FJ40 Mods to Help Flat Towing?

[1973Guppie]

So I got the tow bar attached to the front 40 bumper this weekend and hooked it all up to the new Tundra. Drove it around the neighborhood (35 tops) and it pulls and tracks great. I realize I need to test it at a higher speed, etc. but so far it looks good. I did however have a few questions on how I might improve the towing situation and wanted opinions on if these things would help minimize sway, etc when flat towing.

The rear of my 40 is heavy. I have a spare conferr 2nd tank, spare tire, co2 tank, gas can, BIG tool box, etc. I am thinking that when I tow I could pull the spare, co2, gas can and empty the tool box and store this stuff in the bed of the tundra. I am thinking this will help greatly with the sway at the rear of the truck as it puts all that weight in the tow vehicle and not all the way back there at the end of the truck. All of this combined is alot of weight. I also plan to pull the 2nd tank (aussie type) which should help some too. I have read before that you want to have as much weight as possible toward the tongue of the towing vehicle. Will this stuff above help the towability of the 40?

Also, I have 55 springs and was planning on pulling the rear 40 springs and installing the 55 springs in the rear. I am thinking that doing this would bring the axle farther back and maybe make the vehicle a bit more stable when flat towing? Will this help the 40 be more stable when towing?

Also, I plan to pull the rear driveshaft when I flat tow. Anyone know of any innovative easy devices that allow for a quick release of the driveshaft? I have heard of devices they use on vehicles that sit behind RV's but not sure if they would hold up to 4x4 abuse.

How fast do people drive with their vehicles being flat towed? bar says 45 mph but I am thinking 60 should be ok, especially on a flat straight away.

appreciate comments / tips from those more experienced on this matter than me.

will post up pics of the whole setup later...

Thanks!

Noah

 

[Bond R]

I pull mine 65mph with no trouble. Though i have never had a sway problem. By getting the weight off the back end of your 40 that will put more weigh on the front. That should help the sway if you have one.

Rob

 

[D'Animal]

Why would you pull the rear driveshaft?

 

[1973Guppie]

I know not necessary, but it keeps the TC from spinning, for long distances I think it is worth it.

 

[Degnol]

I know not necessary, but it keeps the TC from spinning, for long distances I think it is worth it.

X2

Ed

 

[nuclearlemon]

for some reason, on long distances, not pulling the driveshaft won't get oil to the right places and you can blow up you tcase. saw it happen at gsmtr.

i'm full floater with hubs on the rear, have towed a few times at 65+. make sure your front end is in good alignment...that's most of it.

 

[Fast Eddy]

How fast do people drive with their vehicles being flat towed? bar says 45 mph but I am thinking 60 should be ok, especially on a flat straight away.

Just remember, it's not pulling it, it's stopping in a hurry that will be trouble. 45 down a wet hill is way too fast.

One of these would be sweet: http://www.brakebuddy.com/index.php

Their 'interactive map' says that in Cali a towed vehicle over 1500 lbs is required to have it's own brakes. That seems wrong. I found:

"Baking (sic) systems": http://www.dmv.ca.gov/pubs/vctop/d12/vc26458.htm

Stopping distance from 20 mph: http://www.dmv.ca.gov/pubs/vctop/d12/vc26454.htm

 

[Bond R]

I have never pulled my drive shaft while flat towing my 40. The only time you need to worry about oil not going where it is supose to is if you are running a aoutomatic. the only benny for disconecting is less wear on the u-joints.

Rob

 

[1973Guppie]

thanks for all the comments guys, do appreciate it....

my initial question does not ask about the rear shaft, but my questions above still stand on the weight distribution issue and moving the rear axle back. Can anyone comment on these more and if they think this stuff would help stability when flat towing?

thanks,

Noah

 

[1973Guppie]

http://cgi.ebay.com/ebaymotors/RV-T...017QQitemZ270135164764QQrdZ1QQsspagenameZWDVW

speaking of braking,

saw this on ebay, thought it was interesting for 300 bones, wonder if it works? anyone ever use a setup like this? seems too good to be true....

Noah

 

[FJFOOL]

Flat-towed my 40 many times 60-65 with no problem. Have to pull the rear drive-line as I have an auto., but with the front hubs in free the front is fine. Have seen rigs with hubs in the rear, thanks for reminding me, I've been wanting to investigate this more. Also, I think the longer wheel-base from the 55 springs would stabilize at speed, as well as removing weight from the rear of your 40.

 

[1973Guppie]

thanks fjfool, yes I would think logically by making the rear end of the cruiser lighter, probably by several hundred pounds (co2, tire, tank, rear gas tank, spare jerry can, tools) would make a considerable difference in the rear end swaying back and forth due to high winds and/or emergency stop. any other comments, opinions appreciated, thinking of getting that ebay brake setup for $300, just wish I could hear some personal opinions on it.

noah

 

[D'Animal]

for some reason, on long distances, not pulling the driveshaft won't get oil to the right places and you can blow up you tcase. saw it happen at gsmtr.

i'm full floater with hubs on the rear, have towed a few times at 65+. make sure your front end is in good alignment...that's most of it.

I have never pulled my drive shaft while flat towing my 40. The only time you need to worry about oil not going where it is supose to is if you are running a aoutomatic. the only benny for disconecting is less wear on the u-joints.

Rob

I'm confused. For a stock FJ 40 or FJ 60 pull it or not for long road trips. Both have H42's.

 

[Poser]

I have never pulled my drive shaft while flat towing my 40. The only time you need to worry about oil not going where it is supose to is if you are running a aoutomatic. the only benny for disconecting is less wear on the u-joints.

