Grease seal thickness

Douglasdzaster

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Hello again everyone. I’m here for more education.
I had a blow out on my boat trailer coming home and couldn’t get off the road for a few miles. Today I was replacing the bearings and cleaning the grease off everything etc. Got the inner bearing packed and dropped it into the race I replaced then I noticed the new seal is quite a bit thinner than the old one. The ID. and OD. are correct. Should I get another seal or will this one work or should I get a different seal? And I’m also curious what keeps the inner bearing from sliding back and forth on the spindle? My spindle is straight not tapered. I hated to not be able to install the hub after all the cleaning. I have it covered so the new grease and parts don’t get contaminated.
I appreciate any advice so I can get back at it.
 
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GA_Boater

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The race of the inner bearing is held against a ridge created by machining the spindle and stops sliding toward the trailer and the race in the hub stops it the other way. No idea about the seal.

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dingbat

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Today I was replacing the bearings and cleaning the grease off everything etc. Got the inner bearing packed and dropped it into the race I replaced then I noticed the new seal is quite a bit thinner than the old one. The ID. and OD. are correct. Should I get another seal or will this one work or should I get a different seal? And I’m also curious what keeps the inner bearing from sliding back and forth on the spindle?
The seal is the most overlooked piece of the puzzle and the route of most evils…lol

Two issues with seals
1. Installer ignorance or error. Pound and go….no dimensional or surface quality inspection.
Sealing surfaces require very specific diameters and surface finishes.

2. Quality parts… most seals they sell for trailers are junk. Most trailer hubs have quite a bit of runout. Both are detrimental to seal longevity and performance.

The seals on my tandem are going on 10 years old. They are reusable. Designed specifically to compensate for shaft to hub run out.

Seals are just as important, if not more important than the bearings.
 
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Douglasdzaster

Petty Officer 1st Class
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Sep 11, 2020
Messages
288
The seal is the most overlooked piece of the puzzle and the route of most evils…lol

Two issues with seals
1. Installer ignorance or error. Pound and go….no dimensional or surface quality inspection.
Sealing surfaces require very specific diameters and surface finishes.

2. Quality parts… most seals they sell for trailers are junk. Most trailer hubs have quite a bit of runout. Both are detrimental to seal longevity and performance.

The seals on my tandem are going on 10 years old. They are reusable. Designed specifically to compensate for shaft to hub run out.

Seals are just as important, if not more important than the bearings.
I’m in total agreement which is why I’m concerned about this one. Do you happen to know what type of seal your using. The seals I have where cheap compared to the one Ive found here at the parts store. Made by National $20. That’s what was on it when I had the blow out and I can see damage but it never leaked.
The replacement seals came from Amazon and I’m afraid to use them so I’m going back with the National.
Thanks for replying. I really appreciate it.
 

Douglasdzaster

Petty Officer 1st Class
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Sep 11, 2020
Messages
288
The race of the inner bearing is held against a ridge created by machining the spindle and stops sliding toward the trailer and the race in the hub stops it the other way. No idea about the seal.

View attachment 354663
Thanks for replying. I was drinking coffee this morning and it dawned on me that it works this way. Then I started kicking myself for missing the obvious. That’s what happens though. I started worrying about the seal and the dominos effect kicks in. I bought these seals trying to save money and was already worried about using them. I should have never tried to go cheaper with such an important part. I’m going to pick up a name brand like I had in it. It’s worth the $20 bucks. That seal got damaged because of the blow out but never leaked. Glad I’m doing this instead of using them and ending up back on the side of the road.
 

racerone

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Dec 28, 2013
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27,875
I ordered trailer bearings at a ----BEARING SUPPLY ----place.-----I told them " not interested " in bearing / seal kits made with " playdonium " from overseas.---I paid a bit extra for real stuff.------But these folks overseas think nothing of stamping brand names on cheap materials.----" The bitterness of poor quality is remembered long after the sweetness of low price is forgotten "-----You are best to buy from a bearing supplier who makes sure that junk does not come through the receiving door.
 

dingbat

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Nov 20, 2001
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The seals I have where cheap compared to the one Ive found here at the parts store. Made by National $20.
Here is the seal that I use.
Note the 7 psi pressure tolerance....

A bearing buddy is setup to relief pressure at 3 psi
Do yourself a favor and mic the sealing surface. There is more than one shoulder diameter for a "standard" 1-3/8" shaft.

Couldn't get my Kodiak disc brakes to seal worth a darn. It wasn't until I mic'ed the collars for Speedi-Sleeves that I found out the OE seals in the hubs where the wrong size.....1.719 vs. 1.688

This handbook covers the specification and installation of rotary shaft seals. Lots of tech info on the various seal designs.

 

Douglasdzaster

Petty Officer 1st Class
Joined
Sep 11, 2020
Messages
288
Here is the seal that I use.
Note the 7 psi pressure tolerance....

A bearing buddy is setup to relief pressure at 3 psi
Do yourself a favor and mic the sealing surface. There is more than one shoulder diameter for a "standard" 1-3/8" shaft.

Couldn't get my Kodiak disc brakes to seal worth a darn. It wasn't until I mic'ed the collars for Speedi-Sleeves that I found out the OE seals in the hubs where the wrong size.....1.719 vs. 1.688

This handbook covers the specification and installation of rotary shaft seals. Lots of tech info on the various seal designs.

Thanks for all the information. I’ll definitely study so I know more for the future. I got a National seal today and finished installing the hub by torque to spec then backed off and finger tight to the pin hole. Topped it off with new Bearing buddies which I’ll check often until all the air works out and it stops requiring grease. Then I’ll check each time before I launch. My spindle is 1 1/16” and the shoulder the seal rides on is 1 1/4” and it’s starting to get a grove so I’ll definitely be checking into speedi sleeves. Thanks for that information as well. I didn’t know they existed.
 

bruceb58

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Mar 5, 2006
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29,921
Thanks for all the information. I’ll definitely study so I know more for the future. I got a National seal today and finished installing the hub by torque to spec then backed off and finger tight to the pin hole. Topped it off with new Bearing buddies which I’ll check often until all the air works out and it stops requiring grease. Then I’ll check each time before I launch. My spindle is 1 1/16” and the shoulder the seal rides on is 1 1/4” and it’s starting to get a grove so I’ll definitely be checking into speedi sleeves. Thanks for that information as well. I didn’t know they existed.
Like Dingbat said, you need to mic the axle where the seal rides. Mine was also 1.687. National seal # 470460
 
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