What Bearings, Races, and Grease Seal do I Need to Replace My Timken 2785 and 1779 Bearings?
Updated 09/26/2025 | Published 05/02/2025
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Question:
I know nothing about trailers. I need the bearings and what ever else to rebuild a hub. I do have part numbers if that helps. inner bearing says Timken 2785 Outer bearing only has a number 1779. Any help would be greatly appreciated.
asked by: Nathan T
Expert Reply:
Hello Nathan,
I had to get some of the parts added to the site, so my apologies for the delay in getting an answer.
You will need one of each per hub:
-Timken 2785 Tapered Roller Bearing Single Cone - Imperial - 1.75" ID for Axles & Hubs # TMK78ZR, with race # TMK88ZR (this might not pop up on our site til tomorrow 5/9 as it was just added)
- Timken Replacement Trailer Wheel Bearing - 1779 # TMK94FR with cup/race # TMK66FR
- Cotter Pin - 1/8" Thick x 1-3/4" Long # 165649
- For the seal you will want to double check the measurements, I am showing that you need Timken Grease and Oil Seal # TMK98ZR which has the measurements I.D. 2.250" / O.D. 3.376". If your measurements are way different, just comment them below.
Don't forget the grease, LubriMatic Prime Guard High Temperature Wheel Bearing Grease - Red - 16-oz Can # L11380
I attached a help article as well for replacing bearings, just in case you need it for reference.
What kind of trailer is the hub on? Not too common of bearing sizes that I deal with on the daily.
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Product Page this Question was Asked From
Cotter Pin - 1/8" Thick x 1-3/4" Long
- Accessories and Parts
- Trailer Suspension Parts
- Cotter Pin
- ABS Fasteners
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Kate F.
9/26/2025
Hey Nathan, Did you get a chance to check the measurements for the seal to ensure it's the right fit for your trailer hub? I'm curious to know how it all worked out for you, as it could help others who are looking to rebuild their hubs too.