Rob

Trying to follow along here....


If you have the transfer case in neutral, then none of the gears are rotating, right?


So if I have a manual transmission and the transfer case is in neutral, the transmission is not rotating, correct?


So why would it be any different for an automatic, since the transfer case is in neutral and the gears are not rotating?

 

[D'Animal]

Trying to follow along here....


If you have the transfer case in neutral, then none of the gears are rotating, right?


So if I have a manual transmission and the transfer case is in neutral, the transmission is not rotating, correct?


So why would it be any different for an automatic, since the transfer case is in neutral and the gears are not rotating?

For the FJ40, FJ60 and the Automatic in the 62 I cannot see why it would matter.

Some manufactures do not have a true neutral in thier transfer case and it does not truely disengage the transmission. I can understand removing the driveshaft on those vehicles.

 

[FJ40Jim]

For the FJ40, FJ60 and the Automatic in the 62 I cannot see why it would matter.

Some manufactures do not have a true neutral in thier transfer case and it does not truely disengage the transmission. I can understand removing the driveshaft on those vehicles.

Exactly. On a stock Cruiser, to put the t-case in neutral, the shifter is put into 4WD, then slipped into the neutral gate between Hi & Low.

This has two undesirable effects.
First, it locks the frt & rear driveshafts together. Now , even though the shifter seems to be in neutral, both frt & rear driveshafts and all the front axle guts & birfields are spinning at 70 MPH. That could be a bad thing if any of those pieces have been modified or are worn.

Second, the hi & low output gears are both uncoupled from the spinning output shaft. At 70 MPH, a Cruiser might have a driveshaft speed of 3000RPM. driving normally, the high speed gear is locked to the shaft, and the low speed gear is spinning on the shaft at approximately 1/2 speed. All the gears in the t-case are spinning, throwing oil everywhere. In neutral, instead of a maximum speed differential of 1500RPM on the low gear, both gears are being held still on a shaft that is spinning at 3000RPM!
And there is no oil splash lubrication if the gears aren't turning.

This is not nearly as big a concern if a hybrid t-case is built using the roller bearing gears & output shaft from an FJ62 T-case, installed into a 86-87 FJ60 t-case.

The simple solution is to remove 4 nuts & bolts from the rear differential flange, then strap the d-shaft up against the frame rail. that means no excessive speed on the plain bearings in the t-case, and no spinning of frt driveshaft & axle.

 

[Poser]

Exactly. On a stock Cruiser, to put the t-case in neutral, the shifter is put into 4WD, then slipped into the neutral gate between Hi & Low.

This has two undesirable effects.
First, it locks the frt & rear driveshafts together. Now , even though the shifter seems to be in neutral, both frt & rear driveshafts and all the front axle guts & birfields are spinning at 70 MPH. That could be a bad thing if any of those pieces have been modified or are worn.

Second, the hi & low output gears are both uncoupled from the spinning output shaft. At 70 MPH, a Cruiser might have a driveshaft speed of 3000RPM. driving normally, the high speed gear is locked to the shaft, and the low speed gear is spinning on the shaft at approximately 1/2 speed. All the gears in the t-case are spinning, throwing oil everywhere. In neutral, instead of a maximum speed differential of 1500RPM on the low gear, both gears are being held still on a shaft that is spinning at 3000RPM!
And there is no oil splash lubrication if the gears aren't turning.

This is not nearly as big a concern if a hybrid t-case is built using the roller bearing gears & output shaft from an FJ62 T-case, installed into a 86-87 FJ60 t-case.

The simple solution is to remove 4 nuts & bolts from the rear differential flange, then strap the d-shaft up against the frame rail. that means no excessive speed on the plain bearings in the t-case, and no spinning of frt driveshaft & axle.

Thank you for typing this all out Jim...


BTW- That is why I trailer my junk....flat-towing is


I was really hoping that Rob was going to come back to the conversation...

 

[FJ40Jim]

And to go into general info on flat towing (i've done it for thousands of miles)...

Yes, take all the heavy, unboltable crap out of the FJ40 and put it into the bed of the towtruck. Use the cruiser to carry the lawnchairs & pink flamingos. Put the spare tires, hi-lift, recovery & toolboxes, jerry cans, etc in the vehicle that has BRAKES. Like eddy said, stopping is the real concern.

If possible, tow the cruiser w/ an empty fuel tank and fill the cruiser at the trailhead. No reason to tow 150lbs of fuel 500 miles if it's not getting burned in the tow truck.

Make sure that the towbar slopes downhill from the Cruiser to the hitchball, so that when braking, the cruiser tries to climb up on the towtruck.

If possible, use small radial tires on the cruiser, inflated to max pressure.

If the cruiser doesn't drive straight normally, it won't be any better when towed. Make sure that there is plenty of caster, steering is not binding (free to self-center), and toe-in is set correctly.

Allow plenty of stopping distance if you've got a 3000lb. trailer with no brakes.

Don't attempt to back up. Just doesn't work. Make sure when parking or stopping for gas you're not gonna get trapped.

Make wide turns. Watch the trailer's frt tires in the mirrors, make sure they are tracking, following after the tow truck. Once the trailer tires are steering after the tow truck, the turn can be tightened up.

HTH and good luck.

 

[1973Guppie]

Hey Jim,

that helps alot, appreciate it. thanks to others as well.

Poser, can I borrow your pink flamingos?

anyone use a braking system like the one I mentioned above? Is this thing a piece of s*** or worth a try at $300?

Noah

 

[Coolerman]

That's the first time I have seen that braking method. If it has a money back guarnetee I would try it. Just make sure you don't have 'two pump brakes' otherwise it will be useless.