GT KARGOMAX and alignments

ozysteve · Member

GT KARGOMAX and alignments

JohnR · Senior Member

Welcome to the Forum Ozysteve.

I can only give you information from our experience with a 23' Jayco Outback Sterling roughly 3 ton.

Purchased new in 2013 with original tyres changed after 60k due to normal wear, a nail and small amount of scrubbing on the inside.

At the suggestion of a tyre place in Dubbo NSW we changed to GT Radial Adventuro AT3's being 245/75 R16. Slightly larger /higher riding tyre.

We have 65k on these tyres with little to no wear and expect to get 80/100k looking at the current level of wear.

Run 45psi and rotate them annually with a service.

Gotta Love your Jayco.

JohnR

-- Edited by JohnR on Saturday 13th of July 2019 12:13:02 PM

Greg 1 · Guru

The toe out is certainly a concern and I would be a bit concerned on anything greater that 1 to 1.5 toe in. Did he check camber as well? If you have a fair bit of negative camber the inside edges will wear badly. This is a common issue with caravan axles it would seem. When they are made, thete appears to be no real effort made to ensure they are perfectly straight and misalignment is the end result.

erad · Guru

My hobbyhorse... 3 mm toe-out is totally wrong. My 16.5 ft Jayco poptop van has a single axle, but it had 10 mm toe-out when measuring across both tyres. I took the axle back to the Jayco factory and they blamed ALKO - the axle manufacturer for the mistake. OK - I guess that ALKO did stuff up when making the axle, but Jayco certainly did not put a tape measure over the axle before they fitted it to the van. Jayco also fitted the axle 20 mm offset to one side, but that was another matter.... So much for Jayco quality control, but from what I have read and seen, other manufacturers are not much better.

Short story made long - I wore out 2 tyres (mainly the left one) in 18000 km. Jayco and ALKO supposedly fixed the alignment, but I wore out another set in about 40000 km. Alltold, I have worn out 3 sets of tyres on the van. Finally, I contacted ALKO and asked them what the alignment should be. For a start, it should NOT be toe-out. The ALKO manager I spoke to told me that they need some toe-in for stability in towing. Personally, I don't believe that, and the toe-in comes from the manufacturing process. They put a circular stub axle onto a square billet of steel axle. The gap between the 2 shapes is filled by weld. Presumably they run a tack weld along one side, then put a heavy weld on the other. As the heavy weld cools, it shrinks and thus the alignment of the axle is moved. They then put a heavy weld down the first side and the cooling should hopefully pull the axle back into alignment, but it can never come back to zero. Thus, you have some toe-in.

My first caravan was a Viscount camper, and it had 11 mm toe-out. So with another 5 or so more caravans, I should hopefully get one with an axle which is OK to use.... The tyres on that van lasted 11000 km and they were totally stuffed. It took 15 years and about 80000 km, but I finally got the tyres sorted on that van and then we traded it in on the Jayco, only to start all over again.

The ALKO manager, to his credit, after about 8 years and I think about 115000 km, said that they would replace the axle on my van. I had to remove and replace it myself of course, and that was not easy, especially as I have a severe respiratory condition. The old axle at that stage had 8 mm toe-in. and the tyres were wearing on the outer edges. The new axle arrived (ALKO paid freight both ways) and naturally I checked the toe-in. It had 5 mm, measured at the tyre tread. I had to align the axle to the van, and weld the locating spring plates onto the axle. I was suspicious, but thusfar, the van has done another 40000 km or so, and the left tyre is just starting to wear. It is wearing evenly, but my tyre pressure monitors show that the pressure on that side increases more than the other side, so alignment may or may not be the problem - it could be slight drag caused by wheel bearings or the brake. Certainly the tyre wear is a lot less that it was before. So maybe 5 mm toe-in (total difference between the two tyres) is OK? I would prefer a lot less toe-in, and am considering removing the axle again and getting it bent in the middle to bring the toe-in back closer to zero.

