ATF over heating?

[pesimsmd]

This weekend I was driving on the beach with thick sand, pulling a M100 Trailer with a rooftop tent. I had been driving about 8 miles, in the sand ranging about 5-10 mph, in 4H (I now know that was the first mistake, should have been in 4L) I notice that I was losing power, then the ATF overheat light came on, I stop and let the car cool off and shifted in to 4L and was able to get to the camp site. What I want to know is there and damage from this, do I need to get the ATF changed, is there any thing I can do to keep this from happening, I like camping on the beach, and will be doing this many more times. Is it possible to get a AFT cooler/radiator?
Any advise would be greatly appreciated.

Paul

[LandCruisers4Life]

Hi, if you got your cruiser with a tow package, it would have the transmission cooler installed on the front of the radiator.

If you don't have a transmission cooler (separate radiator for the trans), by all means get one installed immediately. I would also have the ATF changed at the dealer and have them evacuate the fluid from the torque converter.

PS - Always shift into Low when off road and towing anything. Also lock the center differential.

[e9999]

check the temp at which the light comes on in the FSM.
Figure out the mileage life expectancy of the ATF at that temp.
Compare to 8 miles. Decide whether it's worth changing or not.


You should normally be just fine with the ATF in the Sand, if you're in Low, even heavily loaded.

[mudlover]

Also, Clean out the fins on your radiators. You may be surprised to see how much crud gets stuck in there.

[e9999]

also, if you have skinny tires on the trailer, it would probably help to air them down so they don't dig in too much and work as anchors... (my popup tiny tires are really bad for that, in soft sand they are almost halfway in at times...)

[LandCruisers4Life]

Hey man make sure you give us a little feedback on your situation. Did you have the tow package with trans cooler from the factory? Also was wondering how old your fluid in the trans is. Your Cruiser should have the 4 speed auto, and you can drop Amsoil ATF in there... With the newer 5 speed there's not much choice on fluids.

[TXLX470]

I have driven about 15-20 miles in South Padre Island,TX in very sandy beach without any problems. I was driving in 4H in speeds of 25-30mph...did not lock and did not lower the tire presure either... Yes I do have the tran cooler and I was not towing anything

So those who reccomend 4L, is it beceause of low speed towing in sand???

[LandCruisers4Life]

Originally Posted by TXLX470

I have driven about 15-20 miles in South Padre Island,TX in very sandy beach without any problems. I was driving in 4H in speeds of 25-30mph...did not lock and did not lower the tire presure either... Yes I do have the tran cooler and I was not towing anything

So those who reccomend 4L, is it beceause of low speed towing in sand???

Yes, slow speed towing in sand. Over the years I have done plenty of driving down padre in 4 hi... however towing puts a larger strain on everything, especially if the trailer tires are small. I have never had to lower my tire pressure on padre, even in deep sand at big shell. Most of the time when I start to hit the deeper sand down in Big Shell, I will stop and transfer to 4 low with diff locked. I like to drive a bit slower in the deeper sand to maintain control.

[pesimsmd]

I checked the front of the 100, and I do have a second radiator in front of the main, and I am assuming that it is the transmission cooler. So there fore I have the Tow Package. I have not had a chance to check out the transmission fluid since its recent change with about 1000 miles on the new fluid. I do have one question, why do I need to lock the center diff when in the sand?

[LandCruisers4Life]

Originally Posted by pesimsmd

I checked the front of the 100, and I do have a second radiator in front of the main, and I am assuming that it is the transmission cooler. So there fore I have the Tow Package. I have not had a chance to check out the transmission fluid since its recent change with about 1000 miles on the new fluid. I do have one question, why do I need to lock the center diff when in the sand?

It transfers the torque 50/50 so that the load is shared by all 4 tires going forward through the sand. If not, most of the drive force will be applied to the rear axles. I'd rather have all 4 grabbing for traction myself.

All that said, it sounds like the combination of being in 4 high and not locked is probably your problem. That's my take.

