Anybody press bearing out of ribbed plastic tensioner pulley?

I'm doing the water pump, and decided to finally change my tensioner pulley, since I have more clearance at the moment. The plastic looks to be in great shape. I'm wondering if the bearing could be pressed out. I tried hitting it with a hammer and a socket and it didn't budge....maybe it's molded in place?

I've already got a new one on there. I've heard that the aluminum often stripes out, when undoing the bolt that holds the pulley. Mine appears to be fine. The tensioner was on the truck so I didn't look into the bolt hole, but the bolt didn't bring any aluminum out with it. It didn't even have any corrosion on it.

The pulley with bearings is cheap and readily available. Age does not favor plastic parts. You might change out the bearings and invisibly damage or stress the pulley. If you do local low mileage driving, leave it alone..if bearings are good. If dry, replace.
YMMV

Sent from my SM-G965U using Tapatalk

L29Sub said:

Age does not favor plastic parts. You might change out the bearings and invisibly damage or stress the pulley.

Click to expand...

I didn't think of that. Looking at this some more, I really think the bearing may be molded in any way.

If you do local low mileage driving, leave it alone..if bearings are good. If dry, replace.
YMMV

Click to expand...

Well, it's already replaced.... I've had the replacement sitting on my parts shelf for a couple of years. The original tensioner pulley has lasted and lasted. I'm tempted to put the original back on, and get it to 300K miles..... the truck is almost there. The original idler pulley had to be replaced years ago...12 or 15 maybe? That was only a brass bushing, Though.

Don't know about yours, but the bearing on mine was molded into the pulley. No way to remove it without destroying the plastic. Two bearings were $5, but found a new pulley for $11. Works fine.

I always wonder how good the bearings can be on a part that is so inexpensive. Would be nice if it was replaceable.

letitsnow said:

I always wonder how good the bearings can be on a part that is so inexpensive. Would be nice if it was replaceable.

Click to expand...

I've seen people press a new bearing into the smooth stamped idler pulleys. I used to work for a cleaning company, and we had a carpet extractor van that took power from the vehicles engine to run the carpet cleaning system. It had an accessory drive PTO contraption. The tensioner or idler for that was cast iron, and I had to get a bearing or two for it from the local industrial supply house.

I've popped new bearings into metal pulleys and plastic snowmobile bogey wheels. Last I touched my sled most every bearing was dried up and pitted. I didn't like the thought of blowing that much money, so I pressed them out, removed the seals, hot tanked them, repacked with grease, and reinstalled. I've never gone after a plastic idler pulley though.

Supercharged111 said:

I've popped new bearings into metal pulleys and plastic snowmobile bogey wheels. Last I touched my sled most every bearing was dried up and pitted. I didn't like the thought of blowing that much money, so I pressed them out, removed the seals, hot tanked them, repacked with grease, and reinstalled. I've never gone after a plastic idler pulley though.

Click to expand...

I've thought about trying to pop the seals out, but I haven't tried very hard. They look like rubber. I'm pretty sure the plastic is molded around the bearing now that I've washed all the dirt off.

Even at retail the bearings are about $6 at the cheap end, so that explains why they can sell the assembly so cheap.

At the other end of the scale there are custom-made pulleys for things like hydraulic pump kits that include an idler. Milled steel with a pressed-in bearing retained by a snap ring. In my example, limited availability (wrecker supply shop) and $75-$100 each, with some kits utilizing two of these pulleys. Yep! Out comes my bearing/race tool set and in goes the best new bearing I can locally source, about $12.



That bearing/race tool set was a damn good investment all those years ago when I was replacing front hub bearings and races on pre-1962 GM trucks that used BALL bearings, always going bad. I later ended up swapping the hubs to modern tapered rollers.

Lisle Tool # 12600, same kit still available; I bought mine in the late 80's and still find it useful.



Richard