Here is my complete Crank Fix..

[sdezego]

[TheRealEddie]

After getting advice from another vortexer about pinning my crank while I rebuild my G60 I found this great thread.

So, what's going on here? Is the keyway in the crank sprocket failing?

I don't believe I have any signs that this failure was imminent for me. However, is the general practice to replace the +20 year old sprocket and bolt or can the sprocket/bolt be inspected to determine if reuse is in order? Again, nothing has failed for me....yet....

thanks!
-eddie

[weejunGL]

its not the cog which is the main problem, but the crank nose ... the crank is made of soft metal

[TheRealEddie]

ah ok, so if everything seems ok just reuse the sprocket and bolt and then pin it.

-e

[G60ING]

Don't reuse the bolt, its a one-time use stretch bolt. I think both the crank and sprocket are soft.

[crazynorweegian]

Don't reuse the bolt, its a one-time use stretch bolt. I think both the crank and sprocket are soft.

Two time use bolt IIRC. I think it says you may retorque once in the book. But yeah, replace the bolt at least every timing belt change or ideally every G60 rebuild interval. Maybe I will get around to doing this before my motor goes boom.

[TheRealEddie]

Great, thanks for the info. The bolt is cheap enough.

You don't have to remove the sprocket when doing the timing belt, do you? Just remove the pulley and slide the belt off. At least that's how I recall doing it on my 16v motors. I'd think the PG would be the same.

-e

[G60 Carat]

Well I'm rebuilding an engine, and I have an 85 crank lying around. It's still forged like a G60 crank, but uses a crank bolt with 6 sides?

Think there would be any issue running this type of crank bolt on a G60? Does anybody know if that bolt is the same thread as the 12 point bolts?

I want to use this crank because it's snout isn't all messed up like my G60 one.

edit: I just read the thread pitch is supposed to be the same, so I should be able to use a 12point bolt, but I would swear the 12point didn't fit when I tried one. I'll investigate more tomorrow.

[sdezego]

6 pt bolt is a Non-Stretch bolt and the 12 is a stretch. So, 6 Pt tq specs are different.

If you use the 6, I would use loctite. 16v had the same variations.

[TheRealEddie]

Ok, I'm going through with this and following G60ING's parts list.

Let me know if I'm missing anything:

1. I'll be drilling through the sprocket on a drill press.
2. I'll mount the sprocket on the crank with the bolt on snug. Then I'll transfer drill gently through the sprocket into the crank just to get pilot marks.
3. Then I'll remove the sprocket and drill two holes in the crank. Ill use tape on the bit to ensure I go the depth I need to. I presume it will be just enough so that the pins are flush to the top side of the sprocket (or so).
4. Then I'll ream both sprocket and crank.

Is this basically the idea?

-e

[G60ING]

Drill the holes all the way in with the sprocket as a guide. Use lubercant and you will be fine.

Also before installing the sprocket for the final time insert the pins in the crank and make certain the amount sticking out is less than thickness of the sprocket.

[TheRealEddie]

Also before installing the sprocket for the final time insert the pins in the crank and make certain the amount sticking out is less than thickness of the sprocket.

I plan on just measuring and using tape on the drill bit to know how deep to go. If the dowel is 1 1/2" then just drill that minus the thickness of the sprocket plus a smidge more for margin.

[TheRealEddie]

Hey all,

Ok, so I went with the 3/16" x 1.5" dowels but I'm having second thoughts.

I kinda worked too late into the night last night and screwed up twice. Enough that I have to replace the sprocket, its some $$ but not as bad had I messed up the crank end.

First, the first hole I drilled was too close to the edge of the sprocket wall than my liking. So, I decided to scrap that hole and drill another two.

Secondly, I drilled the two holes (on a drill press) and decided to ream the holes right then and there. Bad idea, I didn't follow my own guide (posted above) and don't have holes to transfer drill into the crank.

Here are some pics:




So back to 1stvwparts.com for a new sprocket.

All in all, I was surprised how easy it is to drill into the sprocket. It's pretty damn soft.

