Was out driving, and I noticed that the truck had problems going into 4th, had to push the rpms the get it to shift. And when it shifted, you could feel the Engine slowing down, the light in the truck got on, and 4th gear was engaged, was smooth running after that. Stopped the truck, and now I don't know if I want to try get into 4th again, the transmission might be ready to self destruct, and I don't want it to happen on the road. Anyone else think my trans is about to fail?

 

According your profile your Ex has 150,000-199,999 miles.
When was the last time the transmission was serviced?
Fluid changed?
Flushed?
Filter changed?

 

My ex has 220.000km on it, only owned I at few months

 

Okay, you have 220,000km/136,xxx miles.

If you don't know the answers to the aforementioned questions, that's okay. Get a baseline moving forward as opposed to worrying about a failure.

 

Noticed that the problem occurs uphill, and that I got a brake caliper that is stuck. Got no fault codes on my SCT tuner.

Are the newer breaker calipers interchangeable? I want better brakes, so since I have to replace the caliper, I want to go for a big brake kit, or newer calipers, or from a heavier F.

 

As Mark stated, you need to change the fluid and filter. While doing this, you can have a look in the pan for any metal or clutch material on the magnet. Easy to do, and something you should do if you don't know when it was done last time. Only use Mercon V fluid in that transmission.

On brakes, the newer calipers are not interchangeable. Slide pins should be checked and lubed every 6 months. ONLY use caliper/brake grease.

I had VERY good experience with these brakes: Great deals from Brakemotive | eBay stores
Much improved braking with them. I have had them on my truck for over 4 years now, and I love them. On my second set of pads, and did not have to turn the rotors because they wore so evenly. I did upgrade to the ceramic pads they offer.

 

I had the exact thing (transmission) happen at very close to the same number of miles. It was a solenoid acting up. As the others stated, I had the fluid and filter changed and it has been great since (over a year now).

 

Sondre Næss, nothing shabby about stock calipers when paired with quality pads and discs. Your rubber brake lines might be worn; worth checking when you bleed / flush the brake fluid. Before buying 4 new calipers, get the stuck one fixed/replaced, change your tranny fluid, and see how she runs.

I bet we have a how to tutorial on each of those fixes in our tech folder if you'd like to tackle the job yourself.