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Ashcroft Locker

Ashcroft Locker

 

Ashcroft Air Locking Differential

 

 

 

Concept

 

There are many types of lockers available for landrover vehicles but all seem to have a weak point or Achilles heel, so we set out to design a locker from a blank canvas to be cost effective, strong and without the weaknesses of other designs.

 

 

Design

 

We wanted a selectable locker which would fit into the rover diff casing with minimal installation work, i.e, without mods to the axle housing. We looked at electric and pneumatic activation and decided pneumatic was preferable for reliability and simplicity. One of the key requirements for our design was zero air leaks as this is one of the main issues with other air operated lockers. To achieve this we opted for a static piston rather than the rotating seal used on other air lockers, which was prone to leaks. We also wanted to ensure we had a full 6mm of engagement when locked as other air lockers have just 2.5mm and are prone to slipping out of lock when loaded.

 

The final design settled on a 4 pin diff centre; one of the diff side gears has an outer ring of dog teeth around it which a locking collar engage with when locked, thus locking collar is on the crown wheel side, the locking collar is held with 4 pins which pass through the diff centre on the non crown wheel side . Outside the diff centre the 4 pins are peened to a steel thrust ring, this assembly forms a robust all steel ‘cage’, not plastic like other designs which were prone to failing.

 

On the non crown wheel side inside the journal end cap is a cylinder in which sits a bronze piston, the piston has a groove around the inside and outside diameters which O rings sit in. Once the piston is fitted a retaining ring is bolted around the end of the cylinder to stop the piston coming out, air is fed to the cylinder through a copper pipe to a 90 deg compression fitting which fits to the outside diameter of the cylinder. When air is applied the piston moves along the cylinder until it reaches the retaining ring, it does not spin in the cylinder, the cylinder is static and sits on a bronze bush at the side of the diff centre. Inside the journal bearing on the cylinder side is a bronze thrust ring to hold the cylinder. A locking tab is fitted to one of the journal end cap bolts and locates in a cut out in the cylinder to stop it rotating.

 

 

The copper air feed pipe goes from the side of the cylinder through the diff housing, it doesn’t have to pass over the crown wheel.

 

The lockers are assembled on our premises and supplied with switch (front and rear fascias), solenoid, air line and all required fittings, excludes air compressor.

 

We have used 6mm pneumatic push fit fitting to the locker as we have found that other air lockers that have threaded fitting and hoses will either tear a pipe or break a fitting if the air line gets snagged on a branch etc, our locker uses these pneumatic 'push fit' fittings which will still get snagged but just pull out so you just need to push back in to fix rather than having to replace hoses etc.

 

Operation

 

When air is applied, the static annular piston moves across and pushes the spinning thrust collar which slide the 4 pins and move the locking collar over the side gear teeth to lock the diff, the diff is unlocked when the air pressure is released and 4 return springs push the locking collar out of engagement with the side gear.

 

 

Materials

 

Whilst we want the unit to be cost effective, the strength is paramount, all steel parts are turned from billet UK spec EN24T, Gears are 8620, locking collar is 300M.

 

Key features :

 

Full 6mm of locking collar engagement

Static annular piston, minimises risk of air leaks

Large diameter piston gives a 55% increase of hold in force over competitors

High spec materials throughout

Competitively priced

 

 

2 year warranty

 

The Ashcroft Locker has been tested in two competition vehicles before lauched for public sale with zero failures and the following results:-

 

Mamby September 2010 1st

Hound of the Baskervilles November 2010 1st

Santa's Challenge December 2010 1st

Muddy Truckers March 2011 1st

Croatia Trophy May 2011 1st

 

Vehicles driven by Jim Marsden, Gigglepin 4 x 4 and Steve Gittens ~ our thanks to them for testing our locker.

 

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Ashcroft Locker

Ashcroft Locker

£495.00

  This model is to suit the "Rover" type 24 spline differential fitted to the Discovery I, Di…

Ashcroft P38/Wolfe Locker

Ashcroft P38/Wolfe Locker

£520.00

This model is to suit the P38 Range Rover and the 2002 onwards 110 rear axle.   We can supply the Ashcro…

Pinion bearing and seal kit - Rover 24 spline

Pinion bearing and seal kit - Rover 24 spline

£27.50

2 Timken Pinion Bearings and 2 seals for the 24 spline Rover differential Only one seal is required but it could …

Pinion Bearing and Seal kit - P38 24 spline

Pinion Bearing and Seal kit - P38 24 spline

£63.00

2 Timken Pinion Bearings and 1 seal for the 24 spline P38 Wolfe differential   Kit excludes the journal …

ASH-AL-01

ASH-AL-01

£10.00

Journal bearing, LR Part No. RTC 3095.    Please note one pair of bearings are included with the locker Q…

ASH-AL-02

ASH-AL-02

£9.25

Cylinder Thrust Washer Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the item…

ASH-AL-03

ASH-AL-03

£24.50

Cylinder Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the items in your shop…

ASH-AL-04

ASH-AL-04

£12.75

Cylinder Bush Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the items in your…

ASH-AL-05

ASH-AL-05

£22.50

Piston Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the items…

ASH-AL-06

ASH-AL-06

£1.25

Outer O Ring Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the items in your …

ASH-AL-07

ASH-AL-07

£0.95

Inner O Ring Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the items in your …

ASH-AL-08

ASH-AL-08

£8.75

Retaining Ring Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the items in you…