So here is the deal, I think 3/16" diameter dowels are too thick relative to the remaining wall thickness on the sprocket and stub of the crank. I want at least 1 radius on either side of a hole. I measure the wall thickness of the protruding end of the sprocket to be 8mm thick. So, a 3/16" hole is about 4.77mm thick which is more than half the wall thickness. Add the fact that it's hard to get the hole right in the middle (ok thats just my crap machining skills) I'd prefer to go smaller. All in all that being said it's not that big, but when I look at the pieces in my hand it just seems too much.

So, I'm looking at moving down to 1/8" diameter dowels which are 3.2mm thick. Yes, we're only talking at 1.5mm difference but when you have 8mm to start with that's a lot, at least to me. Also, I like the idea of stepping up the hole size to better nail the center of the sprocket lip.

Potential parts list:
1/8" steel dowel pins: http://www.mcmaster.com/#standard-dowel-pins/=kbi5ag
7/64" cobalt bit: http://www.mcmaster.com/#cobalt-drill-bits/=kbi5o2
1/8" spiral flute reamer: http://www.mcmaster.com/#reamers/=kbi6bj

Total cost will be about $25 + shipping.

-e
Thoughts?

[G60ING]

The shear strength of the pins will be reduced. Have you found out what the rating is on the new 1/8" pins?

[TheRealEddie]

Yup, strength should be reduced the square of the ratio of diameters for the same material. According to McMaster Carr their strongest pins at 3/16" are rated at 5900lbs, the 1/8" are rated at 2600 lbs (which is consistent with the 2.25 area multiplier). But, I don't know what those numbers mean quantitatively in relation to the problem we are trying to solve; now that would be useful.

I'm guessing that the pins are certainly stronger than the sprocket and crank. The sprocket seemed real soft when I drilled through it. Therefore, I think keeping more material around the holes being drilled into the sprocket and in the crank (which run real close to the crank bolt hole) is important. It turns into going from worrying about the dowel pin snapping in single shear to the sprocket/crank yielding because there is too little meat around the dowel.

Of course I don't have any data so its literally just my 2 cents. If I'm wrong, at least I can serve as a warning to others.

[G60 Carat]

I'm under the firm belief that most of my problems have been self induced. If you have to take the crank gear off, making sure it is fully tight to spec is critical. After breaking a gear in the process of trying to tighten it, I've realized I was never getting to spec...umm well ever before. In fact I'm so confident about this, that the new motor sitting on the stand in the garage is not getting pre-doweled.

While the motor is apart I'm using a block of wood to hold the crank in place, and a new bolt with red loctite. Getting it tight to spec, and that's it. I'll report back in if it strips.

[g60301]

Is changing the crank bolt that difficult of a job? Any special tool required besides something to hold the crank pulley in place?

[TheRealEddie]

After getting the lower cover off you have access to the bolt. I haven't done it myself but I bet you can pull it off without removing the damper pulleys, timing belt, etc. However, just don't accidently bump it off the crank nose. It's best to set the crank to TDC first just in case the timing belt falls off.

Mine bolt came off with an impact wrench fairly easily.

-e

[dovski]

Hya all, excuse me for first post here on a fantastic forum for VAG nuts!

I'm building an AGU for my lotus and am about to get the crank gear off to replace the seals.

It strikes me that tightening or loosening the retaining bolt without using the tool will apply shear loading to the key, gear and crank, potentially weakening the whole on rebuild, especially if the same method is used for tightening ie. holding the crank by any other method than using the gear holding tool.

One of the pictures above of the fractured gear concerns me,,, was that gear held by bolts only accross the two points of failure or diametrically opposite or all four?

I think its imperative that the parts are assembled bone dry with the exception of the the bolt threads. Not having the gear in my hands, is the crank/gear snout tapered fit or parallel?

This cant be an achilles heal to the motors surely? its got to be assembly issues no?

[mattrip]

While this thread is being brought back out...

What is the best way to hold the crank and torque the crank bolt with the engine out of the car?

As it currently sits:

[DigiMatrix]

I use a home-made version of this:



Available here:
http://www.metalnerd.com/cat05.htm

[sdezego]

Hya all, excuse me for first post here on a fantastic forum for VAG nuts!

I'm building an AGU for my lotus and am about to get the crank gear off to replace the seals.

