Flat towing my 40 with my 96 Fzj80

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1973Guppie

1973Guppie

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I know this has been discussed before and I did research but did not find too much info specific to my situation.

I wanted to get opinions on whether or not it is unsafe to flat tow my specific 40 behind the 80? From what I have read and seen I think it can be done safely. I am going to give it a try and set it all up to see how it feels soon here. My 80 is bone stock, but I plan on adding an oem suspension 850&863 springs as well as a 4x4 labs rear bumper. My understanding is that the tow rating is 5500 pounds in USA and more like 7k+ in Aus. I have flat towed it before with a new tundra but well had to sell that, it flat towed great then, only trouble was when I was in windy roads. I have a surge flat tow braking system seen here:
ReadyBrake Supplemental Brake System for Towed Vehicles - Night Shift Auto
I used this system on my tundra and it seemed to work well. I tested it by emergency braking on open road and it helped keep the 40 from swaying when braking hard.

Keep in mind I don't plan to tow much at all. Maybe one time a year on long journeys. I would like to drive the 80 with the 40 in tow out to places like Moab OR the rubicon from San Diego as the 40 is just not comfortable on long drives. Anything local / within 4-5 hours I just drive. That and I don't expect to go fast, would take it very slow. Comfort and safety are the main issues here. I also plan to only keep it to the interstate, for the rubicon for example I would drive the 5 all the way up to near sacramento, leave the tow rig with a friend and drive the 40 the rest of the way. I have learned that flat towing on mountain roads is simply no good.

Not sure what my lifted 40 weighs, I suppose I could get it weighed at one of those truck scales on the freeway? I have read that a stock 40 weighs in near 3500? so can't imagine mine is more than 4500? A couple pics of the 2 trucks are below.

thanks for the help and opinions.
DSC01181.webp
Thanksgiving 2008 014.webp
 
Ready Brake System

Great looking FJ40, can't wait to see what your 80 will look like when done. Tell us a little more on how well that Ready Brake system worked- would you purchase it again after having used it, or have you seen other systems you would consider instead?
Louis
 
Get Landtanks MAF.
PS...that 40 is smoken...dude.
 
You should be fine. I just pulled my 24ft wakeboardboat with my LX and it did great. My total towing package was around 7900lbs. Just give yourself plenty of distance between the traffic in front. That is one of the best looking 40s I have seen.

Josh
 
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I've flat towed my 40 a few times with the 80. It's fine but slow going. Standard towing precautions always apply. The mountain road thing honestly makes me less nervous than interstate, less traffic.
 
lrowe_csp said:
Great looking FJ40, can't wait to see what your 80 will look like when done. Tell us a little more on how well that Ready Brake system worked- would you purchase it again after having used it, or have you seen other systems you would consider instead?
Louis
Click to expand...

I would buy it again. Problem is that I really don't have anything to compare it with. I have never towed, only uhauls and trailers in college, and have never flat towed until I got the setup. I think for the $$ it works well and definetly keeps the towed rig in line by using it's brakes just enough to keep things straight under hard braking. All the other options were just too expensive. I did not want a trailer to store. Of course trailer brakes I think would be better for sure but it is a bigger load and as I mentioned I don't tow very often.

thank you for the kind words on the 40 as well.
 
hedonist said:
if your flat towing make sure you pull your rear drive line. there is a few on this site that will testify.
Click to expand...

yes, I agree with you totally, from the research I have done it is a must and it's only 4 bolts!!

I will post up later with my experiences and let everyone know how it went.
 
I am also thinking that I need to upgrade the 80's front discs to 100 calipers and rotors? I need to do some research but remember reading this is an option? is it just pads and not rotors? or can you actually put on larger calipers? curious because on my 40 I put T100 calipers on it and it helped greatly with stopping power.
 
1973Guppie said:
I am also thinking that I need to upgrade the 80's front discs to 100 calipers and rotors? I need to do some research but remember reading this is an option? is it just pads and not rotors? or can you actually put on larger calipers? curious because on my 40 I put T100 calipers on it and it helped greatly with stopping power.
Click to expand...

I know of a few people that have flat towed their 40s with their 80s...Never really heard much in the way of comments other that it was slow :hillbilly:.

As for the front brakes. Actually the upgrade is to put on 100 series front pads. You need to either turn or replace your front rotors when you put in the 100 series pads because the wear area is different. If your front rotors are close to minimum thickness then replace them...If not, you should be able to get away with just having them turned. When you put in the 100 series pads you need to leave off the anti-squeal shims because they won't fit in with the pads, especially if you install new rotors (too thick) - Once the pads wear down a bit you can put them in if you want or if you turned your rotors that might shave off enough to allow the shims to fit.

