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What tools or methods are used for tightening the Crankshaft
by
Peter
on 22 Jan, 2006 06:36
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usually, it is fairly easy to take the crankshaft pulley nut off with an air tool...but how can one hold the pulley in place when the nut needs to be torqued to the proper specs..
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#1
by
Master ACiD
on 22 Jan, 2006 12:46
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have a buddy hold a pry bhar or large screwdriver down the bellhousing hole and against the flywheel ring gear teeth.
either that, or do what i do which is set the impact wrench on high and zoom it on real good.
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#2
by
andy2
on 22 Jan, 2006 12:59
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In a pinch I've used an old timing belt with vicegrips holding the belt tight around the pully.Put the other end of the loop through the big hole in the control arm and put a log through the loop :lol:
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#3
by
Peter
on 22 Jan, 2006 13:26
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it least the last 2 examples don't sound as primitive as what I always did.. which involves removing the oil pan and then inserting a 2x4 in there to keep the crank form not turning...at least no more leaks in the driveway
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#4
by
935racer
on 22 Jan, 2006 13:32
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If the engine is in the car put it in gear and get a friend to step on the brakes. If the engine is out, than pulling the pan and putting a piece of wood or steel in there to keep the counterweights on the crank from rotating is the easiest.
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#5
by
jackbombay
on 22 Jan, 2006 21:03
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I've used a plumbers strap wrench before, with a big persuader, onthe pulley itself.
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#6
by
dieselweasel
on 22 Jan, 2006 21:22
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If the engine is in the car put it in gear and get a friend to step on the brakes.
I tried that once and there was still enough torque to turn the wheels. I took off the oil pan and used the 2x4 method. The method with the old timing belt sounds good, I'll have to try that next time.
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#7
by
commuter boy
on 22 Jan, 2006 22:57
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either that, or do what i do which is set the impact wrench on high and zoom it on real good.
It's won't even be close to the right torque. My dad the VW mechanic says the only crank bolt failures he's seen are from people that don't torque up the bolt properly, who just use a impact wrench. It'll hold, but not for ever.
I've had no success with standing on the brakes, it's always been a 4 foot prybar jammed into the flywheel through the bellhousing and a six foot breakerbar on the bolt for me.
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#8
by
fatmobile
on 23 Jan, 2006 02:30
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Weld a bar onto a spare crank pully, offcenter so you can put a socket on the bolt. Bolt the pully to the timing gear.
Put the key in the right spot on the crank and snug the crank bolt down.
Rest the bar on the ground and torque the bolt.
This even works on an engine that is out of the car because all the stress is transferred to the ground and doesn't try to turn the block on it's side.
I found something similiar to this on the old forum but I don't remember who to give credit to. They used a piece of flat bar that would bolt to the timing gear so that's what I did. It would have been much easier to have a friend weld it to a spare crank pully, than to drill all the holes in 1/4" stainless.
Here I found a picture of mine:
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#9
by
steve
on 23 Jan, 2006 07:38
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I vote for the prybar against the flywheel teeth through the access hole where you find TDC. I did that last month and it worked perfectly. I could easily torque the bolt to the the proper specs.
I definitely vote against using an air impact wrench. I did that 4 years ago and 3 years later the bolt loosened and broke while zipping down the highway... It's a bad idea to assume that it's good enough! Engineers put torque specs on critical bolts because it's critical for service life. Too little and fatigue life decreases and it may loosen. To much and you'll overstress it. I found out the hard way.
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#10
by
DieselMonkey
on 23 Jan, 2006 12:39
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Guys,
I cant believe that I'm reading that. A pry bar jammed down into the clutch area to take that amount of torque. There is enough torque being placed on the bolt to turn the wheels even with the brakes fully depressed and your not at all worried that the ring gear or some other components being damaged.
To me there are only 3 methods. All involve a new sprocket and bolt.
1) Brakes fully depressed, helps if you have 288 mm VR6 brakes !
2) As rough as it might look, it works fine and causes no damage - Wooden block placed in the crankcase
3) A tool which locks against the ground and takes the torque.
Use Loctite 2701. This is their strongest product.
I personally dont think its all that bad of a design. Had it been left hand thread there wouldnt have been any fall off. If you get 90NM and 90 degree turn on that with loctite 2701, its never coming off.
DM
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#11
by
steve
on 23 Jan, 2006 13:37
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The bently manual has some kind of "keep the flywheel from turning" contraption that uses some thing that grabs a few gear teeth. So, I used 2 prybars to spread the load between 2 teeth. The short distance between the gear teeth and the bell housing makes for very little force required on the prybar handle. Lots of leverage there. I pushed hard to keep the prybar at the gear tooth root so as to not bend over the gear tip.
