HELP!

[Guest prlim2000]

Hi all,

 

Can anyone tell me how to put all 3 gears back on the right position?

 

I was replacing the the timing belt and all 3 seals on all the gears. Now, unlike the cam gear, I notice that there was no reference to the crank gear's dot AFTER accidently rotated the crank gear w/o the belt. So now, I couldnt remember where to reference the crank gear's dot to. That's when everything got all screwed up.

 

Although, on the new belt, there were 3 lines so you can match the lines to all 3 gears' dot...I thought that would compensate for my screw-up.

 

I first matched both the cam gears's dot to their reference dot behind it. Then matched up the lines on the belt to the cam gears' dot and it matched up perfectly! So, this means the crank gear's dot should match and be at the right position wherever that 3rd line on the belt would be...right?

 

Now on the service manual, it stated; after installing the belt, crank 2 revolution and the dots on the gears should match the reference marker behind them. BUT IT DID NOT STATE THAT IT SHOULD ALSO MATCH THE LINES ON THE BELT.

 

After putting everything back together, I started the engine and it sounded like crap (the truck was never driven out tho due to this concern). A guy told me that the timing is off and the LINES SHOULD HAVE MATCHED UP WITH THE DOTS AFTER THE TWO REVOLUTION.

 

Was that my mistake? And if it was, how do I put the gears back in the right position...PLEASE HELP!

[vengeful]

Did you set everything back to TDC before you put the new belt on? Maybe since stuff moved around, the distrubutor is out of position?

[Guest prlim2000]

Thanks for the reply!

 

Yes, i turned it back to tdc before installing the belt but only the cam gears. Remember the crank gear had no reference mark to the the dot on the gear as I said, the only way of finding out was with the new belt because the new belt had reference lines marked on it.

 

I never checked the distributor. What position should it be?

[vengeful]

If it wasn't removed, it should be fine.

 

Your problems are that the Camshafts and the Crankshaft are out of sync. You need to set the crankshaft so that the #1 cylinder is at TDC. You can pull the spark plug and shine a flashlight down to see when it reaches TDC.

[Guest prlim2000]

hmmmm....? I had set the #1 piston to TDC before installing the new belt tho.

 

This is what I did:

1. I position the #1 piston to TDC by removing the #1 spark plug and checking the

height of the screw driver that I placed in the hole...ie, the highest level.

2. Made sure that the cam gears lined up to their reference mark. But dont have

an idea of where to line the crank gear coz had no ref marker on the engine

chassis after stupidly cranking the crank gear like...1 rev?... w/o the belt

3. Slapped on the new belt and reference the 2 lines to the cam gears' ref dot.

4. The 3rd line on the new belt, I use to ref for the crank gear, which did not

have any ref mark. as stated on my original post.

5. Cranked the gears 2 full revolution and the marks on the back plate of the cam

gears matched the cam gears' dot, but not the line on the belt. The crank gear

was also back to the same postion b4 i rotated 2 revolutions.

6. While on the 2 full revolution, I installed the crank pulley wheel back on. It had

like 5 white lines on the wheel and the line farthest to the left (looking at the

front eng) was lined up to a pointer. I guess those are timing markers maybe 5

deg interval.

7. Installed everything back together and engine sound crappy. It back fires and

seems like it is going to die when i give it a little gas.

[Guest prlim2000]

5. Cranked the gears 2 full revolution and the marks on the back plate of the cam

gears matched the cam gears' dot, but not the line on the belt. The crank gear

was also back to the same postion b4 i rotated 2 revolutions.

 

I meant AFTER i rotated 2 revolutions.

[vengeful]

So, you're saying that the belt was aligned before you cranked it 2 revolutions, but it was mis-aligned afterwards?

[jj big shoe]

1. I position the #1 piston to TDC by removing the #1 spark plug and checking the

height of the screw driver that I placed in the hole...ie, the highest level.

