Timing belt help

[tommytwotone]

so I kind of messed up... I just did a head gasket and reinstalled my head...

So What do I do to install my new timing belt????

Thanks all

I appreciate it

[SolReaver]

First research the procedure:
Clark's Garage Home Page
Then do a search on tensioning the timing belt in this forum. There are a few options. I tension by hand, but some people are not comfortable with that. You will want to inspect the timing components to be sure everything is in good shape.

Let us know how it all looks and if you have any questions.

[SolReaver]

Did you install the head with the crank and cam NOT properly aligned?

If so, you may need to remove the cam tower, not really sure, someone sanity check me please.

[tommytwotone]

Yeah I wasnt sure how to cam check... The head is on but the valve cover thing is not yet... is this going to be a problem??? if so how do I fix it???

[Vicious]

Valve cover thingy in our motors case is the camshaft assembly. Rotate engine to tdc and rotate camshaft to the same then install it.

[Techno Duck]

If the valve cover is not on yet, rotate the crank by hand until you are at TDC. Take the plugs out if you have not already while you do this to make your life 10x easier.

You can find TDC by sticking a wood dowel down the #1 plug hole, when it reaches the highest point stop. Now verify the marks on the flywheel are in the correct position. There is the OT mark visible from the top, looking down into the viewing window on the bellhousing. The other mark is a notch cut into the flywheel that is visible from under the car. Check this link on ClarksGarage for more info on that.

Locating and Setting Engine to Top Dead Center (TDC), Cylinder 1

Once you have TDC set, you can put the cam tower on. Set the cam at TDC by lining up the cam gear with the notch on the rear cam gear cover. Once the cam tower is on, put the timing belt back on and verify all the marks are still lined up.

Easy as 1-2-3.

[Picas944]

I just finished doing mine yesterday! First make sure you are using the right tools for the timing belt. http://www.rennbay.com/944-timing-belt-wrench-set-p-124.html

As for the timing belt diagrams use the one on clarks: Timing Belt and Balance Shaft Belt Tensioning
I can send you one from a 944S engine.


For the gasket I used:


as for the camshaft you can rotate the balance belt drive gear with a wrench 360 degrees to the clockwise direction. If it rotates freely then the cam tower is aligned with the springs. make sure the transmission is neutral, otherwise you won't be able to turn it.

Good luck

[Picas944]

I forgot to mention that you must make sure you have the right tension on your belts. I used this tool: Kricket Belt Tool.

you will also need this tool to hold the balance shaft while you are tightening it. Zim's Autotechnik 944 Balance Shaft Holder

Everything is so easy with the right tools.

[tommytwotone]

Do I really need all the special tools to install the camshaft belt. or can I tension it by hand???

[SolReaver]

I tension by hand and so do a lot of "old school" mechanics. It can be done. For the first few times I suggest that you use a tensioner tool in order to get a feel for it. The auto tensioner (if so equipped) gets you close, but they are notoriously inaccurate. Hand methods include "twist" WP pulley, Plucking, by ear and whine threshold. (among others) It really depends on your mechanical aptitude and comfort level. I can walk you through it if you like.

CAVEAT: you are on your own...I am NOT responsible...PERIOD. This works for me, but I am not there looking over your shoulder so, I can't be sure you are doing it right. VERY important to rotate the engine TWICE and check the marks if you slip on the tension (if the belt goes slack) as these things skip a tooth a lot during the job. Also, mark your flywheel at the low bell housing with a strip of paint to be sure of TDC without having to use the stupid sight hole at the top.

A LOOSE belt will EAT your Valves (or worse) use extreme caution. a belt that is too tight will kill your water pump in no time flat, again use extreme caution.

IF you have an auto tensioner...use it. It gets you in the ball park. Mark the components and use these settings as your starting point.

It helps to have the sprocket wrench or some other pin type wrench to get the fine adjustment on the auto tensioner. DO NOT lever against the pulley...EVER!

Twist method entails tensioning the belt by twisting it between thumb and forefinger. You should be able to twist the belt to 1/4 turn with little force, 3/8 ths twist with reasonable force and half a twist with strong force at it's longest span.

WP pulley method is when you can just barely turn the WP pulley against the belt tension. If it slips...too loose...If it can't be turned at all...too tight.

Plucking and by ear entails plucking the belt and feeling and listening to the noise it makes and feeling the vibrations that it makes against your finger or thumb as you dampen it. It takes an ear and a feel that a lot of people just don't have.

Whine threshold entails setting the belt tension as best you can using any or all of the above methods and running the engine. A belt that is too tight will "howl" and a belt that is just right will be almost silent when cold and whine a bit when warm. I leave the covers and alternator and PS belt off for these brief run sessions and listen from the drivers seat with the windows up and from the front of the engine. the whine sounds a little like an electric motor that matches the speed of the engine or an alternator that is full fielding.

The bal belt whines as well, you have to set it a bit low to be able to hear the Cam belt correctly, OR be able to isolate the two different sounds. Both belts make a nice harmonious sound when you do it right, kinda like a cross between a whirr and a hum.

