Beach Driving Assateague Island and Trans Temp Light

trailpixie · **Posted:** Mon Feb 02, 2009 2:19 pm

So we went to Assateague Island in Maryland on Saturday. The weather was beautiful. You can barely tell from these photos that it was 35 degrees with a 30 MPH wind whipping-up the sands. We took lots of pictures, particularly of the elusive Snowy Owl who is wintering on the island this year.

We headed out in the morning. We didn't have a long drive on the beach planned, so I decided not to air-down to go out on the beach. We did fine as we silently cruised down the ocean-side. Around noon, we returned to civilization and then headed back to the beach at 2:00. During our third drive down the sandy trail, the 'Trans Temp' light went on. It seems like it wasn't down shifting and it was staying in a low gear almost constantly. I stopped and let the temp light go off. I put it in low (before I was in Part Time) and proceeded. No more problems. I decided that perhaps it was time to air-down to 20PSI--thinking that might reduce the strain of the engined by reducing how much we were sinking in the sand. It seemed to help our handling and performance on the sand, but on the final return after sunset, the light went back on. We let it cool and proceeded again. Driving on the road since our trip hasn't seen any odd behavior.

does anyone have any ideas about what I should do next time. Did airing down have any effect? Do I need to have the transmission serviced. I know that a dozen people will tell me I need some exotic synthetic transmission fluid, but I am skeptical. It should be able to handle beach driving without overheating the transmission.

Otherwise, I have to recommend to all within 200 miles, that you make a trip to Assateague this winter. It is far better in winter than summer when the biting flies and mosquitoes are unbearable.

You can see more pics of the landscape here:
http://www.trailpixie.net/general/sand_water_sky.htm

blake1827 · **Posted:** Mon Feb 02, 2009 3:13 pm

Being landlocked my only experince was getting stuck on S. Padre Island as a kid in a FWD Subaru Justy. It got bogged down and nearly overheated...
But a quick Google and lowering air tire pressure in sand is key to traction, you really don't need it in 4WD unless your tackling dunes.

from a non bias non 4x4 site...
http://www.ehow.com/how_2093881_drive-sand.html?ref=fuel&utm_source=yahoo&utm_medium=ssp&utm_campaign=yssp_art

Pablo · **Joined:** Thu Feb 02, 2006 10:06 pm **Posts:** 1201

There were a few combinations of cooling systems on these. Do you have a transmission cooler? Does it sit next to an electric fan?

If so, is your electric fan working? The electric fans have been known to bind up with mud, sand, etc. over time. Cleaning them out gets them back up to speed.

I would add a transmission cooler before I would spend money on fancy fluids (if you don't have one).

In case you don't already know: when in the sand and going slow, try to keep it from constantly shifting back and forth. Perhaps use 2nd instead of drive, or put it in 4-low. This will keep the temps lower. Every time you shift back and forth, the trans gets warmer. This is why when the light comes on, it stops you from shifting into higher gears-- it leaves it in one gear until the temp lowers. Stopping and starting at slow speeds in heavy drag (like sand) is hardest on the transmission because it shifts constantly under more pressure and has the least amount of cooling (air moving over it or the cooler).

trailpixie · **Posted:** Mon Feb 02, 2009 4:46 pm

Pablo wrote:

There were a few combinations of cooling systems on these. Do you have a transmission cooler? Does it sit next to an electric fan?

If so, is your electric fan working? The electric fans have been known to bind up with mud, sand, etc. over time. Cleaning them out gets them back up to speed.

I would add a transmission cooler before I would spend money on fancy fluids (if you don't have one).

In case you don't already know: when in the sand and going slow, try to keep it from constantly shifting back and forth. Perhaps use 2nd instead of drive, or put it in 4-low. This will keep the temps lower. Every time you shift back and forth, the trans gets warmer. This is why when the light comes on, it stops you from shifting into higher gears-- it leaves it in one gear until the temp lowers. Stopping and starting at slow speeds in heavy drag (like sand) is hardest on the transmission because it shifts constantly under more pressure and has the least amount of cooling (air moving over it or the cooler).

Thanks for the suggestions.

I have the towing package and the offroad package, so I think I recall that this means I have a transmission cooler. I will check to see if it has a separate fan and if it is working. I think I recall that the transmission cooling radiator just sits in front of the regular radiator and is air cooled without a fan. It was windy and 35 degrees out, so it should have been okay.

