| Author | Message | ||
     ross kowalski Frequent User Username: cdfpw Post Number: 89 Registered: 11-2015 |
I took out the tape measure a while back to look at the dimensions for a trailer hitch on a shadow. I did a quick dimensional sketch. I will make the sketch into a template and check the fit. I will probably make the part that sticks down 3" wide.  | ||
| David Gore Moderator Username: david_gore Post Number: 2176 Registered: 4-2003 |
Ross, The Shadow rear sub-frame makes installation of a tow bar more difficult because the inbuilt flexibility of the sub-frame means the additional loads from towing cannot be directly connected to the sub-frame as this would cause significantly greater wear on the mounts. Attaching the tow bar to the body is the only way however you have to be very wary of possible body distortion if the tow loads are high. Have a look at the tow bars from Hayman Reese to give you an idea of their designs to spread towing loads around the vehicle body for this reason. http://www.pedders.com.au/kits/choosing-right-towbar | ||
| ross kowalski Frequent User Username: cdfpw Post Number: 92 Registered: 11-2015 |
David, I measured for the two "L" shaped things being bolted over the bumper mounts. The bumper mounts are on the unit body and look very robust. I traced the design on a pizza box a few minutes ago, but didn't have a ruler so I used a dollar bill to measure it out. It should be accurate enough to see if it will work. I will try and photograph it in position under the car tomorrow. | ||
| Martin Taylor Experienced User Username: martin_taylor Post Number: 24 Registered: 7-2013 |
I have a shadow tow bar in my shed, I can measure it and photograph if that would help, it has a slot in one side so it can be fitted without dropping the tank to remove the bumper fixing bolts. | ||
| ross kowalski Frequent User Username: cdfpw Post Number: 97 Registered: 11-2015 |
Martin, Yeah, the would be great help. If you photograph it, just put a ruler next to it. Here is what I am looking at right now. The holes are cut big to fit over the bolt heads for testing.  When I looked more closely I saw the spare tire lowering bolt was right where I wanted to put the crossbar. Thanks in advance. | ||
| Martin Taylor Experienced User Username: martin_taylor Post Number: 25 Registered: 7-2013 |
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| Martin Taylor Experienced User Username: martin_taylor Post Number: 26 Registered: 7-2013 |
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| Martin Taylor Experienced User Username: martin_taylor Post Number: 27 Registered: 7-2013 |
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| Martin Taylor Experienced User Username: martin_taylor Post Number: 28 Registered: 7-2013 |
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| Martin Taylor Experienced User Username: martin_taylor Post Number: 29 Registered: 7-2013 |
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| Martin Taylor Experienced User Username: martin_taylor Post Number: 31 Registered: 7-2013 |
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| Martin Taylor Experienced User Username: martin_taylor Post Number: 32 Registered: 7-2013 |
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| Martin Taylor Experienced User Username: martin_taylor Post Number: 33 Registered: 7-2013 |
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| Martin Taylor Experienced User Username: martin_taylor Post Number: 34 Registered: 7-2013 |
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| Martin Taylor Experienced User Username: martin_taylor Post Number: 35 Registered: 7-2013 |
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| Martin Taylor Experienced User Username: martin_taylor Post Number: 36 Registered: 7-2013 |
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| Martin Taylor Experienced User Username: martin_taylor Post Number: 37 Registered: 7-2013 |
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| Martin Taylor Experienced User Username: martin_taylor Post Number: 38 Registered: 7-2013 |
Hope this helps, I could draw around the ends on graph paper if that helps, the right side is slotted as the forward bolt won't come out without dropping the tank, the bolts have to be 10mm longer I think. The left side is offset to clear the exhaust tip, there is a curve in the bar | ||
| ross kowalski Frequent User Username: cdfpw Post Number: 99 Registered: 11-2015 |
Martin, Wow, thats great. The two piece side plates look like you bolt the top on then move to bottom where you want then tack it in place. Was this a commercial unit or a custom one off? I like the bend in the cross piece. It looks like it comes back up after getting past the rear valance then gains additional height with the bent hitch ball mount. I will be using a reciever tube so when it is detached you dont see much of it. I will also be adding safety chain mount holes onto a plate next to the reciever tube. I was also thinking about adding tiedown points into the bottoms of the side plates ( no good anchor points under the rear of the car) I'll try and do up some dimensions on the pictures you sent. The slot also allows you to leave a bolt in the bumper mounts at all times which is helpful for alignment. I sort of remember getting the front bolt out on the gastank side but I think I pulled the bolts off the bumper end as well. Thanks a million. | ||
| Martin Taylor Experienced User Username: martin_taylor Post Number: 39 Registered: 7-2013 |
I purchased this second hand, it is heavy and makes the car too long to fit in my garage fitted, it looks custom made but fits very well, the overhang did scrape on steep driveways so if designing your own you would want to keep that dimension as small as possible, my tailpipe which is also a custom job had to be moved to accomodate it, let me know if you need more accurate drawings as I could draw around the ends on 5mm graph paper then scan it for a very accurate copy of the ends at least. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 1038 Registered: 9-2004 |
