Alternative to flywheel lock during timing belt install

[VII]

Hiya. I'm replacing the belts on my 89 944 and decided to forgo purchasing a flywheel lock and instead to just put the car in gear once the car is TDC. The problem is that even in gear, I get a lot of Crank movement causing the TDC marks to be off once the spring tensioner is applied. I've tried installing the belt so that whatever slack there is is at the spring tensioner roller hoping that the slack would not move the crank but it happens every time.

I have my brother helping me and one of us is usually under the car looking at the mark on the flywheel while the other is messing with the belt. I know a little about the something in the flywheel teeth procedure but would like more info as this may solve my problem. Do you remove the starter? What would work best in the teeth? I would hate to mess anything up, any ideas?

I could buy a flywheel lock and plan to eventually when I go back and do the pump and rollers within a couple months but that means that the car would have to sit on jacks for at least a week and though I have motorcycles to drive, there are some places I must have a car for (University parking pass is only good for my car so I would have to walk or ride my bicycle).

I plan to work on the car in a couple hours max so any ideas are appreciated. Thanks.

[TSNAPCRACKLEPOP]

i think i just jammed an object in somewhere on the pulleys, and installed the lower pulley with the belt on it. not recommended, but works

[John_AZ]

Third try....
I do not remove the front crank bolt to change both belts--it is not necessary. As I mentioned in my first deleted post, the flywheel lock is only used when the front crank bolt is removed.

If you removed the front crank bolt do what TSNAPCRACKLEPOP suggested or get a pair of big vice grips and hold a metal shim between the starter ring teeth and bell housing.

GL
John_AZ
1988 924S + 1987 924S

[kdjones2000]

Heck, I just used a big blade screwdriver in there. It had a diamond type shaft, and with enough force pressing it against the flywheel teeth my partner was able to get that bolt loose.

[VII]

I'll give the screwdriver trick a shot. I'm not removing the crank pulley, just putting the belt on and letting the spring tensioner do its thing. I already have the belt in just fine and everything went smoothly. The problem is that after I slide the belt over the cam with everything TDC, I loosen the lock nuts for the spring tensioner and the spring tensioner moves the crank pulley causing it to be off TDC as it tensions. I just need to keep the crank from turning so that I can maintain TDC as the tensioner tensions the belt. Any other ideas to try just in case? I'm going to head out and give it a go in about 30 min.

[VII]

Another quick question regarding the timing belt: I'm a little confused as to how to get the belt tensioned correctly with the auto tensioner. As I understand, I have no means of checking the cam tension with a tool for the spring tensioner model (save the factory tool) and was planning on using the twist method if needed. Is the spring tensioner supposed to supply the correct amount of tension (for a used belt I hear) if it is let out completely and seems to function fine? My spring is strong and when let fully out it tensions the belt too tight it seems and I cannot turn the belt 45 degrees at any point much less 90 degrees. I have not run turned the car on so I do not know what it would sound like.

So, what is the procedure for timing belt install/tension on spring tensioner cars? I thought it was to just let the tensioner out and you're done? If the tensioner is fully extended and the belt is still not tight enough, how would it be tightened even more? If it is too tight, would I just let the tensioner out until I could twist the belt 90 degrees then tightened the locking nuts?

Thanks again.

[Techno Duck]

Release spring tensioner and it's "supposed" to tension the belt correctly. Every single car I have changed the belts on with the spring tensioner did not put enough tension onto the belt.

The only way to do it right is with the 9201 tool or the tensioner from ArnnWorx. Yes you can also do the twist method but am not a fan of it because it is very subjective. That's not to say I don't do that on my own car...

[VII]

I was actually able to get everything set to TDC just fine without bothering with the flywheel. I have no tensioner tool but the spring tensioner seems to almost make the belt too tight if that is possible? I can barely twist the belt at all. Running it sounds fine, better than it did before actually as I had a sorta bearing type whir or however it would be described. Could have been the bb though, I'm not sure.