I tried it in both 4Lo and Part Time. The light went on in both modes, including after I aired down to 20PSI. It wasn't shifting frequently. I was trying to keep it in one gear, although it seems like it stayed in a lower gear, like first, for a most of the time. After airing down, I was able to get it into a higher gear, maybe second, for more time.

htkrph · **Posted:** Mon Feb 02, 2009 5:37 pm

i dont know on the technical terms but that place looks beautiful. was it crowded?!

trailpixie · **Posted:** Mon Feb 02, 2009 6:03 pm

In the whole day we were there, we saw about six other vehicles--two of them hunters, and the others just driving the beach. It was very quiet.

sleeve84028 · **Posted:** Mon Feb 02, 2009 6:28 pm

Was your KJ loaded down with a lot of gear? The combination of sand, slow airflow, added weight and small transmission cooler might have been all conspiring to cause you to overheat.

I did a search for past history of trans lights coming on when driving the beach but couldn't find any thing in my 5 minute search. I do remember other posts about similar problems though.. So there should be some history on the boards about the issue [and possible fixes].

scoobysnax · **Posted:** Mon Feb 02, 2009 7:48 pm

The off road and the tow pkg both include aux cooling for the transmission and the power steering so it sounds like may have a problem with your trans. I would first check the fluid level and be sure it's in the right spot. Check for leaks too in the hoses. If that comes up fine maybe your thermostat is on the frits. I think you can check this by driving the Jeep a bit and getting it up to normal operating temps. Feel the upper and lower main intake and exit radiator tubes. I believe the one on the bottom should be hot and the one coming out the top should be cool. I'm sure someone else will correct me but if they both feel like the same temperature your thermostat is not opening up. I’m also sure someone with more knowledge will chime in.

As for tips to driving on the beach...

air down
slow steady speeds
no fast starts
4wd part time
O/D off
use the shift lock out. If you're going under 10mph just keep it in first. If you're getting up to 20+ keep it locked out in 2nd so can shift back and forth.
4L helps a lot, keep the O/D off and in the D position. Don't drive faster than 25mph

The deeper and softer the sand the more you'll want to do the above tips. 2wd is only for very hard sand. 4-full time I would not recommend b/c you'll also increase the temp of the transfer case when the clutch is constantly locking up and unlocking the front and rear axles. Some situations may require less than 8 psi and 4L. The lower the air pressure the more your tires will "float." In general in regards to the Liberty, the smaller your tires are (215/75/16) the more you'll need to air down compared to the 235/70/16 size. When I went up to 245/70/16 I noticed a big difference.

As you drive your tires are constantly pushing a wall of sand in front of the tire, could be an inch, could be 4 inches. So your tire is in effect always trying to drive over a small hill or bump. Think about trying to drive up a curb dead on from a dead stop - it's a lot on the engine. But in 4L it's no big deal.

JeepinJarhead03 · **Posted:** Mon Feb 02, 2009 9:15 pm

I had a pretty consistant trans temp issue with a v6 chevy crew cab 4x4 in sand. I ended up putting a B&M tranny cooler on it that took care of the problem, it ran about 60 bucks IIRC. I have a Chrysler/Jeep parts catelogue that lists a 2nd aux tranny cooler for the libbys but it seems to be about 300 dollars.

I'm with Pablo, before spending any money I'd make sure that your electric fan is operating correctly on both low and high speed. The resistors on the elec fans (block with 3 wires going to pack and 2 wires going to fan) do go bad occasionally which can cause the fan to operate on only low speed, or high speed or not at all. Computer controls the fan speed unlike most aftermarket fans that have their own control and temperature taps.
But if you aren't having heating problems at other times I'd imagine that it is working properly.

I havent had any tranny heat issues with my renny but the sand here is usually pretty hard with exception of the beach enterances. Let us know if you figure something out.

-Mike

Jeepjeepster · **Posted:** Mon Feb 02, 2009 9:28 pm

trailpixie wrote:

I put it in low (before I was in Part Time) and proceeded. No more problems.

I know that a dozen people will tell me I need some exotic synthetic transmission fluid, but I am skeptical.

Lowering air pressure will increase rolling resistance.

Really the only thing you can do is get a bigger tranny cooler. All libertys with the 42rle come with a tranny cooler. All the offroad pack gives you is another fan which is driven by the engine. Check the electric fan to make sure its working.

