Towing ?'s - tranny cooler - temp gauge etc - please help

First off I have a 96 4.0 AW4 (auto) with a class 3 = my jeep being rated @ 5000lbs (w/cooler)

Ok, so I just bought a 20' ski boat on a dual-axle trailer w/ brakes and it's not nearly as easy to pull as I had previously thought it would be. I used to pull a single axle 17' boat and this new one feels like 3 of them. When I picked it up the other day after about 20 min of driving my oil pressure (i think, ....its the one with the little oil dropper icon in the upper right) it kept dropping to like 20 when I would slow or stop and rise back up to 40 (or what ever is right in the center) when I would accelerate and drive. This is the oil pressure and not the oil temp, right? but my question is, is this normal? or should I check my oil pump or something? should I be worried about this?

Ok, so I have read around on here quite a bit about people running an aux tranny cooler (I'm prob gonna get the one from summit for like $50ish) and using a temp gauge. does that cooler come with a temp gauge or is that a seperate component that I need to get elsewhere?

When I bought my jeep it already had the tow hitch, I have read that jeeps that came with a tow package have trans coolers...does this mean that if the hitch wasn't factory then I prob don't have a tranny cooler? How/where can I check to tell?

So in conclusion, I have read that if I get an aux tranny cooler I should be fine (within reason) to tow this (guesstimating) 3000lb boat. I have also read that EVERYONE says to keep the tranny out of OD. but since there is no OD on/off switch ....what should I do about that? Some said to just pull in 3rd, (but doesn't the tranny have 5 grears?) so wouldn't I be robbing myself of the gas mileage etc of towing in 4th? (cause IFRC OD would be the 5th gear??) Please let me know if this is correct, or if I am an idiot. And I have done plently of towing, so I know about being safe and taking it slow etc....and I'm getting ready to overhaul the braking system on the trailer to make it the best it can be....cause we all know our cherokees aren't the best stoppers .....especially when pulling something close enough to its own weight. Thanks a ton!! and tell me anything else you think would help me with this.

96CheroKeeClassik said:

First off I have a 96 4.0 AW4 (auto) with a class 3 = my jeep being rated @ 5000lbs (w/cooler)

Ok, so I just bought a 20' ski boat on a dual-axle trailer w/ brakes and it's not nearly as easy to pull as I had previously thought it would be. I used to pull a single axle 17' boat and this new one feels like 3 of them. When I picked it up the other day after about 20 min of driving my oil pressure (i think, ....its the one with the little oil dropper icon in the upper right) it kept dropping to like 20 when I would slow or stop and rise back up to 40 (or what ever is right in the center) when I would accelerate and drive. This is the oil pressure and not the oil temp, right? but my question is, is this normal? or should I check my oil pump or something? should I be worried about this?

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This is your oil pressure, there is no factory guage for oil temp

Ok, so I have read around on here quite a bit about people running an aux tranny cooler (I'm prob gonna get the one from summit for like $50ish) and using a temp gauge. does that cooler come with a temp gauge or is that a seperate component that I need to get elsewhere?

Click to expand...

The tranny cooler that I bought from Jegs did not have the guage with it. I'm 99.99% sure that the Summit Racing one doesn't have a guage either

When I bought my jeep it already had the tow hitch, I have read that jeeps that came with a tow package have trans coolers...does this mean that if the hitch wasn't factory then I prob don't have a tranny cooler? How/where can I check to tell?

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It will be located in front of your factory radiator. It basically looks like a half width radiator.

So in conclusion, I have read that if I get an aux tranny cooler I should be fine (within reason) to tow this (guesstimating) 3000lb boat. I have also read that EVERYONE says to keep the tranny out of OD. but since there is no OD on/off switch ....what should I do about that? Some said to just pull in 3rd, (but doesn't the tranny have 5 grears?) so wouldn't I be robbing myself of the gas mileage etc of towing in 4th? (cause IFRC OD would be the 5th gear??) Please let me know if this is correct, or if I am an idiot. And I have done plently of towing, so I know about being safe and taking it slow etc....and I'm getting ready to overhaul the braking system on the trailer to make it the best it can be....cause we all know our cherokees aren't the best stoppers .....especially when pulling something close enough to its own weight. Thanks a ton!! and tell me anything else you think would help me with this.

Click to expand...

Get a FIRM number on the weight of your boat. It should be listed in the documentation that came with it. There are different kinds of braking systems included with trailers, make sure you know which one you have.

The auto box only has 4 gears, the manual has 5. By putting it in 3, you are basically taking O/D out of the equation.