Incidentally, it should not matter a stuff what tyres you have on the van. Yes, better tyres will last longer, but they will wear out with the toe-out as you currently have. I noted that as the tyres wore down, the fuel consumption increased. I put this down to the fact that with new tyres, the tread can shuffle around, absorbing the misalignment, but as the tread wears down, there is less ability to absorb the misalignment, and thus the whole tyre scrubs, causing extra drag and hence fuel consumption.

-- Edited by erad on Saturday 13th of July 2019 12:27:11 PM

-- Edited by erad on Saturday 13th of July 2019 12:31:39 PM

Old Col · Veteran Member

ozysteve wrote:
his was my reading after he checked wheel alignmentt front pass = 3mm toe out, rear pass 2mm toe in, front drivers 4mm toe in, rear drivers 1,5mm toe in

front pass= 3mm out, front drivers= 4mm toe in, to me sounds like the axle has moved

ozysteve · Member

Thanks for every reply, , awesome support.

I would like to reiterate, , the ONLY tyre im having an issue with is the passenger side rear,! it being tow in 2mm.

All the other three tyres are running fine and NOT wearing anything like the rear passenger.....regardless of their toe in or toe out measurement.

This is whats confusing me? i wonder why

Jaahn · Guru

Hi ozysteve smile

I will tell you why it is only that tire that seems to have the problem. The figures you gave us are terrible and a combination of toe-in and to-out on all four wheels. So what happens when you are driving, the van moves to some angle relative to the car, that causes the least resistance from all the stressed tires. So the other three tires are all stressed the least and the fourth one the most stressed. So the most stressed one wears out fast and the other 3 are wearing out less fast but much more than they should. confuse

"This was my reading after he checked wheel alignmentt front pass = 3mm toe out, rear pass 2mm toe in, front drivers 4mm toe in, rear drivers 1,5mm toe in"

I am not sure how the tech guy checked the alignment, relative to the centerline of the van or not, but the figures quoted are not in any way acceptable for any vehicle. 7mm out over the front two and 3.5mm in over the rear two. And him blaming crap tires is bumkum. As others have said they have got good long wear out of their tires. Take it to a truck alignment place and get the axles adjusted(bent) to a low setting of toe-in on all four wheels. They regularly do this on trucks and trailers to keep their expensive tires in good shape and prevent the expense of tires from being ruined early. In fact a good truckie will stop and check for flats regularly and run his eye over the tires to pickup irregular wear before the tread is gone. disbelief

You might be surprised at the improved fuel economy and also the stability improvement as well as the long tire wear. wink So the alignment might pay for itself anyway.

Jaahn

-- Edited by Jaahn on Saturday 13th of July 2019 04:14:16 PM

ozysteve · Member

Thank you again.....

The thing is this alignment place was and is recommended by the Jayco dealer here in Perth. They are able to do the alignments.....but sent me on my way telling me to change the tyre and I should be good to go........

Im feeling more and more like I did my money!!!

I have called Jayco here, as I bought the van new from them back in 16.......I know its out of warranty, but this has been an ongoing issue form day one!!!!

Jaahn · Guru

Hi ozysteve smile

Yes you have been given a bum steer both by Jayco and the alignment techo. Go somewhere else, there must be some good places there for trucks. Who has a recommendation, that comes from over there??? Huh ! aww

Any vehicle wheels should be set to close to zero toe-in. But for a trailer any toe-out is NOT recommended as it gives stability problems. So the usual recommendation is a minimal amount of toe-in on all wheels. Measured over the two wheels 1-1.5mm is OK. But that must be equal on both wheels and both axles relative to the centerline of the van. Not set so one axle pair points one way and the second one the other. Nor is it acceptable for a pair of wheels to be pointed one way to the centerline with correct toe-in which will mean it will crab. Really this is basic stuff that people seem to have forgotten with their fancy electronic wheel alignment machines, that from my experience the operator cannot operate correctly.

With my vehicles in past years I have fitted new tires plus an alignment on a fancy machine. Soon, after a while observed feathering and poor tire wear. So I have done my own alignments on a flat floor with a tape and string etc and basic measurements including also aligning the independent rear wheels to the center line of the vehicle. The tires then have minimal wear and the handling is better and the fuel too. hmm If you want something done well do it yourself. Done it several times. Probably too old now to get down on my knees and do it again.

