About a year ago, Rockinger presented its own lower link quick-release hooks,
which it developed in collaboration with Finnish manufacturer LH-Lift.
We try them out, both in terms of their design and ease of use.

KEEPING IT BRIEF

  • Rockinger now offers its own lower link quick coupler.
  • The locking mechanism is patented and easy to operate.
  • The hooks are available in five different sizes from specialist retailers.

Like Rockinger, LH-Lift from Finland has been part of the Jost Group since August 2023. So, it was an entirely logical step to jointly develop new coupling components in order to be able to offer customers a full range for three-point linkages in addition to Rockinger’s existing trailer coupling systems. 

Below, originally the Axion lift arms were fitted with CBM hook ends. Differences relate to the locking mechanism and thickness.

LH-Lift products will be well known to Valtra users where they have been used for many years. The new Rockinger Quick Coupler quick-release couplers are a development of these LH-Lift hooks. Rockinger offers the couplers in Cat. I, II, IIIL (e.g. for all front linkages), III and IV sizes. 

Solidly built

We tested out the Cat. III hook size on a (135kW/183hp) Claas Axion 820. First thing we noticed was that the hooks look well-made and robust. This was confirmed when we got out our measuring tape — 40mm wide and about 75mm high below the seat that the ball sits in. 

Compared with the other makes of hook we measured on 200hp tractors, this is 5mm to 10mm more. This may improve stability but does mean you need a little more space for coupling below the ball. 

To put it another way, the hook measures around 15cm from the underside to the tip, which is the minimum space underneath the ball for coupling.  

The linkage ball attached with just a little bit of pressure to the closed hook.

Easy to operate

To open the patented locking mechanism, pull the easy-grip latch upwards, which requires about 75N (7.5kg) of force. This works really well; in fact, you can easily open the latch while leaning over from the other side of the machine. No additional pulling or twisting is required to engage the lock. You could even use a rope to pull open the latches from the cab. 

Opening the hook by pulling on the latch takes about 75N (7.5kg) of force. That’s OK, even when leaning across from the other side of the tractor.

There’s no need to open the latches when coupling a machine. In our tests, a lower link cross shaft could be attached with just a little downward pressure. As you push the open latch towards the tractor, it then springs downwards. This also occurs if, for example, the implement’s ball couplings extend out beyond the hooks, which should prevent any breakages. Initially, the locking mechanism was a bit stiff due to the thick coat of paint. Rockinger plans to fix this. 

Departure-protected

The latch is protected by a kind of horn, which is horizontally flush with the closed tab — great. In an ideal world we like to see a recess in the horn on the hook, wide to better guide the balls during coupling. 

If there is wear or damage, you can easily remove the five-part locking mechanism from the hook by driving out one roll pin and unhooking the spring. The bottom of the housing is open on one side so the spring can be released and dirt can be washed or fall out.

The locking system consists of five components.

The hooks were already welded to matching link arms. Rockinger also supplies these with a special feature: the balls in the eyelets are two-piece. This allows the manufacturer to heat treat both the balls and lower links separately. The balls are then inserted afterwards. Rockinger says, this results in higher wear resistance than regular ball sockets. 

These ball halves are inserted vertically through a notch in the eyelets, hooked into each other and secured with a type of clamping ring. In principle, this mechanism is intended for one-off installation rather replacement of the ball inserts. 

The split ball allows separate heat treatment for the eyelet and the ball.

Summary and prices

Rockinger’s Quick Coupler lower link quick- release hooks impress with their robust construction and very easy to use locking mechanism. The only thing to watch out for is sufficient clearance underneath the ball for coupling the implement. 

Prices start at around £40 for Cat. I. The tested Cat. III hooks cost around £110 each. 

Overall, the hook ends left a very positive impression. They are definitely a workable alternative to well-known makes, even for retrofitting.

LOCKS COMPARED

CBM

With the CBM Opti-Lock, the locking mechanism engages when pulled upwards or backwards.
Alternatively, CBM offers a hook where the mechanism is locked with a slight twist of the handle.
With Walterscheid, the locking mechanism is first pulled up and then back. This locks the front peg into place and secures the locking mechanism.

Alexander Bertling

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