It strikes me that tightening or loosening the retaining bolt without using the tool will apply shear loading to the key, gear and crank, potentially weakening the whole on rebuild, especially if the same method is used for tightening ie. holding the crank by any other method than using the gear holding tool.

One of the pictures above of the fractured gear concerns me,,, was that gear held by bolts only accross the two points of failure or diametrically opposite or all four?

I think its imperative that the parts are assembled bone dry with the exception of the the bolt threads. Not having the gear in my hands, is the crank/gear snout tapered fit or parallel?

This cant be an achilles heal to the motors surely? its got to be assembly issues no?

If you make or use a tool to hold the cog, it is best to use all 4 bolts and snug them up. I can only speculate why that gear pictured broke, but if I recall, the factory service tool uses only 2 bolts to hold the cog while torquing.

All that said, it is better to hold the flywheel or crank while torquing so that it does not put sheer forces on the keyway. Again, factory service tool does hold by cog, so it is acceptable.

This cant be an achilles heal to the motors surely? its got to be assembly issues no?

It is of sorts. The snout is parallel. The problem is really the bolt and torque method, but pinning is still a good idea. The bolts fail after so many engine cycles and that is the bottom line.

[sdezego]

I use a home-made version of this:

[G60ING]

The cog that cracked due to being held by two bolt holes looks like it was held by two holes next to each other. The factory tool uses holes opposite each other. I think if one wanted to you could add a 3rd hole. The nice thing about the factory tool is that it can double as cam counter hold tool (VERY IMPORTANT on TDIs) thus saving even more $$$

Well......ungodly tight was not working for me. I got the bolt to turn maybe a fraction more, before it made a pop sound"





New bolt and new gear again this week, and if I get it to 1/4 turn I'll just stop. I'll just use copious red loctite and pray for the best.

This thread was inspiration for me to create a similar one on TDICLUB:

http://forums.tdiclub.com/showthread.php?t=318602

I used an 11/64" drill through both the pulley and crank followed by a 3/16" reamer.




I used the old bolt to hold the cog square & snug on the crank:



The first crank cog I did went beautifully, the 2nd one had a snag:
A word of warning, make certain you have the holes deep enough. I'd suggest that you do this with the cog off the crank. Put the pins in the crank, and then measure how far out they stand. If you install the pins with the drill bolt in place you will have a challenge to get the drill bolt out...I learned the hard way buy I overcame the lesson.

I would recommend drilling the sprocket out on a drill press or mill. Once the sprocket holes are made you can use a regular hand drill to drill the holes in the crank.

Yes the timing belt does need to come out to do this.

The dowel pins that I used were 3/16" x 1.5"

Here is what I bought if you want to spend the extra money for a box of 50 for $14 Plus shipping if you can't pick them up: http://www.grainger.com/Grainger/Dow...B66?Pid=search

Here is the reamer:
http://www.fastenal.com/web/products...-131588&ucst=t

Here is the final pass 11/64 drill bit (before the reamer):
http://www.fastenal.com/web/products...u=53012&ucst=t


The VW crank holder can also be used to hold the cam gear when doing the TDI timing belt. Its $65 from Worldimpex: http://www.worldimpex.com/parts/oem-...rt_238827.html

You will also need a new bolt, I used the old bolt to hold the sprocket in place while I drilled the crank. I had to grind the sides of the old bolt (shown in the pictures)

I bought the pins, reamer and drill bit because its about once a year that I have my hands on a strange motor that should be pinned during a rebuild or whatnot.

Here is a picture of the dealership tool for torque procedure on the crank sprocket:

If you make or use a tool to hold the cog, it is best to use all 4 bolts and snug them up. I can only speculate why that gear pictured broke, but if I recall, the factory service tool uses only 2 bolts to hold the cog while torquing.

All that said, it is better to hold the flywheel or crank while torquing so that it does not put sheer forces on the keyway. Again, factory service tool does hold by cog, so it is acceptable.



It is of sorts. The snout is parallel. The problem is really the bolt and torque method, but pinning is still a good idea. The bolts fail after so many engine cycles and that is the bottom line.

[sdezego]

While this thread is being brought back out...

What is the best way to hold the crank and torque the crank bolt with the engine out of the car?

As it currently sits:...

