Hope to have the engine back in my rig today or tomorrow.

Looking forward a little bit and trying to see what all I should pick up at the auto parts store.

I see ATF was the suggested fluid, but some google searching led to a variety of discussions on later updated fluid specs by Ford. People even suggested going with GM Syncromesh, to a special recipe, to Red line MTL.

Thought I'd ask a fresh question on this one.

How about for the transfer case?

Thank you!

 

I run Amsoil ATF and have since I bought the truck almost 4 years ago now. When I had the clutch replaced by SkySkiJason a bit ago, that was about 20K miles of running on the fluid. He "unjammed" the fill plug for me and when I installed a new fill plug a bit of fluid came out. The fluid was as red as the day I put it in there.

I plan to use a quart or so of Redline MTF when I change the fluid. But, for the most part plan to stick with Amsoil ATF because I have only a slight amount of gear roll over. Not even enough to complain about or mention really.

 

IF, I was keeping my ride, I'd do the redline stuff as well(carguy has a good thread on it), but until then and wallet would allow, its just plain ol' mercV.... When I acquired my truck, 7/2010, within a month I went with Amsoil..Never again!, that crap made my tranny "loose"...

 

Redline MTL in both the trans and the t-case. It good rid of rattles in both, and made my trans shift better; especially when cold.

 

Generic ATF with a half quart of synchromesh thrown in to reduce gear rollover noises. That stuff is thicker though, so I'd advise against the synchromesh in what you call a climate. I'd probably run a synthetic ATF if I were in your shoes. (thicker fluids make for harder shifting when cold)

 

I used synthetic atf and it made it hard to shift without grinding the synchros especially on the 2-3 shift. I switched to Pennzoil Synchromesh and it is smooth as butter now. Most modern atf fluids seem to have to many additives in them that make it to slippery for the synchros to engage properly. Pennzoil Syncromesh is designed to go in manual transmissions that originally specs atf. The Redline MTL is supposed to be good also but I haven't tried it yet. When you go to fill it up don't use the fill plug take the shifter off of the top and fill it from inside the truck and add an extra quart in.

 

Mercon 5 atf. I think it is citgo branded. Whatever mercon 5 was on sale that day

 

I switched to Redline MTL in my Jeep, I know it's not a truck but my transmission temperatures dropped around 27* and the transmission shifted smoother, it was quieter too. This was after I tried Penzoil syncromesh and did not like anything about it. Don't think you can go wrong with Redline.

 

I agree, the extra quart is a good idea. I did that when I did my clutch and short throw shifter. Although, I am really not looking forward to dealing with the boot again, when its time for a fluid change. I also used The International/ford grey RTV on the shifter tower, so taking it off again might be a challenge.

I would also recommend flushing out the cooler and lines. I got half a Gatorade bottle of of some nasty looking stuff out of mine.

 

The fluid capacity for the ZF6 calls for 5.8 qts if I am not mistaken. So, are you fellas putting in 6.8-7 qts or are you stopping at 6 qts?

Purchased a 12 pack of Redline MTF for my upcoming mod session. This will give me more than enough to change the fluid in the transfer case and the transmission.

 

I think I put 7-8 quarts in mine.

 

When I did mine, it was part of doing the clutch, and a short throw shifter, so I already had the boot off and the shifter removed. I did 6 QTS even of the MTL, and I think I tossed in about 3/4 of a quart of something else I had open and wanted to get rid of. It was either my last bottle of the D4 ATF or possibly just some regular Merc V. So, basically I over filled by 1qt.

If you want to overfill, you pretty much have to do it from the top, with the shifter off. I'm sure the extra QT helps a little with trans temps, but I'm not sure I would go through the hassle of pulling apart the boot and shifter just to do it. That's up to you. You could maybe jack up the left side of the truck real high ( or park on a steep side hill) to get a little more in via the fill plug, but I don't know if that will get you a full quart over.

I know the Ranger M5ROD 5spd is notorious for failures due to low fluid levels. Some of it is due to a common, but easy to miss, leak at the top of the shift tower. However, the general consensus is that they were underfilled/spec'd from the factory, and that an extra quart greatly improves their longevity. Whether the ZF6 would experience the same benefit, I don't know. But a little extra can't hurt. Obviously, too much could lead to foaming, etc.. and other bad things, but I don't see 1 QT over being anything but helpful.

 

I park on the street in front of my house so it is on a little side hill and squirt it in until it starts to come back out then put the plug in quick. Planned on trying redline mtl but ended up driving my truck with the lines unhooked pumping most of it on the ground so I had to fill with what I could get locally.

 

I have filled the transmission from the top since I bought the truck because the fill plug was seized in the case. SkySkiJason was able to weld a bolt to the plug and break it loose for me when he was replacing the clutch.

I have not decided if I will put more than 6 qts in yet, but if I do I will go through the top like I have been doing. The only pain in the *** part is the plastic surround screws toward the firewall, everything else is simple when filling from the top.

I think the transfer case holds ~2.5 qts, so I will probably fill it to the plug first, then use ~6.5 qts for the ZF6. This way I won't have even more half empty bottles of fluid sitting on the shelves in my garage.

EDIT: For anyone looking for Red Line MTL for a decent price, I bought a 12 pack on Amazon for $143. This is about $4 cheaper per qt than you can normally find it.

 

This last fluid replacement, I thought I had more on my thinking cap than in the trans. I felt smarter 😁. So, after a week or so, thinking the trans was "loose" from bring low on fluid, parked truck nose first on driveway to give it "more capacity" but when removing the fill plug, she started to bleed. Think, you got to get the nose up Purdy high to get that Xtra qt if not from the top