Your Tech Questions Answered
Tied One On (the Trailer)
Q What is the proper way to tie down a vehicle when trailering? I have been told to make sure I compress the suspension, as this will help save the bearings and keep the vehicle from bouncing. I have also heard to use axle straps and not compress the suspension. Do I cross the tie-downs from side to side, forming an “X,” or pull from the closest corner of the vehicle? I have seen vehicles tied down multiple ways and want to know which is right.
A The right way to tie down your vehicle is so that it doesn’t fall off. There is no one correct way to tie down all vehicles, but I always tie down vehicles by the axles if possible. I run two front straps straight from tie-down points on the trailer deck to axle straps around the axletube, being sure that the axle straps don’t rub on sharp suspension mounts or compress or tweak hard or soft brake lines. I usually run the axle straps just inside the steering knuckles on the axletube.
In the rear I also run two straps to axle straps, but back there I usually cross the straps to help keep the vehicle from moving side to side. Plus, since the rear diff is usually centered on the towed vehicle, I usually put the axle straps just outside of the differential on the axletube. For straps I recommend Mac’s Ultra Pack from Mac’s Custom Tie Downs (www.macscustomtiedowns.com). Mac’s offers a full line of different tie-down kits and straps.
I find that strapping the vehicle down by the axle allows the rest of the vehicle to move freely via the suspension. I also put the vehicle in low range in the transfer case and set the parking brake (if it has one) to help make sure it doesn’t move while on the trailer. I have been in a vehicle where the towed vehicle came off the trailer, and it is not a good time. Plus, I would hate to be the guy towing a big lifted 4x4 that came off and smashed into a family. That is not a place I ever want to be, so I’m pretty thorough when strapping down.
I have seen many people tie down vehicles above the suspension on the frame. In fact, many tow companies with rollback trucks do just that. I think this is fine, but am always worried that if the trailer were to hit a big bump the suspension could compress and the straps could come loose. Many commercial tow vehicles use chain, but I find straps to be great for the recreational towing I do.
I recommend tying up the ends of your straps with tape, bungee cord, or zip-ties to keep them from flapping. You can also fold them back into the ratchet handle to keep them from getting loose. Be sure and check your straps often. When going on a long trip I usually load the vehicle, get on the road for 20-30 miles, and then stop for fuel and check the straps. This short distance is usually enough to get them settled or jostle them loose if they are inclined to get loose. Make sure to retighten the straps at every fuel stop.
On Track or Off?
Q I have an ’03 F-250 I am setting up for more trail duty, but it is also a daily driver. The factory steering sits far too low because the track bar bracket is in the way. I would like to eliminate the track bar in order to move the steering up out of the way. The only problem is the crossover-like steering setup from the factory instead of the old push-pull setup, but trucks that switch to crossover don’t always use a track bar. The truck does not have the heavy diesel engine, which I assume is why it was installed with a leaf-spring suspension from the factory. I know there are kits available that relocate the track bar bracket and replace the knuckles, but they are also very expensive. Can the track bar be removed without many negative effects, or am I missing some other reason for it?
A I agree, a track bar with a leaf-spring suspension doesn’t make sense. Some manufacturers used them while others did not. The track bar is trying to push your axle side to side during suspension movement, when leaf springs want your axle to move front and back. I feel the track bar was installed to force the axle to move in the same arc as the drag link, but it inherently wants to bind against the direction of the leaf springs.
I think some truck builders use a track bar with leaf springs when they go very tall with the lift and feel the need to keep the axle from shifting side to side under the truck (or the truck moving side to side above the axle) when you steer, but leaf springs are usually pretty good at allowing and controlling suspension movement at the same time. I would say remove the track bar and drive it. If it feels like your steering is pushing the truck side to side when you steer the wheel with the truck stopped, it may be time for new spring bushings, but I think ditching the track bar will only help increase the off-road ability of your truck. Just because the factory engineers installed something doesn’t mean it was designed to work well off-road in the parameters that we like to use our vehicles in.
Divorced or Together?
Q My friend and I want to build my two-wheel-drive S10 into a 4x4. It is a V-6 manual transmission. I have already purchased some military Chevy 1-ton axles and am looking for advice on the transfer case. Do you know of a divorced transfer case that will work with my project? I am on a pretty low budget, but I can do a lot of the work myself.
A A divorced transfer case may seem easy, but I’m not sure it will be really cost-effective. As far as divorced transfer cases that will work with your passenger side front axle are concerned, there is the Suzuki Samurai case, which is probably too small and it has an offset rear output.
Novak Conversions (www.novak-adapt.com) has a kit to put a Spicer 18 or 20 in a divorced setup, and the Spicer 20 wouldn’t be a bad option since your military rear axle is a centered pinion GM 14-bolt. The low range in the Spicer 20 is 2:1, which isn’t very low. You can, however, get a 3.15:1 low gear set for the Spicer 20 transfer case from Teraflex (www.teraflex.biz). There is a Dodge version of the NP205 that would work also, but it is pretty heavy for an S-10 and only has a 1.97:1 low range.
If you want the 205 you may want to consider the Lowmax 205 that has a 3:1 low range from JB Conversions (www.jbconversions.com), though it may require special work to make it divorced. I know Advance Adapters (www.advanceadapters.com) offers its Atlas transfer case in a divorced mounting style, but this may be at the upper realm of your budget.
The issue with a divorced transfer case is the cost of three driveshafts in addition to building a crossmember and running all the shift linkage into the cab of your 4x4. If you’re running the 4.3L V6- you could try to find an SM-465 with a NP205 or Spicer 20 already attached to it from a fullsize Chevy truck or Blazer, which should bolt to the back of your 4.3L V-6 without too much work. Just be sure you get the bellhousing along with the transmission. This won’t give you an overdrive gear, but it will give you a granny First gear for off-road crawling, and it will probably be cheaper and easier to find than building a custom divorced transfer case setup.
Lift N Tow
Q I have a stock ’84 Jeep J-20. I would like to add 35- to 37-inch tires, but I am afraid of losing the utility of the truck. I am planning to install 4.11 gears, lockers, and a 3- or 4-inch lift. How much will a lift take away from the load carrying and towing ability?
A Very good question. Often the springs used in a lift kit are properly rated for the same load as the stock springs. Some can even allow more load capacity, so be sure and check with the suspension company or your local 4x4 shop before you purchase the lift you desire.
The fact that the truck has a higher center of gravity can affect its load hauling and towing ability. I would not recommend lifting a truck that is primarily a tow rig, as that could require drop hitches and greatly reduce braking ability after adding larger tires. Plus, there is no denying that a lifted truck is a taller truck when it comes time to load or unload the bed. With a good trailer brake controller and a slight lift and tires just a few inches over stock, I don’t think you’ll have a problem towing, but a stock truck will almost always tow better.
I have a lift on my tow rig, but that is because the truck sees double duty as both tow rig and exploring camping truck, so I wanted the ground clearance for off-road use. I have seen many tow rigs on 37s, but I’d stay with 35s or smaller and just 1-2 inches of lift or a leveling kit if you are more concerned with towing and hauling than off-road use.
AMC TH 2 GM?
Q I have a ’79 Jeep J-truck with a TH400 automatic transmission. Will this automatic bolt up to a Chevy V-8? I know Chevy used the TH400 also.
A Unfortunately AMC used a different bolt pattern on the TH400 automatics, so they are not the same as the GM TH400. However, the internals are the same, so if you wanted to swap your tranny guts into a Chevy case, then the Chevy engine will bolt onto the transmission.