You need to be sure its on the compression stroke and not the exhaust. Remove the #1 plug and plug the hole with your finger. Then turn the crank CW until you feel a rush of air blowing your finger off the spark plug hole, now you're on the compression stroke. Now you can use the screwdriver trick (being extra careful not to wedge, jam, scratch, or otherwise damage the piston surface) to determine TDC. Measure carefully, remembering that the piston is at a slant and not coming straight up toward the spark plug hole. Once you're sure you've got it at TDC, you can simply line the cam gears to the marks on the cover, slide the belt on and not worry about the marks on the belt at all if you don't want to. Once you're sure everything's in the right spot you could make your own mark on the cam gear and oil sump cover and call that your TDC timing mark for the next time.

[88pathoffroad]

Dude, you spun the crank but NOT the cams? I hope the valves didn't hit anything...

[Guest prlim2000]

got home and went straight to the truck and took it apart. ...while looking at it and figuring out what went wrong coz all the marks seems to line up on the belt and the gears. As I kept turning the crank with the wrench I started to think that the crank gear was 1 revolution off with the cam gears just like both of u guys said. But, I wasnt sure i just needed a second opinion so...I just went on lap top and logged in to this forum to ask and I saw your replies and you guys answered my question. How awsome was that! THANKS GUYS!

 

Now like, 88pathoffroad said...I had thought about the same thing. But, I just started the engine and didnt go anywher with it. You think I had damaged the valve even tho I didnt drove off with it? I sure hope not.

 

Im in my garage working on it and I have my laptop so please feel free to reply for more encouragements.

[4x4le]

You wouldnt have to drive anywhere or even start the engine to bend a valve if it were an interference enging. I wasnt aware that they were if they actaully are. I thought nissans were typicially non interference engines though. Dean or Dan would probably know. Hell if they are i think im gonna lean tward replacing my timing belt around the first of the year!

[Guest prlim2000]

Finished 4:30 am! Yep, and that was the problem. I was 1 revolution off on the crank gear. Let this be a lesson for me or to some...just because you think you lined your dot to dots make sure your on the compression stroke just incase...good call, jj big shoe Started her up and purrrrrred like a ***** cat. I didnt notice any weird bent valve noise...thank god!

 

My experience and lesson to others with this whole thing is that, this is my first time changing my:

-timing belt

and if your changing that...as what others say...you might as well change:

-crank and cam seals

-water pump

-thermostat

-upper and lower radiator hose

-return hose from thermostat

-alternator belt

-spark plugs

-coolant drain and fill

It is not hard at all and I consider myself a 5 from 1-10 of being handy. I think if you can change your brakes by yourself...you can do this. It is mostly unhooking elect. harness (about 10) and unscrewing things. No pounding, heavy or strenous at all and make sure what ever you take off, line it up on the floor and put back in the reverse order and keep the screws/bolts with that part...I did all this by myself in a day (18hrs coz I had to take it apart twice but on the 2nd time I got to the timing belt in 1hr). The only problem was that confusion on the crank gear not having any reference mark to the crank gear's dot. Otherwise I would have finished it sooner. Make sure wear latex gloves(it gets really dirty), get a wide bucket or a bin to catch the fluid that will bleed from your hoses, and REFERENCE THE CRANK GEAR SPROCKET AS SOON AS POSSIBLE AND TRY NOT TO MOVE THAT THING. Oh and the crank pulley was the only thing that needed a little muscle to wrench out, I used a strap wrench to hold in place and atleast 2ft breaker bar...works fine but they say a air ratchet is much easier.

 

And thanks to all that replied ...appreciate it guys!

[zonianbrat]

Glad to hear you got it all back together and it is running good I just did the t-belt change on my truck a few months ago so I know what you are talking about. I am glad I did it as it saved me alot of money (except that I had to replace the harmonic balancer/crank pulley ) other than that it was cool although I did not change my seals as none of them were leaking.

[Guest prlim2000]

ok...now, about the harmonic balancer (crank pulley), what causes you to replace it? Because, when I was pulling out the crank pulley, the lip had chipped off. I think I had position the puller jaw incorrectly. Anyway, I still used it and had no problems with it. Should I change it? Will it cause some weird vibration down the line?