Repacking Timing (and other) Pulley Bearings - a solution for our old pulleys

[idosubaru]

The bearings for most of the pulleys on older engines become void of grease, noisey and free wheeling over time. A new or freshly packed bearing will feel "tight" and not spin freely at all. Very few pulleys that I enounter on older subaru's are worthy of reinstallation. It is a good idea to look at a new pulley at the parts store next time you're there if you're not sure what a brand new bearing feels like. It's easy to assume free wheelin bearings are the norm on are older cars if you've never felt a new one before.

 

It is possible to source new bearings and have a shop install them. It will require a machine shop press to install them unless you are patient and have the tools to do it yourself. I destroyed one pulley in an attempt to do that and don't plan on trying that again. When I sourced new bearings about 5 years ago, the cost of the parts and having a machine shop install them was not good enough for me to jump on board the idea. In some areas maybe this is a better alternative. Now I live in a rural area, don't feel like sourcing the parts and machine shop time is expensive. And of course I'd rather do it myself, it's always more fun that way.

 

Tools Needed:

 

Finish nail or other thin/adequate device.

 

Grease gun

 

Needle Attachment for grease gun.

 

While this is a really simple job, I would recommend having an extra set of pulley bearings already packed and ready to install to make your timing belt job quick and painless. You'll never know if you have any bad pulleys until you have it apart. And while it's not likely one is bad you also don't want to be in a rush while packing the pulleys as doing it incorrectly or in haste will destroy your new timing belt in short order. Overall this is a simple job, I've done it to a number of XT6's and extra pulleys. It only takes a couple minutes and some patience.

 

I highly suggest trying this on a spare or junk pulley, not one you need. The job isn't difficult, but better to practice than rely on getting it right the first time you do it for the car you need.

 

The bearings have a thin metal cover over them to retain the grease and protect them from water and dirt. The idea is to pry back this cover as little as possible in order to insert a grease gun needle into the bearings. As in the first picture, gently wedge a nail (or equivalent) into the inside of the bearing cover. Use as little force as possible to gently lift up the cover. It is better to keep missing it because you're not deep enough or pushing hard enough until you get it just right than to overshoot your mark and damage the cover. The needle is very small and wedged shape itself, so you won't need much room to work with to get it in there. Do not pry up excessively, the bearing cover can and will come up with excessive force (more on this later).

 

Have your grease gun packed with high quality grease for this application and a grease gun needle as pictured in the second picture. Insert the tip of the gun under the cover at an angle as shown. You won't go deep as the bearings are in the way, but you can go under the cover further. AFter inserting the needle, keep it flat against the pulley and use your finger to press tightly against the needle entry area to prevent grease from coming back out as you pump the grease gun. I think *roughly* 2 good pumps in with my grease gun set up works well. Pump the gun once, then take the needle out and rotate the bearing around. Attach it to a drill or just spin it by hand is fine as well to spread the grease around the bearings. Then insert the needle and repeat the procedure again. I would use as little grease as possible to tighten up the pulleys and make them feel smooth, one pump will probably do, though i've used more in mine. Again, keep adding little bits at a time until it feels good and smooth.

 

This is important - Don't pump too much grease in. As mentioned before the cover can come off and continued over pumping of the gun can and will push the cover off the bearing as well. Also if you put excessive grease in, it will start to come out of the pulley after the car is in use for awhile, the high RPM's and forces will heat the grease and push it out. That's not necessarily bad except that the grease could get on the timing belt and it just gets messy and looks funny. You will hear "popping" noises as the air bubbles are pushed out and moved around, that is normal. You may also see nasty brown grease come out around the edges or backside of the cover, this is the old grease/water/dirt coming out. Usually not much comes out, but I have had a couple do that and that's good to get that out but they are all that bad.

 

After installing the pulleys you could check them after a couple drives or a week and see if there is any grease that needs to be wiped off from being pushed out after the engine is ran and heated up to operating temperatures a few times. Some will creep out the edges (like where you inserted the needle, if you packed alot in there). This shouldn't be an issue if you pack lightly, I overpacked the first time I did it since I was experimenting. If you'd like, leave the left and right covers off since they are very easy to see how they look. Unfortunately those two covers don't really give you good access to all the pulleys.

[idosubaru]

i wrote this as an article for the XT6 website, i think it would be most useful to many on here. the same article resides there, the pictures are larger over there if you'd like to check them out or just load these and blow them up.

[edrach]

I'm not sure how you'd do it, but this should go into the Repair Manual section if it's not already there. Good job.

i wrote this as an article for the XT6 website, i think it would be most useful to many on here. the same article resides there, the pictures are larger over there if you'd like to check them out or just load these and blow them up.

[subaru chuck]

I tried this same sort of idea a few months back on my 88 xt 1800 engine. I broke off the needle, as the poor design keeps the owner from greasing the bearings. I merely worked moly grease with my finger past the seals, until I felt a drag on the units, and they turn smooth and quiet. Who out there has a line on these idlers at a fair price?

[idosubaru]

the 1.8 liter pulleys can be found for reasonable prices (http://www.thepartsbin.com i've ordered from before). the XT6 2.7 liter pulleys are HIGH.

 

follow the directions above and you won't have any problems. i can do it in a matter of minutes, took about one time to "get it down". now i've done a few cars already and have some extra sets lying around for next time. very easy. on a scale of 1 to 10 with 10 being the hardest i'd rate this a 1. the only tricky part is getting the nail in and the plate up enough to get the needle in but not too far to deface the bearing, but not that hard at all. less is more for that part.

[85Sub4WD]

I merely worked moly grease with my finger past the seals

I talked to a Mobil Oil consulting engineer some time ago and found out that moly grease is not the correct grease for high-speed bearing applications, strait lithium grease is what you want

 

moly will actually accelerate wear in this type of situation because moly itself is a solid material (just ground up finely - like graphite) it works great for high pressure situations where a back-and-forth movement is encountered (door hinges, pedel system, etc), but it is not good for wheel bearings, CVs or anything where there is a constant direction at high speed because the moly will actually accentuate bearing failure (like graphite would)

 

luckily EA82 pullys are *relatively* cheap and widely available, so this should not be too much of an issue, speaking $$ - still I think it is a gread writeup - kudos to grossgary - especially for pointing out the importance of not overpacking the grease, yet another thing I learned from my Mobil Oil friend - the benifits of living down the street from someone who has been in the lube industry for 50+ years never seem to end

 

once again kudos to grossgary