Common problems/mistakes when replacing the timing belt?

[uncleslam23]

Thanks to the wealth of information on this forum I've been able to do all of my own maintenance on my 2000 4runner. My next big project has me a little worried though.

I picked up this kit Timing Belt Kit Toyota 4 Runner 1996 to 2002 3.4L 5VZFE V6 : Amazon.com : Automotive and I'm gonna try and replace the timing belt, water pump, camshaft seals if necessary, etc.
I've done a ton of reading on here, watched a few youtube videos, and picked up a service manual.....but I'm still pretty nervous about it.

I was wondering what some of the common problems people ran into or mistakes they made while doing this are. Any and all guidance is greatly appreciated!

 

[vipergrhd]

cam seals

The only issue i think that you would have an issue is installing the cam and crank seals,if you never have replaced a seal before have a friend that have experience in doing it. a lot of times they tend to tear the seal on install or pushing it too far in, the proper tool to install it helps for proper depth.Good luck on the install.

 

[agloukhoff]

Common problem: Unable to break the crank pulley loose.
Uncommon problem: Breaking it loose only to have it drop on the floor and crack.

Also when I did my TB etc I chose to do the spark plug tube seals - I could NOT get those ****ers out of the valve cover - but I could sure as hell tear them up enough to ruin them. My mechanic poped them out in less than 10 minutes though...so I just suck.

 

[kball]

Take your radiator out even if you aren't changing it. You'll have lots more room and won't have to worry about hitting it. Although if it's time for the TB and WP it's probably time to change the radiator too. Be sure to get the mating surface for the water pump good and clean before installing the new one. No goop necessary just the metal and rubber gasket. Thermostat jiggle valve DOWN.

 

[Buckaroo]

As previously indicated, the most difficult part is getting the crankshaft bolt loose. You need to somehow hold the crankshaft to keep it from turning when both taking it off and torquing it on. A special tool can be had for about $50 that holds the harmonic balancer. I chose to use a chain wrench which was just a little less $$ because I hate buying specialty tools that I may not use again. I was also replacing the drive belts on this job so I cut them off. I then wrapped one around the harmonic balancer pulley before I put on the chain (to keep from chewing up the pulley). It worked well on both the removal and the torquing. Also, you need to torque the bolt to ~210 ft-lbs when you put it back on. I took the opportunity to buy and nice torque wrench and still feel good about how much $$ I was saving doing it myself.

x2 on removing the radiator - get it out of the way. Not hard to remove and gives you a lot of extra room. If you choose to leave it in, cover it with cardboard to make sure you don't put a hole in it with an errant flip of the wrist.

Good Luck.....

 

[PitbullRescuer]

Nobody mentioned the tensioner being hidden behind the AC compressor?

 

[kball]

Nobody mentioned the tensioner being hidden behind the AC compressor?

I didn't want to start another discussion about the longevity of tensioners. But since you brought it up..

If you want to change it you can do it without touching the a/c bracket.

Otherwise, get the special tool to compress it and reuse it.

 

[nobb]

Don't really need a special tool to compress the tensioner, just a really big C-clamp. If it's anything like the 3VZE that I worked on, I just brought the tensioner to Home Depot, find a clamp on display, and quickly compress the tensioner back in.

 

[kball]

The special tool is so you don't have to take the tensioner off. You compress it while it's still installed on the engine. If you're going to take it off you might as well change it.

 

[Diagram14]

Common Mistake: Thinking that you have mis-installed the timing belt because you rotated the crank 360 and the belt marks are no longer in the same place.

 

[uncleslam23]

Thanks for all the help guys. Probably gonna try and get it in next weekend. So as far as the tensioner goes, since I am replacing it I should just have to bolt the new one on and pull the pin right? And what exactly is a thermostat jiggle valve? Lastly, Diagram14, your comment confuses me. If I have everything lined up correctly, why wouldn't the belt marks line up after I rotated the crank? Again, I'm completely new to all of this stuff, but it seems to me if you rotate the crank 720° then everything should line up again? Am I completely off on that one?

