Have a 93 Chevy G30, been using it for a bit. Bought it cheap. I am about to go pick up a new enclosed trailer. I attatched 2 pictures of the trans, best i could get tonight.

At some point it had a rewiring done on it, as you can see its not stock lol.

Truck runs great, shifts great.

Anything i need to know to about to help it last longer? Truck/trailer combo is pretty heavy.

I plan on changing the filter and fluid this weekend. Anything special needed?
Thought about getting a larger pan, and a temp gauge.

On the right side, can anyone tell me which cooler line is the in/out? Sorry so many questions!

 

The top line is the outlet to the cooler, the lower one is the return inlet from the cooler. Later models have the return line in the rear and omit the internal oil tube that supplies the tailshaft.

You see a lot of discussion here about "not towing in Overdrive with a 4L60-E" but there is no such concern with the 4L80-E. The 80 has a massive dedicated planetary gearset for overdrive. It is intended to hold up under full engine input torque for continuous duty.

Keep it cool and you won't have any problems towing with it. Honestly, they don't run hot unless you have high-stall speed converter in it. The stock spec converter for a 4L80-E keeps the stall speed low and prevents overheating with load.

As for the rewiring... not sure someone did you a favor there. At least get some loom around it.

 

What is the generally accepted "safe max weight" to tow in OD with a stock 80E? 2500lbs? 5000lbs?

I tow an 18.5' double axle trailer, my 72' is approximately 3900 lbs. I believe the trailer is around 1500 lbs. The thought of attempting to tow 5500 lbs in OD scares me.

 

Anything you can move with less than 400ft/lbs of torque. You'll kill 3rd in a stock 80E before you kill 4th.

I've pulled 8300# in OD without issue, aside from some faulty electric brakes. Granted, mine is heavily modified and has a 40K cooler, but it also had a 4200 stall converter at the time.

 

Good to know. Mine is lightly modded with emphasis on low speed TQ. It towed fine with the stock 5.3/60E, but was very thirsty. I'm hoping that the swap I just did greatly improved how well it tows. (And it would be nice if it was better on gas when towing)

 

The only difference in feel towing with it in overdrive will be the shallower overdrive ratio (.75:1 versus .069:1 for the 4L60E)
You will also feel each shift being distinctly crisp and linear under the additional load versus the 4L60-E where the 2-3 will always flare up and/or bog since it's a dual event sequence - the band has to release as the 3-4 clutches apply. Then you have the band in the 60 for the 1-2 and the 3-4. Bands do not have a linear apply feel.
All shifts in a 4L80-E are done by a dedicated clutch pack for each gear and are each single apply events. Neither of the two bands in an 80 do the upshfiting, bands are used for reverse and manual 2 and 1 only. A 4L60-E 2-3 shift will always feel sloppy.
As far as weight, a 4L80-E can pull 20,000+ pounds around in overdrive, which is far more than a half-ton chassis can handle.

 

Great info James, I never towed a loaded trailer in OD with my 60E. I expect to tow between 5000-6000 lbs max. (Combination of car and trailer) I'm going to have to look into solutions to make it more stable at speed.