Allison 3000 transmission

All posts above correct. Please tell us which Allison "expert" told you to only expect another 10-15k before rebuild. AND, what he based that opinion on.

Sure, if he found a lot of metal, water, etc in the fluid/filters he could be right. But, this would be extremely rare.

2001 Monaco Dynasty has 350K and it's fine. My employer ran over 500 units with constant back and forth driving moving shipping containers in the LA harbor terminals 24 hours a day 7 days a week. Saw maybe one a year being sent out for rebuild. These are some of the harshest conditions around for a diesel, they used Cummins, and Allison.

I have heard of one Allison that needed to be pulled to replace a plastic part. The trans will out live the OP and will for sure go longer than 10-15 years provided it is serviced properly

There is not a "recommended" rebuild time, that would be a death sentence for the manufacturer. I can't even remember hearing about a rebuilt Allison on these forums, they just don't break.

I assume (hope) they replaced the fluid with Transynd ?
There was a fluid change around 2005 to synthetic that further extended the factory warranty if the owner switched to it. Don't remember all the details.

My 1988 Prevost with a Detroit engine and Allison transmission has the original Allison and 350,000+ miles. We recently had to open it up (long story) and the shop said there were some signs of wear but nothing to be concerned about. It would have been $4500 for a rebuilt transmission and since the tranny was already out the labor would have been the same. I almost took them up on the offer but it still runs so well!

A big Allison should go many times that mileage. Do the service as recommended and it will be the last thing you have to address.

If you don't beat it up and keep it serviced, age is probably more of an issue than miles. Eventually the internal rubber parts will get hard and fail from age. Not changing fluid can make that happen faster.

If you are concerned, put some miles on the new fluid and send it out for an analysis to see if there are any parts wearing out that would require a rebuild.
There is no set time for any transmission to be rebuilt.

I'd think the answer should have been more like 10 or 15 YEARS. Any modern transmission, if cared for, will last 100s of thousands of miles.