How much "slack" should there be on the trailing side of the timing belt?

[nogard]

Installing this on '99 camry 5S-FE auto. I followed the instructions on the Haynes repair manual. It says to loosen the tensioner pulley 1/2 turn (from tight), then rotate the crankshaft clockwise 1 7/8 turns from #1 cylinder TDC to the 45° BTDC mark on the timing belt cover. Then tighten the tensioner pulley bolt to 31 ft/lbs.

I've installed a new belt and new tensioner kit, which includes the idler pulley, tensioner pulley, and a new spring. I've done 4 timing belts before, two on 3S-FE's, but it has been a while. It seems on this engine there is more slack on the trailing side (fire wall side) of the belt than what I remember on the last timing belt jobs I've done. With the bottom cover on, top cover off, and after setting it up as I described above. If I push on the trailing side of the belt with moderate pressure I can move it about 1/4". That seems like a lot to me. I wanted to check and see what you guys have to say about it.

Thanks.

[reluctantmechanic]

Originally Posted by nogard

If I push on the trailing side of the belt with moderate pressure I can move it about 1/4". That seems like a lot to me. I wanted to check and see what you guys have to say about it.

Thanks.

I just did one about a month ago - there's a trick to remove the slack by rocking the upper cam gear forward (not even a centimeter) while using your right hand to push the belt up a notch....as long as both timing marks are in place, you're set.

hoped that helped.

[Mister_Perkins]

Originally Posted by nogard

Installing this on '99 camry 5S-FE auto. I followed the instructions on the Haynes repair manual. It says to loosen the tensioner pulley 1/2 turn (from tight), then rotate the crankshaft clockwise 1 7/8 turns from #1 cylinder TDC to the 45° BTDC mark on the timing belt cover. Then tighten the tensioner pulley bolt to 31 ft/lbs.

I've installed a new belt and new tensioner kit, which includes the idler pulley, tensioner pulley, and a new spring. I've done 4 timing belts before, two on 3S-FE's, but it has been a while. It seems on this engine there is more slack on the trailing side (fire wall side) of the belt than what I remember on the last timing belt jobs I've done. With the bottom cover on, top cover off, and after setting it up as I described above. If I push on the trailing side of the belt with moderate pressure I can move it about 1/4". That seems like a lot to me. I wanted to check and see what you guys have to say about it.

Thanks.

Your trailing side (Firewall) Should have a little slack in it. The side that runs to the water pump shouldn't have very much slack in it. Refer to your FSM for max Tension is should have

[fenixus]

does the belt holds alignment after you turn the crank 2 full (or 4 or more) revolutions (with tensioner in 1/2 turn loose position) ?

I think you shouldn't have much of a slack on the firewall side (mine was pretty darn tight over there)...

[Mister_Perkins]

Originally Posted by fenixus

does the belt holds alignment after you turn the crank 2 full revolutions (with tensioner tightened in loose position) ?

I think you shouldn't have much of a slack on the firewall side (mine was pretty darn tight over there)...

I was just saying if there was any slack it should be on the firewall side. it shouldn't have very much slack at all though on either side

[carsrus]

Easy way to do it.

Pry UP on the tensioner on the 5sfe and make sure its locked all the way up.

There is no adjustment on the 5sfe tensioner, it should be locked all the way up. It doesnt adjust at all for future slack, which is why you want the belt as tight as possible.

[nogard]

It is lined up fine. There is some slack on the firewall side, and none on the water pump side, but that is the side with all the tension because that is the direction of pull.

With the tensioner loose it does keep alignment, but the belt has a lot of slack on the trailing side. Works better with the tensioner bolt tight.

I didn't think prying was necessary, I thought that was the point of the spring to set the tension to the right amount?

[fenixus]

it's good. if it holds the alignment after every 2 revolutions then just tighten it to specs with crank at 45 BTDC (doesn't have to be exactly 45 BTDC) and all set.

[JohnGD]

I wonder if the tensioner pulley and spring are applying enough pressure on the belt. Can they move freely? Sometimes it may take more than loosening the bolt 1/2 turn.

Did you get a new tensioner spring? Because there was a Gen4 TSB about a revised (shorter) spring, and that a bad batch of the Gen4 timing belt can really stretch.

This is another reason why I think the manual tensioner sucks.

Originally Posted by nogard

It is lined up fine. There is some slack on the firewall side, and none on the water pump side, but that is the side with all the tension because that is the direction of pull.

With the tensioner loose it does keep alignment, but the belt has a lot of slack on the trailing side. Works better with the tensioner bolt tight.

