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How to change your timing belt!


5523Pathfinder
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The steering pump has the same kind of tensioner as the alternator. Easiest to get to through the passenger's wheel well IIRC.

 

Don't worry too much about the dimples on the timing cover. Count teeth between the dimples on the cam and crank sprockets. Should be 40T cam to cam and 43T from the driver's side cam to the crank. Some belts have the locations of the timing marks printed on them to make things easier.

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Found it finally! ( Before the reply, but thank you just the same!) Had trouble getting the new timing belt on, just could not get it to reach with the tension pulley in place, so removed it first. In trying to get the pulley back on, the passenger side cam shifted away from TDC! So, we took the belt off, turned the cam sprocket back to where it lined up with the dimple, and were finally able to get the new belt on with some cursing and wiggling! lol Now, the Chilton's manual said to turn the crank a few times to adjust the tension, and then slowly return to TDC on cylinder 1...now does that mean just bringing the dimple on cylinder 1 side back to lining up with the one on the back timing cover? Or do we have to crank the motor by hand until the belt comes all the way around to lining up with all 3? Also, since I ended up taking the radiator out, do I have to bleed the transmission system somehow after it's all hooked back up? If so, how do I do that? Thanks in advance!

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Another thing...we just bought this pathy a few weeks ago, and thought that the brakes just needed bled because it looked like it had a brand new master cylinder on it, along with fairly new front brake lines. However, after spending an entire day bleeding them over and over again, the pedal still went almost to the floor as soon as we would re-connect the battery and start it up. I traced the lines, no leaks...however, I did find that one of the seals where the res tank goes into the main body was allowing air in (could see bubbles when you wiggle the res) so we replaced it. Bench bled the new one before we put it on ( only able to get the piston to go in about 1/8" at most, no visible bubbles). Reconnected the lines, bled the system twice, and still have almost no pedal...have to pump the brakes to get stopping power. We do have abs, and the abs light on the dash is on...any ideas or suggestions on what to do or check? Mechanics aren't any help, they all just want me to bring it to them and have them do it...Thanks!

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If you roll the crank over twice, the cans and crank should be in the same position as when you started (though if the belt itself has marks, they won't match anything). All you're doing by turning the engine over is making sure it all turns like it should and letting the belt settle in. Unless you're messing with the distributor at the same time, I wouldn't be too fussed about getting it back to TDC, though it wouldn't hurt to get it close enough to re-count teeth and be sure it didn't skip while you were rolling it around.

 

No bleeding is necessary for the tranny fluid, it should purge the air on its own. The cooling system, not so much--there's a bleed screw near the back of the intake (by a sticker that says don't open when hot) so you don't trap a bubble in the intake.

 

Sounds like there's air in your ABS module. I have been lucky enough not to deal with this but from what I've heard, it's a royal pain to get air out of. There is a bleeder on the module itself. I've read that gravity bleeding can help when the system's being difficult but again, I haven't had to find out myself.

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Cool, thanks! As for the ABS, if anyone else reading this has any ideas, has dealt with this before, etc, please let me know! I can't afford to re-do the entire system...hell, can't afford to replace the ABS module, after all the work I've done so far! lol But still, even if the only solution is to replace it and then re-bleed the system, I would appreciate someone letting me know. All the information I have read elsewhere is conflicting, confusing, or down right bulls**t! Thanks Slartibartfast, I appreciate it!

:D

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Ok, so some good news! Got it back together today, turned it over, and it started right up!!!!! Not bad for first job of this magnatude! Even got rid of the battery and brake lights! However, it seems to shift at higher rpms than before. Runs great, idle is great (about 1100). Any ideas what it could be? Thanks.

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Wiggle the connector for the TPS (throttle position sensor), the thing off to the side of the air intake (plenum) right after the rubber flex hose from the air filter box.

It might be other things, but mine acts up occasionally, meaning the RPMs are a few hundred higher. It will reduce immediately for me, so instant results or on to the next thing...

 

B

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Ok cool, thanks! Will have my husband try that when he heads home from work. He also called me with rpm readings...about 3400 at 55mph, 3600-3800 at 60mph, and about 4200 at 70mph, so not too bad, right? Just seems a little higher than it should be. Do these trucks just normally run at a little higher rpm due to the transmission gearing? I read in another thread that the tire size can affect the rpm also ( it has 215/75/15's on it right now, and trying to find a good used set of 235's has proven next to impossible for less than $200!) Running great otherwise! Now if we can just figure out the abs thing...