IIRC there are specific years for which 100 series pads you'll need...You can search for the part number or just call CDan and order them :D
 
I tried flat towing my 40 with my 80 (planned on this setup for a 10 hr drive to Rubicon). My setup at the time was OME mediums, 1.5" spring spacers and RS9000 shocks on the 80. The 40 was my daily driver/trail rig and had good castor and tracked really well on 37's. I hooked it all up and did a 10 mile test run on the highway. It got scary really fast for me. Bumps etc in the road that would cause the 40 to shift at all would transfer to the 80 and start a harmonic sway back and forth that would get increasingly violent until I slowed a LOT.

For me I think the problem was the OME medium springs were just too soft and couldn't control the movement. Needless to say I abandoned the plan to flat tow on that trip and borrowed a friend's Suburban and a trailer.

On the flip side, another local friend just flat towed his 40 to the Rubicon and back with his 80 (stock) with no trouble at all. So in my opinion you should be fine with the right setup, and stiffer springs seem to be better on the 80, so be sure to get the OME heavies. Other advice that has been given is good too.

couple pics right before my white knuckle test run. :p

towing_b.jpg


80towing1.jpg
 
Box Rocket said:
I hooked it all up and did a 10 mile test run on the highway. It got scary really fast for me. Bumps etc in the road that would cause the 40 to shift at all would transfer to the 80 and start a harmonic sway back and forth that would get increasingly violent until I slowed a LOT.

For me I think the problem was the OME medium springs were just too soft and couldn't control the movement. Needless to say I abandoned the plan to flat tow on that trip and borrowed a friend's Suburban and a trailer.

On the flip side, another local friend just flat towed his 40 to the Rubicon and back with his 80 (stock) with no trouble at all. So in my opinion you should be fine with the right setup, and stiffer springs seem to be better on the 80, so be sure to get the OME heavies. Other advice that has been given is good too.
Click to expand...

Instead of heavies I'd get air bags. The bags will increase the spring rate of the mediums, and will help compensate for the softer springs. Much cheaper, and no need for a harsh ride when empty.
 
timbercruiser said:
Make sure the castor is good, or the wheels on the 40 will point the other way when you turn. Usually in the middle of a busy intersection!!!
Click to expand...

yeah, good point!

actually I think the springover on my 40 really helped in this dept., it tracks really well behind the tow vehicle, I never get that problem, even on sharp turns, I tried to lock the tires up but even at full turn it was no problem and it tracked great.
 
Box Rocket said:
I tried flat towing my 40 with my 80 (planned on this setup for a 10 hr drive to Rubicon). My setup at the time was OME mediums, 1.5" spring spacers and RS9000 shocks on the 80. The 40 was my daily driver/trail rig and had good castor and tracked really well on 37's. I hooked it all up and did a 10 mile test run on the highway. It got scary really fast for me. Bumps etc in the road that would cause the 40 to shift at all would transfer to the 80 and start a harmonic sway back and forth that would get increasingly violent until I slowed a LOT.

For me I think the problem was the OME medium springs were just too soft and couldn't control the movement. Needless to say I abandoned the plan to flat tow on that trip and borrowed a friend's Suburban and a trailer.

On the flip side, another local friend just flat towed his 40 to the Rubicon and back with his 80 (stock) with no trouble at all. So in my opinion you should be fine with the right setup, and stiffer springs seem to be better on the 80, so be sure to get the OME heavies. Other advice that has been given is good too.

couple pics right before my white knuckle test run. :p


IIRC, I read this post on mud https://forum.ih8mud.com/80-series-tech/44674-dont-swap-med-heavy-oem-springs.html that said the OME Mediums have the same load rating as the heavies. The difference is the heavies are a bit longer so the springs shouldn't be softer--just shorter.
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ralphy1997 said:
IIRC, I read a post on mud at one point that said the OME Mediums have the same load rating as the heavies. The difference is the heavies are a bit longer so the springs shouldn't be softer--just shorter.
Click to expand...

They're rated for the same height with a lot more weight. They may be a bit longer, but having driven rigs with both, the heavies are stiffer for sure.
 
an update, towed an fj60 on a uhaul trailer with the 80 about 3 hours home, I was ok with how the 80 handled it, it was slow, about 50 on the hills and 55 on the flats but other than that no worries, I did notice that it pushed the 80 a bit on downhills and I would start to get some sway, but as long as you are cognitive about looking for the sway it is easy to minimize it by simply slowing down.

will post up when I get some more feedback on how it flat tows. Need to do some mods to the 80 first.

Noah
 
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