HT740d shifting question

[noturnaround]

Hello, I'm in the process of an oil change. I'm doing a switch from 15/40 to Autran TES295. I've done one change with one more planned.

The question is why does my transmission double shift from 1st to 2nd and 2nd to third. It shifts up to the next gear as expected but immediately shifts back down again then shifts back up and stays there. If I let off the throttle at the time of the 1st shift it will stay in the gear otherwise it shifts back down. This is normal acceleration not hard acceleration. I haven't had a reason for hard acceleration yet, so the result is unknown. I have less than 100 miles on the truck so far. The latest was a drive to the DMV. That drive circulated the oil for the next and final oil change to complete the switch to TES295. I thought I'd better find the reason for this in case the pan needs to be dropped or fluid drained. This unusual shifting was occurring while the 15/40 motor oil was in the transmission too. It is not a result of the switch to Autran TES295.

Thanks

[dbarton291]

What kind of vehicle is this?
What kind of modulator system does it have, cable or air modulator?

[noturnaround]

It is in a large military vehicle called a HEMTT. I know so little about this subject. I believe it would be air. There are air lines for everything. It does hold air very well. It doesn't leak down. What should I look for? There are many air lines in the cab. I had to remove 6 lines last week to get to one that was leaking. So based on that without knowing anything more, I'm guessing air. I'm going to go out and have a look to try an figure this out. I appreciate any help you can give me with this.

[dbarton291]

You might want to find someone locally to help you with this. A HEMTT is a very large and complicated beast.

[noturnaround]

Can the modulator be adjusted on this transmission? I was hoping I could make an adjustment. Is it located on the left rear of this transmission just above the pan? A cable shifts the transmission.

Thanks