At 78K you should drop the pan and clean the mesh screen inside.
What ever you do DON'T get it flush.
Fluid you can go with OEM Matic S or Amsoil
I would have about 7qts on hand IMO.

As for the rear diff your choice of 75w-140 (most here go Mobile 1 or Royal purple)
Get 3 as it will take about 2.2 qts.

 

I wouldn't bother dropping the pan unless you see chunks when you do the tranny drain. The drain and fill is actually easier than a motor oil/filter change, (if you don't drop the pan), you just need to be really meticulous. Below is what I've been doing, starting after my extended warranty was up. Btw Jatco says you never have to change the fluid so I don't feel bad waiting to 100K miles. I'd buy 5 quarts of Matic S, then the next time you'll probably only need to buy 4 quarts, as there will probably be a pint left.

For the rear differential I used the Nissan synthetic since I haven't had anymore axle seal leaks since they put it in at 37K miles.

Drove mine for a few miles, getting the speed up to 55 to get the torque converter to lock, stopped, reversed, then manually shifted from 1st through D, back up to 55 and then when I got home went the all the gears while +parked. Used a work glove when I removed the plug because it was hot. Drained into an large drain pan and used a funnel I use for old oil to first fill the jug marked at 1 gallon, (4 quarts), and then drained the rest into the second jug with the 4 oz. increment lines marked. Added the same exact amount. Each time I never needed the full 5 quarts, but that might be due to the slant of where I was parked, the front lift etc.

I used two milk jugs ... using water to fill one with a 2-cup, (16 oz.), measuring cup, (8 fills), and a kitchen funnel, marked an exact gallon with a permanent marker, and for the other jug, marked it with 1/2 cup, (4 oz,), increments, (8 of them for an additional quart).​

I just completed my third drain and fill of the pan and was curious about the percentage of old fluid was still remaining. There's probably a calculator somewhere that would show this more accurately but here are the rough numbers I came up with.

I've rounded the total capacity to 12 qt. and the pan to 4 qt. (the last couple of times I got out an extra cup or so, and added the same extra amount back in), but I've basically drained 1/3 of the total capacity each time, and wanted to do this over a period of 6 months or so, before the new stuff becomes old.

• 1st change: drained 4 qt old; added 4 qt new.
  Titan now has 67% old and 33% new, (4 qt of 12 are new).

• 2nd change: drained 4 qt (2.68 qt old, 1.32 qt newish); added 4 qt new.
  Titan now has 44% old and 56% new, (6.68 qt of 12 are new).

• 3rd change: drained 4 qt (1.76 qt old, 2.24 qt newish); added 4 qt new.
  Titan now has 30% old and 70% new, (8.44 qt of 12 are new).

• 4th change: drain 4 qt (1.2 qt old, 2.8 qt newish); add 4 qt new.
  Titan would have 20% old and 80% new, (9.64 qt of 12 are new).

• 5th change: drain 4 qt (0.8 qt old, 3.2 qt newish); add 4 qt new.
  Titan would have 13% old and 87% new, (10.44 qt of 12 will be new,). edit planned for this weekend, if I have empty milk jugs ...

After the 5th change I'll probably just do it at every other motor oil change, and not worry about the percentage.

Windows' calculator was used ... simple math though.

I went ahead and used Nissan Matic-S, figuring it might be a little bit more compatible with the old Matic-J, but who knows. If I did a full fluid exchange there are other brands I would also consider using.

 

I changed the rear differential oil yesterday. I let it drain while it was warm for five minutes, and two quarts of synthetic 75w/140w Mobil 1 filled it. You won't need 3 quarts for the rear.

 

Thanks guys I will be doing this next week since I have extra money now. The reason I feel it needs an tranny fluid change is because, it seems to be shifting a lil bit harder and the shifts are taking longer. And I've read a few times when people say that after a tranny fluid change it felt better.

 

If you get stuck you can always call me and I am sure my dad will gladly walk you through any problems you might occur. Have fun!

 

Thanks Bro, for sure I will if I run into anything difficult. Oh I will have fun lol :teethmast:teethmast

 

Anyone have the specs on how tight I need to re-tighten the transmission pan bolts? Like a diagram, I will go buy a torque wrench today. I will be doing it this week sometime.

 

Ok well I did everything today, I just decided to drain the tranny fluid instead of draining and dropping the pan. My fluid started coming out lookin clean but then it started getting darker and it looked dirty. I ended up using the AMSOIL ATF. Then I drained my rear end fluid and that bad boy was nasty, had a bunch of metal shavings on the plug, and I replaced the fluid with Royal Purple 75w-140. Overall I can tell the difference in the way it shifts, smoother, and quicker. Glad I finally got to do it. Now I'm getting a Bullydog GT again so let the fun begin!

 

does anyone have images or good instructions on where to find the drain plug on the tranny? I want to say I located it but question it.

 

Its the big bolt on the bottom of the tranny pan. You can't miss it! Believe it was an 18mm or 19mm.

 

LAZIEGUY247,

Much Thanks. I will look under it this weekend if the weather isnt to cold and balls dont turn even more blue. and hopefully change the tranny oil. You say to get the most out you did 5 changes in how many months period to get it the most effective?
Whats your idea on how long I should warm up the engine before I take on this project?

 

My goal was 5 changes within 6 months, which is about 9000 miles for me, and have one more to go, so every 1500 miles. But it could be less. That's just what I came up with, but due to other things, including the weather, it has been longer ... probably 2000 miles, followed by every other motor oil change, or 15K miles.

 

One last question. Where is the fill valve/plug? Unfortunately this truck is not a every use truck. I bought it as a toy for myself and in 2 years have only put 10K on it. If I drive it 5 miles a week it is a lot.

Needless to say I am very religious about changing the oil every 3 months and most of the time it comes out as clean as it went in. This last summer I used it more as I took it to Wisconsin camping and to Maryland for a weekend road trip from Chicago. Not many places in the city to have fun with a big truck unless you head into the farm areas 2 hours from where I am at.

I am just now looking into decking it out for next summers road trips. Any help and advise for this great truck would be greatly appreceated.

 

You fill at its dip stick, after unbolting it. Drain plug is the hex bolt head sticking out of the tranny pan. There probably some pics on here somewhere.

I wouldn't probably start changing it until 30K miles, unless you haul heavy loads, tow big trailers, or drag race it. My fluid didn't look that bad at 100K miles, but I've read that some looked bad at less. So if you start doing a pan drain every 2 or 3 times that you change your motor oil, it wouldn't hurt anything.