[e9999]

Originally Posted by pesimsmd

I checked the front of the 100, and I do have a second radiator in front of the main, and I am assuming that it is the transmission cooler. So there fore I have the Tow Package. I have not had a chance to check out the transmission fluid since its recent change with about 1000 miles on the new fluid. I do have one question, why do I need to lock the center diff when in the sand?

well, not sure about the 2000, but on the later US ones, there are 4 heat exchangers up front. The main rad for engine coolant, and in front of that one, an equally big (IIRC) condenser for the A/C, then further up front on the DS a smaller ATF cooler taking about 1/2 the frontal rad area, and finally the power steering cooler which is just some bent tubes.
Not sure if there is such a thing as a Tow Package with an associated rad that is not standard.

Locking the center diff will ensure that if you have one end losing traction you don't end up losing torque on both ends at the same time. So, locking the CD will get you moving more surely and make it less likely to bog down if you do lose traction on one end. And there is no danger of putting strain on the drivetrain as you might on solid surfaces. So, yes, it is probably good to use it. I don't think that not having the CD locked would make the ATF go much hotter though.

And L4L, why exactly do you think most of the torque would go to the rear end specifically with CDL unlocked?

[LandCruisers4Life]

Originally Posted by e9999

And L4L, why exactly do you think most of the torque would go to the rear end specifically with CDL unlocked?

Because it is almost always a 60/40 split or sometimes (depending on what full time system you are speaking of) a 70/30 split in torque between rear and front when the center differential is unlocked. You will only achieve 50/50 with the center differential engaged. If I remember correctly, for instance the FJC is 60/40 split (6sp MT).

[WES1977]

Originally Posted by e9999

also, if you have skinny tires on the trailer, it would probably help to air them down so they don't dig in too much and work as anchors... (my popup tiny tires are really bad for that, in soft sand they are almost halfway in at times...)

Yes you can tell a big diffrence when your aired down over not.

[e9999]

Originally Posted by LandCruisers4Life

Because it is almost always a 60/40 split or sometimes (depending on what full time system you are speaking of) a 70/30 split in torque between rear and front when the center differential is unlocked. You will only achieve 50/50 with the center differential engaged. If I remember correctly, for instance the FJC is 60/40 split (6sp MT).

how do you achieve this with a diff?

[LandCruisers4Life]

The Center diff lock will split torque 50/50 between the two propeller shafts (like locking up two axles). You should already know that

[e9999]

Originally Posted by LandCruisers4Life

The Center diff lock will split torque 50/50 between the two propeller shafts (like locking up two axles). You should already know that

50/50 locked? Where does all this torque go if one end has no traction, then? The CDL will mechanically lock the diff, so you can send the torque to the non-slipping end.

60/40 unlocked? so you have a Torsen in your 100 TC, then...?

[LandCruisers4Life]

When the Center Differential is locked, the power is split 50% to the front shaft, and 50% to the rear shaft. What part of that is unclear?

Most full time 4 wheel drive vehicles have a 60/40 split of power when the center differential is not locked. If you have other information, post it. Otherwise I do not understand your point?

[1loudLX]

behold, the new

[e9999]

L4L, please do come back and tell us how your 100 does a 60/40 split, when you have figured it out if you don't know already. I'd be interested.... And read a bit about torque too? In the meantime, enough of this back and forth for me.

[LandCruisers4Life]

I read this on Full Time 4 wheel drive systems in "Four Wheeler" magazine 15 years ago that the vehicle without central differential locked give about a 60/40 split in torque/power between front and rear shafts, and deliver more to whichever is slipping when that happens.

When the diff is locked, it is 50/50 between front and rear drive shafts, and doesn't change.

e9999 you have contributed nothing yourself.

[LandCruisers4Life]

Originally Posted by 1loudLX

behold, the new

I'm not the one beating a dead horse here. My knowledge came from a magazine, and as well I was told by Land Rover that their vehicles transfer about 70% of the power to the rear wheels when the center differential is unlocked. If e9999 wants to show me otherwise, then by all means.

[gaylon]

pesimsmd,

were you aired down on the vehicle tires - to what pressure? The only time this has happened to me is one time when I was too lazy to air down. Aired down to 10# in each and all was well.

[pesimsmd]

As for air pressure on the tires, I know for a fact that the trailer tires where at full pressure, and 100 tires where at 28 psi. I guess this means I have an excuse to get on board air. ( the mods never end, I think I need an intervention on the mod addicition, at least thats what my wallet thinks)