Some are to aid "race-ability" (such as trailer retention) others enhance handling and or race marshaling.
1) Guide flag/pins. Remove the guide pins from the tractor and the trailer (four total) and replace with just a single steel AF/X guide pin on the front of the tractor chassis. As shown in the photos below.
(Please be aware that the steel guide pins are a VERY tight fit in the AW X-traction chassis and require some notable effort to install - but are top notch in the reliability arena! If a steel pin is not available, the second best option for ease of marshaling is to reverse the factory guide so the pin end is down.)
2) Trailer truck/wheel assembly. With the guides removed, the rear wheel truck assembly needs to be "fixed" so that it can no longer rotate.
The easiest and most reliable method I have found to do this is to drill through the boss that is provided from the factory and pin it in place. (some prefer to glue instead of pin - which if this method is done, make sure to roughen the surfaces and remove any chrome from the area to be glued, otherwise it will let go during racing action). :)
To perform the pinning process, the easiest way to do this is to separate the trailer bed from the box assembly. There are 6 pin points that tie the two parts together. Some times it is relatively easy to get these two piece apart other times - they put up a fight - but if you have one of the trailers in your hand, it is simple to see the parting line between the deck and the sides of the box assembly - from there it just takes time and patients to work at carefully getting the two halves apart (some prefer to simply drill the pins out from the bottom side to ease dis-assembly - and use glue to reassemble. No matter which dis-assembly method is used, I recommend gluing the two parts together at the time of reassembly)
The picture below shows two of the six pins (orange arrows) in addition to the factory boss that has to be drilled (red arrow)
After disassembling the trailer to to separate the trailer deck from the box portion, using a pin vise and a 1/16" drill bit to drill at a slight angle from the top side of the trailer deck, through the boss and truck assembly. (note the boss is hollow on the top side so there is not much material that must be drilled through.)
View of boss from top side of trailer:
View of truck assembly prior to drilling:
Angle to drill:
This results in hole being placed in the truck with sufficient room for screw head:
I purchased a bag of one hundred bevel head 1-72 machine screws from RT-HO on eBay (example here: http://www.ebay.com/itm/100-FRAY-STYLE- ... 1e98630136 ) - they work extremely well for this application - but a standard t-jet body screw will also work as an alternate:
With screw installed:
At this point, the pivot screw is no longer needed and is removed for use in another part of the build.
Note - some like to add a drop of glue to the pivot area, to further insure that the unit remains in place / does not move - however I have yet to find this to be required on the rigs I have modified:
3) Trailer pivot. Most of the AutoWorld trailers have the pivot pin in the rear most position. Depending on the trailer type and tractor type, this can result in the trailer hitting the back of the cab as it pivots and/or goes through tight corners. The pin location can easily be changed by taking a set of needle nose pliers, and applying LIGHT pressure and twisting motion to slowly extract it out of the rear hole and install it in the front hole.
In the factory "rear" position:
The two factory holes for the pivot pin - pin to be moved to the forward most location;
Picture of the pin upon removal:
4) Trailer retention Using a 1/16" drill as before (in a pin vise) drill down through the center of the trailer pivot pin. (the screw previously used for the "pivot" of the rear truck assembly will eventually be screwed into this)
Setting the trailer aside temporarily and focusing on the bottom side of the tractor body, a small modification needs to be made to allow room for the screw head that will be retaining the trailer to the tractor. The two small pieces of plastic shown with the red arrow are to be removed via roto-tool, sprue cutter, etc. - down to the bottom side of chassis (yellow arrow) The final area should be relatively flat as the screw head will be interacting with this area:
Upon completion, the trailer can now be attached to the tractor with the screw originally used for the trailer's rear truck pivot:
5) Wheel spacing The rigs come with the wheels set fairly wide. With the other changes made, the handling is found to improve with setting the wheels inward, limiting side to side play. See examples of before after below:
From this point on, the rest of the items are relatively normal "tuning / tweaking" items that relate to the racers preferences.
Hope everyone finds the tips above helpful in helping to get their rigs ready to rumble!
Now let's go racin'! :D
:auto-layrubber:
