Timing belt marking pens

[Jarpin]

Just bought this from Wally world. It says it's oil-based but I know how you're supposed to avoid oils getting on rubber engine belts. My new belt has no markings on it.

Would leaving the cam/crank marks on there after install possibly cause a weak point over say....60,000 miles?

Is it better to use some isopropyl alcohol or acetone to remove the marks after install?

Thanks.

 

[Jetronic]

use chalk to put timing marks on the belt.

 

[KGMtech]

Tire crayon or chalk.

 

[slacktide_bitog]

Sharpie makes water-based markers like that

Are there any other markings on the gears themselves? What kind of car is it?

 

[Nukeman7]

Just bought this from Wally world. It says it's oil-based but I know how you're supposed to avoid oils getting on rubber engine belts. My new belt has no markings on it.
Would leaving the cam/crank marks on there after install possibly cause a weak point over say....60,000 miles?

No, as long as you don't go hog wild and write all over the belt. I have used various color oil based welding marker pens on ~10 different timing belts since 1999 and they have never damaged or degraded anything. I only place a small dab or two on the edge of the timing belt teeth and respective gear cog along with a small rotation direction arrow on the belt's smooth surface. I have subsequently replaced six of those belts 100,000 miles later and they look almost new, albeit stiffer.

Is it better to use some isopropyl alcohol or acetone to remove the marks after install?

Thanks.

NO! The alcohol or other solvent will do more damage to the belt than any oil based paint.

 

[The Critic]

Controversial take: there’s no need to mark timing belts. Take the time to understand how the timing system works, use the factory marks and follow the directions.

 

[Nukeman7]

Controversial take: there’s no need to mark timing belts. Take the time to understand how the timing system works, use the factory marks and follow the directions.

I believe that you and I have shared differing opinions on this practice in a previous BITOG thread before. I don't see it as controversial at all, it is simply a matter of whether one feels more comfortable working without a backup reference point. Some older belts will stretch and have worn teeth where the reference points are off by half a gear notch which will make it difficult to know whether to realign the cam gears half a position clockwise or counterclockwise on a new unworn belt. While this may only happen infrequently, I have experienced it and the procedure is absolutely foolproof with the painted reference marks.

 

[RooflessVW]

Controversial take: there’s no need to mark timing belts. Take the time to understand how the timing system works, use the factory marks and follow the directions.

What if you need a bunch of special locking tools and marking the belt takes half the time and works just as well?

 

[The Critic]

What if you need a bunch of special locking tools and marking the belt takes half the time and works just as well?

I take that you’re a proponent of the “mark and pray” method on TDI’s?

 

[RooflessVW]

I take that you’re a proponent of the “mark and pray” method on TDI’s?

Sixty percent of the time, it works every time

 

[brages]

I replaced a timing belt for the tenth time in my life (maybe the last!!) and, for the first time, I used the paint marker. I found it made the installation of the belt a bit easier and quicker and I would do it again next time (will there be a next time?)

 

[Jarpin]

Ok. So I returned the original pen and bought this silver colored one from Michaels that is alcohol based instead, is that a better choice than the oil based one?

Sorry if this is getting too nitpicky, this is my first time doing a Honda timing belt and I'm just being cautious. With a Subaru and Toyota timing belt I felt more comfortable for some reason. My Toyota simply because it was a non-interference engine too.

 

[The Critic]

I believe that you and I have shared differing opinions on this practice in a previous BITOG thread before. I don't see it as controversial at all, it is simply a matter of whether one feels more comfortable working without a backup reference point. Some older belts will stretch and have worn teeth where the reference points are off by half a gear notch which will make it difficult to know whether to realign the cam gears half a position clockwise or counterclockwise on a new unworn belt. While this may only happen infrequently, I have experienced it and the procedure is absolutely foolproof with the painted reference marks.

I’m not following. If a belt is stretched, resulting in the reference points being “off,” it merely affects the tension vs. slack side of the belt drive.

 

[Nukeman7]

I’m not following. If a belt is stretched, resulting in the reference points being “off,” it merely affects the tension vs. slack side of the belt drive.

Looking at the Honda J35 example below, I had a situation where the new Mitsuboshi timing belt lined up exactly at 68+1/2 teeth in the belt section shown in red below when all three gears were perfectly aligned with the reference marks. Without the paint reference marks, I would have had to guess as to whether 68 or 69 teeth was the correct distance between the CA2 and CS gears. I can't say whether the new timing belt was a fraction short or not, but it worked perfectly for >100K miles until I replaced it in 2022.

 

[Hohn]

Well, was it 68 or 69? I'm doing my van's J35 soon.

 

[Nukeman7]

Well, was it 68 or 69? I'm doing my van's J35 soon.

Pretty sure it was 68...if you use a marking pen, just count the teeth and transfer the marks to the new belt and you can't go wrong. In addition to counting twice, I always have my wife count the teeth and reference marks for independent verification. I have replaced 9 or 10 timing belts without making a mistake with this method. I use a different paint color for each gear or mark 1, 2 or 3 teeth to distinguish the gear.

On a J35 engine, the rear bank cam will be under slight rotational tension and may "spring" backwards/forward a few degrees when the belt is removed. The factory service manual specifies inserting a battery hold down J-hook to lock the cam in place; however, it is not necessary if you apply the paint pen reference marks.

Here is another trick I use: Once you have the belt teeth aligned correctly on the first cam gear, use a nylon Ty-wrap to secure it in place before moving to the next cam gear. Repeat with a Ty-wrap on the second cam gear. Once the hydraulic tensioner is released and the new belt is taut, cut off the Ty-wraps.

 

[The Critic]

Looking at the Honda J35 example below, I had a situation where the new Mitsuboshi timing belt lined up exactly at 68+1/2 teeth in the belt section shown in red below when all three gears were perfectly aligned with the reference marks. Without the paint reference marks, I would have had to guess as to whether 68 or 69 teeth was the correct distance between the CA2 and CS gears. I can't say whether the new timing belt was a fraction short or not, but it worked perfectly for >100K miles until I replaced it in 2022.
View attachment 274960

The "red side" in your diagram is the tension side. The blue side is the slack side.

There should be almost no slack on the red side. If you are off by a tooth, it will be extremely obvious. Plus, it will be difficult to get the belt onto the tensioner pulley.

The Mitsuboshi belts usually fit a bit sloppier than the OE Honda belts. I typically line up the timing marks about 1/4 turn past the reference marks. This makes the belt extra tight on the tension side and the slack side will slip onto the tensioner pulley extra easily.

 

[Trav]

Many belts have paint marks on them OE.

 

[nthach]

If I need to mark a timing belt, I’ll use a Marvy Uchida DecoColor or Markal paint pen.

I like using the OEM marks though. On the rear cam of a transverse V6, there’s such a thing called parallax error so beware. The OEM belt and maybe aftermarket ones are marked for ease of install but once the belt is installed, the belt tensioned and the timing drive is rotated, the belt marks will not correspond with the cam/crank marks.

 

[brages]

The "red side" in your diagram is the tensioner side. The blue side is the slack side.

I thought the tensioner side WAS the slack side (the tensioner takes up the slack when you pull the pin)