Hi, I am in the process of buying a 2nd hand flat bed cargo truck (for lumber). I am choosing between a 12 wheeler (8x4) ISUZU GIGAMAX CYJ51W4 (year 2004) vs a converted ISUZU GIGAMAX 10 wheeler truck to triple axle (14 wheels: 12x2 drive wheel) Which of the two will provide greater carrying capacity and maneuverability? I am also looking at the lifespan of the tires given their very different configurations. The trucks will basically be loaded at around 15 tons. By the way, the engines of the two are the same ISUZU 6WF1. It is just the chassis and tire configuration that are different. Thank you and regards, Justin
Generally speaking more wheels means more weight capacity if they're using the same size tire. Are these extra axles lift axles? Also, generally speaking, a shorter wheelbase will be more maneuverable. If it's equipped with lift axles you'd look for the shortest distance between the steering axle and axle in contact with the ground.
Hi steve, Yes the third axle is a lift axle. I know that the 12x2 configuration will have the higher carrying capacity but its maneuverability will also be more limited. At the same time this will also result to the tires shorter life span due to the higher friction in very sharp turns. I am just not sure if the 8x4 configuration will be a better alternative since this is my first time to actually see one live. I don't have any experience with double eye beam set ups. thanks, Justin
With 15 tons why would one want any more than a ten wheeler unless you got some really weird weight laws. Here a ten wheeler will take that load with rom to spare.
15 tons is our baseline. It is highly possible for us to haul greater weight since lumber comes in different densities. Just to give you an example, some of our trucks have already been caught with a load of 11000 boardfeet. While some easily pass the scale with 14000 boardfeet. So this is just a precaution for us. Thanks!
G'day Justin, After owning an 8x4 Volvo since 2000, I recommend that you go for that configuration. If we are on the same page with our description of axle configurations (in Oz the 8x4 can be called a "twin steer", "eight wheeler" or "octopus"), what you call your 12x2 will get stuck going over a drain or on wet grass! (Even with the axle lift). Mine has a fairly heavy tipper body, and I can still load 15tonnes legal, but it has to be favoring the back or it will still go over on the steer, European trucks being notoriously heavy at the front already. Forget about getting good tyre wear with a twin steer unless you pay lots of money to the wheel alignement man. I think Isuzu have a reasonably simple load-share arrangement between the front axles, but make sure the pins and bushes are greased well as some will always be heavilly loaded, no matter what the brand. I solved mine by fitting four airbags on the front, but still use Castrol APXT grease which has Graphite and Moly and has the highest "4 ball weld" test results of any grease I found. (Not for uni-joints or bearings!). Good luck !
Hi Stondad, Great to hear. I just came from the shop and the truck still looks and sounds very well maintain. My only issue right now is the suspension. It is fitted by airbags but already worn down. Our mechanic is suggesting to convert it to leaf springs. All of our trucks (being 199x models) are fitted with leaf springs and this is the first if ever that will use airbags. Will it be a better choice for me to stick with the airbags? I am afraid that it will experience faster wear given the extreme conditions in the Philippines. It might also be in the expensive side in terms of repair and maintenance. Thanks, Justin
Hi Justin, First my appologies. The grease I mentioned earlier is SBX2 (not APXT) but it looks like I can't edit the post. Maybe Steve or a Mod can fix it please. I presume you mean airbags on the drive axles ? It depends on the brand of suspension, but airbags are easier to change than springs if you are worried about their condition, and their performance varies according to brand too. 25 years ago, we were all frightened of airbags here for off-road, but they have proved themselves to be the best. I have just come off driving in a fleet of Western Stars pulling tri-axle jinkers (one jinker airbag too) with "Newway" and "Hendrickson" airbags on the drive. They are easily as good as the fabled "6-rod" and ride better. I suggest that you try the airbags and I think you will be happy. As with all long rigid trucks, the diff-locks may be needed when empty even turning at some intersections where the camber of the road changes, but this is because of lack of flexing of the chassis. Also, sometimes dumping the airbags helps in sticky situations. Mind you I did see a bogie drive Mitsubishi body truck that was hopeless but it had little wheels. Hope this helps. Ask other people who have run them in your area. Cheers. Maurie.
Hi Maurie, Thanks for all the advise! Checked the airbags on the truck and its of Japanese origin. Can't really read the name since its at the back of the airbag. Will need dismantling to see the actual markings. Anyway, we compared the price for conversion and the difference is marginal than simply replacing with new airbags. I think will stick to the airbags. It's about time for us to try new technology =D It will just require a little more training for my drivers. Thanks again! Will try to give an update after the final repairs are done. -Justin
G'day again Justin, Glad you decided to give the airbags a try. I suspect that you used the price of genuine Isuzu airbags when you did your costing for conversion. In Australia, we are blessed with lots of alternative parts suppliers, which helps keep the price of genuine parts down too. You may not be so lucky in the Philippines. Have a look on the internet and you should find your airbags available in Goodyear, Firestone, Hendrickson, Pirelli, and many other brands. Only guessing, but I would be surprised if you pay any more than AU$150.00 ea for them. I can understand that you want peace-of-mind with your new truck, and that you are not experienced with the new suspension, but I doubt that you need to replace all or any of the ones that are on the truck now. They are very durable, and most designs are "self cleaning" of mud, stones etc. So they can look bad but still be ok. However oil or grease from over-greased uni-joints, or leaking seals is no good for them. This means that your air compressor has to stay in good condition, and special attention is paid to draining airtanks if the truck does not have an air-dryer, so that the inside of them doesn't get oil. Keep an eye on the "ride height valves", which can be troublesome. Air leaks are obvious, but the flimsy linkages from the axles to the valves can wear, come loose, or need adjustment. Sorry Mate I just lost anothe half page of stuff because of the stupid internet and I dont have time to retype it. I tell you more 2moro or phone on +61407155966 Cheers. M.