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
Products Featured in This Question
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.
(click to enlarge)
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
more information >
Featured Help Information
Miscellaneous Media
Continue Researching
- Article: Replacing the Bearing, Races and Seals on a Trailer Hub
- Search Results: spindle cotter pin
- Search Results: cotter pin
- Search Results: grease lubricants sealants adhesives
- Search Results: gs 2125dl seal
- Shop: Timken 473336 Grease and Oil Seal - Double Lip - I.D. 1.719" / O.D. 2.565" for 3.5K Axles
- Shop: Dexter Multipurpose High Temperature Lithium Grease - 1 lb
- Q&A: Bearings and Dust Caps Compatible with Dexter Axles on Travel Trailer
- Q&A: Replacement Grease Seal for 3,500 lb Dexter Axle on Forest River Trailer
- Q&A: Replacement Parts For Dexter D40 EZ Lube 4,000LB Trailer Axle # 7369991
- Shop: Trailer Wheel Bearing Kit for Lippert, Dexter, and AL-KO Axles - 3,500 lb with #84 Spindle
- Shop: Grease Seal - Double Lip - I.D. 1.719" / O.D. 2.565" for 3.5K and 4.4K Axles - Qty 2
- Shop: Cotter Pin - 1/8" Thick x 1-3/4" Long
- Shop: Seal Puller
- Shop: Grease Seal - Double Lip - I.D. 1.719" / O.D. 2.565" for 3.5K Axles with #84 Spindles
- Search Results: trailer hitch
- Shop: Trailer Hitch
- Article: Trailer Wiring Diagrams
- Video: Firestone Ride-Rite Air Bags with Easy Mount Compressor Feature Breakdown
- Q&A: What is the Difference Between a Class II and a Class III Hitch?
- Shop: Trailer Wiring
- Search Results: trailer tires and wheels
- Q&A: Lug Nut Torque Chart for Trailer Wheels
- Article: Brake Controller 7- and 4-Way Installation Kit (ETBC7)
- Q&A: Installation Time for Blue Ox BX1128 Flat Tow Base Plate Kit for 2016 Jeep Grand Cherokee
- Article: How to Measure for Trailer Hitch Drop
- Video: How to Choose a Trailer Brake Controller
- Search Results: trailer wiring
- Article: Wiring Trailer Lights with a 7-Way Plug (It's Easier Than You Think)
- Q&A: Best Suspension Upgrade for 33" Tandem Axles: Road Armor vs Dexter EZ Flex for Ember 22ETS
on Accessories and Parts
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.