I have a 06 with with 289k miles. Truck and Transmission runs great. But I tow a heavy RV I’m debating if I want to replace it so I don’t get stuck somewhere. What’s the life of this 5R110? Any suggestions?

 

The 5R110 is one of the best transmissions you'll find. I'd rank it up there with an Allison. Until 2008 they had a bypass filter that filters fluid particles down to 2 microns. The cooling is so good, there is a thermostat to force the fluid to stay at operating temperature. DO NOT use the wrong transmission fluid.


Keep it serviced and expect half million. That means new bypass filter and main filter every 50k miles. Some change it more often. If you don't keep it serviced, all bets are off. I've got 285k on mine and wouldn't hesitate to drive it anywhere.

There are lots of new vehicles with transmissions that cannot be serviced. I don't believe in that. I had one. It was great until the transmission started acting up at 178k miles.

 

I agree the 5r110 is a great transmission. They even somewhat live at the 500hp level. 08 pan and filter mod, fresh Mercon SP, don’t beat it too bad and they live a long time. I’d be looking at a Sam Wyse when my 5r110 goes. I’m at 258K and it’s solid. I might be waiting a while.

 

That's not actually the truth. Many transmissions have thermostats. The purpose isn't to combat "too good a cooling system" but rather to allow the transmission to get up to temperature more quickly. When the fluid in the transmission is warm (not hot), it performs better. There is less wear and tear on the transmission, better fuel economy, and lower emissions. Those are the reasons a transmission thermostat exists, and it is very common today.

I'll take a little more measured approach. The 5R110 is a significant improvement over the previous 4R100. It is a good transmission that can last a long time. Some transmissions will fail prematurely. Some will last a long time. How the vehicle is used, driven, and maintained will have more to do with it then the overall design. A low mileage 5R110 that has been used to plow snow and tow heavy trailers will not last as long as a higher mileage 5R110 that has been used for commuting or the occasional tow, all other things being equal.

My opinion is that transmissions typically don't fail from one day to the next, they show signs of problems such as hard shifting, slipping, slamming into gear, etc. I wouldn't worry about the ultimate "lifespan" of a transmission, but rather, how is it working now? If it is shifting smoothly, the fluid is clean and full, no signs of problems, you can confidently drive it. That goes for towing with it too.

 

If you are running tunes, then that can also impact things. I have spent quite a bit of time with the SRL+ tune and I have to believe that it is a well written tune. I have not had any transmission issues in 242k miles. Pretty rigorous fluid and filter maintenance helps also!

 

Just to clarify: the original bypass filter only really gets trans fluid sent to it when the transmission gets warm enough for the thermostat to open. At that point the most fluid that will get filtered is around 10% (it's a bypass filter afterall). This is why the upgrade to the '08+ trans pan and filter is such a good thing to do, because it is a very fine filter that is now in the full fluid stream, filtering 100% of the trans fluid any time the engine is running. You can continue to change out the front bypass filter, or just leave it in there forevermore - do not run that canister empty as it affects the flow of oil to the trans cooler. You can also run Mercon LV or any combination of LV and SP...

On edit: Forgot to say the '08+ filter should be changed every 60K miles...

 

I know I'm the contrarian, but I'm not a fan of the 08 pan and filter. Yeah, yeah, yeah. Save your breath. The bypass filter filters down to 3 microns. The 08 filter does not. I've never seen such clean transmission fluid after 280k miles as I've seen using this bypass filter.

I honestly don't know why more aren't running the transmision bypass filter as an oil be bypass filter. It does a great job. I thought about that before deciding on using the Franz toilet paper bypass oil filter.