Sprocket Won't Come Off - Need Help Please

[angusis2fast4u]

Okay so I know that getting the sprocket off the crank is usually an issue for an RB20DET but this one seems to be completely seized on!

We have a puller on it and it is so tight it literally feels like it is about to break. it's been getting tightened with a huge breaker bar. We've left it on over night. sprayed WD40 on it.

What else can I do to get the f**ker off? without damaging crank. Or does it literally come to needing a new engine?

My mechanic friend. Who is doing the job, is completely stumped by how stubborn the sprocket is being.

[GTSBoy]

By "sprocket" I assume you mean "harmonic balance & pulley"?

Judicious application of heat may be required.

Worst case, you end up attacking the whole lot with angle grinder followed by cold chisel and replacement with new balancer. That won't be fun!

[Ben C34]

Is your mechanic friend really a mechanic?

[angusis2fast4u]

Is your mechanic friend really a mechanic?

Yes Ben, Works for mazda so he hasn't come across nissan issues before.

By "sprocket" I assume you mean "harmonic balance & pulley"?

Judicious application of heat may be required.

Worst case, you end up attacking the whole lot with angle grinder followed by cold chisel and replacement with new balancer. That won't be fun!

We were going to try them but if we damage the crank that means dead motor?

plus if i go replace it with another 20 who says that 20 doesn't have a f**ked balancer as well

[jiffo]

Well I'm confused.

Are you talking about the balancer or the crank gear?

[angusis2fast4u]

Well I'm confused.

Are you talking about the balancer or the crank gear?

Probably the gear. I'll get a photo for you.

[angusis2fast4u]

Okay guys, this thing. This is just whatever photos I could find. sorry for the confusion. I'm no engine expert, I just listen to what i'm told. These are in chronological order of when they were taken

[iruvyouskyrine]

There was no confusion, they were being pedantic. Ben and GTSboy don't like people asking easy-to-answer-should-have-searched questions, and how to remove the harmonic balancer falls into one of those baskets.

On my RB20 the crank sprocket came off with a light tap with a hammer just to loosen it. My RB30 was f**king impossible to get off no matter how hard i tried (blowtorch/hammer/lever bar/gear puller). My RB25 one was easy after some degreaser and a tap with the hammer, still required lever bars, but not too much pressure.

I was told to drill and tap holes into it and use a puller of some sort to remove it. Can get a replacement item here

http://www.kudosmotorsports.com/catalog/genuine-nissan-pitwork-crankshaft-sprocket-kit-genuine-nissan-nissan-skyline-r32-gts-gts25-gts4-gtst-r33-gts25-gts25t-gts4-r34-25gt-25gt4-25gtt-p-1197.html

But first thing i would check is the Woodruff key is parallel to the snout of the crank. If it has been hit and it sitting proud of the keyway in the sprocket it will never come off. Might be tricky to understand what im saying, but this picture should help. Just have a good look at it and you should understand what i mean.

[angusis2fast4u]

There was no confusion, they were being pedantic. Ben and GTSboy don't like people asking easy-to-answer-should-have-searched questions, and how to remove the harmonic balancer falls into one of those baskets.

On my RB20 the crank sprocket came off with a light tap with a hammer just to loosen it. My RB30 was f**king impossible to get off no matter how hard i tried (blowtorch/hammer/lever bar/gear puller). My RB25 one was easy after some degreaser and a tap with the hammer, still required lever bars, but not too much pressure.

I was told to drill and tap holes into it and use a puller of some sort to remove it. Can get a replacement item here

http://www.kudosmotorsports.com/catalog/genuine-nissan-pitwork-crankshaft-sprocket-kit-genuine-nissan-nissan-skyline-r32-gts-gts25-gts4-gtst-r33-gts25-gts25t-gts4-r34-25gt-25gt4-25gtt-p-1197.html

But first thing i would check is the Woodruff key is parallel to the snout of the crank. If it has been hit and it sitting proud of the keyway in the sprocket it will never come off. Might be tricky to understand what im saying, but this picture should help. Just have a good look at it and you should understand what i mean.

