Wheel coming off - advice please

[Dustydog]

As the Prof has pointed out losing wheels is not unusual. I had an incident seven years ago with the car. A very strange shimmery vibration as the wheel studs failed. We were lucky. Caught it before disaster . New wheel needed.
My local non franchised garage double check the wheel fastening torques with two engineers using diffent torque wrenches.
My mobile engineer checks the torques on the caravan twice in front of me but says verbally and in writing I must check them myself at 10 miles use.
Ok. Here’s the issue. Where I worked this was called the CYA policy. (Cover your a..e)
IMO the OP with the evidence on both axles from an independent engineer should not hesitate to challenge the dealer.
That said us old lags know full well we all carry a torque wrench and check both car and caravan before departure

 

[camel]

A caravan maker doe's not make the chassis, what do Swift an Co know about caravan chassis apart from putting their sheds on to the top of them,, from the info already out there and in my case it is 115Nm or taking the advice by the Mod it is now 120Nm/130Nm, now last year I went up Scotland down to North Somerset and in to North Wales and the wheels are still on, I'll stick at 115Nm,

 

[otherclive]

A caravan maker doe's not make the chassis, what do Swift an Co know about caravan chassis apart from putting their sheds on to the top of them,, from the info already out there and in my case it is 115Nm or taking the advice by the Mod it is now 120Nm/130Nm, now last year I went up Scotland down to North Somerset and in to North Wales and the wheels are still on, I'll stick at 115Nm,

So what you are saying is that Volvo and VAG who use Borg Warner auto boxes don't know anything about them. So if have a problem with the gearbox do I approach Volvo, VAG or Borg Warner? The answer is self evident, it has to be the designer and manufacturer of the total system who has responsibility for its configuration and specification. Of course the caravan makers will work closely with chassis makers such as Alko and BPW, and the chassis makers will advise the caravan makers of aspects of the specification that affect performance, maintenance and safety.

Do you actually know what the current wheel torque is for your caravan as specified by the maker? Mine changed sometime between 2012 and 2017 and Swift issued an amendment notice. I guess they didn't do that solely to pass the time of day.

 

[camel]

Do I know the current wheel torque setting for my caravan, No, and the wheels have not come off yet, that's why I'm posting on this subject and now I'm told it is 130Nm, not a problem,

 

[Dustydog]

Do I know the current wheel torque setting for my caravan, No, and the wheels have not come off yet, that's why I'm posting on this subject and now I'm told it is 130Nm, not a problem,

Let’s not jest here. All the caravan manufacturers have some very clever engineers on their payroll. They know using physics and mathematics the correct torque for their wheels and nuts/ bolts. Nothing to do with Al-ko.
I know the old lags carry torque wrenches on their travels. Ask yourself why
Better safe than sorry. It’s not just a number plucked from the sky :kiss:

 

[ProfJohnL]

I don't know for certain, but its more likely the chassis manufacturer sets the torque for the nuts, after all the chassis will have a maximum load, and the wheels will be matched to the hubs. I have never seen a vehicle specification that sets different wheel nut torques for different loads , so its probably a one rate for all. That does not imply its safe to reduce the torque from the makers recommendations.

 

[camel]

Dusty,
I do not jest when it comes to vehicle safety, if I have said something funny I do apolgise, :lol:

 

[Dustydog]

I don't know for certain, but its more likely the chassis manufacturer sets the torque for the nuts, after all the chassis will have a maximum load, and the wheels will be matched to the hubs. I have never seen a vehicle specification that sets different wheel nut torques for different loads , so its probably a one rate for all. That does not imply its safe to reduce the torque from the makers recommendations.

Prof I have to agree with you and indeed that’s my view , well it was . You will,recall the Bailey Pegasus and Unicorn issues. The wheel bolts were redesigned by Bailey because of wheels coming off. I guess we will never know which company picked up the bill

 

[Dustydog]

Dusty,
I do not jest when it comes to vehicle safety, if I have said something funny I do apolgise, :lol:

No issues

 

[Grahamh]

Some years ago I was looking after the cars of a QC. He rang me one day to say that his wife and children had been to town for the day and, on the way back, the front nearside wheel detached on leaving the A303. Fortunately (as the speed was low), no one was hurt and no other vehicle involved. As they were recovering the car it was noted that all 3 remaining wheels had the nuts finger tight. He asked me what had I done to the car. I replied that, as per usual I had checked all fluids, tyre pressures and fuelled the car. I also told him that the car had been for it's annual service at the main dealers just 2 or 3 days before, whereupon he hung up. The two mechanics at the dealers responsible were sacked and his wife had a brand new E Class! I ALWAYS check the nuts/studs now whenever the wheels are removed.

