I have never changed the fluid in an automatic transmission except during a rebuild. I do change the filter and top off what drains from the pan every 75,000 miles. Never any additives.

I always add an additional transmission cooler to every vehicle I buy.

I consider dropping the pan and changing the filter and topping of changing the fluid.

Get your trans fluid from Walmart, cheapest place to buy oil gear lube etc.

That cooler will be my Last addition I hope !! I acquired a 23.4" travel Trailer from my X. I've been informed I may need that.

I lived in a 26 foot for a while. It works for one person, but not good for two.

What does your living in a 26 footer have to do with the above subject?

Seeing how I will never purchase a new trk, too old-too poor, I have been replacing needed parts to my 04'F150. Stuff like Monroe Load Leveling rear shocks, front struts,oil and filter, serpentine belt,w/s wipers etc. Next is the transmission fluid and filter. I picked up the filter kit yesterday. The last time I had the tranny stuff chg'd was when the trk had 50K ish miles on it. It now has 122,000 miles. Time to change IMO. Have you had your fluid and filter chg'd lately? For those of you that have an Old trk.....!! I bought my filter kit at Advanced Auto Parts in Tx City. If you look online, you can get a 25% discount (with purchase code applied). I didn't order it online, I just took a pic of the ad and showed the clerk.It cost me a hair under $20, Reg $25 and chg.

Transmissions are $1,700-$2,700 exchange. Fluid and filters are cheap.

I have worked for a Major transmission distributor for 40 years. Temperature will kill them!!!!!

A good additional aftermarket air to oil cooler, and synthetic oil is your best bet. This oil will drop operating temps 10-25 degrees based on load.It's worth the money.

Service intervals should be in your owners manual. I would not exceed 50-75K per change if you tow.

Be Safe

Happy towing

I WOULD NEVER change the trans fluid period, trans fluid is one of those things that seems to become mated to the trans, it seems like people change their trans fluid and boom the trans goes out very soon after.

It is a CLOSED system like your power steering system and you DONT change the ps...

I worked in a few auto related places over the years and this is my honest opinion and its the same opinion you will get from transmission shops who arent trying to sell you something or hoping to get your trans rebuild job down the road.

Considering your user name and your experience with transmissions, what is your honest opinion on the Allison 1000 bolted behind the Duramax?

Straight BS!

Yes if you neglect it too long then no changing it wont do a thing. Stick to the maintenance schedule and it will prolong the life of the transmission.