Jaahn

Greg 1 · Guru

Jaahn is correct. Ideally you should have some slight toe in but equally on all 4 wheels. Toe in will give better stability, toe out will make the van tend to dart about and be inherently unstable. The axles should be bent back to ensure they are aligned correctly. The bloke that did the alignment for you and gave you the advice he did needs to find some other employment cause he's not much chop where he is.

Moonraker · Senior Member

I think others here are correct. If like my van both wheels on front axle should be at most 2 to 3 mm toe-in and rear axle wheel parallel/straight or very slightly toe-in 0.5mm. And chamber 0 or very slightly neg. in at top. A good truck trailer wheel aligner should be able to sort it out and check both axles are running square to the chassis. Might be a good idea to phone the factory in Melbourne to see what they say. Should still be in warranty if "not fit for service" and you have tried unsuccessfully to get it sorted through the dealer during that time. Good luck!

-- Edited by Moonraker on Sunday 14th of July 2019 02:05:28 AM

-- Edited by Moonraker on Sunday 14th of July 2019 02:06:24 AM

erad · Guru

ozysteve wrote:
Thank you again.....

The thing is this alignment place was and is recommended by the Jayco dealer here in Perth. They are able to do the alignments.....but sent me on my way telling me to change the tyre and I should be good to go........

Im feeling more and more like I did my money!!!

I have called Jayco here, as I bought the van new from them back in 16.......I know its out of warranty, but this has been an ongoing issue form day one!!!!

Sorry, but the Jayco dealer you are dealing with is talking out of his fundamental orifice. With a solid axle, there is no alignment adjustment, other than bending the axle. As for telling you that you are OK to go, Sure George - you can go and keep on scrubbing the tyres out. Just get anywhere away from me and leave me alone. Go to a proper wheel alignment place (Preferably a truck specialist) and get the alignment checked and reset by someone who knows what they are talking about.

Sadly, yours (and mine) case are not the only ones. I walk around caravan parks, looking at tyres. Probably only 1 in 20 have problems (we are special people), but the ones I have found - the owners had absolutely no idea that their tyres were worn threadbare on the inside. Probably a lot more have had a blowout and destroyed the tyres and could not / did not look at how the tread had worn. Quality control in caravan manufacture is a joke. I have had this problem now since 1987, and when I buy my third caravan (probably never now), before I even hook up to drive out, I will put a tape measure across the tyres to check the toe-in, and if it is not correct, no payment until it is. Even in vans with independent suspension, the quality control is so good that people are wearing tyres from new. I guess that most caravans do not travel far enough within their warranty period to discover these problems. I certainly have used mine - about 150000 km on this Jayco now (since year 2000) - including the bent chassis where Jayco fitted the axle 20 mm offset and the U bolts hit and bent the chassis. I keep an eye on it, but thusfar it is OK.

-- Edited by erad on Sunday 14th of July 2019 09:44:13 AM

-- Edited by erad on Sunday 14th of July 2019 09:46:44 AM

-- Edited by erad on Sunday 14th of July 2019 09:48:28 AM

patrol03 · Senior Member

I am sure I have written this somewhere before but I will do it again. Trailer axles should not have toe-in or toe-out. In particular solid axles Toe-in is used only on STEER axles so that tyres do not scrub when turning a corner. A trailer axle can be bent in a press to give positive camber if needed. Most of us have seen the odd 6X4 old trailer emerging from the local nursery loaded with sand and displaying a bucket load of negative as the wheels splay out at the bottom. This will also happen on a caravan which is often over weighted on one particular side. Problem could be built in, overloaded or both, particularly if on the near side.

Other places to look for problems are U bolts and their tension. If you have a loose one then the centre bold, dimple or locating tag where the spring pad meets the axle may be worn/rusted and allow movement in the location hole thus causing tyre scrub

Unnoticable wear in the shackle pins may also be present. This is often due to the pins not receiving grease on a regular basis as the exit hole in the middle of the pin clogs up with a mixture of fine metal mixed with mud rust and grease. Where the grease gun will not look at the job, the pin is easily removed, holes cleaned out and a bigger flat filed on the pin to allow a pathway for the grease.

