4 Sets 25580 15123 Boat Trailer Axles Bearing Kits for D42 Spindle

In this review the author tested the 4 Sets 25580 15123 boat trailer axle bearing kits to see whether they deliver a reliable, ready-to-install replacement for tandem axles rated 5200-6000 lb. The bottom line: this kit is best for owners who want a complete, practical spare set that fits 1.25' to 1.75' #D42 spindles and includes extras so a single failure on the road does not strand you. The review focuses on fit, materials, and the included extras that separate this kit from a basic bearing purchase.

Key Features

• Seamless compatibility: The kit is built to fit tandem axles with a 1.25' to 1.75' #D42 spindle, giving a precise replacement match for 5200-6000 lb trailers.
• Complete luxury kit: Each pack contains inner and outer bearings and races plus grease seals and hardware so most jobs can be completed without hunting down extra parts.
• Extra removable caps and spindle nuts: The supplier includes spare dust caps, rubber plugs and spindle nuts which act as immediate backups for roadside repairs.
• Premium materials: Bearings and races are made from alloy steel and manufactured for precision to reduce running noise and wear under load.
• Double lip grease seals: Grease seals feature a double lip design to help prevent leaks and keep lubricant in the hub under wet trailering conditions.
• Spares included: Shims, washers and cotter pins are provided so you have the common small parts needed during installation or service.

Who It's For

This kit is aimed at boat owners, small commercial trailer operators, and DIY mechanics who maintain tandem axle trailers rated between 5200 and 6000 lb and need a complete bearing replacement set that fits a #D42 spindle. The inclusion of extra caps, plugs and nuts makes it especially useful for those who value having immediate spares for field repairs.

Those who should look elsewhere include owners of single-axle trailers or trailers with spindles outside the 1.25' to 1.75' range; also, if an OEM branded, vehicle-specific kit or sealed, maintenance-free hubs are required, a different product will be a better match.

Pros & Cons

Pros

• Comes as a full hardware set with inner and outer bearings, races, grease seals and installation parts so shops and DIYers can finish an axle service without extra shopping.
• Good perceived build quality and fit, with customers noting the kit works well on 6000 lb axles.
• Includes spare dust caps, rubber plugs and spindle nuts which provide practical redundancy for trail repairs.
• Double lip grease seals and alloy steel bearings aim to reduce noise and leakage under load.

Cons

• Some users had mixed impressions of the seal performance, so long term leak resistance may vary by installation and conditions.

Specifications

Fitment	1.25' to 1.75' Tandem Axles, #D42 Spindle
Rated Axle Capacity	5200-6000 lb
Inner Bearings	4x 25580 (I.D. 1.75')
Outer Bearings	4x 15123 (I.D. 1.25')
Grease Seals	8x 22333TB, double lip design
Included Hardware	4x cotter pins, 4x dust caps, 4x rubber plugs, 4x spindle nuts, washers and shims
Material	Alloy steel bearings and races

Our Verdict

For trailer owners who need a comprehensive replacement bearing kit for #D42 tandem axles, this set delivers strong value by combining correct fitment, alloy steel parts and helpful extras like spare caps and nuts. It is a practical choice for preventive maintenance or roadside repair, though buyers should install seals carefully to avoid the mixed seal outcomes reported by some users.

Frequently Asked Questions

Will this kit fit 6000 lb tandem axles?
Yes; the kit is specified for 5200-6000 lb tandem axles with a #D42 spindle and matched bearing sizes.

Are replacement dust caps and plugs included?
Yes; spare dust caps, rubber plugs and spindle nuts are provided in the kit for repairs or backups.

Do the grease seals prevent leaks?
The seals use a double lip design to reduce leakage, but proper installation and hub condition affect long-term performance.