Technical Information

One this page you will find technical information for axle & brake assemblies, wiring diagrams and type loading etc… Simply scroll down:

Rubber Suspension Axle/Brakes

axle-assembly

  • 1. Black Plate LH
  • 2. Blanking Plug
  • 3. Adjusting Wedge Nut
  • 4. Side Wedge
  • 5. Adjusting Bolt
  • 7. Expander Assembly
  • 8. Shoe Carrier
  • 9. Reversing Shoe
  • 10. Standard Shoe
  • 11. Retaining Spring
  • 12. Reversing Shoe Spring
  • 13. Top Spring
  • 14. Bottom Spring
  • 15. Cable Bracket Top Half
  • 16. Eyelet
  • 17. Back Plate RH
  • 18. Reversing Shoe Assembly
  • 19. Blanking Plug
  • 20. Hub
  • 21. Wheel stud
  • 22. Wheel nut
  • 24. Oil seal
  • 25. Inner Bearing
  • 26. Outer Bearing
  • 27. Split Pin
  • 28. Washer
  • 29. Axle Nut
  • 30. Hub Cap
  • 31. Locking Nuts with Domed Washers
  • 32. Balance Bar
  • 33. Brake Cable
  • 34. Cable Abutment Nuts

Brake Cables

brake-cables (1)

Euro 13pin Caravan & Trailer Wiring

Terminal Number

Function

13 Core wire colour

13 Core wire colour

1

Indicator LEFT

Yellow

Yellow

2

Rear fog light

Blue

Blue

3

Earth for contacts 1 to 8

White

White

4

Indicator RIGHT

Green

Green

5

Side lights, marker lights & number plate lightRIGHT

Brown

Brown

6

Brake lights

Red

Red

7

Side lights, marker lights & number plate lightLEFT

Black

Black

8

Reversing lights

Pink

Pink

9

Positive direct from battery

Orange

Purple

10

Positive ignition key on

Grey

Grey

11

Earth return for contact 10

White/Black

Clear

12

Signaling connection to trailer

White/Blue

Buff

13

Earth return for contact 9

White/Red

Black/Red

There are some variations between 13 core cable colours, the above appear to be the most popular.

12N (Normal) Lighting

Terminal Number

Function

7 core wire colour

1

 Indicator Left

Yellow

2

 Rear fog light

Blue

3

 Earth

White

4

 Indicator Right

Green

5

 Side lights, marker lights & number plate light Right

Brown

6

 Brake lights

Red

7

 Side lights, marker lights & number plate light Left

Black

Wheels & Tyres

pcdcalc2

How to calculate the Pitch Circle Diameter P.C.D

Measure the distance between the centres of two adjacent holes ‘S’ and then complete the following equation.

Due to the accuracy of measuring it may be necessary to round to the nearest available PDC measurement.

Trailer Tyres & Tubes

Trailer and Caravan Tyre Markings & Condition:
Car, caravan and trailer tyres must have at least 1.6mm of tread over the central 75% of their width for their entire circumference, although a tyre with under 3mm offers little grip in the wet. Tyres must be free from deep cuts and bulges (which indicate they are breaking up) and it is illegal to use cross-ply and radial tyres on the same axle. (Make sure that the tyres you fit to your trailer are of the correct rating.)

Additional Tyre information:
See links above for detailed tables on Tyre Load Index, Tyre Speed Symbols and Tyre Load & Pressure Ratings.

Tyre sidewall markings:
The illustration below provides an explanation of the markings currently found on a tyre sidewall.

tyres

* do not apply in the U.K.

Retreads – must also show either ‘RETREAD’ or ‘REMOULD’ on the sidewall, together with ‘BSAU 144’ in place of ECE Type Approval Mark.

Aspect ratio – ratio between the height of the sidewall and the width of the tread, expressed as a percentage. In the example above, the figure is 70%.

Nominal section width – on radial tyres this is expressed in millimetres, on cross ply tyres, inches are used.

Tyre Load & Pressure Ratings

Tyre size

Max speed

100 km/h 60 mph 130 km/h 81 mph
Axle Load kg PSI/Bar Axle Load kg PSI/Bar
400 x 8 (4ply) 540 60/4.2
400 x 8 (6 ply) 680 75/6.2
500 x 10 (6 ply) 860 50/3.5
5.20 x 10 616 32/2.2
145 x10 693 35/2,4 630 32/2.2
145 x 10 (R/F) 781 42/2.9 710 39/2.7
140/70 x 12 1060 62/4.3
155/70 x 12 1800 90/6.2 1636 87/6.0
145 x 13 825 53/3.7 750 32/2.2
155 x 13 935 35/2.4 850 32/2.2
155 x 13 (R/F) 1045 42/2.9 950 39/2.7
165 x 13 10445 36/2.5 950 33/2.3
165 x 13 (R/F) 1166 45/3.1 1060 42/2.9
175 x 13 1166 36/2.5 1060 33/2.3
175 x 13 (R/F) 1276 45/3.1 1160 42/2.9
175 x 13 (6ply) 1407 54/3.75 1340 54/3.75
183 x 13 (6ply) 1500 54/3.75 1460 54/3.75
185/70 x 13 (Avon 950) 1900 87/6.0 1800 87/6.0
175 x 14 (6ply) 1491 54/3.75 1420 54/3.75
175 x 14 (8ply) 1628 65/4.5 1550 65/4.5
185 x 14 (6ply) 1628 54/3.75 1550 54/3.75
185 x 14 (8ply) 1785 65/4.5 1700 65/4.5
195 x 14 (6ply) 1785 54/3.75 1700 54/3.75
195 x 14 (8ply) 1995 65/4.5 900 65/4.5
600 x 16 (6ply) 1533 52/3.6
650 x 16 (6ply) 1890 62/4.3
750 x 16 (6ply) 2100 51/3.5