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How to change your timing belt!


5523Pathfinder
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Some folks have had issues with aftermarket water pumps dying prematurely. Some haven't. That said, I wouldn't waste my money on aftermarket parts for this job. For the $40-50 extra it costs for Nissan stuff, it's well worth it to not have to go in there again any time soon.

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oh, one more thing i need to get straight...

 

so, you're all the way into the front of the engine, and you've set everything to TDC, you've removed the t-belt and now you want to replace the cam seals...

 

how do you go about loosening each cam pulley to get at the seal? i'm assuming there's no way to loosen those cam bolts without moving that individual cam off TDC.

 

it okay to jack with the position of the cam while you're working on that one, and then reset it to TDC before moving on to the other?

 

OR, do you loosen the cam bolts, THEN set to TDC, then remove the belt, the cam pulleys and seals etc, etc?

 

just trying to get the order right so i don't screw myself over.

 

thanks,

 

GMA

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I thought I'd share some things I learned on my timing belt adventure. I'll add more as I finish up...

 

... I made a plastic sleeve for the lower bearing install and tapped it in with an extension, walking around it. Be careful when tapping the seals in, it takes very little force so don't drive them in too far! If you do, odds are you will ruin it getting it out.

 

 

what's this lower bearing? i've not seen it mentioned in any of the other parts of the thread, but i could just be overlooking it...

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I used a strap to hold the pulley in place and a couple of zips from the impact will loosen the cam bolts. You might be able to getaway with using an old belt or sticking a screwdriver into one of holes to have it secured somewhere....

 

The cams are under pressure/tension and if it moves it's not going to do anything really bad like as if when your motor was running and then the timing belt breaks. You can always move it back to TDC. no biggy.

 

I've used aftermarket parts on all of my timing belt changes with no ill effects so far.

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what's this lower bearing? i've not seen it mentioned in any of the other parts of the thread, but i could just be overlooking it...

Sorry, my bad, I don't know why I wrote that. I meant to talk about the front crank seal; corrected in post.

 

are the off the shelf parts from autozone/ checkers/ etc. good enough, or is it worth it to wait a bit and order nissan factory parts?

I went with factory parts as I do want everything to last the full 105k miles until the next change. I know the last factory parts did so I'll stick with them.

 

Alkorahil runs a dealership on line parts department and has really good prices!! Great guy to work with, check out the link to him in the "Services" section.

 

B

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finished the job and it started right up!! yee-haw.

 

several little tidbits that i think might help newbies to these kinds of projects (because i'm something of a newbie... just moving on to this level of work after changing a few alternators, etc...)

 

- buy a set of misc. size plugs/ caps to seal up the hoses and nipples (hehe) on the radiator as you remove hoses early on

 

- have lots of drain pans for both transmission fluid and coolant, as both will run out when disconnecting said hose

 

- on my 96 pathfinder, i found out (too late... after cracking it pulling it out) that the fan shroud has a way to clip out part of the bottom half of the shroud. that would have made removal way easier

 

- plan on having plenty of room to lay things out, so you can remember what order you removed items. it's an intense job and it gets a little fuzzy on re-attachment

 

- loosening and removing the power steering pump belt is a pain. the tensioner bolt is tucked away and hard to get to... best access is from the bottom, on the ground. a side-ratcheting box end wrench is ideal for this job. a normal ratchet doesn't really fit and it is very fiddly with a non ratcheting wrench. also, when you've removed that belt, it is an ideal time to go ahead and change your oil filter, since it is right there.

 

- the cam shaft seals are a PAIN to get out, it'll take some digging...

 

- i used a steel brush attached to a drill and a dremel with a steel brush to buff the paper gasket residue off from where the water pump was sitting, and to clean the thermostat housing, etc. worked really well and then i used some compressed air to blow out all of the residue.

 

- rent or borrow and air compressor and air wrench. made this job SO much easier. i don't know how one would remove the cam shaft bolts otherwise... would have been a much harder job without air power.

 

- once i got it all apart, the previous mechanic had NOT lined up the lines on the belt with the dimples on the cam sprocket. watch out for that kind of thing... the dimples on the sprockets TRUMP the lines on the belt, if the belt has not been installed properly.