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  • 1 month later...

A lot of great information and pictures. Thanks for the post. Is there suppose to be a roller or something on the stud next to where the tensioner is mounted. I did mine over several weeks so might have misplaced or forgot something. Thanks for post.

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  • 1 year later...

Hello NPORA members,

Admitted new member, but I’ve read through the entire 10 pages of this thread, viewed a dozen or so YouTube videos, and consulted my Factory Service Manual (FSM). Reading 5523Pathfinder (original poster – thanks !) comments & others have been extremely helpful. I’d like to keep this beast going for many more years as I am the second owner after purchasing in 1996 w/ 39K on it & would like to do more 4 wheelin’ with it.

I still have a few questions about replacing the timing belt (my 1st time) on my 94 Pathfinder SE 3.0L V6 4WD VG30E engine (estimated 210K miles on vehicle, speed sensor/odometer quit working about 7 years ago). I believe the original timing belt was replaced by a shop since I purchased it, but failing memory & no records can’t prove that (the current timing belt is a Gates, so I’m assuming it has been replaced before).

The old belt, still intact, is a Gates T249 (roundtooth) and I estimate has about 100K miles on the belt, thus time to replace it.

After rotating the crankshaft, I can line up the left & right cam gear punchmarks perfectly with each dimple on the upper rear timing belt cover. When this is done, the following alignments are observed:

1) distributor rotor points to #1 position as marked on the cap

2) #1 piston at its uppermost travel (observing position of a small kebab stick in #1 spark plug hole)

3) crank gear punchmark is at ~ 4:30-5:00 position

4) crankshaft keyway at ~ 11:00

5) left-most timing mark on the crank pulley (out of seven marks) points straight up (12:00) & at timing pointer on front lower timing belt cover

6) tensioner pulley hex key hole is at 6:00 position

There is no alignment mark for the crank gear punchmark to line up with, even though the FSM illustrates there is (page EM-13). YouTube videos I’ve seen show, at least on the VG33E engine which I’ve read is identical to the VG30E, that the crank gear punchmark is around the 4:30-5:00 position when cam punchmarks are lined up & #1 piston is at Top Dead Center (more accurately, it looks like the crank gear tooth just to the left of the punchmark tooth (when facing engine) points to the right “lobe” at the bottom of the oil pump housing.

There is supposed to be 40 belt teeth between the left & right cam gear punchmarks and 43 belt teeth between the left cam gear punchmark and the crank gear punchmark. Before removing the old Gates belt, I counted 39 and 44 belt teeth between these sets of marks. The old belt is somewhat taut (I can twist the belt towards me a little more than 90 degrees, maybe 100-110 degrees, between the cam gears.

Also when at TDC, the three white lines on the old belt were located as follows when facing the engine (belt oriented to front as per arrows):

(I rotated the crank a couple dozen times to try and get all 3 white lines on the belt to lineup with the 3 cam/crank punchmarks - this was the closest I could get).

Dotted white belt line = one tooth to the left of passenger side cam gear punchmark (right cam gear)

1st solid white belt line = on top of driver’s side cam gear punchmark (left cam gear)

2nd solid white belt line = one tooth to the right of crank gear punchmark

It looks like the old belt is a tooth off at the right cam punchmark & crank gear punchmark and the new Nissan belt I bought (not installed as yet) will be the same (it has the same 3 white lines in the same places). I can “hop” the old belt over (clockwise) one tooth and get 2 out of 3 white lines on the belt to line up with punchmarks, but the belt tooth count will still be 39/44.

I don’t’ see how slacking the belt between cam punchmarks to get 40 teeth would work (this would create a lot of slack & it doesn’t seem like the tensioner would take it all up), and stretching the belt between the left cam punchmark & crank gear punchmark to get 43 teeth would work (don’t think it will stretch that far).

So, my question (finally, sorry !) is how to achieve the 40/43 belt tooth count and get the 3 white lines on the belt to line up with all 3 punchmarks ?

Thanks for your patience & thanks in advance !

 

Mark

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My experience is that the dimples on the backing plate are more of a guideline. The dimples on the cam gears get close, but do not necessarily line up exactly.

 

I would say that one of the cams rotated a little when the last person did it, and they didn't realize it.

