When to change Allison Transmission oil

I'd have it analyzed first, It may not need changing.

http://www.allisontransmission.com/

In 2005 is when Allison switched to Transynd fluid and the extended change interval. If that is what you put in 10 years ago, you should be OK. If DEX III was put back in your transmission, since that is what it came with, I would change it and the filter.

I have an 08 and did the change at 50K. The analysis had some high readings, so i'm going to do the next one at 80K and see how it looks, nothing alarming, just suggesed a more frequent oil change.

I'm in the same position 66K and 9 years old. I'm going to change the trans fluid at 70k only because it makes me feel good; Like I change the engine oil every 5K to make me feel good.

I do change the spark plugs every 50K and put a ton of anti-seize on them - I had 2 plugs snap on an engine which had 80K - a night mare to rectify

Modern trans oils last a LOT longer than years past. If it is in your 2002 you may want to have that checked out. Many modern vehicles (like Toyotas) have sealed transmissions even because the oil is so good.

crasster wrote:
Modern trans oils last a LOT longer than years past. If it is in your 2002 you may want to have that checked out. Many modern vehicles (like Toyotas) have sealed transmissions even because the oil is so good.

Yep, they figured our they can make more money selling transmissions than they do selling filters and gaskets.

crasster wrote:
Modern trans oils last a LOT longer than years past. If it is in your 2002 you may want to have that checked out. Many modern vehicles (like Toyotas) have sealed transmissions even because the oil is so good.

Don't kid yourself, sealed, unserviceable transmissions are a terrible idea.

lj2654 wrote:
I'd have it analyzed first, It may not need changing.

That's what I would do.

I took mine to Allison Shop at 50K- and 10 year coach - where they took a sample of fluid and was advised that I should have the transmission re-sampled at 70K.