I do have another question though concerning the balance shaft belt. Between the lower tensioner and the upper pulley there is a slight twisting of the belt begining about where the balance belt idler roller is. It is not much but definately a little torqued. Does this mean the belt is not tight enough? The belt is fine at idle but when the revs increase the balance belt sorta moves side to side along the tensioner pulley and upper pulley span and looks as though it may be hitting the WP and whatever else. I'm assuming it is too loose? I was a bit tired of working on the car so I have not tried to tension the adjuster yet. It did not seem loose when it was initally put on but who knows.

How would I go about doing the twist method on the balance belt? Where would I do the twist and how much twist should I get out of it? Also, I've read a bit about the preload and clearance of the bottom of the idler roller but I'll take any tips that anyone has to offer. Again, there have been recent postings and I've read them, I'm only asking for any extra info anyone wants to put in, if any.

Thanks a million.

[John_AZ]

You need to do some searching on tension.

If your cam belt is as tight as you posted-it may snap
If your belt is as tight as you say you will ruin/burn out the water pump bearing.

Please search on tension methods. This comes up every other week on every forum.

GL
John_AZ

[Rasta Monsta]

I nominate John_AZ to pen a summary of tensioning approaches and have it made a sticky.

[FRporsche]

screwdriver trick worked for me when I couldn't find my flywheel lock.

[John_AZ]

Originally Posted by VII

I was actually able to get everything set to TDC just fine without bothering with the flywheel.

I have no tensioner tool but the spring tensioner seems to almost make the belt too tight if that is possible? I can barely twist the belt at all. .

VII,

Yes it is possible for the spring tensioner to overtighten the belt. Sometimes I need to spin the crank 2X CW..STOP at TDC and REVERSE the crank CCW 1/2 cam teeth.
I WAKEUP the spring tensioner and set the tension. REPEAT-Stop at TDC-check tension again. REPEAT. MY final test is the WP pully test--MY method explained in past posts.

Some owners use the 90 degree twist, the Krikit or Optibelt tool. One of the safest tools for a new owner to buy/use are the www.arnnworx.com tools (read his belt tension methods). Some like Rasta Monsta will call his wife to set the belt or use his official Porsche P9201 tool. If you can wait, member many944s will send you his P9201 tool.

You can always have a shop tension and retension after 1500 miles.

GL
John_AZ

[bazar01]

I use the spring tensioner all the time. If you release the spring tensioner when the engine is cold, it will be very tight and will whine. You need the tensioning tool when setting it cold.
If you don't have the tensioning tool, all you need to do is warm up the engine at idle, turn engine off, then just loosen the spring tensioner pivot and hold down bolts so it relaxes the belt tension, spin the crank one turn clockwise then lock the spring tensioner. Do not turn the crank counter clockwise one full turn!
Works everytime.

[John_AZ]

Originally Posted by bazar01

I use the spring tensioner all the time. If you release the spring tensioner when the engine is cold, it will be very tight and will whine. You need the tensioning tool when setting it cold.



If you don't have the tensioning tool, all you need to do is warm up the engine at idle, turn engine off, then just loosen the spring tensioner pivot and hold down bolts so it relaxes the belt tension, spin the crank one turn then lock the spring tensioner.
Works everytime.

Every owner has a "method". You have to choose the method that gives you the least "FEAR factor".

Part one of bazar01 is absolutely correct and I compensate by rolling the crank back CCW 1/2 cam tooth. Spin crank twice-recheck--repeat. Final test WP pully.

Part two of bazar01 has faults.

I have respect for bazar01 and his mechanical ability. His "feel" of belt tension makes this style of test work.

Porsche specifies only do cam belt on cold engine. If you warm the car while on idle------do you wait until the temp guage moves up to 1/4, 1/2 or until the fans kick in? I do understand the idea of having the engine warm and the block metal expanded.

Here is the second fault.
"then just loosen the spring tensioner pivot and hold down bolts so it relaxes the belt tension, spin the crank one turn then lock the spring tensioner."

This again defies the WSM by porsche. Porsche says DO NOT SPIN CRANK while A & B are loose.





This is the "DO AT YOUR OWN RISK" section.

