Receiver Hitches

[DrRob]

Are they legal in the UK?

I'm sure someone told me once they weren't.....?

Want to fit this:

http://www.extreme4x4.co.uk/acatalog/RR_CLASSIC____DISCO_1_QUICKLY_DETACHABLE_TOWBARS.html

Cheers

Rob

[Gazzar]

I thought they were legal (or required) on newer cars. Ask the seller? Does it have the various certifications and stuff?

G.

[Tanuki]

Depends on the date of first registration of the vehicle.

See http://www.ntta.co.uk/law/towbars/type_approval.aspx

and

http://www.towbarsdirect.co.uk/faqtypeapproval.htm

[Dave W]

It also depends on the status of the vehicle as commercial vehicles are exempt from the '98 on changes.

If it's older than '98 there's no problem anyway.

[Gazzar]

I was wondering about making up a receiver hitch for the series, rather than the dixon bate ground anchor! Are they as strong as the old school slider hitch?

[David Sparkes]

I was wondering about making up a receiver hitch for the series, rather than the dixon bate ground anchor! Are they as strong as the old school slider hitch?

Their strength depends on the design, you declare the intention of making one up yourself, so that is a question you need to ask the man in the mirror.

I suggest your designer looks at the Defender versions that Extreme 4x4 offer.

The 'difficulty' with a Series mounted 50mm ball hitch is that it imparts the pull load into fresh air, below the cross member (when the ball height is correctly matched to the trailer hitch height).

Thus the need for drop plates is created,

and then the need to stop the drop plate folding up,

and then the need to stop the leverage imposed through the rigid drop plate from twisting the rear crossmember.

When the designer looks again at the Defender QD designs they will see how the fixed element of the design counters the twisting motion presented to the receiver hitch.

Next, you will see that Extreme have created a QD drop-plate accessory to get the necessary 'low' height of the 50mm ball.

That accessory MAY not hang down far enough for the Series vehicle, especially once any parabolic spring lift, or 7.50 tyre lift, has been taken into account.

The advantage of the QD receiver hitch design is that the 'ground anchor' element can be quickly removed (unless, for some obscure and illogical justification, the vehicle driver is likely to tow a 50mm ball hitched trailer across land so uneven that the drop plate will catch).

Next, your designer needs to consider the rear crossmember on the Series, is it Military or Civilian?

The Military version, so I was advised by Richards Chassis, is the less able to withstand the twisting motion imparted by the necessary drop plate for 50mm ball usage. This is because the military version is less deep (has less vertical height), than the civilian version. The RC recommendation is owner fabricated forward facing arms, that have the forward ends through bolted to the chassis rails, as close to the bottom plate of the chassis rail as can be managed. Naturally, the rear ends of these arms are bolted to the point the 50mm ball hitch is fitted to the drop plate.

The advantage of using a Military cross member for the QD receiver hitch is that the hitch can be tucked up against the lower plate of the Military cross member, like the Defender examples, thus minimising any ground anchor effect of the basic receiver hitch.

The disadvantage of using the Civilian cross member is that the basic receiver hitch, even if tucked up against the lower plate of the Civilian cross member, will always be catching the ground, just not as much as the DB slider arrangement.

If your designer cuts a square slot in the lower edge of the Civilian cross member, welding into the slot the square tube of a receiver hitch, surrounded by local load spreading plates, then the disadvantage of the permanent ground anchor is removed, BUT, how is the user to insert the QD pins? Extending the fixed receiver hitch tube rearwards to give length for the pins, will compromise the ramp angle, and you are left with the same disadvantage as with the underslung receiver hitch.

Generally, the permanently installed support frame for the receiver hitch has two forward facing arms, bolted to 'strong points' on the main chassis rails. Your designer needs to think where these strong points are, on the Series chassis. The answer may be different depending on both the wheelbase, and the fuel tank arrangements.

Let us know what solutions your designer suggests to the design criteria I've identified. The list should not be considered complete; there may be other criteria that didn't spring out as 'obvious' :-)

HTH

[honitonhobbit]

Pre August '89 is legal, post is not but there's not a Dibble in the country who would know that except the CIT or SOCO folk; so don't have an accident

[DrRob]

Thanks chaps! I'm legal

[rovernut]

Pre August '89 is legal, post is not but there's not a Dibble in the country who would know that except the CIT or SOCO folk; so don't have an accident

Don't forget roadside inspections by VOSA. They know and will leave you wondering how to get your tin tent home without your tow vehicle

[honitonhobbit]

I've yet to see VOSA pull someone for a receiver hitch - and I've spent a fair few hours watching them pull folk for just about everything else. The fines aren't big enough so they leave the small fry

[Ed Poore]

Digging up an old thread but thought it's worth pointing out that the majority of newer Discos (3 and 4) and the L322 like mine have these fitted as the standard tow bar option. Have a look through PF Jones or Westfalia's website to see what I mean.

I think they would still be around except that the L405 I think now has an electrically deployable one.