Member Since: 06 Aug 2007
Location: Saddleworth
Posts: 2302
LRM tow ball "scare"
August edition of LRM contains a letter suggesting that the removable tow ball is not fit for purpose, and - worse - that JLR now advise that the removable towball is only advised for "occasional lightweight towing".
I would be interested in the views of our Australian friends who must (if towing in the outback) have stressed these things more than most…
My view is in the following which I have not yet sent off to LRM. It needs, so I am told, de-technicalising.
The "vertical wedge" shape is as described…
PICTURE OF DETACHABLE UNIT HERE, WITH STEEL LOCKING PIN RETRACTED (top 3" is the wedge)
and when inserted, the ¾" hardened steel lock pin shoots across…
PICTURE OF DETACHABLE UNIT WITH STEEL PIN PROTRUDING
… and into the subframe casting.
The pin is under the control of the lockable green handle which is pulled axially and rotated against a strong spring to pull the pin in for mounting and demounting on/off the car.
The pin operates in shear to retain the tow-ball unit under download forces and should fail at around 30 tonnes. It is angled at 75Ëš to the back face of the wedge, and shaved off on the shear-load face in a curve with an average shave angle of 15Ëš
So, whilst the hardened ¾" locking pin is not normal (i.e. sitting at 90˚) to the shear-load but effectively at 60˚, it is of a section and shear strength way in excess of anything that would fail in normal loading AND has the advantage of a spring-loaded wedging function maintaining the unit into its location.
I cannot see it failing, and my guess as to the result of testing to destruction with a download would be a crack failure of one of the robust castings, rather than the tow-ball assembly simply slipping out.
My assessment of the play experienced by the writer is that the wedge mating surfaces in the socket are not clean and scale-rust-free, allowing the unit to locate and wedge safely in without being as snug as in a new and clean setup. Some (safe) movement could then be expected within the wedge fitting.
I am surprised that JLR have "run scared" burbling on about "occasional lightweight towing" with a setup as robust as this. This response shows a lack of a realistic engineering review and is presumably in the wake of their lawyers' reactions to similar consumer comments, without putting their confidence in their well-designed and robust device.
END.
(Note to more technical brother)...Need to do the sums for the 30 tonnes bit, but what do YOU think?
Later - (I can DO sums!)
Not my field but @ 150,000psi shear strength for hardened steel and ø = 0.709" = 106,350lb = 47.4 imperial tons for the full ¾" bar.
Shaved off as it is to â…” x-sectional area at the bite-point, â…” x 47.4 = 31.6 imperial tons or 28.66704 metric tonnes
How the b****y h€ll was THAT for a "seat of the pants" guess????
Need some red wine……
I know there have always been those who never trusted the removable tow ball, but - for heaven's sake - it is a piece of agricultural engineering, chunky as heck.
I would be interested in comments 2006 D3 finally swapped for a 2016 D4 Graphite in Graphite grey. No mods
1st Aug 2013 6:42 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
The subject has been done to death on here since the original TSB revision came out.
I'm still on my original 2006 ball.
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26770
Hi Andrew, hope your well. I too am still on my original 2004 tow bracket. It has outlasted 2 D3's and is now in use on my D4, towing a 23ft twin axle Elddis Crusader at maximum payload.
There is a slight bit of movement when its fitted, but to be honest, if it was too tight (or perhaps had dirt or corrosion on the mating surfaces) then the locking pin might not engage properly, and it would be unsafe. There is no knocking in use whatsoever, and the height is perfect for my caravan.
I would suggest LR are playing safe, to the lowest common denominator. Some people out there would not be capable of feeling a locking pin engage, or understanding the mechanics of the lock, and would possibly fit the bracket incorrectly.
I clean and grease the mating surfaces, oil the lock regularly, and fit the red blanking block when not in use.
1st Aug 2013 8:10 pm
AndrewW
Member Since: 06 Aug 2007
Location: Saddleworth
Posts: 2302
Hi Gareth - all good, thanks. Hope you and yours are, too!
This forum has so much stuff on it… I did the best search I could for such info and caught no sign of it being "done to death"
Anyway it might serve to re-assure a few LRM readers, since the mag has brought the topic up.…
Incidentally, I left my tow ball attached all winter (easier for towing folk out of snow) and paid the penalty with a seized lock mechanism after 4 months! Three hours of patient effort unseized it, and after stripping it down we fitted a grease nipple centrally in the "pear-shaped" steel plate on the other side.
All the best!
A2006 D3 finally swapped for a 2016 D4 Graphite in Graphite grey. No mods
1st Aug 2013 8:29 pm
Robbie
Member Since: 05 Feb 2006
Location: ¯\_(ツ)_/¯
Posts: 17932
Gareth wrote:
I clean and grease the mating surfaces, oil the lock regularly, and fit the red blanking block when not in use.
Perfect. I wish more would take the same care as I have seen some shocking examples!
Land Rover - Turning Drivers into Mechanics Since 1948
Member Since: 09 Mar 2007
Location: hants
Posts: 2144
Robbie wrote:
The subject has been done to death on here since the original TSB revision came out.
I'm still on my original 2006 ball.
has the wife got the other in a top drawer Illegitimi Non Carborundum
2nd Aug 2013 7:39 am
rockcrawler
Member Since: 31 Oct 2012
Location: Ferring
Posts: 2884
I regularly tow a twin axle caravan with a removable towbar and so far have had no issues at all.