If in doubt, use a screwdriver with half the thickness of the gear tooth. If the screwdriver breaks then you've saved your ring gear from breaking...
I figured that the force on the flywheel teeth would not be that great due to the radius. let's say it's 10" radius. then the force on the ring gear tooth is 180 lbs. if you try to use 2 teeth then its half that. I don't know. It just didn't seem like that much force for these teeth to take...
The 2x4 idea is fine, except I didn't want to mess with taking my oil pan off.
The bently manual says to NOT use any thread locking compound. I of couse ignored that advice... However I didn't want to use the strongest loctite for 2 reasons. First, I didn't want it to be absolutely permanent. and second, It's not a small bolt and strong loctite is increasingly effective as the bolt diameter increases. So I used medium strength on mine. Although, they say that a properly torqued bolt won't come out.
This engine (my 1.6L TD) max torque is 98 ftlbs. I would prefer to NOT put 150 ftlbs through the geartrain all the way to the wheels. It's probably capable of it. Who knows. Plus I didn't have anyone to step on the brakes either. And I hate that springy feeling when trying to tighten a bolt and the torque springs all the way through the drivetrain. I like a nice solid stop.
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#12
by
vwmike
on 23 Jan, 2006 15:05
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This engine (my 1.6L TD) max torque is 98 ftlbs. I would prefer to NOT put 150 ftlbs through the geartrain all the way to the wheels. It's probably capable of it. Who knows.
150 ft/lbs should be barely breaking a sweat for the drivetrain.
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#13
by
DieselMonkey
on 23 Jan, 2006 16:10
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To each there own I suppose, i'll actually be doing this to my mk3 tommorow night AGAIN ! when I built the engine the brakes wherent fitted up, so my only option was to tighten the bolt to 90NM using 2 tools I CNC milled that bolted to the g'box flanges, marked the 90 degree rotation on the bolt head and went at it with an air gun. I needed to go from 12 o'clock to 15 mins past, well I only made it round to about 10 past. It pissed me off big time because I'd used a new bolt, wheel and Loctite 275. I just said enough is enough, built the engine further and got it running, but its been on my mind ever since and I know its simply not good enough, so I ordered all the new parts again today and called Loctites HQ to ask about there strongest threadlocker. They said if you use 2701 and give it a full 8 hours to go off, it really shouldnt move unless you heat it to 200 degrees C, thats its break away temperature.
I've got 288mm VR6 brakes now so with the help of a buddy, hopefully they should hold when I'm swinging a pull bar on it.
Another thing I noticed. I measured this a while ago, the last time I fitted one. The cranks notch will take an 8.02mm slip gauge, an 8.01mm has play and an 8.03mm will not go. The pully's key measures 7.98mm. There is noticable movement in the pully wheel, so naturally, when your applying the turning force, the wheel will want to go clockwise with the bolt, that gives it that 0.04mm gap. If your turning clockwise and the pully wheel hits its limit on the > face and leaves the gap to the <, the pull of the cam, inj. pump, alt and PAS pump will obviously make the wheel want to turn anti-clockwise and because its a RH thread, once it moves that 0.04 back, it WILL wind itself out in a short space of time.
So, i've decided i'm going to get 2 people, one to step on the brakes, and the other to hold the pully wheel to the < using an oil filter wrench on the OD. Once its tightened to full spec with 2701 threadlocker on there and with the wheel tightened in that posistion i've mentioned... HOW could it come off. That bolt is not having a lot asked of it. Its a very strong bolt and fine thread too.
The updated harmonic damper is £260 + VAT. I'm not paying that, i'll go so far but that is just a bit too much.
Mine still has its original alternator. I'm not up to date on the TDi alternator i've heard mentioned. Not convinced either, theres so little resistance there.
I think had it been LH thread, there would have been practically zero failures in this area. At least it has a key, renault actually have a current DCi with a floating crank wheel. All pully's are floating on that engine..... So its more accurate, but I can help feel like its unsafe, not even taper locked like the VW camshaft. I hate to even think about it ! yet, never heard of a failure !
I've never heard of a 1.6 Diesel throwing the bolt and wheel. Has anyone else ?
DM
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#14
by
DieselMonkey
on 23 Jan, 2006 16:19
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One other thing. Tried welding a bolt to the wheel - used parts of course, the wheel is an odd cast steel alloy. Just blew a hole in it !
You might think thats a bit too far even if it does work, but you could always just cut the head of the bolt and take the remainder out with vice grips if you ever needed to. But it doesnt work !
DM