Thanks again for all of your help, you guys are saving me a ton of time and money(and helping me have a little fun as well!)

 

[TheDurk]

Thanks for all the help guys. Probably gonna try and get it in next weekend. So as far as the tensioner goes, since I am replacing it I should just have to bolt the new one on and pull the pin right? And what exactly is a thermostat jiggle valve? Lastly, Diagram14, your comment confuses me. If I have everything lined up correctly, why wouldn't the belt marks line up after I rotated the crank? Again, I'm completely new to all of this stuff, but it seems to me if you rotate the crank 720° then everything should line up again? Am I completely off on that one?

Thanks again for all of your help, you guys are saving me a ton of time and money(and helping me have a little fun as well!)

The metal marks will line up, but the marks on the belt would only return to the original position if the total number of teeth on the belt were equal to double the number of teeth on the crank sprocket. Well, they aren't, the belt has considerably more than that, so the belt is in a different position every time the the engine comes back to TDC. It eventually repeats, but it takes way too many turns to be useful. The marks on the belt are only useful when putting the belt onto the engine. After that, forget about them, just use the metal marks.

The crank sprocket is pretty small--in two turns the belt only goes a few inches--exactly the circumference of the cam sprockets. The belt is a lot longer than that.

 

[Diagram14]

Sorry for the confusion. Durk has it sorted out though. I only brought it up because it seems rather often that someone posts about the marks on the timing belt not returning to the install location. It also seems that they have pulled and re-installed at least once. Just trying to save you some time.

 

[kball]

Jiggle valve...

Here ya go

 

[DeTwizzle]

Beyond what everybody else has said, I found it rather difficult to get the new timing belt on properly. Especially when trying to get the third notch on the crankshaft pully to line up with the marking on the block. I actually had to spin the teething on the crankshaft back one notch to have the markings line-up after pulling the pin on the tensioners. Just remember that you have 3 marking to reference, not just the 2 on the cams.

 

[uncleslam23]

Awesome, thank you guys again. This forum has become an indispensable tool for me lately. I just bought a 2000 with 160k and practically none of the routine maintenance done on it. There's no way I could afford to have this stuff done at a shop or dealership. More importantly, I'm learning a lot about the vehicle and having a pretty damn good time doing it. I appreciate all of your help and I'm keeping my fingers crossed that I don't have to start a new thread soon about my engine blowing up after incorrectly installing a timing belt!

 

[Brian757]

Send me a PM if you need anything or if the going gets rough and you get stuck. I am in the midst of finishing my TB/WP job.

 

[4runnlim]

Re; 1998 toyota 4Runner 3.4L V6
I cannot for the life of me remove the tensioner bolts in order to replace it with a new one. I think I nearly rounded one bolt. The other bolt started turning, but I’m wondering if i broke it. I already compressed the pin while installed, but still cannot get the belt on, so my intent was to remove the tensioner to make it easier to do so. Any ideas?

 

[ShooterMcGavin]

Re; 1998 toyota 4Runner 3.4L V6
I cannot for the life of me remove the tensioner bolts in order to replace it with a new one. I think I nearly rounded one bolt. The other bolt started turning, but I’m wondering if i broke it. I already compressed the pin while installed, but still cannot get the belt on, so my intent was to remove the tensioner to make it easier to do so. Any ideas?

Have you removed the AC compressor bracket to access the tensioner bolts?

 

[stir_fry_boy]

Re; 1998 toyota 4Runner 3.4L V6
I cannot for the life of me remove the tensioner bolts in order to replace it with a new one. I think I nearly rounded one bolt. The other bolt started turning, but I’m wondering if i broke it. I already compressed the pin while installed, but still cannot get the belt on, so my intent was to remove the tensioner to make it easier to do so. Any ideas?

Did you use some penetrating oil on the bolts? They shouldn't be that tight.

I've posted in multiple places how I put the timing belt on, and it is exactly how many Toyota techs do it. Remove the top idler pulley. Route the belt starting with the crank. When you get it in place correctly on the cams, install the top idler with it on the belt. Torque the idler to spec. That's seriously the easiest way to do it.