However it would be interesting to hear from anyone that has had any horror stories towing with theseD3 Metropolis Bonatti Grey-Alpaca Leather-adaptive headlights-fridge-EGR blanking kit-Harmen Karden-Cruise-4x4 info enabled-Tinted Windows-Heated F&R Seats-Rosen rear Entertainment-LED'S everywhere -Smoked Side Repeaters-Rear Aircon-Vredestein Wintrac 4 Extreme-Puddle and Footwell Lamps-Stainless Steel Side Protection Tubes- NEW ASHTRAY ( thanks to dsd1036 )
Club BAS Remote FBH
Club MXS10 Ctek
Club Beanie Grill
Rear D4 Lamps
Geoff Gearbox Flush
BAS Remap
2nd Aug 2013 8:22 am
garrycol
Member Since: 06 Dec 2010
Location: Canberra
Posts: 1130
In Aust we have a different tow bar but how it clips up into the rear cross member is the same as in the UK. Our bars are rated to tow 3500kg with a 350kg tow ball weight.
Here we have a number of reported failures ranging from the tow bar falling out of the cross member to the actual tow bar failing with fatigue cracks then failing. The last unsubstantiated report was of a D4 towing a 23ft van that hat the whole rear end of the car ripped out - this has not been confirmed and the whole rear end ripped out is most likely as the van came away something has caught the rear bumper and pulled the outer covering off.
In my view the aussie authorities should have forced LR to do a safety recall but this has not happened. I do not use a LR tow bar on my car and use a Mitch Hitch which is a different system and there have been no issues on a correctly installed tow point.
Garry
2nd Aug 2013 8:26 am
B16 KJR
Member Since: 10 Jul 2006
Location: Rosyth, Fife
Posts: 3005
I replaced mine as did other forum members with a towbar from TowTrust, due to excessive play and clonking whilst towing
2nd Aug 2013 8:58 am
nismotec
Member Since: 24 Apr 2015
Location: bournemouth
Posts: 62
Sorry to re ignite this thread and I know there are other threads, but I can't find the answer. has anyone actually had a tow ball drop out and if so, what bit actually fails? I've lived and greased mine and it goes in and locates and locks ok. But after towing, the ball can be wobbled a bit by hand. If I turn the lock handle slightly,without unlocking, I can make the pin move a bit to take up the slack again .. if this is as bad as it gets and can't fall out I'm not worried.but if it's the sign that it's about to fall off I need to do something quick as we are off up to Gloucester in a month .
29th Jun 2015 1:14 pm
SADISCOBOB
Member Since: 08 Oct 2010
Location: Alberton
Posts: 246
TOW BALL
I have towed all types of terrain in my 2006 D3 from deep deep sand to rocky roads to the very worst corrugated strips, from Botswana to Namibia and the latter in the Northern Cape, all towing 1 to 1.5 ton loaded trailer, ( mostly beer ) and I have had no problems with standard LR system. It is still as solid as when I bought the vehicle at 90 000 klm ( now 156 000 klm ). The joint still works well without any 'free' movement. I do however have an advantage of you guys in Europe in that I don't have a rust problem ie: no metal loss within the joint.
The joint is standard but I have modified the Hook from being a great Plough to being a more sensible tow hitch ..........by cutting the hitch on the vertical down section and welding a 16mm horizontal plate which carries a bolted ball. The welding was carried out professionally with the LR leg going through the plate with weld above and below the plate............think this would probably not be legal over there but I think it is OK here??? It has however, been very capable with the worst possible towing conditions and I have been very happy with the LR joint---It did withstand a total trailer chassis collapse in Northern Cape but I hope for many more trouble-free tow hitch Klm.Life always good with a Landy
2006 LR DISCO 3 4.4 V8 HSE
DISCO 1 2.8 TDi
DISCO11 TD5
RR CLASSIC 1980 3.5 V8
29th Jun 2015 2:29 pm
SADISCOBOB
Member Since: 08 Oct 2010
Location: Alberton
Posts: 246
tow ball
Meant to add : I would be a little concerned with adding grease nipples to the assembly of the joint as the thread tops/bottoms of the 'female' thread are perfect stress raisers and I do believe that this joint design is a fairly high stress area. The mod I did is in a more easily checked area for cracks and I do crack-detect occasionally. The 'body' of the joint is very difficult to check for this though and I would certainly be cautious of a joint that was loose.....forces inside the joint only increase when there is a loose joint.Life always good with a Landy
2006 LR DISCO 3 4.4 V8 HSE
DISCO 1 2.8 TDi
DISCO11 TD5
RR CLASSIC 1980 3.5 V8
29th Jun 2015 2:41 pm
Gareth Site Moderator
Member Since: 07 Dec 2004
Location: Bramhall
Posts: 26770
As far as I know, the later removable tow brackets have a ratchet arrangement on the back of the handle that prevents you turning it anti clockwise unless you pull the handle out to release the ratchet.
I have an early tow bracket, which does not have this ratchet, and like yours, it is loose after towing, and I can also make it loose by turning the handle against its lock.
I believe that the taper on the locking pawl that fits into the forward face of the rear crossmember gets pushed back by the angle it sits against the crossmember.
If you fit your tow bracket, then crawl under the back end of the car, you should see the back of the hole where the locking pawl fits in. Try and push it back with a stout screwdriver. Mine moves a certain amount, and the handle turns a little. I think the newer tow bars ratchet stops this happening.
Mine is going into dealer soon for investigation, although I am not expecting a free fix, as my tow bracket is the same one that came with my 1st D3 in 2004. I just want to be told that its either safe, or not.
You cannot post new topics in this forum You cannot reply to topics in this forum You cannot edit your posts in this forum You cannot delete your posts in this forum You cannot vote in polls in this forum
