Originally Posted by mwells4654
Now it looks like a $500.00 repair. Front seal and pump bushing.
My question - Is this normal for the 4L60E transmission to have this type of problem? I have been asking around and have been told the 4L60E transmission is for light duty towing only and if I am going to tow a 5th wheel or other campers I need the 4L65 or 4L80 transmission. Am I looking at purchasing a different pickup in my future for when I want to tow my Overlander cross country?
No, not normal. The pickle you're in is that you can't fix the likely root causes without an overhaul and that's typically a $3500 repair soup to nuts. I'm not an expert but I'd guess that there is a problem with parts alignment or tolerances or lubrication that's leading to the repeat failures.
I doubt that it has much to do with the short heavy tows you've done. Coincidence maybe, or maybe you're watching more closely and see a leak that's been there for a while.
If you're thinking of replacing the truck anyway maybe it's best to just put in a new seal and sell it.
I have a 4L80e in my pickup and a 4L85e in my suburban. The 4L80e failed after 70,000 miles but the PO had been having his hourly help use it to plow parking lots and I suspect that it had a really hard life.
I would characterize the overall forum experience, with automatic transmissions and larger trailers like yours, like this: Many people find that, even with careful preventative maintenance, the transmission has to be replaced after 100,000 to 150,000 miles of towing. Even if the transmission is a 4L80e. Of course, there are all kinds of variables, like rear end ratio, and driving style, and combined vehicle weight, and how much driving is in the mountains. And to some degree I think it's a matter of luck.
Lots of people tow with a 4L60e but with a heavier rig like yours it's going to have a shorter life. It's a matter of tradeoffs, upgrading to a 3/4 ton chassis isn't cheap either.
I don't think the consumer Allison transmissions are bulletproof either but we'll know in time. There aren't enough older ones out there with 150,000 miles of towing on them to serve as the basis for an opinion. But then again for the cost of the powertrain upgrades maybe just putting the money in the bank to replace the 4L80e when it finally goes is better economically.
I'm probably not much help here but that's the way I see it I guess.