 

- and as others have said, slow and steady wins the race. read and re-read and think carefully about each step.

 

thanks so much for this write up and for those who've contributed. it is a MIGHTY GOOD feeling to turn that key over and hear that engine start up again after such a big job...

 

good luck, y'all!!

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Just two notes...

- the cam shaft seals are a PAIN to get out, it'll take some digging..
2) If you are replacing your seals, take a suitable tool (punch, drift pin, etc) and tap the old seals in a little first (.02-.05") just to break them lose. It will make pulling them out 10X easier. The first one took me 15 minutes to figure out, the second took 2 minutes...

 

and

 

- once i got it all apart, the previous mechanic had NOT lined up the lines on the belt with the dimples on the cam sprocket. watch out for that kind of thing... the dimples on the sprockets TRUMP the lines on the belt, if the belt has not been installed properly.

Unless I misunderstand, no it only matters when first installed. Due to the different # of teeth, it does not line up again until a certain # of revolutions. That number I do not know...

 

B

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Unless I misunderstand, no it only matters when first installed. Due to the different # of teeth, it does not line up again until a certain # of revolutions. That number I do not know...

 

B

 

2nd that. The first time I did the T-belt I lined up the lines like I was suppose to and then cracked the crank several times. The lines never lined up again. I freaked a little at the time, but knew I had installed it correctly so I put it all back together and it ran fine. So B is right in that the lines only line up at the initial install.

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oh... right on about the lines and teeth... that makes sense, i suppose, since the belt would have to go through either three or six full cycles to get lined back up...

 

and re: the cam seals, i was just saying... even with some tapping we had to perform some violence on the existing seals to get them out...

 

thanks for the follow up, fellas.

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  • 2 months later...

Newbie here, first post. Its been almost a week since i took everything apart (including a hazy vegas trip) so i dont quite remember how the crankshaft pulley plate went. It has a keyway in it, and theres clear "wear mark" from the sprocket on it, but the keyway on the crankshaft doesnt extend to the sprocket. So do i slide it all the way back against the sprocket, where it looks like it will just spin like a loose washer on a bolt, or do i just slide it on to the rear edge of the keyway, where it looks like it will spin its way off, and back to the sprocket anyway?

Edited by rt8349
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Can you take a picture of what you are talking about? Or look at some of the posted pics and maybe point out what you are talking about.

 

The crank sprocket has a "keyway" groove machined in. The halfmoon keys shoudl be placed into the groove on the crank, then install the sprocket. There are actually two plates, one on the inside of the belt, and one on the outside of the belt. The plates do have a keyway cut into them, but they are not supposed to be "clocked" in any special position. Just slide them on and go.

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this is just a washer on the fwd side of the crank sprocket, under the lower timing cover. its actually shown in the 4th pic down, on reply #27 of this thread. It just doesnt feel right when i put it on, what will hold it in place?

Edited by rt8349
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The lower timing cover will go over it, then when you put the crank pulley on, that will hold it in place.

 

Here is a part explosion of how it all goes together...

 

timingexplosion.gif

Edited by 5523Pathfinder
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Thanks, my only other concern is torquing the damn pulley. I dont have air tools, and im a little worried about pulling the starter and using a screwdriver on the flywheel. How likely am i to break it?

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Well, thats hard to say. I guess it depends how worn your flywheel is. Do you have a 5 speed or auto trans? If its a 5 speed, you could put the trans in gear, block the wheels, and tighten as needed. With auto, yeah, your going to have to either block the starter, or if you have access to a strap wrench, you could put that on the crank pulley and tighten as needed. Sometimes you have to get creative if you dont have the right stuff on hand.

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Its an auto. Yea, i am pretty creative, being a helicopter mech. Ive got it at 60 ftlbs now. I was going to go off your drawing in the post vs my book. The chilton says 136-150 ftlbs, but that book has already lied to me. It wanted 85 ftlbs for the water pump bolts, (12mm) and rather than warning you about using a 3 jaw puller and breaking the outer lip on the pulley (like the haynes manual does) it shows a picture of it being used. Im half tempted to call it good at 70 ftlbs, but its not my truck.

