Trailer towing

[torfinn]

I have just returned from my holiday. During this I towed my 2500 pounds camping trailer (caravan). I have stock setup 225 tires, AW4 and 4.0 and it is an 89. THe tranny has a cooler. The trip was almost 2500 km (1600 miles). No major problems at all.

A minor problem is that when driving at straight road at 80km pr hour the rpm are at 1500. When there is a slight uphill or headwind I cant maintain speed without depressing the gas so much that I almost floor it and a following kickdown. It wont downshift easy. Later I learned the trick to shift it down to 3 manually. It would then have more power at 1800 rpm at 80km/H.

Is this normal behaviour of the aw4 with trailer towing? Or should I maybe have run it in 3 all the time. Any thoughts?

regards
Torfinn

 

[scoobyxj]

Maybe, maybe not. Does the shifting pattern seem to behave the same way when not towing a trailer? If so the TV cable may need adjusted, or the TPS may be going bad. I have found when towing, and at certain times if I need to keep the torque converter from locking up tapping the brake pedal will unlock it. On that note your going to want to use care with that method that you don't overheat the tranny. I'll drop it down to third, and let TC lock up when I incounter long grades, strong head winds, or hilly roads.

 

[asheets934]

When towing with an AW4 you should not put it in overdrive. Towing is to be done in third gear.

 

[torfinn]

I have to admit I just read the instruction manual an it says to use 3 when towing, and even 2-1 when towing in steep grades.

I would have expected the trans to jump out of lockup easier. Just touching the brakes wont let it out of lockup. If I just keep on depressing the pedal it will eventually go from 4 lockup to 3 lockup without unlocking. This will result in a hard shift because the pedal is almost floored. If I shift it manually from D to 3 it will unlock and shift to 3 and then lock again a second later.

The TPS is brand new. Changed it during the trip. The transmission acted equally with the new and old one. Just changed it out of preventive maintenance.

regards
Torfinn

 

[scoobyxj]

I'm going to bet the TV cable is out of adjustment. To set it push the little lock tab down and have some one push the pedal to the floor then release the lock. Best to do this with the engine off. On your other comment of the TC not unlocking when you hit the brake pedal. It should come unlocked instantly as soon as the brake lights come on if not a second earlier (my 2000 has one switch though I think your 88 has two). Then lock back up when you let off the pedal as long as you moving fast enough, or are not giving it a lot more throttle. Do you have cruse, and if it works does it cost after you tap the break pedal? If not the switch that controls the cruse, and tranny might be bad, or loose.

FWIW as stated in an earlier post you should use 3rd, but on flat ground I still use overdrive unless I'm towing somthing quite heavy.

 

[xjtrailrider]

2500# on flat ground its O.K. to use OD but plan ahead for a grade and just ease it down into 3 and get the revs up for the hill. I agree with the others about adjusting the TV, it will help the shifting in all situations!

I tow with my XJ almost every day and for loads under 3500# its a great tow vehicle.

 

[langer1]

Is your Power Comfort switch working? When mines in Power mode it down shifts very easly. When it's in comfort mode it acts like yours.

There is a fuse for that switch marked "Trans" in the fues box.

 

[Matthew Currie]

Is your Power Comfort switch working? When mines in Power mode it down shifts very easly. When it's in comfort mode it acts like yours.

There is a fuse for that switch marked "Trans" in the fues box.

I'm not 100% certain, but I think it will also default to comfort if the switch itself is broken. My 87 was also pretty reluctant to downshift in comfort mode when towing, unless you put the pedal right to the metal.

 

[gjxj]

Ive been towing for years just like that, OD on flats, then manually drop to 3 for significant hills. Downshift before the hill while under light load. If you run in 3 all the time like the manual says it really hoses your mileage.
I pull the trailer ~10k mi/year -- my trailer is only 1200lb or so though.