Put the Flywheel on and use that to hold the crank via a wedge in one of the teeth to block or using a box end wrench on a pressure plate bolt with open end in bolt on block or engine stand bracket, etc. (saw the later done by a pic posted by G60ing).

..orr, you can use a block of wood between the crank and block. Just make sure it is wide to spread the load. It does work...

The right way is to use a flywheel lock.

Here is one I made for doing 02m's

[G60 Carat]

Hya all, excuse me for first post here on a fantastic forum for VAG nuts!

I'm building an AGU for my lotus and am about to get the crank gear off to replace the seals.

It strikes me that tightening or loosening the retaining bolt without using the tool will apply shear loading to the key, gear and crank, potentially weakening the whole on rebuild, especially if the same method is used for tightening ie. holding the crank by any other method than using the gear holding tool.

One of the pictures above of the fractured gear concerns me,,, was that gear held by bolts only accross the two points of failure or diametrically opposite or all four?

I think its imperative that the parts are assembled bone dry with the exception of the the bolt threads. Not having the gear in my hands, is the crank/gear snout tapered fit or parallel?

This cant be an achilles heal to the motors surely? its got to be assembly issues no?

So a block of wood to hold the crank with the oil pan off is bad?

[dovski]

I took my block to the "Seat" dealership and for around $8 they allowed me to use their tool to hold the gear as in the previous pics using two opposing holes. I'd definitely say, the torque when doing/undoing should not be held by the crank as the fragile key and keyway are then taking all the torque reaction and subsequent shear from tightening as would holding the opposite flywheel end. The factory tool method worked easily with a lot of grunt used when the block was in the trunk of my car.
Even I tried using a pickaxe shaft on the no.1 conrod and a breaker bar, but after reading the tales of woe on this fantastic forum I decided to use the dealer tool and it worked a charm. I now have a new bolt and pulley arriving tomorrow too, thanks to your advice, now should I pin ??

[mattrip]

So a block of wood to hold the crank with the oil pan off is bad?

I used the block of wood trick to hold the crank when removing the bolt. As S noted above it works for torquing as well (may go this route) if I cant piece together a holder.

G60Carat- can you confirm what your were using to hold your crank when you broke the crank gear?

For the record: My engine ~125K miles, driven hard, lots of piston damage from detonation, and the crank gear and bolt were fine. Bolt was very hard to remove. 2x4 wedged between the crank and block and I could not break it loose with my 1/2" breaker bar and leverage pipe, had to use beast of an impact.

Rebuilding now and debating on pinning or only going back with a new bolt and the proper torque.

sdezego I was reading your post on the 16V forum about using the ARP crank bolt and having to machine the bolt shoulder. Would you recommend this route on the PG motor? If so I was looking at the bolt below and grinding the washer down to fit. Opinions welcome I already bought the factory VW crank bolt.

[G60 Carat]

The tool I made only held onto to the 2 bolts on one side, it was just biggest piece of steel I had lying around, I basically cut a small moon shape into a 4" x 2' long piece of steel, and drilled the 2 holes.


Earlier I mentioned I won't be bothering to pin the current engine on the stand. This is simply because after the fact I was talking to a much more experienced engine builder. He basically informed me, the key way is in no way designed to hold any sideways loading, it's only there to line everything up. All the holding force is on the torque spec and the stretch on the bolt. (hence the high torque figure and one time use bolt) So pinning it might help save your bacon if the torque spec was off, but it shouldn't be needed if full torque is reached. He also mentioned I should see if it states a light oil on the threads or dry, because the specs should actually call for that, and usually it's a light oil. This gives you a more accurate torquing as your not fighting near as much thread friction.

Instead of a light oil, you can use a very small amount of red loctite, as it acts like a lubricate until it sets up. But it's also important to not over use the red loctite (or oil) as this can give you a hydro lock false read. Essentially your are compressing the lubricate/red loctite and this can through out your final read.

Because of all this new information, I can't see how using a block of wood between the crank and block wall to hold the crank would be worse then any other way of locking the crank. It shouldn't put much more stress on the key way, and even if it did. Once fully tighten, the key way would be irrelevant.

I also learned I was storing my torque wrench wrong, so there is always that too.

