04gt 3650 Oil Change

[StangPro]

We've gotten a lot of good responses from the RP fluid. The only other one that we've heard a lot of owners say works well is the Amsoil (not sure which they each used).

Mobil1 or anything else Ford/TTC recommends is junk and the fluid level change is a joke.

 

[trinity_gt]

We've gotten a lot of good responses from the RP fluid.

In the 3650, you use RP Max ATF?

Mobil1 or anything else Ford/TTC recommends is junk and the fluid level change is a joke.

Well, I had the TSB work done recently and I know the trans is noisier at idle, in neutral than it used to be. I was thinking "ya, normal for a reassembled trans with new gears etc" but the more I think about the lower fluid level the nervouser I get...

I'm going to be buying an MGW shifter soon and will do a 3.6L RP fluid change while I'm in there. I just want to make sure what I put in is the right stuff. I think the consensus is that the trans needs ATF not "synchromesh" fluid, that the factory stuff is junk and that RP Max ATF is at least as good as anything else.



Right?

 

[40th GT]

I have heard people's experiences about the GM Synchromesh, and I have yet to hear a complaint.

 

[GTRookie]

I just changed my trans fluid this weekend to four quarts of RP Synchromax. The trans appears to shift easier and it is definitely quieter. I only did 14k but the fluid looked dirty compared to the new fluid. Of course I don't know what the existing fluid looked like when it was new; the RP actually looks purple (hence the name I guess).

 

[Give Me TP]

I called Tremec and talked to John, he said do not use GM Syncromesh (he did not mention RP Synco Max) because it swells the fiber material used in making the Synconizers in the 3650 transmission. He said use Mercon III / Dexron III at a quanity of 3.0 to 3.2 ltr. I now use Motorcraft MERCON ATF #XT-2-QDX but I could not bring myself to lower the fluid level from the specified 3.8L of the '03 owners manual to what he suggested. I did fill it to the 3.7L as specified in the '04 owners manual though.

He said the specified fluid of Mercon Synthetic or any synthetic, is too slippery and there is not enough friction for the syncronizers riding against the dog rings to get them up to speed to match gear engagement. That is why the TSB and the new '05 Manual states using Motorcraft MERCON ATF #XT-2-QDX fluid.

Sounds familiar. I drained the factory fill in mine over a year ago when I changed to a short throw shifter and refilled it with 3L (about 3.2 quarts) of Havoline Dexron III. The transmission has performed flawlessly since.

 

[01TrueBlueCobra]

So which RP should I use. RP Synchromax or RP Max ATF. Can you refill the tranny from the shifter if removed.

 

[Give Me TP]

Refilling it through the shifter hole works great

 

[01TrueBlueCobra]

Refilling it through the shifter hole works great

So all you have to do is drain the tranny and then remove the shifter and fillit up through there

 

[hotrodnut]

Although filling the trans through the shifter is a great way to do it I found that if you get a 3-4 foot section of a fuel line size hose, stick a funnel on one end and fish the other end down between the engine and fenderwell on the passanger side, slip it in the fill hole of the transmission it will make it a much quicker job.

 

[Give Me TP]

So all you have to do is drain the tranny and then remove the shifter and fillit up through there

Yes, but I was changing the shifter anyway, so I had it off for that.

 

[cobra2798]

Amsoil synthetic works for me

 

[cobra2798]

I have the 05 GT and I'am looking to improve the car all I can, has anyone tried the Amsoil for the Manual trans. or rearend?

I switched to the amsoil synthetic and it helped alot. I have the 3650 in my 01' cobra and it has some problems. The amsoil made my shifting alot smoother and made the tranny much more quiet. It is not a total fix but makes the car much more enjoyable to drive.

 

[05SonicBlueGT]

Which amsoil the ATF?