ASH-AL-09

ASH-AL-09

£0.08

Retaining Ring Screws, M5 x 12 C/Sk skts BZP Quantity 1 (8 required per Locker) SHIPPING COSTS In order to calculate you…

ASH-AL-10

ASH-AL-10

£19.00

Selector Cage Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the items in your…

ASH-AL-11

ASH-AL-11

£0.15

Main body Screws, M8 x 25 cap low head Quantity 1 (8 required per Locker) SHIPPING COSTS In order to calculate your ship…

ASH-AL-12

ASH-AL-12

£30.00

End Cap Small Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the items in your…

ASH-AL-13

ASH-AL-13

£1.85

Side Gear Washer Quantity 2 (Two required per Locker) SHIPPING COSTS In order to calculate your shipping costs you will …

ASH-AL-14

ASH-AL-14

£25.00

Side Gear, non locking Quantity 1   SHIPPING COSTS In order to calculate your shipping costs you…

ASH-AL-15

ASH-AL-15

£7.75

Cross Pin Boss Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the items in you…

ASH-AL-16

ASH-AL-16

£25.00

Side Gear, locking Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to p…

ASH-AL-17

ASH-AL-17

£0.20

Planet Gear Washer Quantity 1 (4 required per Locker) SHIPPING COSTS In order to calculate your shipping costs you will …

ASH-AL-18

ASH-AL-18

£12.00

Planet Gear Quantity 1 (4 required per locker) SHIPPING COSTS In order to calculate your shipping costs you will need to…

ASH-AL-19

ASH-AL-19

£0.25

Spring Pins, 5/32" x 1.5 " seloc pins Quantity 1 (3 required per Locker) SHIPPING COSTS In order to calculate your shipp…

ASH-AL-20

ASH-AL-20

£12.00

Cross Pin short Quantity 1 (2 required per locker) SHIPPING COSTS In order to calculate your shipping costs you will nee…

ASH-AL-21

ASH-AL-21

£15.00

Cross Pin Long Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the items in you…

ASH-AL-22

ASH-AL-22

£70.00

Main body Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the items in your sho…

ASH-AL-23

ASH-AL-23

£40.00

Lock Ring Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the items in your sho…

ASH-AL-24

ASH-AL-24

£0.10

Lock Ring Screws, M5 x 16 C/sunk skts BZP Quantity 1 (4 required per Locker) SHIPPING COSTS In order to calculate your s…

ASH-AL-25

ASH-AL-25

£1.00

Return Spring Quantity 1 (4 required per locker) SHIPPING COSTS In order to calculate your shipping costs you will need …

ASH-AL-26

ASH-AL-26

£40.00

End Cap Large Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the items in your…

ASH-AL-27

ASH-AL-27

£2.00

4mm Copper Pipe, 350 mm long Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will…

ASH-AL-28

ASH-AL-28

£7.50

Actuator Switch Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the items in yo…

ASH-AL-29

ASH-AL-29

£3.00

Actuator switch fascia - front Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you wi…

ASH-AL-30

ASH-AL-30

£3.00

Actuartor fascia switch - rear Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put …

ASH-AL-31

ASH-AL-31

£15.00

Air Solenoid Valve Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to p…

ASH-AL-32

ASH-AL-32

£3.00

90 degrees elbow push fit - 1/8" bsp taper (solenoid) to 6mm airline, Quantity 1 SHIPPING COSTS In o…

ASH-AL-33

ASH-AL-33

£3.00

90 degrees elbow push fit - 1/8" bsp parallel (diff housing) to 6mm airline, Quantity 1 SHIPPING COSTS …

ASH-AL-34

ASH-AL-34

£5.00

Bulkhead fitting adaptor Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the it…

ASH-AL-35

ASH-AL-35

£0.20

Bulkhead fitting O Ring Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the ite…

ASH-AL-36

ASH-AL-36

£5.00

6mm x 5m nylon air line Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the ite…

ASH-AL-37

ASH-AL-37

£3.00

O Ring kit (includes 3 rings - Bulkhead, Outer and Inner O Ring) SHIPPING COSTS In order to calculate your shipping cost…

ASH-AL-38

ASH-AL-38

£1.00

1/8" bsp, M/M coupling Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the item…

ASH-AL-39

ASH-AL-39

£0.40

Journal End Cap M12 x 65 HT Bolt Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to pu…

ASH-AL-40

ASH-AL-40

£0.40

Journal End Cap, M12 x 55 HT Bolt Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you…

ASH-AL-41

ASH-AL-41

£1.00

Cylinder Locking Tab Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need to put the items …

ASH-AL-42

ASH-AL-42

£6.00

1/8" bsp, 4mm Comp fitting, 90 elbow. Quantity 1 SHIPPING COSTS In order to calculate your shipping costs you will need …

Drill Bit

Drill Bit

£7.50

Drill Bit  29/64" Required to install a hole in the your diff housing required for the air feed when inst…

Tap

Tap

£18.00

1/4 - 19 BSPF Tap required to drill a hole for the air feed when fitting the Ashcroft Locker SHIPPING COSTS In order to …

1/8 BSP 90 Deg 5mm Push Fit Elbow

1/8 BSP 90 Deg 5mm Push Fit Elbow

£5.50

We are getting asked if the Ashcroft locker solenoids (ASH-AL-31) can be used in place of the ARB ones, yes, no problem …

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