It the foregoing makes no sense at all to you, or makes you nervous...pick up a kricket or some other reasonably priced tool, they are really not that expensive and you will be doing the job again in 1000 miles and repeating the whole thing 30K or three years from now anyway, so it is a prudent investment. OK?

[mikepellegrini]

+1 on the twist method. My kid and I have used it on all four of our cars through multiple belt jobs and it works just fine.

The definitive thread on tensioning without the tool: Clark's Garage Message Board :: View topic - Belt tensioning without the tool

[John_AZ]

Originally Posted by tommytwotone

so I kind of messed up... I just did a head gasket and reinstalled my head...

So What do I do to install my new timing belt????

Thanks all

I appreciate it

After reading all the posts and the link from Clarks, I am confused.
TommyTwoTone has 3 posts and registered in May 2010.

I think he should read the Haynes manual and do it with drill bits like the pictures show.

John

[John_AZ]

On second thought...

The 944 series is an interference engine. If the cam belt breaks, the valves hit the pistons.

The best tool for a new owner is the Arnnworx P920X. Good DIY maintenance information included as well. Home Page

The methods mentioned above are for owners who have experience.

Please tell us what year and model car you have.

Here is a guide on changing belts.

Timing Belts

GL
John_AZ

[SolReaver]

Yea, good point John (as always) a novice mechanic or owner may not be technically savvy enough to do it without a tool. Also, the arnworks tool is pretty good (or so I hear)...But doing it with drill bits? I know the green text is sarcasm, but does tommy? How does one tension with drill bits? I have used all kinds of methods including incantations, harmonics, and wine glasses, but never even thought to try drill bits. Anyhow... I was just answering the question...CAN you do the belt without a tool. YES, you can. Or at least I can and others agree that it is possible. Whether doing so is a "good idea"...well...that is a different question.

Now, If someone IS savvy, talented, experienced or just plain handsome enough (the last applies to yours truly) I am going to respectfully disagree and say that The money spent on the tool could be used for that nifty sprocket wrench and a cool 27mm thin with enough left over for a 24mm crowsfoot and some triple squares. Possibly even a box full of good used metric open ends and sockets. Those tools will get you a lot further along in all the other work that these cars will need.

I officially sold my Kricket lat week, it was actually confusing me the last time I did the job and it was slowing me down. I never did find out how to calibrate it and to tell you the truth, I think it was off a bit as is my auto tensioner. The auto T set high, the cricket read low and my thumb was right on. Pulley good, twist, good, slight whine/hum on warm up and we are good to go. I agree that it is good to have a "sanity check" when doing the job, but at this point in my life I can assure you that sanity is overrated.

[John_AZ]

Originally Posted by SolReaver

I officially sold my Kricket lat week, it was actually confusing me the last time I did the job and it was slowing me down. I never did find out how to calibrate it and to tell you the truth, I think it was off a bit as is my auto tensioner. The auto T set high, the cricket read low and my thumb was right on. Pulley good, twist, good, slight whine/hum on warm up and we are good to go. I agree that it is good to have a "sanity check" when doing the job, but at this point in my life I can assure you that sanity is overrated.

Sol,

The Kricket does work on the balance belt. The tool has to be kept on the exact same belt cog each time. The black indicator shaft has to sit on the top of the same belt cog. But like you mentioned, it comes down to the "whine" test and experience on the belt.

Second, you are right, the spring auto tensioner on our cars is too tight.

Cars with the spring tensioner are supposed to be set at TDC.

I compensate the tension by turning the crank CCW 1/2 cam tooth-from TDC. I then release the spring tensioner top 2 13mm nuts and gently rock the tensioner pully to "wake up" the spring tensioner spring. Do Not snap the roller on the cam belt.

Tighten the 2 top 13mm nuts. Rotate the crank 4 revolutions-stop at TDC and check the tension. This is where I use the WP pully test. Many others will use the "twist" method.

Thanks Sol, your sanity is intact.
John

[ernie9944]

Originally Posted by tommytwotone

Do I really need all the special tools to install the camshaft belt. or can I tension it by hand???

I,m gone to go against everybody else pieces of advice here & give you this one ,don't take a chance to DIY your timing belts yourselve specialy the first time get a mechanic or somebody who does know how to do (T-B /BSB) on a 944 to do it watch how it's done then the next time you can DIY them,why take a chance ruining a perfectly good motor.

[ernie9944]

Just complementing ---Picas944 pics hope he don't mind just in case you still decide to DIY the job

[John_AZ]

Originally Posted by ernie9944

I,m gone to go against everybody else pieces of advice here & give you this one ,don't take a chance to DIY your timing belts yourselve specialy the first time get a mechanic or somebody who does know how to do (T-B /BSB) on a 944 to do it watch how it's done then the next time you can DIY them,why take a chance ruining a perfectly good motor.

I agree with ernie,

BUT, if you get this estimate from your shop---RUN!

[ernie9944]

^^ Not talking about a shop John there always mechanic that will do work on the side ,you supply all the parts he install them ,been doing it this way for over 27 years the catch is to find the rigth guy.

[TSNAPCRACKLEPOP]

tommytwotone can come to kc and do mine while i supervise, then he will have the experience!

wow, pica, that sure is a nice pix!