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McMalz
X-TRAIL NEWBIE
Date Registered: 06-2007
TOTAL POSTS: 17
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Re: Chassis problems
Hi John
In our case the ballweight is 150kg with the van loaded (had it weighed twice by Jayco & Hayman Reese), when the Hayman Reese WDH was fitted the measurments taken from wheelarch to ground (vehicle loaded not connected to van) Front 770mm Rear 745mm. Vehicle connected to van (no hitch) Front 785mm Rear 700mm. Vehicle & Van hitch connected Front 760mm Rear 740mm. In order to bring the rear end of the vehicle back to a level position an upward force is applied to the vehicle via the towbar which is variable by means of the chain on the WDH, this setting done by Hayman Reese at time of installation. If all the contact points between towbar and the chassis were as substantial as three of the four were I believe there would not have been a problem. Note~The damage to the lefthand rear part of the chassis rail can only be seen if the bumper is removed.
Our Xtrail carried 2 persons up front & 80kgs of luggage in the rear which was mainly over the folded down rear seat to keep most of the weight as far forward as could be. The van is a 2004 16ft poptop Tare 1178kg Gtm 1358 Atm 1478kg. 120kg towball weight (unladen) with the 300kgs of cargo including the water,gas & WDh the towball weight then increased to 150kgs as the load is spread evenly through the van (you'll just have to take my word on that). I think you would agree John that our rig was not beyond the limits set by both manufacturers, we have travelled 40,000kms with the van attached, with 99.99% on the bitumen although I have to admit that conditions on some roads travelled, ie Hughenden to Winton, one of the worst encountered so far, the fact that this road was traversed by us after the repairs were done to the Xtrail made it seem all the worse.
Well John, Ihope I've answered your question, as there are so many variants as to the weights of vans/towball weights it is hard to say what is required for all.
Cheers
Mal
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18/Jun/2008, 11:00 am
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Hammo9
X-TRAIL NEWBIE
Date Registered: 11-2007
TOTAL POSTS: 10
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Re: Chassis problems
Hi All,
Just thought I'd have a look at my car as I have a Nissan towbar and tow a van with about 150kg ball weight and I have a Hayman Reese WDH.
I removed the rear bumber bar and had a look and found that, whilst I had no cracks, there certainly is evidence that the tube on the left side is starting to push up into the chassis rail. The rail is deformed upwards (inwards?), not much, but certainly in a bit.
My thoughts are that when you use a weight distribution hitch, it is actually lifting the rear of the car and forcing weight back onto the front wheels. It does this by excerting a twisting force onto the tow bar with the centreline of the twist pretty much through the towbar square section. It's a bit hard to explain but, if you stand at the side of the car directly in line with the square section of the towbar and imagine the whole thing twisting, forcing the front of the car down and the rear of the car up, (which is what happens when you put the WDH bars on) you can imagine that the rear bolts holding the towbar on actually have an UPWARD force on them which pushes the tube through the chassis rail. It's not a problem on the drivers side as there is a large contact area but on the left it is only the tube cross section. A larger pad inside the chassis rail will not solve the problem as the problem is underneath the rail. My car is still in bits and I'll look again tomorrow. I am thinking of putting a steel angle inside the chassis rail with a bolt horizontally through the side of the rail but I would really like to increase the bearing area above tube. Not sure how yet...
Ken
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26/Jun/2008, 8:20 pm
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jalalski
Date Registered: 02-2004
Location: SUTHERLAND, SYDNEY
TOTAL POSTS: 29100
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Re: Chassis problems
Thanks Ken,
Very valuable information indeed and it seems we have a pattern emerging with the chassis cracks that directly point to the use of the Weight Distribution Hitch and that weak left hand side mounting point.
Nissan were partially correct in saying that the WDH is not recommended to be used with this towbar, but that still leaves the question on how to enforce and strengthen that left side mounting point to be able to handle the load.
Please take photos of your trial fitting, so we can all think about this together and hopefully find a solution.
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26/Jun/2008, 8:33 pm
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Hammo9
X-TRAIL NEWBIE
Date Registered: 11-2007
TOTAL POSTS: 10
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Re: Chassis problems
Hi everybody,
I have just emerged from under my car where I have spent a fair bit of time today.
I am now quite sure that my explanation yesterday is pretty correct - the surface area of the tube is not enough to stand the forces of a weight distribution hitch which actually exerts a substantial UP force at the rear mounting bolts and a substantiol DOWN force at the front bolts. The front bolts seem to be OK as no problems have been reported as far as I know and the right side rear bolt is also OK as it has a substantial surface area.
Haymen Reese obviously realise this as Mal reports, they change this area to get a larger surface area under the rail on this side.
I have now modified my car to hopefully solve the problem as follows (I did take a couple of photos but they are still in the camera. perhaps someone can tell me how to attach them?)
Inside the chassis rail there are 3 unused holes in this area, 1 about 70-80mm behind the one being used where the tube goes and 2 on the inside vertical wall of the chassis. All are quite accesible with the bumper removed.
First I loosened the 3 bolts on this side and removed the rear one. The bar drops a bit and you can remove the tube as well which causes the problem.
Then I got a peice of 65 x 65 x 5 steel angle 150mm long, ground a radius on the outside corner and slid it into the chassis rail. It is a bit tight so I had to fiddle a bit but it went in. Next, with the end of the channel aligned with the back surface of the chassis, I marked through all 4 holes and drilled 1/2 inch holes through all 4. I had to put a washer behind each hole on the vertical leg of the angle to pack it out a bit as the chassis is not quite 90 degrees.
Once I had the little tube in my hand I realised I could use a piece of 1/2" water pipe instead. This is 23mm OD instead of about 17mm of the original and about double the wall thickness.
Using 7/16 UNF high tensile bolts and nuts with washers and spring washers, 3 x 1.5" and a long one through the tube, I think 3.5" long, I bolted the whole thing together.
So now the tube is bigger and the chassis rail is reinforced with the angle it looks much better.
Hopefully it will solve the problem and my solution is of use to others.
Regards,
Ken
Admin Edit: Added photos as requested.
Last edited by jalalski, 27/Jun/2008, 7:59 pm
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27/Jun/2008, 6:26 pm
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jalalski
Date Registered: 02-2004
Location: SUTHERLAND, SYDNEY
TOTAL POSTS: 29100
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Re: Chassis problems
Mal,
I don't think Nissan will do so, especially now that it is almost certain that using a WDH will cause this. The fitting of the Nissan towbar can certainly be improved by Nissan and I do hope they take note of that.
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29/Jun/2008, 7:05 pm
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