Badly adjusted wheel bearings could also contribute to adverse wear.

I hope this helps. Ian

Jaahn · Guru

Hi Patrol 03 smile

While you mention some important side problems, loose shackle bolts and worn pins, your statement "Trailer axles should not have toe-in or toe-out. In particular solid axles Toe-in is used only on STEER axles so that tyres do not scrub when turning a corner" is not correct IMHO.

That soild trailer axles should not have toe-in or toe-out is correct in theory but as people have discovered they actually can and do due to poor quality machining. There lies one serious problem. And to correct a badly machined axle it can be bent insitu by truck alignment specialists with some heavy duty gear they have for truck use.

Toe-in is used on front vehicle axles AND rear independent suspension axles on any type of vehicle. Adjustment is provided for the purpose of getting the toe correct on the rear of independent suspensions. But it is important to get the wheels adjusted to the "thrust line" or the centerline of the vehicle or it will "crab" sideways a bit.

The front toe-in/out has nothing to do with the scrubbing going around corners. It has to do with the suspension deflecting under running conditions and compensating for that, so the wheels run near parallel in normal running. It is clearly stated in any text book or decent internet site on the subject.

In my experience the toe-in/out has the largest effect on tire wear of any alignment problem, excessive toe-out causes inside edge wear, excessive toe-in causes outside edge wear. Excessive camber might make these effects worse or more worser depending how they combine. BUT with solid trailer axles just the toe is needed to be set to a good figure if the camber just looks OK.

If the solid axle is being bent to achieve good alignment then it should be set to a slight toe-in for maximum stability under all conditions while they are doing it. Proven to be the best setting, but too much will increase wear noticeably.( but increases stability)

If you have independent trailer axles then IMHO you have introduced another area to cause problems and require adjustments that may not be available and perhaps pivot wear problems. But that is not being discussed here.

Cheers Jaahn

-- Edited by Jaahn on Sunday 14th of July 2019 06:04:19 PM

patrol03 · Senior Member

Thank you John for your detailed reply, however toe in is put on steer wheels in order to have toe out on turns.This reduces the scrubbing as the front wheels on turn travel in different arcs. You may check this with your own vehicle when static with the steering on full lock..quite an amount of toe out. Maybe my explanation and assistance to others was too simplified, but it was in good faith.I do agree with you that excess of toe in/out causes scrub and excessive camber can exacerbate the problem. Cheers Ian

Jaahn · Guru

Hi smile

Time to put this to bed. I and other contributers have answered the original poster and provided information to help(I believe !), and be also available for other GNs who have similar problems and have been brushed off or told lies by so called professionals. furious

To continue a discussion will risk going to the same way as the battery discussions end !

Cheers jaahn

some information on general vehicle alignment. Go to the toe section and read the last paragraph; https://www.tirerack.com/tires/tiretech/techpage.jsp?techid=4

Ian you might like to look at this description on the steer wheels motion using the very old Ackerman principle ; https://en.wikipedia.org/wiki/Ackermann_steering_geometry

Greg 1 · Guru

I am sorry patrol03 but toe in is not just used on steer wheels but is used on other axles as well particularly in independent rear ends, but also on live axle cars. My race car runs 0.5 degree toe in on a live rear axle to improve high speed stability. Your description of why toe in is used on the steer wheels is also not correct. Most rear wheel drive vehicles use some toe in to compensate for flexion in the suspension bushes which tend toward a toe out condition at pace. Some level of static toe in means that the wheels do not move into dynamic toe out which is an unstable condition making the steering very darty. Some race cars employ some toe out to make turn in sharp and responsive but loose high speed stability as a result. If a caravan has slight toe in, it does help with stability, but the amount should be small 0.5 degrees or so. I would not be looking for any negative camber on a van but if the OP van is chewing out an inside edge of a tyre it could well be the axle is bent to give negative camber which will also cause the inside to wear as in excessive toe.

