66RFE Lifespan

[FlatbedHemi]

Just finished changing the fluid and replacing the thermostat with the bypass. Took a little longer than I expected, but I was working a lot slower than the guys on YouTube, trying to not make a huge mess. Overall I was pretty surprised at the condition of the fluid. It was still bright red and showing no signs of burning. It was a little dirty, but again, still bright red. The pan was clean with no sludge in it, but the magnet was pretty well covered in silver sludge. Still not as bad as the 4L60E I had in my silverado. I think the 4.88 gears really help keep the transmission from straining too much.

Been watching the temp gauge on my dash and it pretty well stays between 165 and 172, with most of the time bouncing from 168-170, so I feel pretty certain the thermostat was still working, but now that the bypass is in, I don’t have to worry about that one anymore. Temps with the bypass on are running about 155 now.

Like I said before , I worked a little slower than most, and ended up with quite a bit draining out during the process. Ended up having to put 10 qts back in. Not sure how much it holds total , but I figure that’s a pretty good chunk of it I replaced.

Gonna do a much better job of keeping it maintained now. Keeping my fingers crossed that we’ll keep her going for a while longer.

 

[buckeyexx]

I would say you did pretty well. I just changed mine and put a little over 9qts back in just doing the valvebody and filters. When I did the bypass I lost about a quart at that time so 10qts going in for you sounds right.

 

[HEMIMANN]

Just finished changing the fluid and replacing the thermostat with the bypass. Took a little longer than I expected, but I was working a lot slower than the guys on YouTube, trying to not make a huge mess. Overall I was pretty surprised at the condition of the fluid. It was still bright red and showing no signs of burning. It was a little dirty, but again, still bright red. The pan was clean with no sludge in it, but the magnet was pretty well covered in silver sludge. Still not as bad as the 4L60E I had in my silverado. I think the 4.88 gears really help keep the transmission from straining too much.

Been watching the temp gauge on my dash and it pretty well stays between 165 and 172, with most of the time bouncing from 168-170, so I feel pretty certain the thermostat was still working, but now that the bypass is in, I don’t have to worry about that one anymore. Temps with the bypass on are running about 155 now.

Like I said before , I worked a little slower than most, and ended up with quite a bit draining out during the process. Ended up having to put 10 qts back in. Not sure how much it holds total , but I figure that’s a pretty good chunk of it I replaced.

Gonna do a much better job of keeping it maintained now. Keeping my fingers crossed that we’ll keep her going for a while longer.

Performing exactly as it should! And running trans oil temp exactly where it should - and did - before EPA got these vehicle makers jumping through ridiculous hoops to get miniscule fuel mileage gains at the expense of product durability and price.

You just took your truck back to pre-absurdity era, congratulations. How many miles were on your trans oil?

personal rant - I hate the term 'fluid' for transmission oil, as if it is something magically different than all other oil lubricants. It's not - it's oil, usually a bit higher oxidation (temp) resistance than engine oil, without some engine oil additives, and some added transmission oil additives (friction modifiers).
<end rant>

 

[FlatbedHemi]

You just took your truck back to pre-absurdity era, congratulations. How many miles were on your trans oil

A tick over 126k.

 

[trooper632]

350,000 on my 2011 Ram 3500, and we pull a 40 dual tandem gooseneck loaded with hay and equipment all the time, no issues