-Ben

The oil pressure gauge will read high when the engine is cold because the oil is thicker. My '92 reads around 50-60 psi when cold and about 25 psi when the engine gets warm and the oil thins out. Once at operating temp it will go up and down depending on engine rpm. The AW4 is a four speed and when towing and the trans starts shifting between third and fourth definately shift manually into third to keep the trans from overheating as the fluid is very thin and heats up quickly. Aftermarket trans coolers usually don't come with a temp guage. I bought a B&M supercooler and mounted it in from of the radiator where a factory cooler would normall sit. As an added benefit I installed a Permacool transmission filter between the trans and the transcooler. It is bolted beneath the radiator and consists of a spin on oil filter and has a temp gauge in it. Just an idea since it provides extra filtering and the ability to monitor temps. They are offered at Jegs and summit racing but I think Jegs offers free delivery.

Ok, now you've figured out if you can pull it, but can you get it stopped safely?

A good rule-of-thumb I use to help me decide if I need extra breaking or stabilization. Passed on to me by an old farmer when I was hauling hay.

Trailer brakes - When the trailer weight equals 1/2 the vehicle curb weight.

Load levelers and trailer brakes - When the trailier equals the vehicle curb weight.

A new, larger, tow rig - When the trailer equals two times the vehicle curb weight.

The XJ are not known for their breaking ability and they are relatively light weight (approx. 3000 lbs curb weight), so if you are pulling a 3000 load I would proceed with caution. At the least, I would look into trailier brakes. Comming out of the mountains in Canada a few years back I warped the rotors on my XJ towing two snowmobiles, probably around 1750 lbs total weight. Scared the hell out of me, I didn't know if I was going to get it stopped for a minute. Once I got it pulled off the road and my wife's fingernails removed from my arm everthing turned out fine. Once the rotors cooled I was able to stop with only a slight shimmy the rest of the way home. Once home, I replaced the rotors with some higher quality rotors. Good Luck.

Woody

I tow a 3100# 19' bass boat(single axle trailer) with my 96'. I would guess that a 20' boat and a dual axle trailer would wiegh more. I run a 30,000 gvw Hayden tranny cooler like what is used on 1 ton trucks, its overkill but trannys are expensive. I also run a B&M tranny temp guage to keep up with it(it usually runs 170 degrees on a 90+ day). My XJ has been modified in other ways for towing also: OME constant heavy load rear springs and med load front, 4.10 gears and 8 ply 30" tires, Currie JeepSpeed chassis stiffeners and a few performance mods. You will be fine if you have brakes on your trailer, I run TieDown Eng. surge/disc brake set-up which brings me to stop real well. Use "D" and give some distance to whats in front of you. And by all means put a cooler on it!

Thanks guys, you have given me a much better idea of how to go about pulling this thing around gear wise. But, of course I have a couple more questions.

I know this may sound rediculous but when the tranny is manually put into 3rd, is it only in third the entire time? Or does it work its way up to third, for instance, from a stop, dropping down into 1st, then 2nd, and then staying in 3rd? Or should I manually start out in 1-2 gear from a stop, and then bump it into 3rd as I get going?

The braking system on the trailer is the kind where the momentum of the trailer (when applying the jeeps brakes) forces the ball to move some sort of mechanism forward inside the tongue, resulting in the trailer braking. anyone know what this type is?

And finally, I took a look at the front of my jeep to see if I had the factory tranny cooler. (oh, and my hitch is a draw-tite, so its def aftermarket) Someone posted earlier (sorry, can't remember who without looking back) that the factory tranny cooler looks like a half-width radiator. After inspecting my jeep I still can't tell what I have. It appears to me that I have one, but I don't know if it is or not. It looks like I have one but it looks like its a half-height full-width that sits in the lower part of my radiator. But I just don't know enough to tell if this is in fact my radiator, and the thing behind it is just something else? or if this is a tranny cooler?

Could someone please post some pics of perhaps just their factory radiator, and maybe even some with a factory tranny cooler?

Thanks a billion in advance!!

which side is tha half width part on? It could be your AC condensor. That would be on the passenger side.
You have "surge" brakes on your trailer.
When the trans is in 3rd it uses all gears up to that point. SO just drop it in 3rd and forget about it. You could probably tow in OD if it was a long flat stretch, but forget about it going up hills.

Your AC condensor sits directly in front of the radiator and is almost as long and about half as thick. You can identify it by tracing the hoses. They runout of the passenger side and run back to the AC compressor. The factory transmission cooler is much smaller. If I remember from my set up it is only about 10" to 12" long, 8" to 10" high and about 1" thick. It has two hoses running out from it. One hose comes from the radiator just under the pressure cap and the other hose is a return line that runs back to the transmission. The tranny cooler sits in front of both the AC condensor and radiator. Hope this helps