erad · Guru

There has been a lot of discussion here about alignment. We all blame the manufacturer (generally rightly so). It is possible (even highly likely) in this case that the left front wheel of the van has hit a large pothole and bent the axle back, thereby causing toe-out on that wheel. Whatever, the dealer is way off in recommending new tyres of better quality - the better tyres will scrub just as well as the cheapies. The axle needs attention. Whether is is zero toe-in or some small amount, th axle is not right and needs to be corrected.

ozysteve · Member

Ok. Thank you all. I will be making some calls today. However I would like to add I have never hit any pot holes . I bought the van brand new and I am very careful when driving to miss kerbs. This is without question a manufacturing issue, however being out of warranty will be my hurdle. My argument will be it's not "fit for purpose " and hasn't been since day one , that and being guided to the alignment caravan repair shop by jayco I'm not happy.

ozysteve · Member

OK.......i made a call to the guys that were apparently supposed to do the alignment....rattling some cages there. Let see how that goes

However, during my conversation he brought up the potential of a TRIANGULATION issue......this is the first time that was discussed with me. I understand what it is, but do WE think it could be the problem with just the one tyre scrubbing?

value your advice and input people

thanks so much

Jaahn · Guru

Hi Steve smile

Triangulation is just a way to establishing the centerline of the trailer and checking/adjusting the axle mountings so they are square to the centerline. First step, why is he telling you now ????? Not competent. IMHO confuse

BUT is does not change anything to explain the reason the one tire seems to be the only problem. Re-read my explanation again. Those toe reading are bad and all over the place. If the axles are out of square the van just tracks at an angle to the tug. You can probably see it in the mirrors. aww

So a proper alignment includes the centerline check as well as the toe for all wheel, to ensure the wheels are correct. Not rocket science. Just common sense hmm

Jaahn

erad · Guru

I cannot see the triangulation issue as being significant in your case. You can easily check the triangulation. Drop a vertical line down from each wheel centre to the ground and mark it (with a piece of chalk). Mark where the towball is (vertically direct under the centre of the coupling). Then move the caravan away from that position. Measure the distance from the towball to the front wheel centres. Ideally you should have it in the centre of the tyres, but the outside edge will give you a guide. Then check the distance between the front and rear wheel centres. For good measure, check the diagonals from the towball to the rear tyres as well. This will give you the triangulation. If the diagonals are not the same, the caravan will crab a little and will not follow the tug's centreline. The van will still travel in a straight line, but it may track a few inches one side or the other from where it should.

None of this really matters, unless the front axle is out of kilter relative to the rear axle. If, for example, you left front axle U bolts are loose and you have broken the center pin which locates the axle on the spring, then you will have conflict between the front and rear tyres, and probably all of them will scrub, but moreso the rear left tyre in your case. If the distance between the front and rear tyres is the same on left and right sides, I think you can forget triangulation as an issue. Whatever, triangulation will not normally affect tyre wear because the van will try to run with its wheels straight, even if the van is running a few inches off centre relative to the tug. If this was the case, you will experience some additional tyre wear because the van will always be slightly turning, but I think you would have noticed this by now.

For what it is worth, I doubt that my pothole theory applies in your case either. It is always possible, but if the damage has been caused by a pothole I would expect the axle to have some camber bent into it as well (the wheel would be leaning in at the top). In my case, the wheels were sitting vertically yet they had toe-out. Since only one wheel has been reported as having toe-out, I would say it is almost certainly a manufacturing problem. And if they say it was an impact problem, you can always come back saying it was not fit for purpose if it bent that easily.

ozysteve · Member

Now they are saying it could be triangulation!!

Jaahn · Guru

ozysteve wrote:
Now they are saying it could be triangulation!!

Hi smile

This is what they are talking about.

https://www.alko.com.au/wp-content/uploads/2014/10/axle_triag_procedure.pdf

But as myself and erad say it is not your answer. Perhaps another way to get more money to do that ? or they do not really know anything useful.

Jaahn

PS if you do that as shown you should really support the van weight by the axles so the springs are sitting in the normal travel position or the arch of the unloaded springs might affect the readings by more than their 4mm allowance. Why did they leave that out ??

-- Edited by Jaahn on Monday 15th of July 2019 03:27:14 PM