S33k3r
Full Access Member
It came from the factory with a 4L80e, can confirm. 
2500 Overheating when towing
- Thread starter 02Yukon2500
- Start date
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Mudsport96
Full Access Member
Odd never had an 80 fail towing in 4th. Not saying it isnt possible, just never had it happen to me or anyone i know with even a stock 80e. And i drug a 93 fox back from san Diego to Peoria il on a car hauler at 80-85 in 4th.
02Yukon2500
TYF Newbie
Radiator was flushed a couple months back when I bought the truck. I always do all fluids and filters when I buy something to be safe.
All the air dams are in place and both the trans cooler and radiator fins are clean.
I've started collecting the parts to upgrade the trans cooler. I'll look into the valve upgrade.
I don't see anything obviously wrong with the fan clutch, but it could be dying... Trying to decide if I want to just replace it or switch to electric. Leaning toward going electric as I think it will help a lot with the AC getting hot when stopped.
Thanks,
Danny
All the air dams are in place and both the trans cooler and radiator fins are clean.
I've started collecting the parts to upgrade the trans cooler. I'll look into the valve upgrade.
I don't see anything obviously wrong with the fan clutch, but it could be dying... Trying to decide if I want to just replace it or switch to electric. Leaning toward going electric as I think it will help a lot with the AC getting hot when stopped.
Thanks,
Danny
rockola1971
Full Access Member
It doesnt fail the first time you tow like that. It takes wear and tear (miles) on the tranny and/or subtantial weight being towed (not neccessarily overweight). Just like a 4L60E wont fail the first time you tow with it...usually....unless its worn and has the right amount of weight combined with right amount of wear on the 2-4 band. 700r4/4l60/4L60E are way more prone to do it. While the 4L80E is a totally different design and can handle alot more HP and weight....it isnt bulletproof. If the 4L80E was such a keeper GM wouldnt have stopped making it in 2013.
Sam Harris
Supporting Member
The e-fans will absolutely help with the A/C. It’s a night and day difference. However, I don’t think they work quite as well as an un-worn clutch fan for towing. I could be mistaken though.
S33k3r
Full Access Member
It depends on the efans you get. Specifically, you look at the max volume a clutch fan blows, then get efans rated for the same amount. You only really get into trouble trying to do things on the cheap, just like anything else. The OEM efans will flow less air vs. the clutch fans, at higher RPM, but I'd have to compare specifications to give specifics. On the other hand, how often will your engine be at those high RPMs?
rockola1971
Full Access Member
When im towing and a sly copper saw me go by at 85MPH+ and the next thing I know im wanted dead or alive with 8 smokeys on my tail and my 2-4 band is slipping like a F chassis on 2" of ice!
02Yukon2500
TYF Newbie
I'm skeptical of that. I would bet most of the airflow at speed is being driven by air pressure on the front of the vehicle, not the fan. When running down the highway, the RPMs are low most of the time. As a result, the fan isn't "pulling" much. Sure, you can't put a fan on there that will hinder flow, but I doubt the OEM fan will. If I'm right, the flow at speed should be about the same, but vastly improved when stopped or at slow speeds.
But I'm hoping those that have done the conversion will chime in with real world feedback...
Danny
S33k3r
Full Access Member
I'm a member of several 2500 groups, and they point out 1) GM kept putting clutch fans on the 2500 and 3500s. And 2) you will be hitting those upper rpms under load (towing, inclines, etc.); so you'll have more cooling at low speed in those conditions. And if you tow a lot, you are likely to be in slow speed, high load conditions regularly.
rockola1971
Full Access Member
The highest airflow wins. If the fan clutch or efan has a lower cfm than the incoming air from driving forward then incoming air wins and vice versa. So if you are moving forward at 55mph and at that speed there is 2000cfm of air coming in across the radiator and the fan(s) put out 850cfm of air then there is no air moved forward from the fan(s) because the 2000cfm of incoming air overcomes the 850cfm. The fan(s) take care of business at idle and lower vehicle speeds.