 

[camel]

Well said Prof, that's what I said three posts ago,

 

[camel]

Looking back through my paper work from previous caravans from eight years ago I came across one for having two tyres fitted to my caravan at a tyre company than stocked tyres for horse boxes etc, and the fitter then torqued up the wheels to 130Nm,

 

[Lutz]

I don't know for certain, but its more likely the chassis manufacturer sets the torque for the nuts, after all the chassis will have a maximum load, and the wheels will be matched to the hubs. I have never seen a vehicle specification that sets different wheel nut torques for different loads , so its probably a one rate for all. That does not imply its safe to reduce the torque from the makers recommendations.

You are right, but the chassis manufacturer will only specify torques in conjunction with wheels supplied by him too. However, many caravan manufacturers source their own wheels, often alloy ones, and the chassis manufacturer cannot be expected to accept liability for them.

 

[Petemate]

Very interesting thread. I check the torque settings on the caravan wheels every trip, both outward and homeward bound. On the car, I tend to check the bolts about once per month, and after a few miles following any removal/refitting of the wheels either by myself (serviceing) or a tyre dealer. Regarding the caravan, I service it myself but every couple of years I pay for a chassis service as (at the moment) I do not have a torque wrench big enough. After the chassis checks, I do check the bolts after a few miles (about 10-15 depending on which direction we are going and availability of an appropriate lay-by) As yet, on all the cars and caravans I have owned and the one folding camper (Pathfinder) I have NEVER found any of the bolts move when I have checked them. Perhaps I have been lucky. I do remember reading some while ago about the increase in the torque settings and after the last chassis service the year before last was when I started using the higher figure. Even then, the bolts didn't move so I assume the fitter used that higher figure.

 

[Buckman]

If you have been unfortunate enough to have a blowout or punctrue on a caravan wheel have you ever seen the Mayday or Arrival mechanic use a torque wrench? Even if using Red Pennant this not oes not happen even though the practice is probably recommended by both clubs?

 

[Poggys]

I can understand your disappointment but what advice does your owners handbook give for checking wheel nut torque after replacing wheels. Mine says 9 miles and you did 55+ miles. Proving that they did not torque up the nuts could be virtually impossible given both the distance driven and the time since it was serviced. Proving over torque stretched the bolts would be feasible but but complex. Was it a NCC approved service Center?

 

[Poggys]

There is a major difference between a car and a caravan in the wheel and brake area.
I purchased a caravan second hand a Coachman Amara on its first journey I lost a near side wheel. After retrieving it and getting professional help it happened again after 4 miles. I am a qualified engineer NOT A MECHANIC AN ENGINEER the caravan was recovered to a trailer company and when we inspected it the problem was found to be that the bolts had been over tightened and they were probably put on with a powered nut runner. The problem is that most caravan brake hubs are made with alloy not steel and the threads are far weaker than steel normally found on cars this is a big DIFFERENCE as if over tightened the threads are weakened beyond there tensile strength and therefore when they are tightened again any impact on the wheel can cause the thread to fail.
There are only two solutions one is to replace the hub and bolts or to have the holes drilled out and replaced with studs and nuts a much better solution for an alloy brake drum.
Always tighten the bolts to the correct torque never add any more torque and do not fit wheels with any other powered device.

 

[otherclive]

There is a major difference between a car and a caravan in the wheel and brake area.
I purchased a caravan second hand a Coachman Amara on its first journey I lost a near side wheel. After retrieving it and getting professional help it happened again after 4 miles. I am a qualified engineer NOT A MECHANIC AN ENGINEER the caravan was recovered to a trailer company and when we inspected it the problem was found to be that the bolts had been over tightened and they were probably put on with a powered nut runner. The problem is that most caravan brake hubs are made with alloy not steel and the threads are far weaker than steel normally found on cars this is a big DIFFERENCE as if over tightened the threads are weakened beyond there tensile strength and therefore when they are tightened again any impact on the wheel can cause the thread to fail.
There are only two solutions one is to replace the hub and bolts or to have the holes drilled out and replaced with studs and nuts a much better solution for an alloy brake drum.
Always tighten the bolts to the correct torque never add any more torque and do not fit wheels with any other powered device.

This thread is over four years old and I don’t think that the OP closed the loop.

 

[Sam Vimes]

Thread locked