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Towing A-frame?
nstrug - 13/4/09 at 07:25 PM

Does anyone have any thoughts about using a towing A-frame? On the face of it, its a really cheap alternative to using a trailer, but I'm concerned whether long drives might damage the gearbox as it will obviously be meshed and spinning, but with no oil pressure.

Is this a reasonable concern?

Nick


Benzine - 13/4/09 at 07:27 PM

Are they not illegal for use other than for recovery?


"unbraked ones are illegal fullstop, braked ones are only legal for recovering broken down vehicles to the nearest safe point, once you proceed beyond that safe point it then becomes transportation of the vehicle, not recovery and is therefore illegal" from
http://www.mig-welding.co.uk/forum/showthread.php?t=4542

and a bit half way down this page:
http://www.ntta.co.uk/faq/default.htm



[Edited on 13/4/09 by Benzine]


Guinness - 13/4/09 at 07:39 PM

It was discussed recently on Pistonheads:-

H ere

Obviously the guy selling them claims they are legal.

If anyone can back that up, I'd be tempted.

HTH

Mike


mark chandler - 13/4/09 at 08:15 PM

Impossible to reverse, but the car will follow you like a faithful puppy dog at speed.

You see quite a few campers towing smart cars etc al in the summer like this, I did try a couple of times 20 years ago then got a trailer so do have some limited experience.

Do not use if the towed car has a pump in the gearbox, aka auto or heavier duty manuals, so not good for v8 rover lt77 gearboxes for instance.

Regards Mark


nstrug - 13/4/09 at 08:22 PM

Just wondering as one of the styluses (antnicuk's cousin's I think) at Woodbridge last saturday arrived and departed on one.

As long as the car is under the unbraked trailer limit (which any BEC is, easily) why would this be illegal?

Still worried what it does to a gearbox with no oil pressure.

I can see that reversing might be an issue...

Nick


zilspeed - 13/4/09 at 08:39 PM

The reason it's illegal.

You can't consider it as a trailer as trailers need to have auto reverse hubs. All braked trailers must now have auto reverse hubs.

As has always been said in this subject, lots of people have been getting away with this for years and nothing bad usually happens.

However.

Imagine the aftermath of an accident, the Plod that wear the funny hats will use you for target practice.

Worth it ?


myke pocock - 13/4/09 at 09:10 PM

If the gearbox is "meshed and spinning" why wouldnt it have oil pressure and does a gearbox actually use oil pressure as such as theres nothing to pump the oil around apart from the gears effectively splashing the oil around. I have heard this argument in the past but I A frame my trials car and havnt been concerned with it from that point of view.


SteveWalker - 13/4/09 at 10:14 PM

I don't know about manual gearboxes, but autos definitely have a pump driven from the input shaft. Towing these is generally not recommended for more than 10 miles or so. Some Auto boxes apparently also have a second pump on the output shaft (supposedly these can be bump or tow started like a manual), they would probably be okay being towed long distances.

As to the requirement for auto reverse hubs, that surely only applies where brakes are actually required, up to 750kg (or your tow cars max. if lower) is okay unbraked. The questionable bit is that this weight is the maximum gross weight: now a car, plus two adults, plus "luggage" can add up to too high a figure - I know that when using an A-frame you wouldn't have anyone in the car, but would it be accepted that the MGW was different for towing than for driving?


spaximus - 14/4/09 at 06:44 AM

It is a dogs dinner of a law. The rules on auto reverse brakes on trailers is for those made IIRC in the last ten years before that no such rule.
When even the department of transport, who should know use the phrase, "we belive they are legal but only the court can say" shows how stupid it is. A frames are legal it would appear for all to use, dollies are only for recovery use that is clear.
If you have room a trailer is always the best, if not then an A frame is okay unless someone wants to make a test case of it


mad4x4 - 14/4/09 at 06:48 AM

If it is a 7 or a light built KIT then you may be able to "flaut" the law with the under 750 KG rule. (trailers under 750kg don;t need brakes)

BUT remember - "IT LOOKS LIKE A CAR so therefore it is a CAR not a TRAILER........" Try and talk your way out of that one with an A**l traffic COP after an accident....>!!!


nstrug - 16/4/09 at 09:12 PM

quote:
Originally posted by myke pocock
If the gearbox is "meshed and spinning" why wouldnt it have oil pressure and does a gearbox actually use oil pressure as such as theres nothing to pump the oil around apart from the gears effectively splashing the oil around. I have heard this argument in the past but I A frame my trials car and havnt been concerned with it from that point of view.


Sorry, I should have been more specific - I have an R1-engined BEC, and the gearbox gets its oil pressure from the engine oil pump. There is no oil to splash around as the gearbox is not anywhere near the sump and does not have its own oil supply.

This is why I was worrying that towing would damage the gearbox.

Nick


MautoK - 17/4/09 at 04:05 PM

A trialling colleague used to A-bar his Hillmap Imp to PCTs, with a Granada as tow car.
On reaching home after a 100 mile drive following one event he noticed the Imp's gear lever was in first gear....