Rawze.com: Rawze's ISX Technical Discussion and more

How do I check and change my transmission fluid? 2011 isx15 2250 Peterbilt.. can someone help

I'm not very experienced with this, however on mine there is a plug on the driver side of the transmission that you can remove to check and add oil. Pull the plug (again, on side, not bottom) and stick your finger in. Level should beat or near the bottom of the hole. as for draining, look for another plug somewhere on the bottom of the transmission, usually somewhere near the lowest point. Drain it from there (open the side plug too to help it drain faster), usually helps if the oil is warmed up first so it flows out easier. Once you've drained all you can get plug up the bottom and pump fresh oil in to the side until it reaches the bottom of the hole. Not sure if it's required, but I'd run it 50-100 miles or so and then check the fluid level again to make sure it's not low.

Please, someone correct me if I got anything wrong or to add tips and tricks, as I have only learned how to do it, not actually done it personally.

Ok I’ll do that.. is there any type of trans fluid I should use that’s works best?

Trucks don't use car type tranny fluid they use gear oil and alot of it.

Do I get a 50w gear oil

Get a 5 gallon bucket of 80W-90 synthetic if your has synthetic in it.
Of course always check manufacturers recommendations if in doubt.

Ok will do.. appreciate the help

Youtube can be helpful. (These guys have some good how-to videos and then they have a lot of videos where they just push all kinds of tools)

Came to the parts place and they said they don’t have 80w-90 in synthetic only non synthetic