Why do people still screw up timing belt jobs?

[pauleyman]

I don't get it. It seems like once a week we have a post on a botched job. I'm tired or reading about it. I just wanted to share my experiences.

After 20 years and more belts than I can count I'll summarize by saying this. No matter what method you use to line up marks, put belt back on, what tools you use the following will ensure it's right.

Once the belt is on rotate the motor at least 6 times until all 5 marks line up with dowels up on the cams. (3 marks for no balance shafts).
This is NO almost right. The marks are either dead on or they are not. Period. If it's wrong you start over. NO exceptions

The tensioner protrustion must be in spec. Its either in spec or it isn't. There is no close enough. There is no almost.

Why does the manual tell you to rotate the crank? Two reasons. One to check the marks and more importantly for those that haven't figured it out, to remove all the slack from the idle side. In case you didn't figure this out yourself you may find then the tension was correct then you rotated the motor and now it isn't. Thats becuase there was a little slack on the idle side. Once I have the marks lined up I rotate the crank just a hair to make sure there is no slack on the idle side so I can set tension correctly.

Either way once you rotate the motor you have eliminated any possible slack and the tensioner protrustion will be what it's going to be and the measurement is either in range or it isn't.

I can't see any more plain objective way to state it.

I did my first timing belt job in 1993 before there were videos, forums, vfaq with nothing more than basic tools and the factory service manual which I followed to the letter. The car should run exactly as it did before. No better, no worse, no nothing.

I trust nobody but an experienced dsmer to set tension. I don't even trust mitsu techs unless I know them. I've seen too many people ignore the procedure or try and short cut it.

If any of the measurements, marks are wrong. You start over.

Once I had the belt on the first time it took me about 10 tries before I got it right because I didn't quite know how. Once I fooled with it for about 45 min I figured it out and by following the factory manual I knew it was right and had zero doubts. No "good luck" needed, no crossing fingers. It was right, I knew it, I buttoned it up and didn't look back.

I hope others do the same. Maybe this will help somebody.

 

[livedsm4g63]

No joke I usually set then tension a handful of times before I am completely happy with it.

 

[Tyeler18]

Amen.

 

[Dhan]

While we're on the subject of t-belts. Why does it say not to rotate the crankshaft counter-clockwise in the manual?

 

[97gsxIA]

Well I'd get used to it. These are the newbie forums afterall. People will learn, they just need to figure it out hands-on before rushing to the forums to pour their hearts out. A harmless question here or there is of no concern to me. I enjoy helping the kiddos out. Keeping the life style of being a DSMer alive.

 

[livedsm4g63]

While we're on the subject of t-belts. Why does it say not to rotate the crankshaft counter-clockwise in the manual?

Usually every manual will say this. The reason is because they say it may cause the timing belt or b/s belt to jump.

 

[97gsxIA]

While we're on the subject of t-belts. Why does it say not to rotate the crankshaft counter-clockwise in the manual?

It's possible to throw timing off over a 1/4 turn counterclockwise. just make sure you don't turn counter clockwise that much and you should be fine. If you DO, then just check the timing and tension again after 6 turns clockwise.

 

[nickk90]

Usually every manual will say this. The reason is because they say it may cause the timing belt or b/s belt to jump.

I dont think their is any "may cause" about it. It will cause the timing to jump a tooth

 

[livedsm4g63]

I dont think their is any "may cause" about it. It will cause the timing to jump a tooth

Negative, you can get away with doing it. Ive done it a couple times with no issues, so have many others. It will jump if the belt is super loose though.

 

[pauleyman]

If you also turn counterclockwise you pull taught on the tensioner side, not on the idle side. It's possible to jump a tooth etc. I will turn counterclockwise several teeth just so I can rotate clockwise to remove slack and check marks without having to turn 6 times.To this day I still turn a full six times and recheck before I button up. Typically I can set tension and put the pin back in by hand. Takes practice. Go no go gauge and a mirror are used to check the tensioner.

 

[Dhan]

Usually every manual will say this. The reason is because they say it may cause the timing belt or b/s belt to jump.

It's possible to throw timing off over a 1/4 turn counterclockwise. just make sure you don't turn counter clockwise that much and you should be fine. If you DO, then just check the timing and tension again after 6 turns clockwise.

I see, that makes sense. I thought they said not to because it could damage something in the engine, but I could never figure out what could be damaged. Thanks for clearing that one up

 

[pauleyman]

It's been some years and I feel an update is needed. Lots of people ask about turning counterclockwise. Yes you can jump a tooth but if you do then you would realize it immediately. Even if you didn't once you rotate the motor you would realize it fix it and set tension again. I do it this way. Once all the marks are lined up I put a wrench on the exhaust can and turn counterclockwise just a tooth or two. Then I rotate crank clockwise and put marks back in time. I do this to make sure there is no slack in the idle side. Then i can proceed with tensioning the belt without concern there may be slack that shows up and causes me to have to retension. Once tension is done I still do the factory recommended six rotations, heck marks again, check tension again and that's it. If it isn't right I fix what isn't right and repeat the steps above.

