Probably a bent axle.

My favourite subject... My Jayco Poptop van is on its 4th set of tyres. They wore out due to misalignment. The problem (if it is a solid axle) lies in the manufacture. They have a square solid bar - damned heavy - they could use a slightly large hollow section bar and get the same strength with a lot less weight. Then they get stub axles (round) and weld them onto one face of the square axle. They must have a jig to position the stubs first, and they lay a weld on one side. As the weld cools, it shrinks, thereby causing a slight misalignment. They should then weld on the other side to correct the misalignment, but I suspect that they complete the weld on one side and then go and do the other side. Whatever, they must hope that the shrinkage of the weld on the other side will counter the initial shrinkage. It doesn't, and you are left with some toe-in. In my case with the first axle, it was 9 mm toe-in. Naturally, the tyres wore unevenly.

I would have noticed this if Jayco had assembled the axle to the van correctly, but they put the axle in back to front so that it had 9 mm toe-out. This meant that the tyres wore on the inside edge and I didn't notice it until they had done 18000 km and the steel belt was showing on the inner side of the tread. To top off this quality control blunder, Jayco also set the axle nearly 20 mm offset so that the U bolt hit the chassis rail and put a dent in it. The repair method proposed by Jayco was useless (they wanted to weld a plate on the side of the chassis member, not the lower edge (the dented face) so I left it as was and to this day it doesn't seem to have bent the chassis any further. NAturally, the axle has been centered properly now.

I fought with Jayco and they shoved the problem on to Al-Ko, who manufactured the axle. To make a short story long, I kept fighting both until eventually (after wearing out 3 sets of tyres) Al-Ko asked me to measure up my axle and they supplied me with a brand new axle (for free including freight) and I had to fit it myself. Interestingly, the new axle had 5 mm toe-in, but up to now the tyres seem to be wearing evenly so I guess that this must be an acceptable level of toe-in. I asked why they had any toe-in and they replied that some toe-in is required to ensure stability when towing. I suspect that it is more a manufacturing issue, but they should know their product. I also had a wheel hub crack and when I asked Al-Ko where I could get a new one (it was about 4 years old at the time), they asked me to return the cracked hub and its mate to them (freight free) and they gave me 2 new hubs because they reckoned that the brake drum diameters may have been different. Naturally, I do not hold back about the level of Al-Ko's service and backup, especially when compared to that of Jayco, which was abysmal on this point and a few others I had issues with. Al-Ko certainly backed me all the way - full credit to them.

Now, addressing the original poster's problem, by rotating the axle for increased ground clearance, you will change what should be ..mm toe-in to ..mm toe-out and will wear your tyres. What the actual value of toein is is anyone's guess, but 5 mm seems to work for me. I would prefer a lot less - maybe only 1 mm toe-in at the center of the tread. Further to this, as has been suggested, you may have hit a large pothole somewhere and this could have deflected the wheel backwards, thus bending the axle and thus causing you to have toe-out. You can get the axle bent in a press to bring the wheels back to a toe-in situation. And if you rotate the axle to give you extra height, I would also rotate Left to Right (you have to take the brake levers off and swap them so they still work) and you will have the correct toe-IN and the brakes working.

Sorry for the long reply, but as you can probably guess, Jayco are not the most popular supplier of products for me. I wqander around caravan parks and look at tyres. I have found quite a few vans with tyres worn on the inner edge and when I tell the owners, they feel much the same.

-- Edited by erad on Wednesday 22nd of June 2016 07:27:29 PM

Warren-Pat_01: It is easy to check once the axle has been removed from the van. I set it up on my front lawn on two workmates, and measured the width from tyre shoulder to the other tyre shoulder, front and back. I rotated the wheels to check that they were not bent or warped - they ran true. Difference front to rear is the toe-in. The original axle was straight - no bends and the stub axles were still as welded, so it wasn't a case of hitting a large bump for my case. It has hit quite a few bumps since then but the wheels still run true and the tyres still wear evenly. I took photos of the axle set up on the front lawn and sent them to Jayco for comment. They conveniently ignored my letters, faxes and phonecalls for quite a while until I loaded the axle into my trailer and took it to their factory/showroom. Their after-sales service was abysmal. This was 15 years ago, but from what I read, nothing has changed. And it is not only Jayco who are like this - they all seem to be slack with their quality control.

