Replacement Timken Grese Seals for Dexter 3500 lb Axle

Updated 04/07/2026 | Published 03/31/2026

Question:

Which Timken Grease Seals do I need for a 3500 lb Dexter Axle? I think the SN on the axle is 181040021 but it is old and hard to read. It is on a 2006 Jayflight 20BH if that helps.

asked by: Jacob H

Expert Reply:

Hi Jacob,

For a typical 3,500 lb Dexter axle, the most common grease seal used is the 1.719" inner diameter by 2.565" outer diameter seal, which is Timken part # TMK58ZR.

That seal usually pairs with the standard bearing set of L68149 (inner) and L44649 (outer), which is what most 3.5K axles, including many Jayco trailers from that era, were built with.

Since your trailer is a 2006 Jayflight, there’s a very good chance this is exactly what you have, but because the serial number is hard to read, I wouldn’t want you ordering based on a guess. The safest way to confirm is to pull one hub and check the numbers stamped on the bearings or measure the seal surface on the spindle. That guarantees you get the right fit the first time.

If you’d like, I can help you match it up once you have those numbers or measurements. Are you planning to just replace the seals, or are you doing a full bearing service while you’ve got it apart?

expert reply by: Heather A

Jacob H.

4/6/2026

Thanks for the info. I'm planning to inspect and re-pack the bearings and then replace the seals. I think I will order these to have on hand.

Heather A.

4/7/2026

@JacobH Awesome, let me know how everything comes together. I am still around!

4/6/2026

Jacob These are what I used on my 2019 Keystone Cougar. They worked great! Hope this helps you. I don't remember what my axles are. I'm at work and can check when I get home if that would help any.

Terry

4/6/2026

I have a 25' Bigfoot trailer with dual 3500# Dexter axles. I use Timken bearings and races (Etrailer #TMK73VR and TMK23VR) as well as the Timken grease seal (#TMK58ZR). I follow Dexter's recommendation and apply a thin layer of Permatex High-Temp Red RTV Silicone Gasket to the outside metal diameter of the grease seal. I have put over 30K miles on the Timken bearings without any issues. I clean and repack my bearings (replace grease seals) every 12K miles or so and use Mystik JT-6 Hi-Temp Grease #2.

Heather A.

4/7/2026

@Terry That’s a really solid setup and maintenance routine you’ve got going. Using Timken bearings and races along with the matching seal, and sticking to a consistent service interval like that, is exactly why you’re seeing that kind of longevity. The Permatex on the outer edge of the seal is something a lot of experienced folks do for a little extra peace of mind, and clearly it’s been working well in your case. Sounds like you’ve got a system that works and you’re sticking with it, which is honestly the biggest factor. Are you mostly highway towing with that Bigfoot, or do you get into a mix of conditions?