Sounds like you were limiting it to a lower gear which is good. Use 4low as often as you can if youre going slow enough.

The liberty came with syn fluid from the factory, ATF+4. Its a good idea to change the fluid more frequently if youre driving offroad often. I like to drop the pan at least every 30k with a filter change. Only use ATF+4. This will not solve your problem, its just something that needs to be done.

scoobysnax · **Posted:** Tue Feb 03, 2009 12:01 am

Decreasing tire pressure in the sand will actually help the rolling resistance. It allows the tire to float rather than dig into the sand. Check out the website below which gives more info. And after all that just try heading to the beach and test both ways. Keep it in 4x4 part time and drive around a bit. Now get out and drop all 4 tires down to 10 psi and note the difference. It’s pretty dramatic (in soft sand.)

http://www.4x4now.com/sfjun96.htm

tjkj2002 · **Posted:** Tue Feb 03, 2009 12:08 am

The KJ's with the 42RLE have a tranny cooler but it is a stand alone cooler that can not control temp spikes that driving in sand can and will create,even with HD cooling.The KJ's that have the 45RFE trans have the tranny cooler in the radiator which can control temp spikes,does not need HD cooling for this action either.

The best bet would to keep it in 4low and the lowest gear possible(1st or 2nd) to keep the trans temps in check.

To get a better trans cooler setup get a radiator ment for a '02 KJ,then you will need to cut and modify the pressure line from the trans(the one going to the cooler) and route it through the cooler built into the radiator.Then run a line from the otherside of the cooler in the radiator back to the 42RLE's original cooler.That way you will get the temp spike regulating ability of the in-radiator cooler and the added cooling of a stand alone cooler.

htkrph · **Posted:** Tue Feb 03, 2009 7:41 am

maybe has nothing to do with it... but having your KJ affect its performance or something while in 4hi or 4lo? thats just for my SA.

trailpixie · **Posted:** Tue Feb 03, 2009 10:41 am

So here is what I am hearing:

1) inspect trans cooling system
2) check fluid levels
3) air-down a bit more--closer to 10psi
4) run in 4Lo
5) pay attention to temps and let the jeep rest when it gets hot. This happens sometimes.
6) if I do all of the above, don't worry.

scoobysnax · **Posted:** Tue Feb 03, 2009 11:38 am

no need to drop down to 10 psi right away. With my 245's that I normally run at 35 - 37 psi on the street I will drop them down to 25 psi on the sand - most of my beach driving is on small beach so I'm not going that far and while the sand is deep it's also pretty coarse so traction is not too bad. If I'm on a longer beach section I'd go to 20 psi. If the sand is very soft and you can fill a little wheel spin or the engine in struggling then go even lower. Test it out a bit until you think you've found your sweet spot. Lower them in 5 psi increments so you can notice a difference each time.

Good luck!

sandman · **Joined:** Fri Sep 08, 2006 10:40 am **Posts:** 40

I'm very familiar with assatuague Island as I drive my 04 liberty on NJ, DE, and MD beaches. I havea few friends who also take their KJ's on the sand. I have never had or heard of anyone getting a trans temp light before. We surf fish and that means alot of gear including large coolers full of ie, drinks and hopefully fish. It sounds like your doing the right thing by airing down, I normally run at 16-18 psi in 4HI when on the sand. Only time I've used 4LO is for very chewed up areas where the sand isn't hardpacked. At that time of year and judging from your pic the beach was fairly well packed, without alot of soft stuff. Im not sure why your getting the light but it doesn't seem right, especially since you didnt have a loaded vehicle. I could understand it if you were out in the summer when the beach gets chewed up by guys who don't air down or don't know how to drive in the sand, crossing the ruts can put alot of strain on your trans but it doesnt seem like this is your case.

Remember:
air down
stay in the tracks when possable
slow and steady

ReneDave · **Posted:** Wed Feb 11, 2009 12:42 am

In medium soft sand like Assateague's keep it in 4HI, turn off overdrive (probably the biggest help to keeping your transmission cool), air down to 18PSI, and disable the ESP. Put it in drive and keep a steady pace. Only use 4LO if you get bogged down in deep or soft sand, and then only after you've aired down a bit more. It's not at all uncommon for the transmission to heat up in soft sand with overdrive turned on, and not uncommon for the brakes to overheat if ESP is left on.

Beach Driving Assateague Island and Trans Temp Light

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