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Discussion Starter · #1 ·
So I serviced my LML Allison today.... used the new Allison preferred fluid, the Castrol 668 fluid.

Is this stuff for real? 4 years or 300,000 miles between services in normal situations?

Dang.... that's a long way!!!

I've always used TES-295 prior, did a single drain and refill at 50k miles, and a double dump and refill + new internal filter every 100k miles. Spin on filters every 30k miles..... NEVER had a single transmission issue.

I think with this 668 stuff I'll go 150k miles then double dump it and refill + new internal filter and skip the 50k service all together....

Thoughts from those who actually use it , appreciated..... Thanks


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