timing chain replacement trick??

Question

i am replacing the timing belt on my 3.4 dohc and i have to release the tensioner to get the belt off,i was told to loosen the star bolt on it and rotate the little square piece on it counterclockwise to loosen the tensioner to get the belt out,,question is--i loosened it and can't quite get a grip on the little square to get the tensioner loose enough, is there a special tool or socket to grip this on the tensioner ?.is this the proper procedure? what is the trick to it???

Shep · Accepted Answer

Check the procedure at  this is a tough belt job on that engine and requires step by guidelines and display of the recommended tools.

robert -wanda fox · Answer

thanks for  the response,but all i want to do is turn the tensioner torelease the tension on the belt,i was told by a retired gm mechanic thatonce the star pivot bolt was loosened,the square lug was used as a handle topivot the tensioner to loosen the tensioner pully,the info at auto zone goesinto taking the entire ass, off,i don't want or need to take the entire ass.off,just release the tension to slip the belt off. doesn't anybody have asimpler way and answer to just does this??

Shep · Answer

The hydraulic tensioner must be set back using a paper clip to fabricate a holding clip that is accessed thru the plug on the rear of the  tensioner actuator, hydraulic pressure on the actuator plunger is holding pressure on the tensioner, the rubber plug to access the hole to hold the plunger in is at the rear of the actuator ,get a small screwdriver into the screw slot at the end of the actuator rotate clockwise till the plunger is retracted, then the paper clip ( straightened out 1/2 it's length) inserted into the other hole will hold the plunger in. This part of a 96 step process in the Dayco T' belt book! Holding the cams is a different procedure for 91-93, 94-97. I really think you need a comprehensive manual to do this.

robert -wanda fox · Answer

can this be done while on the engine or does the ass. have to come off???/ iwill be getting a better look at it probally tomorrow,i can't believe allthat just to get some pressure off the belt to change it!!also once the beltis off  ,i can't just set the cam timing marks with my hands??i thought theywould turn freely to line up,i can't believe it's like rocket science tojust let up on the tensioner and remove a nd slip a new belt on then line upthe timing marks.  thanks for your patiance and understanding

Shep · Answer

You need a tool to hold the cams in the proper position or the valve spring tension will move them out of synch. I am telling you get a Dayco book, or borrow one, or a step by step guide with pics here, or you are going to get buried. The tensioner stays on for this process, you are backing it off to allow the belt to come off.

robert -wanda fox · Answer

i am really starting to get a little confused now,i don't see the logic ofall these steps just to release the tension a bit to slip a belt off andon,gm techs are nuts,wouldn't a few friends helping hold the cams also doinstead of hold down tools??  what is a dayco book??  could i get some infofrom the library on this book?? i know you are probally making this assimple as possible and i must seem a little dense,i guess intill i reallyget down and do it for the first time i won't fully understand the thoughand mechanical process of how this system works.once again though i cannotrelease the tensioner without taking the ass. off,(right ?)   thanks

Shep · Answer

Dayco is a book made by the belt company for all t'belt replacement instructions, maybe your parts house has one. You cannot just take the tensioner off while still tensioned by the hydraulic actuator.

robert -wanda fox · Answer

thanks again shep,i took a better look at the setup(will do tomorrow),i seenow that the tensioner/pully  is extended out putting tension on thebelt,the manuals are telling me that the tensioner plate must come off firstthen the plunger actuator to release the pully,the things you are pointingout such as the paper clip in the hole in the rear to hold the plunger backare things that come after i have removed the plate and ass.(right?)it sortof sounds like you can stick a screw driver in a slot and turn it to releasepressure,i'm sure i am not getting this info right.i am going to first afteraligning the timing marks(remember  i told you the belt did not break soeverything is still in place,the teeth in the belt shaved off from age andwear and the main crank spocket is just turning in the belt)then removeplate and actuator,i guess i'll learn and see at that point and understandmore how it works.what is with the point i'm reading about the actuatorbeing filled with oil??when i take it down...

Shep · Answer

It is a sealed unit no oil will come out, do not remove the vent plug or you will loose oil. turning the actuator in on the end allows you to lock the plunger with the paper clip to hold the tensioner actuator off the belt, remember the cams will turn when the belt is removed, as I told you.

robert -wanda fox · Answer

okay had ir apart and understand now the mechanics of getting thebelt,tensioner off and new belt on, now to next problem,according to mymanual and the advice of a gm mechanic,before putting belt on and tensioneri aligned the driving sprocket  timing mark at 6;00 to the indentation onthe casting(as shown in manual)and the right and left cam marks facing eachother (3;00 and 9;00),upon starting the car i.t started right up but nopower and a deep throaty sound coming from the air intake upon giving itgas,it has no backfires or missing,but no power,upon re checking the timingmarks ,the cam marks are now out of alignment,upon thier supposing to belined up even with each  are now about 4 to 6 teeth(cam) off,andthe other is around 3 to 5 off,this much deveation is probally the cause forthe power loose,am i at least on the right track with the timing procedure??is this lost power probally due to the timing being off yet??

Shep · Answer

Yes, as the belt rotates and the tensioner comes into play the timing can change, turn the engine by hand on the balancer to check the timing before starting it.

timing chain replacement trick??

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