50mm SQ Axle – Slimline Electric

50mm Square Slimline Axle | For Caravans, Trailers or Boats

A 50mm square axle is the best choice for towing your rig straight and true. Loaded to 1450kg, this axle will never experience vibration fatigue.

Couplemate manufactures axles from BlueScope steel in our Wynnum, Brisbane workshops.

Question: What is the difference between a good and bad axle?

A bad 50mm square axle will have a bearing tolerance of more than 0.05mm. A good axle will have a bearing tolerance of 0.02mm to 0.04mm. Less than 0.02 tolerance is considered a tight fit and is usually reserved for ball bearings,

If your bearing has a bearing shadow under the bearing on the journal, that indicates a gap between the bearing and the journal. This gap significantly lowers bearing life. A good 50mm square axle may have a bearing life of between 20,000 kms or more.

This 50mm Square Slimline Axle Suits the Following Bearings

• NSK LM12749 Ford Outer Wheel Bearing
• NSK LM68149/10 Ford Inner Wheel Bearing
• Ford Slimline Seal – 492015
• 45.2mm Australian Grommet Dust Cap (Pair)

Solid Axle Ratings

• Holden Bearing Profile – 1,000kg Max
• Ford Bearing Profile – 1,450kg Max
• Dexter Bearing Profile – 1,590kg Max
• Ford Parallel Bearing Profile – 1,600kg Max
• Al-ko Bearing Profile – 2,250kg Max
• Dexter Bearing Profile – 2,250kg Max
• Al-ko Bearing Profile – 3,000kg Max

Note: After ordering your 50mm square axle, please advise your axle length (tip-to-tip or face-to-face) and axle profile (2t, 3t, parallel, or slimline).

Calculating The Correct Axle Measurements

1. Measure the offset wheel. The wheel offset is the distance between the hub’s inside and the rubber’s outside.
2. Add 50 mm to the offset. Alternatively, choose your own distance between the rubber and the chassis.
3. Multiply by 2 for both sides. Add your chassis width to the above number.

Still unsure of what measurements to take? Check out this handy guide below:

[P] – Check material specifications. What size and profile is the axle (for example, 45mm Square)
[T] – Overall axle length (tip to tip)
[F] – Hub face-to-hub face measurement
[A] – Chassis width
[C] – Tyre clearance
[B] – Back offset
[H] – Tyre to chassis
[G] – Axle pad centres

Identifying Bearing Combinations

You will also need to identify your bearing combination, which you can do by removing a hub and bearings and locating the number laser-engraved on the bearing. You will need both the inner and outer bearing numbers.

Solid Axles rarely cause problems.

The price of a 50mm square parallel axle can vary greatly. Axles are manufactured in various places, including India, China, Malaysia, and Australia.

The main problem comes from imported steel, which can cause fractures along the beam and inconsistent hardness.

Other Common Problems and Tips:

If your square parallel trailer caravan axle is not engineered correctly, you may experience excessive bearing wear.

1. Rough seal journals can cause grease to leak through the rear seal.
2. Some suppliers use non-virgin or scrap steel and forge it into a solid square or round shape for axle production. Always ask for Australian Steel.
3. Chinese bearings are the second most significant cause of axle failure.
4. If you plan to get onto a highway, use Japanese bearings.
5. Combining Japanese Bearings and a Square Axle will significantly reduce rig maintenance.
6. Are your tandem tyres wearing unevenly? How to Align Caravan Wheels
7. Axle Steel explained.

Solutions

We rarely have problems with these larger kits.

A Couplemate assembled axle with Japanese bearings gives you our unconditional guarantee of a well-made, well-backed axle assembly.

Caravan upgrades are explained here.

Other Square Axles

• 39mm Round Axle – 750kg
• 39mm Round Galvanised Axle – 750kg
• 40mm Square Axle – 1000kg
• 40mm Square Galvanised Axle – 1000kg
• 45mm Round Axle – 1450kg
• Marine 45mm Round Galvanised Axle – 1450kg
• Square Axle 45mm – 1450kg
• 45mm Square Parallel Axle – 1600kg
• 45mm Galvanised Square Axle – 1600kg
• Square 50mm Slimline Galvanised Axle – Marine
• 50mm Square Axle – 2500KG
• 50mm Galvanised Square Axle – 2250kg
• 60mm Round Trailer Axle 2t or 3t
• 60mm Round Axle – 3000kg
• 60mm Galvanised Round Axle – 3000kg

Finally, a hollow axle is a lightweight solution to a heavy-duty square axle.