which sensors should I replace while replacing the filter/fluid?

[jeep-N-montero]

So I am going to replace the trans filter on our 4l80e and was curious if I should replace any sensors while I'm in there? It currently doesn't have any issues, but with almost 140k miles on the original fluid I was curious if I should be worried about any of the sensors, or should I simply wipe the magnetic surfaces where applicable and call it good?

 

[NevadaLover]

If it has no issues then all it needs is a filter and fluid, and clean the magnet like you said, one thing to remember is the 4L80e uses Dexron VI which is synthetic and costs more but the benefits far out weigh the costs.

 

[ckupq]

Yes the trans pan. Replace it with one with a drain.

 

[jeep-N-montero]

Luckily it came with the drain plug from the factory, got it done Saturday amidst a bit of cramped fingers and swearing under my breath, between the heat shield and crossmember some of the bolts were a real PITA to get to. The fluid was a bit brown and the magnet was so covered it was no longer effective, very glad I took care of it before winter and our road trip starting Friday to Maine and back. I will likely do a few drain and fill cycles to get more of the old fluid out, but we aren't towing this trip so should be fine for now.

 

[jeep-N-montero]

If it has no issues then all it needs is a filter and fluid, and clean the magnet like you said, one thing to remember is the 4L80e uses Dexron VI which is synthetic and costs more but the benefits far out weigh the costs.

It's what I used, GM still owns the rights to Dexron VI so even the cheap Supertech stuff at walmart requires specific formulation.

 

[NevadaLover]

Perfect, next thing is the biggest cooler you can mount in place of the stock cooler, the stock works but a bigger cooler will pay huge dividends in the life of your tranny, autos like to be kept cool and in return will last alot longer!

 

[jeep-N-montero]

Perfect, next thing is the biggest cooler you can mount in place of the stock cooler, the stock works but a bigger cooler will pay huge dividends in the life of your tranny, autos like to be kept cool and in return will last alot longer!

I actually have a few to choose from in the garage, one of which is off an f350 and is one of the largest factory trans coolers ever used on a truck, may do this in the spring but the current cooler does fine when towing our boat.

 

[JackE]

Once upon a time I used the A/C condenser out of a '72 Blazer to cool the tranny on my built '62 Scout as a tranny cooler. It worked wonders on that rig. If I had the room, I would do the same on my Suburban. It also increased the capacity by several quarts. I will also be adding a screw on type filter to the cooler line, just one more added level of protection in an easy change format.

 

[rayra]

I was towing about 2000# worth of trailered building materials this weekend and my trans cooler really seemed to pay off. I was keeping well below my prior unladen operating temp, despite having the vehicle cargo area stuffed with tools and towing that trailer. Gross weight was north of 8500#

Only thing not to like is the GM 'Tow Mode' activation is re-set whenever you shut the vehicle off. You have to remember to re-activate it.