Gsmikie, need TH400 expertise/advice

[78 Arizona Chief]

Hey there out there in Quartzsite,
I just finished installing my NOS Quadratrac t-case this evening and decided to change the trans fluid and filter while I was at it. I change the fluid and filter once a year and this is that time. For reference, I usually only put about 3,500-5,000 miles on the jeep a year. Anyway, fluid as usual came out super clean and there was nothing in the pan. I do have a deep Hughes pan on it and got out 8.5 quarts just dropping it. Anyway, I put a new Fram filter and gasket kit on it and refilled the trans. Took it for a drive and it appears to have almost a faint shudder while cruising. It will shift normally through all the gears and down shift normally except if you pull it into 2nd manually, then nothing happens. It is as if the jeep went into neuatral. If you tap the gas, it feels like it will engage but then disengage as soon as you let off. This is all while I am holding the shifter in 2nd. Pull it to first and it will go into first gear. Any ideas?

On a related note, I have been filling this tranny every time with Mobil 1 Synthetic ATF since as far as I can remember. Tonight, I noticed that 6 of the 8 quarts said 'New formula' on them and smelled different. The new formula also seemed more thick to me. Could this have something to do with it?

I drove the jeep three days ago and the tranny acted totally normal. Thanks for any and all advice.
Kevin.

[78 Arizona Chief]

Hey thanks so much for the super fast reply. It is definitely not low on fluid. It is right at the add line when it is cold, and it is higher than it was before I drained it. The o ring does sound promissing. Can you pick those up at Napa or the other parts stores?

Also, I assume the Mobil 1 although expensive is a really good fluid to use. And I also assume because the 'new formula' says it is for all Dextron oils that is OK. What do you think?

If the O ring doesnt do it, should I look at the govenor and is it something that just quits? Thanks so much for all your help over the years.
Kevin.

[1977cherokeechief]

if i was you, and you were going with a full synthetic fluids, go for the AMSOIL

[78 Arizona Chief]

gsmikie,
hey there just an update. I dropped the pan again, bought and installed a new filter, o-ring, pick up tube, spacer sleeve and bolt for this. Filled it back up and took it for a test drive and there is no change. It still drives totally normally until I manually pull it into second gear and nothing happens. When I give it gas it will then engage, but if I let off it is as if it were in neutral. Any chance you could pm your phone number so I could call you to discuss? Any other ideas of what I should look at? Thanks so much for all your time.
Kevin.