As stated above, Al-Ko asked me to measure up the axle and they then sent me a new one, asking me to send the old one back to them (freight both ways paid by them). I removed the axle (not easy, especially when you are arthritic and asthmatic) and measured it up. The new axle arrived and I checked that it was the same dimensions. I then fitted the new axle to the van. I had to weld the centre bolt locating plates after I had carefully measured the diagonals from the towball to the centre of the wheelk hubs. That was a bit harder to do. Once set up, it was easy to weld the locating plates to the axle.

My bitch was that Jayco didn't do it in the first place. OK - I guess that Al-Ko had set the axle up wrongly in that the brakes were mounted back to front, and Jayco experts simply located the axle somewhere and welded the locating plates in place. Had someone actually checked the toe-in, they would have noted something funny. Even so Jayco still managed to mount the axle 20 mm offset - now that takes skill.

Actually, I initially removed the original axle and fitted it the other way round (not flipped) because I needed the van at a certain location for work purposes. With 9 mm toe-in instead of 9 mm toe-out, the van certainly ran a lot better - it used a lot less fuel and it seemed to handle better. So maybe some toe-in is needed, but not that much. Personally, I cannot see that any toe-in is needed for a vehicle which is dragged along a road and not steered.

My van is nearly 17 years old now, and it only took 12 years to get it right. But as said, I think it is OK now. We have just completed a 12500 km trip and the tyres are still wearing OK. All up, the nex axle (and tyres) have now done just over 30000 km and they still look quite good. Probably now is the time when I should sell the van and start over with a new one to sort out....

Thank you All so much for your Information.
It is greatly excepted...I will be starting the check list and get back with verdict..
Happy traveling to you all...I need to get this sorted before of to Q/Land again...

After reading Karen's post, [belatedly], I gave the crystal ball a rub and it told me two things: [1] Karen's van is fitted with the German BPW Swing 'V' tec rubber torsion axle. [2] It most likely is not fitted with shock absorbers. Designed for use on totally different roads [and distances] , these axles are not suited for use on the long straight, often undulating, roads of Australia. I recently travelled in company with a new Elddis van fitted with this suspension and after a trip of some 6,000kms. the outside tread on the nearside tyre was totally depleted. By design, this suspension varies toe in as it oscillates supposedly to improve handling and stability on the tight, twisting roads commonly encountered throughout Europe. Despite reports of tyre wear problems dating back several years, [and the replacement of axles without improvement] neither Elddis or BPW admitt to a problem with this suspension. Without the support of the manufacturer, the Australian importing distributor is unable to offer a solution; although it is rumoured that future Elddis vans for export to Australia will be fitted with a different [ALKO?] axle. Whilst this does little to help with Karen's problem, it may help prevent her seeking a fix whilst no simple fix is available. Others should also be vigilante when considering the purchase of any van fitted with this suspension. Don't fall for the "wrong tyre pressure" or "you have hit a kerb and bent an axle" stories because fitting a new axle of the same type will achieve nothing other than to postpone your complaint for another 6,000kms.[and then be hit with "it's out of warranty"] Quite clearly vans fitted with this suspension are not suited for the purpose [touring the vast distances of Australia] for which they are being sold. Imagine buying your lovely new van, and setting off on the big lap, only to find that you need to replace 4, 5 or more tyres on the way around. Hardly fit for purpose! Australian consumer law is quite specific in that any product sold within Australia must be fit for the purpose for which it is sold. I would be most interested to hear from other Elddis van owners experiencing similar problems.