3650 TSB and lower fluid level

[BMan5150]

Just wanted to post my experience in messing with lower, different fluid levels with the 3650 tranny. I got a copy of the TSB that applies to the 3650 owners complaining about gear clash/grind on the 1-2 and 2-3 shift especially when cold. Part of the TSB recommends using regular Mercon ATF fluid vs. the Mobil One Synthetic ATF and also lowering the fluid level from 4 quarts to around 3.1 quarts.

I drained and refilled my 3650 with 3.3 quarts of Motorcraft Mercon ATF (per TSB fluid specs/part #) and immediately the 1-2 shift seemed better/easier, but not by a large margin. Then, about 100 miles and one week later, I noticed the shift quality was getting worse on the 1-2 and seemed far worse on the 2-3. I immediately drained my tranny and refilled it with 4 quarts of Mobil 1 synthetic ATF and immediately noticed improved shift action. However, all this did was bring it back to the normal "cruddy" shift quality. I'm back to living with this and still accept the fact that this 3650 tremec, while notchy as heck, seems to be pretty bullett-proof (hasn't broken yet! )

Another interesting note is that despite the fact that my car was completely level, 4 quarts of tranny fluid still left the fluid level below the fill hole - enough that it wasn't even close to spilling out. I should also mention that I do have Steeda lowering springs, which might slightly affect fill levels since I was on a drive-on lift but I can't imagine it would be that significant. I couldn't even feel the fluid with my fingers.

So, from my own personal experience, I would not recommend lowering your fluid level per that TSB for improved shift action. It just plain didn't work for me. I'm trying to focus on the fact that despite some serious abuse, this tranny is still holding up just fine. I guess I'll take that, although it would sure be nice if the tranny shifted well on top of being a sturdy piece of equipment.

It's definitely very frustrating when you get 10 different answers to this simple question - "what is the fill procedure with the 3650 tranny and what are the fluid specs?" Tremec and my Ford Manual says 4 quarts of Mobil One Synthetic; there's a TSB from Ford that says 3.1 quarts of Mercon non-synth. Based on my own personal experience, I'm sticking with Tremec and Ford's original specs.

 

[RageStangX]

If mine doesnt get any better im going with my own treatment a tub of butter,crisco and vaseline mixed up.

 

[hotrodnut]

I've been through it too, went with the different types fluid and different levels and some would make the 1-2 shift better while making getting into gear from a stand still harder and then some making the other gears harder to shift but 1-2 ok . After 6 different tries of different fluids and levels I finally settled on using 3.7 (quantity fill level of the '04s) of the Motorcraft MERCON ATF #XT-2-QDX as recommended for the '05 and the TSB for the '01-'03 TR3650. That combo has given me the smoothest butter like shifts thus far in the Florida temperature zones.

 

[LI-SVT]

What about Synchromesh?

Did you guys try the GM Synchromesh? I might try that next. I currently have Mobile 1 at the lower fill level. I still get a gind when the trans is cold. If I could just get rid of the grind I would be happy!

 

[hotrodnut]

Did you guys try the GM Synchromesh? I might try that next. I currently have Mobile 1 at the lower fill level. I still get a gind when the trans is cold. If I could just get rid of the grind I would be happy!

Yes, I tried that one and it made the 2nd gear shift better but getting into all the other gears were not as good.

After that change I called Tremec and talked to a Tech and he said do not use the GM Syncromesh because the syncro's in the 3650 are not brass and the material will swell and ruin them.

 

[LI-SVT]

Ah...Well then I guess the only chance of getting rid of the 1-2 grind is the TSB for a rebuild. Thaks for the info, will steer clear of Synchromesh.

 

[StangPro]

I couldn't shift to second at all below 40F outside, and this is after the rebuilt under warranty.

I switched to Royal Purple Synchromax and it's much smoother now, and using second gear in the cold is a choice.

It definitely helped.

The fluid level change is a band-aid BS "fix" in an attempt to get as many cars out of warranty as possible before they admit there's a problem.
It's all about the benjamins

 

[Mustang5L5]

Tremec and my Ford Manual says 4 quarts of Mobil One Synthetic; there's a TSB from Ford that says 3.1 quarts of Mercon non-synth. Based on my own personal experience, I'm sticking with Tremec and Ford's original specs.

