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Removing crankshaft pulley

19K views 38 replies 17 participants last post by  rawill 
#1 ·
I've decided not to attempt replacing the timing chain on my 9k since the complexity of the job with the 2.0 engine worried me that I wouldn't get it done in the time available (few hours today and some on Saturday coming up), so I'm focusing on the crankshaft pulley and engine mounts only.

I've drained the oil, but can't get the crankshaft pulley nut to come free. I had my wife sit in the car with the brakes hard on and the transmission in 4th gear but it didn't hold the engine steady. I didn't see any way to lock the flywheel so I might try the 'crank the engine' approach.

The engine rotates clockwise when looking from the RHS wheel space with the covers removed. I've got the belts off already so any cranking will be very momentary.

Which way does the nut come off? Is it a normal right-hand threaded nut? Can I position a breaker bar so it will hit against the subframe or the RHS control arm to break the nut free when I crank the engine?

Craig.
 
#2 ·
I've learned a certain technique not too long ago, but I've never used it. Basically what you do is remove the spark plugs and stuff a rubber hose into one of the cylinders. Then you rotate the engine until the piston gets stuck, and remove the bolt. Hope it helps. ;)
 
#37 ·
Oh my gosh !
This is nearly identical to the method a man suggested with my LawnBoy mower. Simply jamb a small rope into the combustion chamber, preventing the engine from turning.. I think the rope will work better than a hose.
 
#3 · (Edited)
1/4" sash cord works well when using the technique described by mrbooby.

Look into the cylinders through the plug bores and find one near (but not at TDC - maybe 2" from the head) Take the rope and while imparting a motion as if you were coiling it up, feed it down the hole. Get as much in there as you can. It will compress a little bit, but eventually the piston will be unable to travel upwards.The crank will then be locked for harmonic balancer/flywheel removal.
 
#4 ·
If you use that method, make sure the Valves are closed.
If you were not on the compression stroke, the Valves would be open and could bend.
Feel for compression with a finger in the Plug hole before inserting cord, hose, other.
 
#5 ·
near (but not at TDC - maybe 2" from the head)

Maybe not everyone is familiar with TDC (top dead center) and I should probably tried to be more articulate. Thanks to J Mesthene!



At top dead center the piston is at the upper end of it's compression stroke and both the intake and exhaust valves are seated closed.

Caution: While at the top of it's exhaust stroke, the piston will appear to be in the same position in the cylinder as while in compression. But at this point in the 4-stroke cycle, the exhaust valve will still be slightly open. Jamming a cord in the compression space can easily prevent the valve from seating. This will often cause piston/valve face interference, which in turn, can result in a bent valve stem as the engine is barred over. So: Be sure that the piston is at the top of the compession stroke.

To determine whether the piston is at the top of exhaust or compression stick your finger in the plug hole and crank the engine over with a breaker bar. If you are approaching TDC (the top of the piston travel in compression stroke) the developed pressure will literally try to blow your fingertip out of the plug hole.
 
#8 ·
At top dead center the piston is at the upper end of it's compression stroke and both the intake and exhaust valves are seated closed.
There are two TDCs during the 4-stroke cycle. The Piston reaches top dead center at the beginning of the intake stroke and at the beginning of the power stroke.
TDC refers to the Piston position, regardless of Valve position.
 
#6 ·
I'm not sure I want to try stuffing things into the cylinders. Failing a proper way to lock the flywheel, the starter cranking method seems like the most sensible choice.

So who's done this before? Which way does the crankshaft pulley nut turn (given that the engine rotates clockwise when facing it from the RHS)?

I've got the front of the car up on jackstands at present.

Craig.
 
#7 ·
Hey Craig I have done it several times with Hondas and Toyotas it sound intimidating, but just bump the key it will be fine. You do not want it to start up so unhook the coil pack. You could use an air gun and just hit it with that. I have seen people use those potable air tanks if you do not have access to an air compressor and loosen stuff that way, but for a big bolt you will probably need 125+or- psi
Steve
 
#9 ·
Thanks for the feedback. Yes I have the DI cassette disconnected (first thing I do when I do work under the car). I don't have an air gun but I do have an air ratchet. That may work.

