Cam Gear moved during belt change
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togofaster1126Junior Member
- 31
Cam Gear moved during belt change
So while replacing the timing belt i made a mistake. This build of mine is cursed my vg30 went so smoothly now this vg33 is giving me the biggest nightmare ever. So i had the belt off ready to put the new timing belt on when the left side cam gear moved without me seeing which direction i moved in so now i don't know whether to turn it counter clock wise or clockwise to get it back. I'm now wondering how to insure that my cam gear is where it is suppose to be. Ive read through the fsm and it said nothing about this that i can find. Also while rotating the cam separately cause any damage to the engine? i was told that if the engine is a tdc that i can rotate the cam but this was for a Subaru engine. I feel like a newb at this point making such simple minded mistakes but any help would be greatly appreciated. -
frostvectronSenior Member
- 1044
Don't worry your engine is not damaged if you rotate it by hand just a few degrees.
The cam gears have dimples that should line up with marks on the backing plate.
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togofaster1126Junior Member
- 31
Okay thanks for the response and good it rotated from say where the mark 11 o clock to 5 o clock position. Only problem is i dont know if it was counter clock wise or clockwise and thats why im currently pulling my hair out haha. I -
turbofedzSenior Member
- 289
You can always loosened all the rocker shaft bolts an set it back.make sure is at TDC.that is the proper way as per FSM. -
FrozenZSenior Member
- 584
Weird, it rotated a lot further than normal, on the ones I've done it'll only snap about 60 degrees and that's never been a problem to rotate back either way. If you want to be absolutely for-sure safe, depending on how torn down the motor is right now it might be worth it to pop off the valve cover and back off the rocker shaft bolts, turn the cam, then tighten them back down. -
togofaster1126Junior Member
- 31
Alright well i backed off the bolts and such now just trying to figure out what position the cam should be in or how to figure out where to set the cam at. I know at tdc the left side cam should be set to where the number 1 valves are both closed correct? -
707Redz31Senior Member
- 375
Just line up the dimple on the cam gear with the one on the back cover. Since a cam is locked to the gear in a fixed position and has a circular profile any rotation forward or back a full 360' from it being lined up is back in the same spot. Loosen the rocker shafts and move it back, or remove the belt, move the crank backwards a small amount, check piston position with a chopstick and move it back then line the crank up, reinstall belt and count the teeth. Its been made into a more complicated issue than it is. Lol -
togofaster1126Junior Member
- 31
Ah i see your saying if the cam gear turned counter clockwise out of aliment to the dimples that i could turn it clockwise to line the dimple back up and it will be fine either way? i wouldnt have to worry about turning back counter clockwise to line it back up, as long as the cam gear is lined up to the dipple on back timing cover that its fine?
okay so put everything back together and may or may not have had an issue. So i was adjusting the tension on the belt after putting cams in right position.and went to rotate then engine. When i did i came to a spot when rotating it clock wise where i thought it locked up i didn't force it or anything, I then turned the motor counter clockwise and thought it got to another spot where it locked up so i stopped and went inside for a bit to think. When i came back out i rotated it and it rotated fine with no locking up. This may sound dumb but maybe i just needed to turn the crank harder because the compression of the engine was stopping me from turning the crank?
The question i have is if their was a valve hitting or something is their anyway that i could turn the engine after? Im thinking if their was a valve hitting or something that no matter what i couldn't turn the engine. Im just confused because it felt like it was locking up but now it turns fine…
I think im just going throw the engine in and try starting itLast edited by togofaster1126; 05-17-2016, 05:50 PM. -
nismopuAdministrator
- 2221
You are over thinking things. It's just an over glorified air pump. It takes quite a bit to bend valves on interference engines. Line the dots up and count the teeth as per the fsm. Button it up and start the sucker! Lol."Its the s12's sexy over weight step daughter, the z31" -
707Redz31Senior Member
- 375
To bend a valve by turning over by hand you really have to force it. I have done it before. Lol this is why it helps but isnt necessarily crucial to have the spark plugs out when doing the belt job because it takes away the resistance that compression causes which could be mistaken for valve train misalignment. But to answer your question from before, yes if the dimples all are lined up the best you can get them with 40 teeth on the belt between cam gear dimples and 43 between driver side cam and the the crank you are good to go. Doesnt matter which way you turn the cam gear. -
irace911Senior Member
- 172
I see his point. TDC exhaust valve open vs. TDC intake valve open vs. TDC no valves open. I'm assuming the valves should be close. It's a interference engine. When the marks line up it, none of that matters. It goes to its fixed stock position. The cam gears open and close the valves within a 360° turn. Which ever way you turn it, it will always go where it should be as long as the marks line up.
LOOSEN UP THE ROCKER ARMS, LINE CAM GEARS UPP, PUT BELT 40 IN BETWEEN CAM GEAR RIGHT/LEFT, DON'T TIGHTEN THE ROCKER ARMS WITHOUT THE BELT ON OR YOU'LL RISK MOVING THE MARKS, DON'T FORGET THE TENSIONER, ROCKER ARM BOLTS TIGHT. TIMING BELT DONE.
THE IGNITION ROTOR HAS A SPECIAL POSITION ALSO. TDC PISTON 1 AND THE ROTOR TO ITS PROPER POSITION. STOCK IGNITION TIMING DONE.
TIMING DONE. THE SERVICE MANUAL HAS IT ALL.Compressed Springs is the scariest shit EVER!
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mtherkampSenior Member
- 243
I know I was really cautious and nervous when I did my timing belt, but when I followed the process and got everything lined up, it worked out just fine. Don't over-think it just go slow and double-check everything before you start it up.Butter (credit where credit is due): "You have this "gift" where you can make cooking a Hot Pocket seem like you need a certain wavelength microwave and involve brown mustard." -
togofaster1126Junior Member
- 31
thought i would let you guys know i got it straightened it out and was just worrying to much it turns out because it ran like a top when started except for another issue concerning oil…
Thanks to all who helped meLast edited by togofaster1126; 05-31-2016, 02:39 AM.