ALKO A Frame and Damper Mount Problem (would appreciate more input)

[DixieDean]

Hi everyone

I have a 2009 Coachman VIP 545/4 which I tow with my Land Rover Discovery 3. It gets a lot of use and goes annually and sometime bi-annually on a European trip taking in such places as the Netherlands, Germany, Austria, Switzerland and Italy.

I have had no issues with the caravan but a few with the chassis.

About 5 years ago I had to have the front horizontal damper securing bolt (there are 2 fixing the damper cylinder to the V shaped damper frame) replaced as it had broken. It had to be replaced again 18 months ago, and again at the last service. My service engineer told me to cut the weight down as much as possible in the front locker, which I did by putting as much as I could apart from 2 calor lite 6KG bottles in the rear of my Disco when travelling.

I recently had an issue with the Trailer Control led light failing and replaced it myself. However I notice that again the bolt had bent and split in the middle. My service engineer has been and replaced it. I examined the old bolt and it appears to have rubbed against something as there are signs of the thread being worn away over about 1/2 inch.

I also note that of the 2 folded pieces of metal welded onto the front of the A frame members (they are each a vertical folded piece of metal welded front and back onto the inside of the end of the A frame (beneath the V shaped damper holding unit)) 1 has come completely unwelded and the other has come unwelded at the front.

Finally, I note that the V shaped damper unit has a small hairline crack across the metal immediately in front of each of the front bolt holes.

My service engineer said that it might be a good idea to get these cracks and the two brackets welded as a further precaution.

I would be very interested if any chassis experts could say what is going on please. It is, to say the least, very alarming.

I've attached 2 photos, one showing one of the small hairline cracks, and the second showing one of the two brackets I am referring to which were welding into the ends of the A frame on manufacture. It is the bracket seen through the gap between the 2 pieces of metal circled in red. The one in the photo has come adrift at the front but is still attached at the rear.

I feel it is worth mentioning a problem I had with this van from new in that every time I slowed down fast it would give my towcar a massive thump up the rear. About 15 months ago when the van was service by a mobile engineer, he did something to the brakes which meant this didn't happen again, and indeed, I thought it was probably causing the broken damper retaining bolts, but apparently not! I also had to have a new rear cross member on my Land Rover when they were recalled about 6 years ago due to excessive play in the removeable tow bar slot. It was replaced with a fixed tow bar.

 

[Jcloughie]

First, well spotted. These are a concern and there are many who would not notice.

One possibility. ’Real’. 4x4’s can cause road shocks through to the caravan. Shocks that softer suspensions would absorb. Perhaps overtime and a long distance, this might just be the cause of your issues.

I have heard of shock proof hitches for the vehicle, I think they are American, and I don’t know if they are legal over here.

John

 

[Jcloughie]

Are there problems welding to galvanised surfaces? And once welded, what would be the best anti rust treatment?

John

 

[DixieDean]

Hi John, thanks for your interest. Yes, of course my Disco has air suspension which gives a great ride, but my service engineer also suggested it may cause issues for the same reasons you stated. I'm hoping this thought may be developed by those more in the know.

It is possible to weld it, and I know of someone who can do the repairs with a Mig. He says galvanised steel won't be an issue, but thinks it will be for reassurance really, rather than structural.

 

[Damian]

Looking at the photos it appears that the damage is due to excess shocking from being towed and the tow vehicle not having soft enough suspension to absorb as much as it would be preferable to do, and possible overloading of the hitch (but that is speculation).

You could have fitted a Dixon Bate shock link, which is what I would have done as soon as the first problems arose.

Welding is possible if the person knows what precautions to take when dealing with galvanised material, and rust prevention on the welded part can be done with cold galvanising.

Welding if done correctly will return the the metal to "as new" if the weld is fully penetrating the damaged area, however if the vehicle setup is not addressed the same problems will happen again.
There is no such thing as a "cosmetic"weld, it is either correct or not, there is no middle ground!

 

[DixieDean]

You could have fitted a Dixon Bate shock link, which is what I would have done as soon as the first problems arose.

Thanks for that information, Damien, much appreciated. Another industry person has also suggested I replace the damper. Would you concur?

 

[Damian]

The damper either works or not, its just a shock absorber.

You can test it by pushing the hitch head in as far as you can and watch to see if it returns to its resting position smoothly and slowly.

It should take quite a force to move it inwards.

If it pushes in with little effort and either fails to return or has to be pulled out by hand, it needs replacing.

 

[Thingy]

With past experience, I would look beyond the damper and check to see if you have any vertical play in the drawbar. I had one fail on a brand new caravan and had about 12mm of play +/-. If those kind of shocks have cracked the chassis, the drawbar assembly must have had a beating too.

 

[Damian]

I agree with Thingy, and should have mentioned that in my last post.
There should be almost no play in the drawbar tube, and it is quite likely with the damage done to the chassis that it may be a further item to check and deal with .

 

[DixieDean]

The damper either works or not, its just a shock absorber

Thanks Damien. The damper appears to be working correctly. Since the new front damper bolt was fitted the whole towbar/damper assembly is now quite rigid. I can't see any other signs of damage to the metal work and I've checked all the way along to the axle.

I've attached a photo of the bolt concerned. The service engineer didn't have a new locking nut and just put the old one on the new one. Am I thinking right that a brand new one should be fitted? Is it worth fitting 2?

 

[Trevormc]

From the early 1980's I fitted a Dixon Bate shock link to both my last 2 Land rovers ( s 11A and Dicovery ), It is now sitting in my shed doing nothing. If you are interested send me a PM or mail me ask one of the moderators. Will say they are not cheap, but they do the job.

Trevor

 

[RogerL]

Something isn't right here - a Discovery 3 on air springs shouldn't need any device to dampen shock loads, nor should the over-run damper need replacing a regular intervals - once in a caravan's lifetime but not twice.

 

[DixieDean]

Something isn't right here - a Discovery 3 on air springs shouldn't need any device to dampen shock loads, nor should the over-run damper need replacing a regular intervals - once in a caravan's lifetime but not twice.

Hi Roger

Its the front damper retaining bolt that keeps snapping, not the damper itself. I've checked the damper and it's functioning correctly. You can see the bolt in the photo above.