Last season while camping at an RV park, I was talking with a gentleman who told me to always turn off the overdrive on my E150 when towing my 25 foot travel trailer. He said the overdrive would burn out and cost me a fortune. I run a big V-8 and have only small issues with big inclines. Has anybody got an opinion on this?

 

Pat -

Two schools of thought here:

1) Leave OD on while towing, unless the tranny is "hunting"

2) Never run OD while towing, for the reason you mentioned

Someone posted here awhile back about a tranny tech who said the same thing as your gentleman.

I use the #1 method but if I ever hamburger the OD I may switch to #2. Maybe some tranny gurus can jump in here.

Steve

 

pat,

have you gotten any more done on the 32 ?it looks sweet . post some more pictures.

 

There is nothing fundamentally wrong with towing overdrive. The problem is that people don't pay attention to what their truck is doing and it hunts gears going up hills. Shifting gears is hard on an automatic, and if it does it too many times over a short period, the tranny will overheat and fail.

So to cover their butts, manufacturers recommend that you lock it out of OD while towing. That's the only real reason that I've ever heard.

 

Drive in the tallest gear that the torque converter will stay locked in. An unlocked torque converter is the main heat generator in an automatic transmission.

 

Bingo!

The trick is to really watch the tach and "feel" for the torque converter clutch unlocking. In addition to the heat generated in the fluid from the converter "working", the TTC in the E4OD transmission is a known weakness. Minor slippage is difficult to detect. By the time it becomes major, other transmission symtoms, like VERY HARD shifts result.

Jim

 

I agree with rclarke. Keep the torque converter locked up. That little "shift" going into overdrive is the converter locking up. BTW was the 'gentleman' driving a chevy or maybe a dodge?

 

I pull a small toy hauler with my Explorer. I was told to leave overdrive off by pretty much everybody. But, beeing the rebel I am...I can cruise down flat road with it in OD and the tranny seems hooked up, so I leave it. If Im pushing into a slight wind or grade (very slight) I hit the button to save it from hunting. Is this reasonable behavior, or should I just leave it off?

Granted its not a real tow rig, I have to get it in third (second once ) and put my foot in it to get over any hills.

 

i take mine out ..the owners manual says you should even if you have a load in or on the truck ,,, but with that said,, if you are on even terrain i dont see a problem but hilly areas or such i would take it out of OD..

 

I burned up a 94 F150 with the 351, pulling a 16 foot trailer with a small tractor on it. It was years ago when I didn't know better. I didn't know the truck didn't have a lock up converter so when I was crusing along in od, the rpms was low enough for it to not catch good enough, and with the weight, built up the heat and it was toast. So yea, if you have a lockup converter, and you keep it in a rpm range where you know it will be fully engaged, you should be ok...

 

A '94 F150 did have a lockup torque converter. It may not have been locked when you were towing in OD, depending on you speed and load.

 

Good to know, its my dads truck. That happened when I was 20, about 7 years ago. He still drives the truck. Thats what he told me the shop told him. I don't have any idea what tranny it has, never needed to. Was it E40d its got?? That sounds right, but the shop told him it didn't have a lock up converter. Maybe that was just what they told him since he wouldn't know anybetter. Glad I didn't have to rebuild it. I had hell rebuilding the 4t60e in my wifes 96 lumina. Hard as heck to get it out of the car and back in. Then I got a video and a manual, and did the rebuild myself. Ended up the cross pin in the diff. broke and the cross shaft was grinding on the final drive housing. Thats probably why it failed. I replaced the housing and pin, new pump cover, new valve body, a new pipe baffle looking thing and what not. All new seals, clutches, bands. I messed up when I didn't replace the solenoids inside. I checked them, and they seemed ok. But when all back together it wouldn't shift into first or overdrive. There was a solenoid not working properly. We traded it in on a liberty. I did the rebuild on my B2's C4 myself though. A TCI rebuild and shift kit, and it didn't include the low reverse band, so I bought that seperately. If I'm going to rebuild it darn it, I want to do it all. It works. GOOD... It will bark the 39.5's shifting itself through all three gears. And your probably right. In od the rpms probably wasn't high enough for it to lock up, thus all the heat and failure.

 

My '97 Mountaineer with a 302 and 4R70W said it's OK to tow in OD as long as it isn't gear hunting. I was pulling a 6x12 enclosed U-haul (before U-haul quit hooking up to Explorers) full of furniture and stuff moving home from college, and on the flats the transmission was staying cooler (according to the trans temp gauge) in OD. Once I got to the hilly parts and the the transmission was gear hunting and the torque convert wasn't staying locked very long, I took it out of OD to keep the transmission cooler.

The best thing to do is to install a transmission temperature gauge to keep an eye on temperatures and to have a big cooler for that extra piece of mind.

 

What is the RPM range that is required for the torque-converter to lock up?

My v10 runs at about 1800 at 65mph in od.
I am about to tow a car 1,300 miles and I would like to get the best mileage possible.

 

Most lockup torque converters show 200-400 rpm change between unlock and locked. I have noticed my v10 sometimes requires a very slight increase in throttle to lock the torque converter when I have downshifted to 3rd or 2nd. An E4OD torque converter will lockup in 2nd, direct, and OD. I haven't been able to detect lockup in 1st.