Transmission oil change due to time?
I'm buying an Alfa with a C7 and an Allison 3000. The tranny had an oil change 4 years and 25k miles ago. Do you change the trans fluid due to time?
Forum Discussion
Bruce Brown wrote:twodownzero wrote:
If the trans pan has a drain plug, I would drain and refill the pan every time you change the oil.
Thats a bit excessive, isn't it? :E
I don't drive automatics, so I'd really be the wrong person to ask. The last time I changed the oil in my pickup, it had 14,227 miles on it, and oil analysis showed the TBN was 7.8 and I could have left it in there for at least another 3,000 miles. So perhaps you think it's excessive because you change your oil way too often and so you think I'd be talking about a more frequent interval than I'm actually talking.
Your trans pan probably holds 4-6, maybe 8 quarts of transmission fluid, which is 1/4-1/3 of the actual capacity. Changing a bit of it every time will eventually get all of it out, and you could change the filter every 3rd time or something. That's how I'd do it anyway.
Fluid is cheap compared to serious transmission work. The fluid in an automatic transmission is the life of it. It's not like a differential or a manual transmission where the fluid, in theory, could last nearly indefinitely.
