The stock shifter in my car feels notchier than it should be, so I'm looking for any remedies. I've read that the RP synchromax will help make my shifts smoother. My concern is that Ford recommends a ATF and some say using any type of synchromax is a no-no because it's not compatible with the synchros in the 3650. So what do you guys think? Is there anyone that has used the synchromax for 80k+ miles without issue? And is 3.2 quarts enough?
Tranny Fluid Change First, this job is a bit easier for me - I have my own lift. I drain the tranny with the oil warm. There are two plugs, one on top, one on the bottom. I take out the top plug first, then the bottom -this lets the oil drain out fairly quickly. When the fluid is fully drained, re-install the bottom plug. Now, I use a suction gun. It looks like a grease gun. I think I bought it at AutoZone, or one of the car parts places. It has a piece of plastic hose attached to the end. I pull the plunger all the way back, unscrew the end cap and holding the gun vertically, pour it full of fluid. I screw the end cap (with the plastic hose attached) back on. Next, I stick the free end of the hose into the open upper hole and start pushing the plunger in, forcing the oil out and into the tranny. I just do this over and over until the tranny is full. They used to tell you to fill until the oil starts to run out. Now, they want the oil level to be a little below the bottom threads, maybe 1/4" or so. That's how I do it, it's a WHOLE LOT EASIER on a lift. Using the suction gun would be harder with the car on ramps or jack stands. Some have said once the tranny is drained, they run a piece of hose down from inside the car through the shifter opening and with a funnel in the open end of the hose just pour the oil in and let gravity take the oil into the tranny. I've never done it this way. Good luck.
I have been hesitant to post because I dont know enough to know that synchromax is NOT a problem. I run synchromax and I do like it quite a bit. I have only had it in there about 10k miles and one year. I remember, last year, when I was researching this, I came accross some info on how Ford has never tested synchromax, and that is why they dont recommend it. RP did the long term testing in a 3650, and it came out MUCH better than with the stock fluid. Of course they would though, and now since I cant remember where I came accross that, so its just an internet rumor. Only thing I can say is that I run it, and I like it. It does make for smoother shifts and you have to assume that is because the synchros are meshing better. If they are meshing better, then aren't there going to be less wear and tear? I even put RP oil in my engine after putting it in my tranny because the difference was so noticeable. That synerlec stuff seems to make everything very slippery.
I have been running RP Syncromax over 20K miles and I'm completely satisfied with it. Smooth, effortless shifting.