Bazar01 can do it due to his mechanical knowledge, I do not recommend this method to a NEW owner.

GL
John_AZ

[Techno Duck]

My opionion, just get the arnnworx tensioner. The newest version is $150 but still a great deal. The factory tool used sells in the $300 range and a broken belt will cost you $500 at least in parts alone. Cheap insurance if you ask me. I beta tested the Arnnworx tool and compared it with the 9201 and it was accurate. It's also far easier to use, getting consistent results with the 9201 is very diffiult. The arnnworx tool also allows real time adjustment of the tension while the 9201 requires you to 'set, lock and check'.

I use the tool for belt jobs I do for friends, but admit I use the calibrated hand and fingers on my car on occasion.

The kriket and optibelt tool are also largely useless on cars with the spring tensioner. I also wouldn't even trust them on a timing belt.. A serpentine belt yes.

Just my two pennies.

[VII]

It appears that my spring tensioner works too well. The car was ran for a total of a couple min and the belts sounded great but I did notice that the timing belt was leaving a rubber residue on the waterpump and idler roller which makes me think it is much too tight. I also tried to spin the waterpump by hand and for the life of me, could not. I have no adjustment tool and the twist method supposedly does not work on spring tensioner models so I will adjust the tension to what seems reasonable then drive the 1/4 mile to the local porsche dealer and have them tension it.

I'm still nervous about the blance belt. I adjusted the tensioner until the side to side movement went away but then the belt seemed too tight with a slight whir. Backing off a small amount to loosen the belt the BB has the side to side movement again. The new belt was not twisted in a weird manner and went on smoothly with no issues. It still has a little tourque to it and almost rides on the idler roller lip at idle, it is as the revs increase that it moves side to side on the roller. I figure I'll get it within reason and have the shop do the BB as well.

[bazar01]

Originally Posted by John_AZ

Every owner has a "method". You have to choose the method that gives you the least "FEAR factor".

Part one of bazar01 is absolutely correct and I compensate by rolling the crank back CCW 1/2 cam tooth. Spin crank twice-recheck--repeat. Final test WP pully.

Part two of bazar01 has faults.

I have respect for bazar01 and his mechanical ability. His "feel" of belt tension makes this style of test work.

Porsche specifies only do cam belt on cold engine. If you warm the car while on idle------do you wait until the temp guage moves up to 1/4, 1/2 or until the fans kick in? I do understand the idea of having the engine warm and the block metal expanded.

Here is the second fault.
"then just loosen the spring tensioner pivot and hold down bolts so it relaxes the belt tension, spin the crank one turn then lock the spring tensioner."

This again defies the WSM by porsche. Porsche says DO NOT SPIN CRANK while A & B are loose.

I forgot the OP is new to 944 timing belt replacement. Do not follow my method then, my bad.

However, loosening the A and B bolts will not cause the belt to jump time. With the amount of belt wrap on the crank and camshaft pulleys and the spring pushing on the tensioner against the belt, there's no way for the belt to jump time if you turn the crank CW manually, John. The spring tension is strong, you cant even compress the tensioner unless it is mounted on a vise. Compress it by hand, don't even try it.

To the OP, If you are not comfortable, then just follow the workshop manual, and get the arnworxx or the 9201 tensioning or take it to a shop with the proper tools.

[AKCJ]

Regarding locking the flywheel - I could not get the screwdriver or vice grip or other home grown methods to work, and I tried several. Ended up buying the flywheel lock from arnnworx and it works very well.

The arnnworx tensioning tool is the cats meow. When I changed belts in June I finished both belts and then stood back and said "is that all there is to this?". EZ!

The first time (a year ago) with the new tool took a bit longer to get things sorted out.

[HondaDustR]

In my experience, the spring tensioner tends to not tighten quite enough. It also doesn't tension correctly unless the engine is rolled backwards a few degrees first (I do 1.5 cam belt teeth backwards). It is also important to rotate the engine a bunch of times, loosen the bolts and let the tensioner take up the slack, and repeat 3 or 4 times so the belt can settle in to its "groove" on the pulleys before getting serious about trying to find the right tension, because it will keep loosening up until it settles. Removing the spark plugs makes this alot easier.