Which way does the nut fit on? Is it a standard RH threaded nut? I'll have a go at cracking it loose on the weekend and might use the subframe to stop the breaker bar from rotating.

Craig.
 
#15 ·
tomorrow I'll give the pulley replacement a go. When re-installing the big nut that holds the pulley on, any good ways to make that torque up? My torque wrench definitely will have the right torque setting on it's dial (mine goes up to 150 ft/lb - I use that setting for 32 mm hub nuts as that's the highest it goes to!).

I don't have a rattle gun. :cool:

Craig.
 
#16 · (Edited)
The 'crank with the starter' method has now worked - after four attempts and lots more penetrating fluid! I got the nut in such a position as I could slide the breaker bar into an open area of the frame above where the subframe attaches and that held the bar and socket steady.

Now I am having problems getting the pulley to come off the crankshaft. I realise it's not quite an interference fit but I will persist with more penetrant and long screwdrivers levering the back of it against bolts heads on the bottom part of the cover immediately behind the pulley.

How do you correctly re-torque the nut after installing the new pulley btw? It's not really possible to run the engine backwards to use a similar method (combined with my torque wrench set to 125 ft/lb) to tighten it up again.

Craig.
 
#18 · (Edited)
tightening up crank pulley nut....

Ok I got the crank pulley off after a LOT of penetrant and lots of very gentle levering with long screwdrivers and a small pry bar.

New pulley is on and I also did the seal behind it. Now how do I get the nut tightened up to 125 ft/lb? I can get about 30 or 40 by quickly yanking the torque wrench before the engine turns.

I'll co-opt my wife to do the 4th gear stomp hard on brake method and see how much tighter it will get. Shame it's dark but at least it's not 40 C out there!

Craig.

PS. Also replaced the engine mounts. Front one turned out to be ok, but the back one was shot (torn rubber, etc.). I now have a good (used) hydraulic one at the front (I pulled the one from my car as it's filthy) and a new solid one at the back.

PPS. Now 2.30 am on Sunday morning! We were able to use the 4th gear + brake method to hold the engine enough to tighten the nut on the new crank pulley up to 90 ft/lb and no more, so I've just left it like that. Temp is still well over 20 C outside but the last few hours have been really good for finishing off re-assembling all the stuff I took off to do the mounts and crank pulley.
 
#22 ·
Not for a 9000, as far as I know.

I was able to do the crank pulley on my 5-spd manual 9k carlsson using the 4th gear + brake method (with now ex-partner helping). Ironically the next night I wrote off my red 89 900i driving to work but that's a different story.

I didn't get the crank pulley nut on mine tightened anywhere near the factory torque spec but it has not failed since it was done in Feb.

Craig.
 
#20 ·
It might be best to tighten the best you can either hold the belt or smack the wrench with a hammer be careful and then find someone with an impact gun to tighten it to say about 120psi. I have done that before, just do not drive it too much until it is tight.
steve
 
#25 ·
Ive just removed a crank pulley on a 9000 motor out of the car. Took cam cover of inserted socket extension bar through rear cam wheel and stopped denting of head by putting rubber hose between extension bar and head surface. came undone with torque wrench to the left .To tighten put extension bar through front pulley and turn nut to the right. this method wont work if the timing chain is off of course.
 
#26 ·
I took another automatic flywheel and bolted it thru that large bolthole near the starter in line with the auto fwheel connected to the crank . The teeth mesh perfectly and the more force applied either way locks it in more tightly . I've used it on many of my 900s for years . Don' t put anything in cylinders except macrame cord and only for changing valve seals or v springs . It is use very lightly in this application so its ok . Turning that crank nut this way is a heavy application and you will bend those skinny valve stems . You won't make friends and influence people that way .
 
#27 ·
Resurrecting this from the dead to provide more input. If you do have air tools and a large enough/powerful enough tank. I found that I needed to have the tank set for 120psi in order to get the crank pulley bolt off. I wasn't aware that my tank had been set to 80psi and spent 3 hours attempting to find ways of preventing the crank from moving.

Having been unsuccessful with every other attempted method, I checked the compressor to discover that it was set too low. Upped the PSI to 120 and the bolt came out like a charm.
 
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