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  • 2 months later...

thanks a lot. this thread is so useful especially when I cannot find Haynes manual for Qx4. Today I sucessfully changed my timing belt(QX4 99), prepaired two months to buy tools from Canadian Tire, including strap wrench which broke by me. when I get time, I will try to post some pictures. By the way, where is the starter and how to expose the flywheel. I tried to block the engine from turning when I tightened the crank pulley(reassemble, timing belt changing finished), that's when I broke the strap wrench. Finally by the broken strape wrench stuck on the water pump body, that way to hold the engine, I tightened the crank pulley bolt to 200 N-m. The way I loosened the bolt is by using the long handle(1.5 ft from centre to mid of handle) torque wrench ($54 from Canadian Tire, on sale) and start the engine. You can do this by a breaker bar, one end hold on ground or on the girder of your car, other end of course on the bolt, then start the engine and quickly turn off( you don't want the engine run continuously). Youtube has lots of video show this way. My crank pulley bolt came off within one second, you will feel very good after you tried lots of ways to remove that stubbon bolt.

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  • 2 months later...

Hi all, this post has been extremely helpful! I'm in the middle of replacing my timing belt on my 2000 and have a few questions before I proceed. I've read post that state the cams should line up but mine don't. My right cam is aligned but the left is off a few teeth to the right. I have not removed the belt yet and I have the number 1 piston at TDC but was wondering if I should:

 

A - Remove the belt and manually adjust the left cam punch mark to the punch mark on the rear belt cover

 

B - Install the belt and line up the marks by the rear belt cover and the crank punch mark.

 

C - Mark the Right, left cams and crank and install the belt.

 

See pics (left cam off and right aligned respectively) below for additional info. Any suggesting would be greatly appreciated.

post-29874-12842215397_thumb.jpg

post-29874-128422158143_thumb.jpg

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The marks you are looking at may be the ones from the cam pully to the crank pully, not cam to cam. Also, the marks are only for install, once the motor is rotated, they no longer line up until x number of revolutions.

 

Assuming the motor ran fine and like you said, the belt has not been removed, this is what I would do.

Mark the belt appropriate to the marks on all the pulleys.

Count the teeth in between the left to right cams and right cam to crank, and record. (43 and something else, it is listed in this thread. These numbers are the key)

Take note of the tensioner position.

Remove old belt, watch to see if the cam pulleys move. Don't panic if they do.

Mark new belt (if not already marked) and install on the pulleys, aligning marks appropriately. I found left pulley to right to crank was easiest for me. Move the cam pulleys now if necessary as appropriate to align.

Tension belt

Count teeth between marks to double check.

 

 

Done!!

 

B

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Thanks Precise1 for the reply. When I count the teeth between the cam punch marks there are 40. There are 43 between the left cam and the crank. So if I understand you correctly, I should simply mark the position of the cams (in case they move) and install the belt using the marking on the belt to align with the punch marks on the cams and ensure that the teeth count remains the same (40 from cam to cam and 43 between left cam and crank). Sorry if I seem overly paranoid, I just paid the pathfinder off last month and the last thing I want is the ruin the motor. It runs great and I'm simply trying to put some of the car payment back into the thing. Thanks again.

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Yes, I believe we are saying the same thing but let me paraphrase and say it differently.

 

Mark on the old belt where pulley punch (clocking) marks are (sounds like they are right being 40/43 teeth) and remove the belt. Match the new belt to the old belt and make identical marks in the identical places. Install the new belt with the marks lining up to the marks on the pulleys like the old one was and you are all set. This method maintains relativity, see? It can only be done when it is known that there is no issues previously, but is a perfectly valid method without finding TDC of cyl #1, etc like you would have to if the belt jumped teeth, broke or whatnot.

 

I wholeheartedly support practical paranoia, especially when it comes to something like this. It took me 2 days to replace my timing belt but then I replaced everything; all seals, hoses, T-stat, water pump, belts, fan clutch, etc. Then I counted teeth and adjusted tension 3-4 times, just to be sure. It is now good to go for the next 100k miles.

 

If you still aren't certain, ask away and I or someone else will answer in kind again. No one will fault you for your caution... ;)

 

B

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