Towing precautions and mods

[Dave98XLT]

I have been towing my boat (about 3500lbs) with my bone stock 98XLT 4WD SOHC. I wonder what type of risks to the transmission and engine I am taking doing this? I would like to be able to tow long distances but haven't gone more than about 75 miles so far.

What would be considered the optimum vehicle for towing this type of load, when I say optimum, the smallest vehicle I can get away with for fuel economy reasons? Or is it possible to mod the explorer for this?

I would consider adding an oil cooler or two to help reduce wear to the engine or trans. It already has a small cooler of some sort in front of the radiator. What is the easiest route to take to get any needed additional cooling? Will this alone do the trick?

Is the transfer case another concern running ATF?

The trans shop told me to take it out of OD in the mountains but OK to use OD on fairly level roads. Not real happy with the 4spd trans performance, sometimes it drops down from OD to 2nd gear on a hill. I figure I am stuck with the downshift problem and need to learn to drive so it doesn't happen so much, take it out of OD when approaching hills, etc.

Other than that I am pretty happy with the ride and braking when towing. Rear discs help a lot and you definitely want all the air out of the brake lines. And no texting while driving!

Thanks for reading, and I would appreciate some advice. I know there are whole books written on this site about mods but I am hoping someone can help me avoid too much experimenting or worse killing the vehicle.

 

[colintrax]

At 3500lbs everything is going to get pretty similar gas mileage. Too heavy for TDI VW.
What gear ratio is your truck?
A transmission cooler and frequent fluid changes are a must.
You have a 5 speed, not 4.
If you run stock tires, have a low axle ratio, and keep up on maintenance I don't see any reason you should consider another vehicle. However a F150 would be a better option

 

[VR4]

Get the biggest trans cooler you can fit. Don't bypass the internal or any other trans coolers. Heat is the single biggest thing that kills an auto and towing with an underpowered engine just creates more heat.

They say stay out of od so it doesn't hunt for gears but lockup helps prevent excessive heat from fluid shear in the converter. It's a very fine line.

 

[Dave98XLT]

What gear ratio is your truck?
A transmission cooler and frequent fluid changes are a must.
You have a 5 speed, not 4.

The codes are:
Axel = 45 3.55C
TR = D A5LDE/ 5R44/55E

Per the owners manual the max trailer weight is 4500lbs.

I still think it is a 4sp.

I would like to find out the threads on the transmission pressure test port. I want to install a trans oil temp gauge there. Is this a good place to get a temp reading?

 

[colintrax]

The codes are:
Axel = 45 3.55C
TR = D A5LDE/ 5R44/55E

Per the owners manual the max trailer weight is 4500lbs.

I still think it is a 4sp.

I would like to find out the threads on the transmission pressure test port. I want to install a trans oil temp gauge there. Is this a good place to get a temp reading?

You'll have an easier time keeping it in 5th if you change the axle ratio to 4:10
Go to the junkyard and grab the axle and front different from a 4:10 truck. Your engine and transmission will thank you.
Your truck has a 5r55e transmission. 5 speed, reverse, 550ftlbs, electronically controlled. It doesn't use 2nd gear under "normal" driving which might be why you feel it's a 4 speed.

I installed a temp sender right in the pan. Drilled and tapped a hole in the side

 

[Dave98XLT]

...
Your truck has a 5r55e transmission. 5 speed, reverse, 550ftlbs, electronically controlled. It doesn't use 2nd gear under "normal" driving which might be why you feel it's a 4 speed.

I thought the SOHC engine had a 4-speed. Not the case?

Is installing a temp gauge in the test port not a good idea just to get an idea how the temps run?

 

[colintrax]

I thought the SOHC engine had a 4-speed. Not the case?

Is installing a temp gauge in the test port not a good idea just to get an idea how the temps run?

Not the case, the v8 get a 4 speed. The OHV and SOHC v6 get a 5 speed.
I assume it's fine to stick one in the test port, but why? Doesn't take but a few minutes to drill and tap a hole. You can also buy an aftermarket pan that'll increase the oil capacity and come with a bug for a temp gauge

 

[Dave98XLT]

I will look into these options. Thanks for the advice. What is the difference running in 4th versus going to the shorter gears? i will answer my own question, more shift points and better gear selection.

I need to tow the boat before I can get these mods done so can anyone advise on what the thread adapter size is for the test port so I can install a gauge and at least know when to slow down when things start getting hot? I don't think my mechanic will drill and tap a port without removing the pan. If I install the gauge at least I am taking the first step towards sanity.

Also regarding an extra cooler, the small stock cooler is in the way of mounting a large cooler, so I guess it has to be moved to in front of the new coooler. And a Tee fitting instead of in series is recommended in another post.