This is some pictures of the tow bar I made and fitted some years ago. 1st and 2nd pic is the strait bar and ends fitted to the bumper brackets.   next pic is the rear strenthening plate behind the body cross member and boot floor by the spare wheel.  New old stock tow bar.   Hope this will help. | ||
| David Gore Moderator Username: david_gore Post Number: 2178 Registered: 4-2003 |
Martin and Ross, I would be very reluctant to use this tow bar for a loaded trailer with a gross mass in excess of 600 kgm [1200 lbs/0.5 ton] as it does not have the rigidity and load distribution characteristics of tow bars with a higher rating. I have a Hayman-Reese Class 4 tow bar on my 4WD which is made from thick wall 50mm square RHS steel and rated for towing up to 4000kgm trailers: http://www.haymanreese.com.au/products/heavy-duty-towbars-class-4 Compare the construction and attachment mounts on this tow bar and you will see the reason for my concern about the trailer mass limit for your proposed tow bar. | ||
| ross kowalski Prolific User Username: cdfpw Post Number: 102 Registered: 11-2015 |
Patrick, Thanks for posting your images. I really like the center support I'll have to do something like that. David, I wouldn't put a lot of weight behind the car, I think you would be safe at 2500lbs on the bumper mounts and a reasonable center support. The problem with trailer hitches is not the hitch breaking, twisting or falling off, it's the suspension of the tow car and it's weight. Weight wise it should be fine not getting pushed around by the load, and suspension wise, assuming 250lbs tongue weight it should be fine as well ( I personally have had well over 250 in the back and it dives fine) I bet with electromagnetic brakes out back you wouldn't even know you were towing anything. Best, Ross | ||
| Jean-christophe Jost Experienced User Username: jc_jost Post Number: 24 Registered: 3-2016 |
Can't help sending this message from a lurker : This forum is pure delight. Fantastic pics and documentation. | ||
| David Gore Moderator Username: david_gore Post Number: 2179 Registered: 4-2003 |
Ross, My concern is not the load on the tow bar - it is possible distortion of the body panels due to load transfer from the tow bar mounts to the body shell. I recall the Australian off-shoot of General Motors experienced this problem some time ago when their most popular car model was released with a new body shell and owners began to complain about buckling of the body panels on the rear of the car after towing a relatively moderate trailer load. GM subsequently fitted modified body braces to stop the buckling. I doubt you would appreciate the expense of rectifying body distortion from inadvertently towing a load sufficient to cause distortion - one never knows if and when this might occur due to unexpected circumstances. Temptation invariably has unexpected consequences........ | ||
| Martin Taylor Experienced User Username: martin_taylor Post Number: 41 Registered: 7-2013 |
Point well taken David, mine was fitted more to protect my very expensively rechromed bumper. | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 1039 Registered: 9-2004 |
David if the car has not suffered with corrosion then the body structure is more than strong enough. I have a 90 litre Lpg tank as well as the towing of a small plant trailer. A tip for the cars that are not in every day use when after three days or so the rear trim height settles, If you have a tow bar I put a block of wood under the hitch after use to hold the car in its position to take the wieght of the springs.  | ||
| David Gore Moderator Username: david_gore Post Number: 2183 Registered: 4-2003 |
Hi Pat, Given the corrosion [visible and otherwise] present in cars that have not spent their life in a dry climate, this is even more reason to be circumspect about using the car for anything other than light towing duty. This particularly applies to cars which have spent time in regions of the world where salt de-icing of roads occurs. Your idea of using a block under the tow bar tongue has much merit for reducing permanent spring "set" over time. | ||
| ross kowalski Prolific User Username: cdfpw Post Number: 108 Registered: 11-2015 |
David, Patrick is right about the weight thing. I personally can attest to that. Not to get into gory details, but you can put 500lbs in the trunk of a non-corroded frame car and not damage anything. But, That means that the 500 lbs is between the two rear frame horns and not bolted to the end of it and the rear trunk floor. That could be a totally different animal as you say. I am always good for being a guinea pig so when I get the hitch done I will put some known weight to it and see what happens. Patrick, Can you take a wider shot of that hitch with the covers off? I'm not exactly sure what I am looking at there. | ||
| ross kowalski Prolific User Username: cdfpw Post Number: 109 Registered: 11-2015 |
Martin, There is a measurement I cannot really see. How much does that center piece bow in the middle? | ||
| Martin Taylor Experienced User Username: martin_taylor Post Number: 42 Registered: 7-2013 |
From the edge of the bar, the bend is about one inch at the middle  | ||
| Patrick Lockyer. Grand Master Username: pat_lockyer Post Number: 1040 Registered: 9-2004 |
And for info the witter, dixon bate is just under 2 1/2" My bar is strait with end of bar fixing to the bumper brackets the real loading is of course through the centre of the cars body lovely as Bob would say! When towing 2 ton gross I take it easy on the torque due to the weaker point of the transmission mounts.   |