 

[Spleen8urLSX]

I seen this pop up and how long ago it was and thought to myself well this aged well, people still can’t get this right.

 

[curt-s]

Mentioning setting tension by the ease in which the tensioner grenade pin can be slid in and out might be akin to throwing an actual grenade in the conversation here and running

 

[CrackedDSM]

Don’t set the tension at all and just pull the pin and let the tensioner screw the entire alignment of everything up, I say.

It allows you to stretch/build up your guesstimating muscles too by trying to set everything as far out as the tensioner is gonna pick up so everything aligns perfect.





(Obvious sarcasm here)

 

[CKOPOCT]

Some may think that it's the job of the automatic tensioner to take up any slack. After all, that's what a serpentine belt tensioner does, right? So why should the timing belt be any different?

Answer - because the timing belt tensioner only adjusts by a very small amount. If there's more than a miniscule amount of slack in the belt, the torque on the belt when the engine is cranking can cause it to jump a tooth or ten - bye bye valves.

 

[FIBA M - EC17PSE]

I dont get how people still do the tensioner pully counter clockwise for 6 bolt and clockwise for 7 bolt! Dan from evo spec posted a 7 bolt pic yesterday and it was timed like a 6 bolt! Thats a damn shop doing this! Aint no way i trust a shop if they cannot figure out a 6 bolt or 7 bolt timing direction. Im not saying it’s dans shop btw! Just he posted it up for a raffle for a built engine but still. Gonna show something off at least show off the correct setup! Names behind it and everything!
There is a reason its directional because its too close to the tensioner bracket and could foul, while unlikely its possible.

I get the first time is tricky but i also did this by the book first time in a tight garage floor and went well. I just followed precisely and now i do them well and done many for me and friends all while local shops are scared of it?

 

[19Eclipse90]

I dont get how people still do the tensioner pully counter clockwise for 6 bolt and clockwise for 7 bolt! Dan from evo spec posted a 7 bolt pic yesterday and it was timed like a 6 bolt! Thats a damn shop doing this! Aint no way i trust a shop if they cannot figure out a 6 bolt or 7 bolt timing direction….

If it was a 1G 7-bolt, I would venture to say there’s nothing wrong with it. See discussion here: Timing Belts and TDC (long write up)

 

[FIBA M - EC17PSE]

If it was a 1G 7-bolt, I would venture to say there’s nothing wrong with it. See discussion here: Timing Belts and TDC (long write up)

Turns out i missed some info to. I see its now an EVO engine from the hydro tensioner. I originally saw what was a later tensioner arm. So i overlooked the tensioner itself. So my bad on that one. But this still shows the pully as being clockwise even though the Evo is anti clockwise its supposed to be. Look how close the belt is to the bracket!

Thats why it got changed to make more clerance and to make it easier to preload and tighten and not over preload vs the 1g way

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[19Eclipse90]

I’m with you - I don’t like the way it looks.

Since it is not original equipment, however, I cannot say whether it is right or wrong.

 

[FIBA M - EC17PSE]

I’m with you - I don’t like the way it looks.

Since it is not original equipment, however, I cannot say whether it is right or wrong.

Reguardless of original block its all made to the same data points and its using oem arm, bracket etc. its still times as it should be unless designed differently but i dont see any changes that suggest that and nones made on the bullet site about adjusting timing differently last time i checked. (I considered buying one for my build) So read up a bit on them

 

[steve]

Without a waterpump to run into I guess it might rotate in either direction but it looks like the belt might come close to rubbing something either way.

 

[CanadianTalonTC]

I seen this pop up and how long ago it was and thought to myself well this aged well, people still can’t get this right.

Some of the first work I did to my DSM was redo a botched timing job by a Mitsubishi dealer back in 2011ish . Every time I touch a timing component I seethe about the fight I had with the car thinking "the timing is good, the dealer did it!". The only reason I had brought it to them is cause I didn't have time to do it, but it turned out I had time to do it and a lot of other stuff including trying to get my money back (got the labour back). I dropped it off in running condition and when I picked it up they said at the counter "It's got quite a lope!" and I was like wtf. They stated they retimed it 3x (I do not believe this).

I'm kinda mad again typing this out.

 

[Justin DuBois]

Uh, the tension pulley - the two pinholes are towards the top (6-bolt style) I'm wondering if it lines up better rotated down (7 bolt style) - It does have a 7 bolt front case.
Also - I'd like to see where the cam gear marks are with a cam gear lock tool. Sorta looks like the crank is just a couple degrees before TDC. The oil pump isn't in time - and I can't see the marks on the crank to see.