What makes this weight unsafe for 96 F1Z-FE?
Is it the strength of the frame? Is the lack of power of the motor? Is it the limitation of the suspension? Ability of the brake system? The FSM says not to?
What makes this weight unsafe for 96 F1Z-FE?
Is it the strength of the frame? Is the lack of power of the motor? Is it the limitation of the suspension? Ability of the brake system? The FSM says not to?
@Dr Gil, Factory tow ratings are a combination of all of the things you have mentioned. Also add vehicle weight. I had no problems towing my 4,500 lbs boat on I-15 / I-40 from Orange County to the Colorado River. In doing so it's not a speed run and his almost impossible to accelerate on the long steep grades once you get slowed down in traffic.
Most guys think it's related to engine power but that's the last thing you need worry about. I can't recall the numerous times I've seen someone post about towing several thousand over and how great it was. It's all a matter of time before you need to make an emergency stop or swerve to avoid something and loose it. I've probably seen 20 accidents on south bound I-15 coming down the Cajon Pass trying to turn on to I-210. The drivers ride the brakes all down the hill and end up with no brakes left at the. bottom.
Start making mods with big lifts and tires and the capabilities diminish rapidly. Loading the vehicle beyond GVWR and you might want to notify your next of kin.
The Land Cruiser is a relatively light weight, short wheel base coil sprung vehicle. Worst possible configuration for towing heavy loads.
Now the next thing is trying to increase the capacity. Nothing is going to work, nothing you can do would make it legal.
FYI. .... I've towed my setup for over 100k miles, safely but always cautious.
I still think the load on the cooling system is problematic. More load requires more power which means more heat to be dealt with by the the cooling system.
Brakes are another matter and I would think a trailer of that size would have some form of brake though my 3,000 pound boat did not.
I agree with Broski, !00%. If it was just 5K lbs trailer, but looking at your signature you are already added a minimum of 1,500 lbs with everything you added mod wise and other cargo you really need to look at the GVWR limits not just tow rating. Either value exceeded could put you in legal jeopardy. None of that changes by adding by adding a turbo or big brakes.
Just asking these questions points out that you don't have a lot of experience towing. Using a tow vehicle at the limit's even though legal is not something a novice should do.
Thanks for all the input. Nope, I don't have a lot of experience towing, that's why I'm getting input from more experienced
people before trying something that's not a good idea.
For sure as @Broski said. You’ll regret the rabbit hole of effort/$ trying to make an 80 a tow rig. It will tow smaller stuff ok and better with some upgrades as mentioned. Nothing wrong with towing the 80. Broski has a really nice set up, for example.
I believe its based on the engine/transmission mostly but a few other factors. A 4th gen 4runner with a v8 is rated for 7500 pounds and its basically the exact same size as an 80. But if you look at the rating for a v6 4th gen its less. A 200 series has an even bigger v8 is rated for 8500 pounds but only slightly larger than a 80. As far as braking, the tow rig brakes I dont think are that relevant. Trailer brakes are what I think you should use to stop when towing. Your towing equipment though also limits your weight. Your hitch may only be rated for say 3000lbs for example. You also have the weight applied on the rear axle. If the rear axle is overloaded it could bend the axle, or have the suspension bottomed out with which you also unload the front axle and put a lot of stress on the frame. If the front axle is too unloaded you loose steering control, although this can be countered with a weight distribution hitch. But then again a hitch has its own rating. My pickup is rated for a certain amount of pounds. As I approach that limit of pounds, the motor gets fairly slow. Also the trans gets fairly warm on hills. I can fix this with increasing engine power, a beefier rear suspension, and more trans cooling. I know this because my same pickup with a bigger engine is rated for more weight. What limits my v8 80 series is the cooling system, the rear suspension, and the hitch off the top of my head.
Another data point in case it's useful: I've pulled a 3k lb (roughly) single axle, with brakes, popup camper all around the US with my '97 1FZFE with 33" tires and about 1" lift and it does well on lower elevation / flatter terrain. Add in headwinds or hills and the 80 starts to struggle to keep speed even with the low profile of the popup camper. In evasive maneuvers my setup is ok at this point but it still requires a careful hand on the wheel and required repairs and adjustments to get it to it's current state.
As mentioned above the coil springs and in my opinion relatively high center of gravity of the 80 can allow the input from the trailer to be felt more than it would be on a more stable tow vehicle. I've got air bags in the rear springs and they help firm up the 80, I've adjusted caster in the front-end to make it more stable and shocks/bushings/bearings/etc. are all tight which is a requirement to tow in my opinion. Any slack in the suspension/steering or if the 80 has a tendency to wander it could get sketchy fast while towing. The camper I pull is well balanced and doesn't sway at this point but early on it swayed some on downhills and the 80 wasn't as dialed in and it was a bit sketchy in certain situations. I kept tuning the suspension/steering and camper setup until it became stable in all conditions but I still tow with it carefully.
Jumping from 3k lb to 5k lb would amplify any shortcomings in the setup a good bit and could put you in the ditch if things go wrong. The 80 may tow fine for hours of driving then the next thing you know your are descending a hill with a turn and uneven surfaces and the trailer starts steering the 80 towards the semi next to you...
Towing with an 80 seems best suited for 1k to 2k loads and a well maintained 80 close to stock height, tire size and suspension configuration. Pushing beyond those will likely result in compromises and performance limitations. For some, like me, the work to make the setup safe and the slower speeds on hills are worth it but there are some real limits and I think 5k lbs for extended trips is beyond them.
Another data point is worth calling attention to. In Australia, The Cruiser Company makes its high clearance tow-rated bumper, now imported through Long Range America. It's rated at 3500 kg/7700 lb with a braked trailer. The average Aussie 80 series is one of the several versions of turbo-diesels not generally available here. Just guessing, but doubt that the available OEM brakes are substantially different than the later 4 disc imported here. And mind you the Aussie have pretty strict requirements for engineered mods. I wouldn't write off the 80 as a tow vehicle for loads that exceed the 4500 lbs listed in the North American manual. Then again, it would probably not be the first thing I ever towed with that kind of weight.