The TSB also includes replacing 1st gear, 2nd gear, both the 1-2 and 3-4 synchro assemblies and the shift rail system. All these parts have been redesigned. I have driven a post-fix T3650 and there is a big difference, but it's still a clunky trans in general.

Changing the fluid level isn't really gonna help when these parts all need to be changed.

 

[STANGALANG]

I's there a better trans to put in it? I'm new to the whole 3650 deal, cause I just bought mine but can they be replaced like with the TKO or something better?

 

[98laseredgt]

my 01 i just bought shifts like butter and it has the 3650 in it. is there any way to tell if the TSB has been done? my tranny has packaging tape that says "Tremec original equipment" on it.

 

[Give Me TP]

I drained and refilled mine over a year ago with 3L (3.2 quarts) of Havoline Dexron III. Along with an aftermarket short throw shifter, the occasional 1-2 grind and 3rd gear lockout I used to experience is completely cured.

 

[SRMobile]

I had the 3650 TSB done at first it was much better but then got abit worse. I put on about 1000km's on it and now it shifts like butter!

Patience! You have to let these new parts wear in abit.

 

[cobra2798]

I drained mine and filled with 3.5l of havoline dexcronIII-atf. Along with the change and aftermarket shifter the problem is a lot better than it was but not completly gone. I decided to take a different approach and let the car warm up for about 5-10 min before driving. I was told it had something to do with the hot/cold viscosity of the fluid. Letting the car warm up that long haspretty much solved my problem, shifts like butter all day long even at high RPM's!

 

[SRMobile]

I decided to take a different approach and let the car warm up for about 5-10 min before driving. I was told it had something to do with the hot/cold viscosity of the fluid. Letting the car warm up that long haspretty much solved my problem, shifts like butter all day long even at high RPM's!

Correct me if I'm wrong, but if your car warms up for 10 - 15 mins your only warming up the motor.. Not the tranny.

 

[cobra2798]

I was told to try this by a friend of my fathers who has the same problem with his 01' mach1. He says he was told to do this by a technician at a mustang performance shop in N.Y. i dont know who he is cause im in florida. I would think that even know the tranny is not in use at the time the fluid would still warm up bringing its viscosity to the correct thickness. You could be right but i swear it works for me and ive tried everything! it seems that a combination of a few small things has got my tranny working the way it should and thank god cause my car is out of warrenty and i aint got that kind of cash for the tsb, that i heard works and ive heard it dosent work so i think i would be takin a chance on it anyway! If you have any suggestions let me know!

 

[hotrodnut]

Correct me if I'm wrong, but if your car warms up for 10 - 15 mins your only warming up the motor.. Not the tranny.

The fact is . . . if you have the car in netural and the clutch out, the input shaft of the transmission will turn. The input shaft is geared directly to the cluster gear and it will turn too, therefore, the oil in the trans is getting splashed around and warmed up, although not up to the normal operating temp, it does help considerably warming up for a few mins for the initial drive off and gear shifts.

 

[MineralG2k2GT]

just to add my .02 sents..i added 4 qts of royal purple synchromax and the car has never shifted so smooth. made a big difference

 

[raykrv6a]

Another interesting note is that despite the fact that my car was completely level, 4 quarts of tranny fluid still left the fluid level below the fill hole - enough that it wasn't even close to spilling out.

I think Tremac said 3.7 liter's. Whatever that is exactly in quart's, I don't know.

I mixed half Mobil 1 syn and half Mercon and that works for me. No crunch and goes into 3rd at high rpm as there is enough friction in the syncros.

 

[Delacruz1776]

I'm going to try the purple synchromax. I'll be installing an MGW shifter this weekend and will try the purple. Hopefully I'll see a difference, cuz it does get frustrating leaving the light and struggling to get into second. I feel like I have to baby it.

Raykrv6a...if you don't mind me asking, what did you pay for your KB charger (kit)? I wouldn't mind getting into those hight 300's.

 

[SRMobile]

The fact is . . . if you have the car in netural and the clutch out, the input shaft of the transmission will turn. The input shaft is geared directly to the cluster gear and it will turn too, therefore, the oil in the trans is getting splashed around and warmed up, although not up to the normal operating temp, it does help considerably warming up for a few mins for the initial drive off and gear shifts.

Thats why I hang out mostly in "Talk"