I changed my fluid and filter with atf 4 fluid and it made it seem like a new transmission again probably 1500 miles ago and I knew it was going out then and trying to take it easy on it and probably a week ago I hooked up a 16 foot trailer with two four wheelers on and seriously hurt it now if I stop I have to pretty much floor it to get it to move than when it’s moving it’s ok. I’m assuming it’s torque converter? I don’t really have the funds to get it rebuilt at this moment so I saw where somebody was running hy guard
amd it made it firmer?

 

It’s a a518 with overdrive

 

Hard to say if it's the torque converter....could just be worn clutches and misadjusted bands in the transmission. At this point do you have anything to lose by trying the HyGard fluid?

 

No I guess not saw a thread about how to adjust the line pressure so I will try that first

 

Adjust the bands. When you do fluid changes they need to be checked. Drop the pan and adjust the bands #1.

Here's a little secret. I talked to PDD about their fluid. It is a blend of ATF+4 and type F. What ratio? I have no idea. Don't mix synthetic with non synthetic fluid.

Hyguard is available in several different weights just like motor oil.

Nothing wrong with my once rebuilt 518. I bought a replacement due to HP, and TQ concerns. I will be running the Suncoast fluid for warranty purposes for 3 years. Probably a blend like PDD's in house fluid.

Deeper discussion on transmiXXer fluids here https://www.cumminsforum.com/threads...#post-30117733 you might get more confused!

Cat2 rated for 500hp and whatever torque. Can't believe they shipped this with a steel pan. The pics show a deep aluminum pan. I got a PPE on Saturday. Looks nice.