[g60301]

This whole issue scares me. How is one to tell if the key way is worn out? Is it better just to replace the crank bolt and forget about the whole issue? . Seems like a pain in the ass job to change a bolt . And if my block was rebuilt by p.o. would you assume they would of installed a new crank bolt?

[crazynorweegian]

This whole issue scares me. How is one to tell if the key way is worn out? Is it better just to replace the crank bolt and forget about the whole issue? . Seems like a pain in the ass job to change a bolt . And if my block was rebuilt by p.o. would you assume they would of installed a new crank bolt?

It is a $5 bolt that takes like 30 minutes to replace. Just do it. Hell, do it every 10k as part of a check up. I do mine almost every year (since I am usually doing something else down there). I just used the gun on mine last time but I might actually do it correctly with the tool next.


I talked to some "experts" as well about the pins and they all said you only need them when you didn't torque correctly. I probably didn't torque correctly, but I am not really worried about it just yet.

[G60ING]

It is a $5 bolt that takes like 30 minutes to replace. Just do it. Hell, do it every 10k as part of a check up. I do mine almost every year (since I am usually doing something else down there). I just used the gun on mine last time but I might actually do it correctly with the tool next.


I talked to some "experts" as well about the pins and they all said you only need them when you didn't torque correctly. I probably didn't torque correctly, but I am not really worried about it just yet.

I pinned my TDI's crank cog because when the timing cog has issues the cost of the repairs are in the thousands (20:1 CR). Sure if you do it correctly you have no issues, the pins just provide some extra safety margin and peace of mind. Besides pinnings is relatively cheap.

[G60 Carat]

I talked to some "experts" as well about the pins and they all said you only need them when you didn't torque correctly.

As I said earlier, this is the same advice I received from someone with about 100x times the engine building experience of anybody else I have ever met. And it made good sense to me, I never had issue with a stripping a Factory installed crank gear. It wasn't until the first time I put my own on. Plus breaking that gear, and not even getting it half way tight, really taught me how much force is actually going into tightening that bolt.


Also new crank bolts in Canada are a few cents over $10

This is not something you can do without a crank gear holder that holds all 4 bolts, or at very least 2 across from each other (even then It's going to be a lot of force on those 2 bolts) or removing the oil pan and blocking the crack with a piece of 2x4 or something. The crank has to be locked. Holding the brakes in gear or whatever, not going to work, not even close.

[crazynorweegian]

I am considering doing a pin again, despite my feelings about it not being necessary on a properly torqued bolt. I am getting ready for some summer cruise miles this year, so if I have time before the first planned trip, I may do it.

HOWEVER, the point of this post is to tell you all what I found while researching crank counterholds. VW3415 is the factory crank tool for tightening the bolt. There is a cheaper (updated?) version that is the Schley 67600 (there is a VW tool designation that I forgot). This updated version uses 3 points instead of two. The best commercial option is the crank yank which has a replaceable handle (for when you bend it doing the stretch), uses 4 points, and is adjustable albeit absurdly overkill and stupid expensive. The best option I have found so far is available through Techtonics Tuning and is very similar to the DIY counterhold that bolted to the block and uses 4 points. It is made by JRE and has a TT catalog number of 126 300.

http://techtonicstuning.com/main/ind...oducts_id=2028

I am ordering this tomorrow and using it to tighten my bolt while I install an ABA crank pulley.

[sdezego]

I am considering doing a pin again, despite my feelings about it not being necessary on a properly torqued bolt.

You are missing the point of pinning somewhat. Pinning takes stress off of the bolt during engine cycles. It also adds extra insurance. Properly torqued bolts WILL fail at some point. There is no magic number, but for the G60 it seems to be between 100k-140k, but a lot of factors and not ALL will fail obviously.

I will never build another VW motor w/o pinning the Cog. $.02

Also, the best method to hold the crank is NOT by the COG. Not saying it will cause problems and I have done it many times, but the Factory tool is a service tool. Not a factory assembly tool. You are putting near (200-250)lb-ft to of tq directly to the keyway (and/or pins) when you hold by the cog. The absolute best way is to hold the crank via the Flywheel, but this is not easy in most cases when motor/trans is in the car.