Once the cam belt is settled on the pulleys, set the engine to TDC, roll back 1.5 teeth on the cam, and loosen the tensioner bolts. Tighten the bolts and roll the engine forward at least 2 complete turns. Leave the engine at TDC and try to turn the water pump pulley. You must not roll the engine backwards even a tiny bit for this check, or it will give a false reading. If you miss the TDC mark, go around again. If you're at least close, it's ok, as long as you didn't let the crank go backwards at all. If it turns by slipping on the belt, but is somewhat difficult to turn by hand, then the tension is good. If it is pretty easy to turn, or nearly impossible to turn, go around one turn, then roll the engine back 1.5 cam belt teeth, loosen the tensioner bolts, and tweek the tension by pressing the tensioner into the belt or away from the belt. Don't move it much, it's a very subtle tweek. Tighten the tensioner bolts, rotate the engine forward at least 2 turns, stop at TDC, and check the water pump pulley again. You will go through this cycle at least 5 or 6 times before you zero in on a good tension and learn how your specific tensioner behaves. There's not really enough room to do the 90 degree twist on the auto tensioned cars, and it's probably the most difficult to get an "accurate" feel for, anyway. If it passes the water pump test, it's going to be within safe tension range. Some people get pretty particular about getting it set really accurately, but it's just a fiberglass reinforced rubber belt. As long as it's not cranked on there or slapping around, it'll be fine. The water pump pulley method is the most consistent "by hand" method I've used so far. Naturally, what you choose is completely at your own risk. I haven't had a belt failure yet in all the 10 plus times I've had my belt off, but if you can't sleep at night without doing it "right", send a PM to many944s, who lends his official factory tension guage to Pelican members, or just take the car to the shop.

Keep in mind, though, if it's a new belt, it has to be slightly tighter for the first 1500 miles to account for initial stretch, but not too much or you'll be buying a water pump pretty soon. In that case set it so that the water pump pulley is almost too hard to move, but still just movable by hand. When running, if the belt whines, it's too tight. If it slaps, it's too loose. You might think the correct tension is a little loose for a belt, but the engine does expand quite noticably as it warms up, which tightens the tension a bit. Don't forget to tighten both tensioner bolts! Also remember to tension with the tensioner at - 1.5 cam teeth from TDC, and check the water pump pulley resistance at TDC. It all has to do with what side of the belt the "slack" in the tension is on.

As for the balance belt, it runs a much looser tension than the cam belt. Finding the right tension takes a little trial and error to find a good tension that's quiet (too tight sounds like a supercharger...cool, but not good for the belt) and also doesn't allow the belt to vibrate excesively (which also makes much the same noise, but from rubbing on the idle roller or the water pump pulley, and is typicly a little more rpm dependent). The belt shouldn't sag on the longest stretch, but it should deflect with pretty minimal effort. The smooth roller should be set about 0.5mm away (between 0 and 1mm, but ideally not touching) from the top edge of the teeth of the long stretch of the balance belt. Setting this stupid roller is probably the most frustrating part of the job, since the oblong slot for the mounting stud makes it really hard to keep the roller right were you want it while tightening the bolt. If it's too close, it will whine. If it's too far away, the belt will vibrate too much, rubbing on the water pump pulley and making noise. Get the gap right, and then just play with the tension until you're satisfied.

[944Spec_bound]

Originally Posted by VII

Hiya. I'm replacing the belts on my 89 944 and decided to forgo purchasing a flywheel lock and instead to just put the car in gear once the car is TDC.

I know your not removing the crank pulley, but I almost killed myself doing that. Car in gear, front up on jack stands, breaker bar on crank pulley bolt, pulling like a madman to break it loose, makes the rear tires try to move the car forward.
Duh! I almost rolled it off the jack stands with me underneath it!
Stupid,stupid, stupid me.

No matter how well you chock the tires, I wouldn't suggest anyone do that to save money for a tool. Just thought I'd throw that in there.