Thanks man. Usually I wouldn't have posted this as I already have a mechanic looking at it but this is literally last resort before needing a new engine. Which I would prefer not to do as I would not trust buying a used RB. With your RB30 one, just clarifying, you drilled and tapped the holes into that one, and eventually you got it off without damaging the oilpump/crank??

Thanks for the link to Kudos. I have spent like 1.5k already there for all new headgaskets hoses etc. they are a very very good company

[angusis2fast4u]

"If it has been hit and it sitting proud of the keyway in the sprocket it will never come off." if this has happened. What do I have to do to fix it so it can come off?

[Duncan]

these are sometimes easy but more often a total PITA to get off.

the one things I've always found is once you start to pull it crooked it gets impossible to remove....so before you go further give it some light taps back towards the engine, get some light grease on the crank nose and try again, evenly and slowly. but it is likely if you've already put force on it that it will be cocked and never coming off.

if so, just cut it off. as long as you are careful towards the bottom (eg cold chisel) you won't damage the crank, it will just need a quick cleanup with wet and dry

[Duncan]

oh btw your engine was not at top dead centre before you removed the timing belt which will make it very tricky to put back together. you are going to need to either rotate absolutely nothing until the timing belt is back on, or slowly and carefully rotate the crank and both cams (by very small amounts) back to TDC. Or just remove the cams, then rotate everything, then put the cams back in

[jiffo]

So a couple of things.

Don't lever it.

That's the oil pump housing you're levering against, thin alloy and easy to damage especially with big bars like in your photo.

Judging by the puller equipment, you're going to need a new gear so just get stuck into it.

Drilling and tapping the gear won't cut it as there's a good chance the gear is now cocked over a bit.

So drill a series of holes in the root of the gear almost down to the crank.

Find a steel stool to support the crank.

Jack up the car, slip the stool under the gear, lower the car slightly so the stool is supporting the crank.

Cold chisel and split the gear along those drilled holes.

Jack up, remove the stool.

The gear will then slide off and all will be revealed.

I think you'll find the key has sheared and the remains are jambed in there.

Buy new gear, woodruff key and probably the rear belt guide plate.

[Ben C34]

Duncan it appears his head is off already so no worries with tdc.

[Duncan]

wot...now I've got to look at all the pics??

btw good post jiffo...you obviously know the pain

[angusis2fast4u]

I was told that my block is in good condition so I didn't want to have to replace the engine. I'll try to get this done to it.

I guess my situation at the moment is either try and fail, so I buy an new engine. Or try and get it right and save a lot of money!

Sorry Ben, I didn't want to create a "generic how to remove harmonic balancer" thread but this was literally a case of the F**ker is not coming off.

Thanks guys. I'll try to keep you updated on how it goes.

And thanks Jiffo! you obviously realize the pain this is. I appreciate you helping me out with this

[Ben C34]

I'm curious why you are taking it off anyway? I assume to change the oil pump?

Why?

Why not pull the engine out and do it on a stand? That way you can easily ensure you are playing the gear off squarely. As mentioned once it kicks over it pretty much locks up. From that point pulling harder just makes it worse you can try tapping it back on all the way to square it up.

Who told you and how did they establish your bottom end is actually ok? It's pretty near on impossible to know for sure by just looking at the bores. And then you still have no idea about the bearing condition.

It'd actually lot of work on an unknown condition engine, and has turned into a far more difficult job unfortunately.

When you try to cut it off, cut where the keyway runs so you don't damage the crank.

Good luck with it.

[angusis2fast4u]

I'm curious why you are taking it off anyway? I assume to change the oil pump?

Why?

Why not pull the engine out and do it on a stand? That way you can easily ensure you are playing the gear off squarely. As mentioned once it kicks over it pretty much locks up. From that point pulling harder just makes it worse you can try tapping it back on all the way to square it up.

Who told you and how did they establish your bottom end is actually ok? It's pretty near on impossible to know for sure by just looking at the bores. And then you still have no idea about the bearing condition.

It'd actually lot of work on an unknown condition engine, and has turned into a far more difficult job unfortunately.

When you try to cut it off, cut where the keyway runs so you don't damage the crank.

Good luck with it.

Nah just to change the seal... Was meant to be a quick job lol. Mercury Motorsport told me it was in good cond...

[Duncan]

seriously, is this forced induction all of a sudden? off topic and personal attacks removed.