Grease seal thickness

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Douglasdzaster
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Joined: 19 Sep 2020, 09:15
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Location: Smithville,Texas

Grease seal thickness

Post by Douglasdzaster »

Hello everyone, Seems I have a question for the experts again.
I had a blow out on my boat trailer coming home and it was a good ways before I could pull over and stop.
I had just replaced all the bearings and seals before this trip. But the blow out ruined the seal while heating things up. I was replacing everything on the hub today and when I went to install the seal I noticed it’s about half the thickness of the old one and there’s a decent gap between it and the inner bearing. ID. and OD. Are correct.
Will it work? And what does keep the inner bearing from sliding out of the race or at least back and forth? My spindle is straight not tapered.
I appreciate any help I can get. For now I have the hub on the work bench covered to keep everything out and went ahead and greased the spline good to protect it which I’ll clean up again before installing the hub.
1983 Monark 1652 / 1992. 3 cylinder 40 hp. Yamaha

KMixson
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Location: North Charleston S.C.

Grease seal thickness

Post by KMixson »

On a straight shaft the bearings ride inside the race which is driven up to the step on the inside of the hub on the inside bearing and the outside bearing. The distance between the bearing and seal will be correct if the races are installed correctly and the correct parts are installed. The seal should not rub on the moving bearing. On spindles you can see where the old seal was riding on the spindle in most cases. It will be a dark rub mark. If it is burred up or has residue from the old seal you can clean it with fine sandpaper to have the new seal ride on a smooth surface and from wearing too fast. If it is heavy gouges you need to replace the spindle or use a seal saver(Speedi-Sleeve) on that spindle. The seal itself should be riding on the spindle with a little resistance. It should not have a gap in between the seal and spindle. As you install the new bearings preload them to make sure they are seated correctly. Tighten the castle nut as you turn the hub to where the hub has a good bit of resistance to turning and then back off the castle nut and tighten it to the correct torque. Then install the cotter pin and hub cap.

Douglasdzaster
Posts: 115
Joined: 19 Sep 2020, 09:15
1
Location: Smithville,Texas

Grease seal thickness

Post by Douglasdzaster »

Thanks for the reply. I was about to get on here and correct myself. I just realized the bearing rides against the rise where the seal goes.
So as long as the seal doesn’t touch the bearing it should work?
I still have the box the hubs came in from last year. I’ll check but I think it said 40ft.lb. Of torque. Then back off and finger tight . That seems like a lot of torque to me but I’ll check the box.
I really appreciate the advice thank you.
1983 Monark 1652 / 1992. 3 cylinder 40 hp. Yamaha

KMixson
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Joined: 25 Apr 2008, 16:54
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Location: North Charleston S.C.

Grease seal thickness

Post by KMixson »

The race is mounted inside the hub. Then the inner bearing goes in to the hub and the seal is installed on the hub. The inner bearing will be floppy loose in the hub until you install the hub on the spindle. The 40 ft. lbs. of torque is the preload to make sure the bearing races are seated correctly. That will seat them even though you may have felt they were seated when you installed them. Remember to turn the hub as you are torqueing the castle nut. Then you back off the nut and install it finger tight. Technically you want a thin film of grease or oil riding between the bearing rollers and the bearing races. If you tighten the nut too tight the grease or oil will be squeezed out and the bearing will get hot and fail from being on metal to metal contact. It is a good idea to recheck the torque on the castle nut after some use, but no one ever does.

Douglasdzaster
Posts: 115
Joined: 19 Sep 2020, 09:15
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Location: Smithville,Texas

Grease seal thickness

Post by Douglasdzaster »

Thanks for replying. I picked up the better seals today and put it together the way you described and topped it off with a new bearing buddy that holds 3 psi of pressure in the hub to keep water and debris out. I’ll be taking my grease gun with me to the ramp regularly and until all the air pockets are out and it no longer is needing grease when I check them.
1983 Monark 1652 / 1992. 3 cylinder 40 hp. Yamaha

MrGiggles
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Location: Springfield, MO

Grease seal thickness

Post by MrGiggles »

Seal thickness doesn't really matter as long as it isn't seated too deep and touching the bearings. In some cases it is better, because the seal will ride on an untouched area of the spindle that isn't worn.

Bearing buddies are a good idea on paper, but I don't really think they work that well in the real world. I've never had one hold pressure for any length of time. I still use them, but pull them off occasionally and check the bearings like I would without them.

Douglasdzaster
Posts: 115
Joined: 19 Sep 2020, 09:15
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Location: Smithville,Texas

Grease seal thickness

Post by Douglasdzaster »

Thanks for the reply. Yeah I’m not buying the never have to pack your bearings bit. I’ll be checking them and cleaning and repacking once a year regularly.
1983 Monark 1652 / 1992. 3 cylinder 40 hp. Yamaha

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LDUBS
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Location: Clayton California

Grease seal thickness

Post by LDUBS »

Douglasdzaster wrote: 12 Jan 2022, 21:45 Thanks for the reply. Yeah I’m not buying the never have to pack your bearings bit. I’ll be checking them and cleaning and repacking once a year regularly.

I sure agree with your approach. Mine are sealed bearings. It is bothersome that I can't do routine maintenance. There is just that little peace of mind from doing the maintenance that I miss. But the trailer mfg has reassured me they work so I guess I'm OK.

Sorry about the detour off subject.
Have Rod - Will Fish

Douglasdzaster
Posts: 115
Joined: 19 Sep 2020, 09:15
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Location: Smithville,Texas

Grease seal thickness

Post by Douglasdzaster »

I understand that would be like not removing the bb and trusting everything is ok. If there factory bearings I’m sure they’re good. I’d feel like you though and probably replace them after a while.lol
One thing I’ve learned don’t by the cheep stuff. It’s worth the extra to get a good name brand or better straight from the bearing manufacturer. I had a blow out and couldn’t get off the road for several miles and I had just replaced everything in the hub with good parts. That hub got hot but the bearings didn’t look bad and the seal looked damaged but it never leaked. I went ahead and replaced everything and in with new grease which is what started this thread. I was going to save money with these other seals I already had. After all the advice and thinking about how that seal never leaked. Those cheap ones are in the trash now. I’m bad about worrying and replacing things on my boat ahead of time anyway. If I would have used those seals I wouldn’t have been able to sleep. Lol. Heck I change my lower unit oil way more times than it’s recommended.
1983 Monark 1652 / 1992. 3 cylinder 40 hp. Yamaha