

 

Read my reply

in this thread Ben.

 

Try again.

http://www.aus300zx.com/forum/showthread.php?t=277146&highlight=drill

 

its very simple .. all you need to do is drill it out , drill 2 hole one on the other side away from the first hole .. hell drill as many as you want ,, but do not touch the crank ,,, get a chisel one or 2 hits will get it of..

as above ,,
Ive done this many time ,,


even on my car ...lol....

these are not meant to just come of ,,, if it does then your crank may not be in the best condition . as a lot of people use sand paper to get rid of the rust ,,, a very light rub is more then enough

 

Is is important lining everything up when there is no heads, pistons or rods attached?

Everything is coming apart since my recent piston meltdown, so I can't see how lining up the crank etc is going to matter when it's all soon to be in pieces. Apart from helping the lube penetrate that is.

Thanks for the replys people, i'll have a bit more of a go with lube and levering, then might just bite the bullet and start drilling.
I'm not sure if I own a cold chisel. Remember seeing one ages ago but could be anywhere.
I've got every sort of grinder except a small one so i'll go with the drill/tap/pull method I think.

Thanks again
Ben

 

i just used a standard size angle grinder wheel , cut in a little bit , one or two taps with the chisel and she slid straight off .
give it a shot

 

That's the way I have always done it as well. No lunched engines yet either... Drilling and tapping is prefferable, but an enourmous PITA compared to the angle grinder and cold chisel.

Only had one VG ever that the crank sprocket just slid off in my hand and that was Eric's vert (ed300zx).

 

The sprocket has slid off pretty easily on mine both times Ive done the 100 thou service. My car is due for its 3rd 100 thou service soon, so will see how my luck runs

 

the first one i did i wrapped wire around the back of it

and tied it to a bearing splitter bolted onto a puller and used the bearing splitter as a sliding hammer, this worked well. the wire i used was a bit weak but did the job. next one i do i think i may make a tool out of tubular with a slot in the back and threaded hole in the front. I haven't measured to see if it is feasible yet but will have to soon.

let us know how you go.

 

Hey all, thanks again for all the advice.
I managed to get it off ok.

I drilled a hole with the intention of drilling another one and tapping them, but got impatient and lazy so made a small groove with the ol' grinder (as much as I could get in there with a 115mm wheel anyway) and then hit it with a big hammer and splitter thingy (cold chisel? not sure exactly what one is)

Anyway, here it is.





Surprisingly it didn't take much of a hit at all to split it.
How easily does a new one go on?

Ben

 

new one slides on smooth as silk .
did for me anyway

 

Might need a light tap with a rubber mallet, but should go on easy.

 

Shine the Crank Snout up with some Scotch-Brite and you should be good to go. Upon installation of the new Gear apply a thin coating of Grease to the Crank and inside of the Gear. This will allow for an easier removal next time also.