Tow rig, auto tranny warning signs?

Unsure it it's my paranoia or what. Have a 96 chevy conversion van, I use to tow my subaru race car that is 2900 lbs, plus trailer ~1800lbs for a total of 4700. I bought it this spring and has been perfect. Tows great. I live in Vermont, and hills are a part of life. I left for an event this weekend, and didn't warm up the van, temps were in the high 40's. Immediately out of my driveway I have to start up a moderate hill. Didn't want to shift out of first as easy as normal, seemed to be holding it more than normal. It did eventually shift and all seemed well. Less than 3 miles later I had to go up another big hill from a stop and same thing happened. Never really noticed this behavior before. Wondered if it was symptom of a very cold transmission under high load. Certainly think it would have warmed up quicker in that situation.

Is this typical of a cold automatic? I've not had enough automatics to know if this is typical. Is this a warning sign? No slipping. Fluid level appears fine. Doesn't smell burnt. Seems to behave normally beyond first gear.

I bet the fluid wasn't warm enough based on the trans fluid temp sensor.

Some cars with ECTs will hold gear longer when cold to light off the cat for emissions purposes.

I would say dirty trans fluid would be your first indicator of trouble. Asked my buddy (an excellent trans guy) what he though about the 'leave it alone' approach to auto trans maintenance and changing fluid. He said he loves it....keeps him in business.

My Liberty was the same way and usually warmed up in a couple miles.

My 1996 Chevy truck (5.7) does the same thing on a cold morning when I pull out of the house and go up a small hill.

ahhh. Good. I was getting nervous. I'll let Vango warm up a bit next time.

my '97 F150 4x4 shows the same symptoms ... this summer it would go into torque converter lock-up within a mile of the house when the temps were in the 60's ... this morning ( and this afternoon ) the temps were in the high 40's ... in the 3 mile drive to work ... no tclock-up ... and when leaving work it took 5+ miles to do the lock up thing ... same as my Suby ... in the winter mid-30's after work it would take as much as 10 miles before it would go into lock-up ( as much as half a mile before it would shift into 4th)

If you didn't know it already, trannies take a lot of abuse. Keep the fluid freshif you haven't serviced it already.

4L60Es have a temp sensor that is part of the internal wiring harness. It does modify shift points based on temperature. I've seen a few that failed and the shifts are super high (if it shifts at all) and really soft. Plugging those into a scanner shows a trans temp of -64C

Long story short, yes, it should shift differently. Warning signs are different for every tranny - even the same exact tranny in the same model/year. Basically look for changes or hiccups. If its a one-time thing, ignore it. If the same symptom or set of symptoms begins happening more than once you're headed down the path to rebuild-ville.

.........well, it was a warning sign. Tranny died towing my car to Mt Philo.

Rebuild or replace with something uprated. What transmissions are compatible.

being a conversion van, I'll assume its 2wd.....if so, just about any 4l60 should work. (I'm probably wrong with this assumption though)

I guess I'm interested in finding something a little beefier out of the box. Even if it means changing my computer etc.

What you mean died? Lost everything or does it still have reverse and manual low?

Your best bet would be to rebuild what you have, apply every updated part, and install a Sonnax Sure Cure kit. I'd also go ahead and replace the converter, as it probably has some miles on it and might be "too loose" now.

Lost all gears, no reverse.

Could have just broke the sun shell...... Stupid powerflow setup. But the only way to know is disassembly.

Have a reputable shop/guy in a polebarn build one up for you.

torque convertor ? drive plate, oil pump or input shaft are likely. Stupid idea, does the drive shaft turn when on jack stands and the transmission in gear. Is there any noise ?

sachilles wrote: .........well, it was a warning sign. Tranny died towing my car to Mt Philo. Rebuild or replace with something uprated. What transmissions are compatible.

Just have it rebuilt to uprated specs. Spend the money there rather than trying to retro a different trans in.

Kenny_McCormic wrote: Have a reputable shop/guy in a polebarn build one up for you.

What he said

Brian wrote: Just have it rebuilt to uprated specs. Spend the money there rather than trying to retro a different trans in.

Also what he said.

The 4L60E is a perfectly fine transmission, has been around forever, and everyone knows how to rebuild it. So far, I've put 8,000kms on a rebuilt one towing/hauling 7000 pounds through the mountains, no problemo. $1500 for the rebuild with the guy pulling and installing the tranny himself. Don't know how you can beat that!