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+1 on the dimples on the timing cover, they're kinda in the right area ish but they didn't line up right on mine either. They're good enough to tell you if you've got the engine on top dead center exhaust stroke instead of top dead compression but that's about it. Count the teeth between the marks on the crank and cam sprockets and ignore the marks on the cover.

 

You'll need to set your ignition timing after putting it back together if whoever put it together last adjusted it to compensate for the driver's cam being a tooth off. Hopefully you pick up a little power from having everything timed right!

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Thanks for the replies Citron & Slartibartfast.



Yes, with the old belt removed and rotating the driver's side cam one tooth to the right (when facing the engine), I can place the old (or new belt) on such that all 3 white lines on the belt will align with the three cam/crank gear punchmarks. If I do this, the two cam gear punchmarks will no longer align perfectly with their respective dimples on the upper rear timing cover, but instead each cam gear punchmark will be off about half a tooth relative to the dimples.



Rotating the driver’s side cam one tooth to the right will also achieve the 40 belt tooth count between cam punchmarks and the 43 belt tooth count between driver’s side cam punchmark and crank gear punchmark, solving my current dilemma.



I didn’t want to start rotating individual gears without the belt on as I’ve read this can cause serious timing alignment issues, but it sounds like a one tooth rotation on the driver’s cam will not screw things up.



I guess my Pathy could run O.K. all these years with the driver’s cam and belt tooth count off by one?


Or maybe the belt jumped on me just prior to me tearing into it?

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I helped a friend do the timing belt on a DOHC Kia a while back and the last guy had left one of the cams a tooth out. It still had plenty of get-up-and-go like that. I wouldn't be surprised if the last guy tried to time yours by the dimples and it's been like that since.

I was nervous about turning cams with the belt off when I did mine. While trying to get a cam bolt out so I could do the cam seals, I turned one of the cams a little too far. Spring tension took over and it jumped on me. It scared me a bit, but didn't hurt anything (which makes sense--the cam jumped because of the valve springs pulling valves up, not pushing them down). +1 for not messing with it any more than you have to, but I think you'd have to try pretty hard to bend a valve by hand. "Hey, that's weird. I tried to spin this cam the whole way around for the hell of it and it's got this tight spot. Bill, hand me that cheater pipe!"

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Thanks Slartibartfast.

 

I'll be moving that driver cam gear one tooth clockwise and getting things together after a thorough cleaning of the front of the engine.

 

I'm replacing a lot of things while I'm in this deep, although I think I'll forego replacing the oil pump after reading about what's involved.

 

Can't wait to get this Pathy running again, it's been a 22-year old love/hate affair.

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think I got it figured out, made sure #1 was at TDC, took the old belt off, gave the passenger side cam gear a little nudge, it jumped forward, I turned it opposite untill it kicked back the original way then fine adjusted the dimples to line up, I then put the belt on with the lines lined up, counted 40 cogs up top and 43 between the DS and Crank dimple. should be good right?

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Sounds like you've got it! The lines help you align the belt to the marks on the sprockets when you first put it on, but yeah, you'd be at it all day turning the engine over trying to make them line up again. So long as the count stays at 40 and 43 between the marks on the sprockets, you're good.

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  • 1 month later...

Thought I'd give an update on my Pfinder T-belt project.



Got it all put together, started up & all ran/looked/seemed normal.


Only issue was a dirty MAFS & upon cleaning it according to 88pathoffroad's thread, things were fine w/ no more error codes.


(Damn, why do these things happen just after you've fixed something?)



I used a $7 digital fishing scale purchased on Amazon to apply 22 lbs force while measuring T-belt deflection between the cams after adjusting to what I think was the right tension. Think I got it pretty close this way.



Thanks again to thread starter 5523Pathfinder and Slartibartfast & Citron for some key guidance along the way - another Pfinder rescued.



Next are a starter, clutch, & VSS - the self-punishment never ends !



Just can't beat the hive-mind intelligentsia in this forum !

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Glad to hear she's running again. As for the forum.... LOTS of old-timers and wrench-heads in here and I've always seen a fairly quick response from the 'hive'

 

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  • 8 months later...

It's attached to the power steering bracket. 12mm

One thing missing and I can't see how it's attached. The metal tube between the lower rad hose and the tstat housing is attached to the engine but I can't see where and how. Vg30 1995 wd21. Thanks
 


Sent from my SAMSUNG-SM-N920A using Tapatalk

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