I didn't think prying was necessary, I thought that was the point of the spring to set the tension to the right amount?

[nogard]

After talking with a few people at work, who are millwrights, on pieces of equipment with toothed belts and sprockets the belt doesn't have to be super tight. For some reason looking at this one it just seems a little looser than I ever remember timing belts being.

Yes it does keep alignment, it rides a little to the outside of the cam gear, but no more than flush.

I do have a new spring, I bought a tensioner/idler pulley kit. There are two spring in there, one for the 3S-FE which is longer and one for the 5S-FE. The spring is the same length as the spec in the Haynes manual. This is the first time I got a new spring etc. In the past I didn't know any better and just reused the old one. I did measure then to make sure they weren't way out of spec.

The pulley does pivot freely. Once the belt does stretch it will have even more slack in it. I could see how a shorter spring might add just a little more pressure.

I will call the dealer and see what they have to say about the spring. I will see if they stock them or if they have the length spec or a revised version.

[71Corolla]

You really don't need to by a new spring. And honestly, there is zero reason for the spring to wear out it does almost nothing. It's only purpose is to put the "correct" tension on the belt before you tighten the bolt. After that, it just sits there doing nothing.

All you really need to do is, loosen the bolt on the tensioner pulley, then by hand, put a bit more pressure on the pulley than generated by the spring, and tighten the bolt. If you're really paranoid you can check the belt deflection as per the service manual, but I've used the above method without any problems, you would really have to put some effort in to make the belt too tight.

I agree with JohnGD, it's not the best design at all, it should have a tensioner that puts constant, consistent pressure on the bearing.

[fenixus]

Originally Posted by 71Corolla

You really don't need to by a new spring. And honestly, there is zero reason for the spring to wear out it does almost nothing. It's only purpose is to put the "correct" tension on the belt before you tighten the bolt. After that, it just sits there doing nothing.

I think that's the whole point. if his replacement spring (non OEM as I read) is the same length as the old one, then it might be the older longer design or stretched a bit (springs do that over time).

I would just get a new OEM spring, it's like $3 and try it out. I replaced my Spring (new is OEM) recently and the faulty GMB tensioner (new is aftermarket Koyo $30) and the new Spring was a tad shorter than the old one, perhaps that's all it needs.

[71Corolla]

Oh I agree with you, for the price, you absolutely have no reason not to get a new one. All I was saying is, the spring is probably just fine. I've compared the old spring to the new ones and they have all been exactly the same. I just find that the spring doesn't put quite enough tension on the bearing, so I help it along. I don't know if that is the correct way, but I find it works for me.

[fenixus]

Originally Posted by 71Corolla

Oh I agree with you, for the price, you absolutely have no reason not to get a new one. All I was saying is, the spring is probably just fine. I've compared the old spring to the new ones and they have all been exactly the same. I just find that the spring doesn't put quite enough tension on the bearing, so I help it along. I don't know if that is the correct way, but I find it works for me.

right, helping the spring tension works too

[nogard]

That is exactly what I ended up doing what adding a little more tension by pulling up on it by hand. That seemed to help, a little.

Then before putting the other belts on and alternator, etc. I started the car to make sure it would work. It started right up without a problem, I didn't expect anything less. Not like the first time I did a timing belt on my '88 celica when I was 17 and some how the timing got off and it was firing 180° out of phase. Now I know better to put it together, turn it by hand and check my work. Then start it before it is all back together. Right now just the bottom cover is on and damper pulley. Seems like after I ran the car and shut it off the belt was a little tighter. I like the way it is now, that seems right. I revved it and watched the belt deflection, even took it to redline a couple times. The belt is solid, hardly any deflection, the way it should be.

I called the dealer and asked about the TSB, they said that was for the 3rd gen ('92-96) 5S-FE. So I'm sure I have the right spring, but like was said it isn't the best design. I think adding a little pressure by hand is the trick. It will only stretch over time.

One other great time saving trick for torquing the crank pulley bolt (used a impact to loosen it) and the cam loosen and tightening. Use the old timing belt start wrapping it around the cam pulley as you turn it and once the loop is small enough loop that around the water pump. Works like a strap wrench to loosen and tighten it. If you are replacing the A/C belt use that to also wrap around the crank pulley and the hook the other end around the A/C. This works great like a strap wrench to tighten it with a torque wrench.

Also this was mention on here, but to put the cam and crank seals in it works great to push the new seal in as far as you can by hand. Then put the old seal on backward on top of it. Then put the pulley on behind that and use the bolt to press it in. I didn't know about this when I was putting the cam seal in. But I used this method on the crank seal and it went in like butta'.