3650 fluid swap (help needed)

[40th GT]

I am currently in the process of changing the tranny fluid. I have the fluid drained out and I was trying to fill it back up through the shifter hole, but it isn't working. I know many people on these boards have done it before without problems, but it's not working for me for some reason. something in the tranny is blocking the new fluid from going in.

edit: I didn't bother getting a fluid pump because I was sure that the shifter hole method would work..

 

[white-04]

Did you stuff a rag down in their while you scraped away the gasket? If not, maybe there's a bunch of gasket stuff down there? It worked fine for me.

 

[stangman]

so what is it doing? is it overflowing when you put too much down? or just slowly going in?

 

[Mustang5L5]

There is a tiny hole at the bottom of the shifter area. It will drain, but drain slow.

I have done it by this method. IS your car sitting at an odd angle?

 

[stangman]

also, did you undo the fill plug on the outside of the tranny? if not, undo it & fill it that way until some fluid comes out of the hole. that's how you know it's full & also, it might help fill it as well

 

[40th GT]

Thanks for all the responses.

I was able to get it in right after my original post. I thought 'the shifter hole' was the housing that the shifter bushing goes into. I didn't know about the one at the bottom of the area.

The new fluid I used was Mobil1 atf with 12 ounces of Lucas Transfix, but the flush didn't help much. It stills feels a bit notchy and its really bad in the mornings. oh well.

Those of you who are about to do fluid swaps/shifter swaps, don't forget to use loctite/threadlocker on the shifter-related bolts. Mine backed themselves out for some reason.

3.3 quarts is correct?

 

[metroplex]

The new 3650s are supposed to use about 3 qt of non-synthetic ATF to get rid of the notchy shifter and the 1-2 grinding. I think nothing has changed in the new 3650s other than the ATF fill specs due to all the problems experienced in the 01-04 GT's 3650s.

 

[katshot]

That sounds EXACTLY like my trans issues. Very notchy feel, and grinds on the 1-2 shift. Worse when cold.
So maybe all I need to do is replace the fluid with non-synthetic ATF? Thank God I read this thread, this issue was really bothering me.

 

[metroplex]

Yep, try 3.0 qt of Mercon ATF (non-synthetic). specifically Texaco/Havoline Mercon ATF. It sounds weird and awkward to not use a synthetic, but Tremec engineers have stated to use non-synthetic ATF (specifically Texaco/Havoline Dexron III/Mercon) in the 3650, at least for the 05-up Mustang GTs.

Apparently the requirement to use Mobil 1 ATF along with overfilling (using the instructions given by the manual or service manual) contributes to the notchy shifting and 1-2 grind especially when it is cold.

 

[katshot]

Is there a service bulletin out on this? Why only suggesting to use on '05+ cars since the others w/3650 have the same issue?

 

[metroplex]

IIRC the 01-04 GT manuals stated to use Mobil 1 ATF or a synthetic Mercon ATF. Tremec said that the synthetic ATF like Mobil 1 has caused some problems with the TR-3650, and overfilling will cause abnormal behavior as well.

The 05-up GT manuals now state to use a regular non-synthetic Mercon ATF and to fill it with about 3 qt of ATF. I believe there is a rather large thread floating around somewhere on Stangnet that covers the 3650 issues and what people have done to try and fix it.

 

[CrimsonKid]

I just flushed mine. Easiset way to do it is to drain it all. Tak out the fiil plug at the top and fill the tranny from the shifter until fluid comes out of the fill plug. I was able to get 4 quarts into mine.

 

[metroplex]

What type of ATF did you use and are there any shifting issues with 4 qt of ATF?

 

[stangman]

fwiw, i filled mine to the hole last time as well & i have no shifting issues & use the mercon dexron-lll atf

 

[BurningRubber]

I dont think you can fit 4 quarts of it in.

You do not want to overfill it past the fill hole. Thats why its a good idea to leave the fill plug off and only fill it untill it dribbles out.

 

[stangman]

I dont think you can fit 4 quarts of it in.

You do not want to overfill it past the fill hole. Thats why its a good idea to leave the fill plug off and only fill it untill it dribbles out.

yeah, you can fit it in. as a matter of fact if you fill it to the fill hole, it'll be about 4 qts

 

[metroplex]

fwiw, i filled mine to the hole last time as well & i have no shifting issues & use the mercon dexron-lll atf

What brand of Mercon / Dexron III ATF? What type (synthetic, non-synthetic, or synthetic blend)?

 

[stangman]

What brand of Mercon / Dexron III ATF? What type (synthetic, non-synthetic, or synthetic blend)?

valvoline non-synthetic

 

[SilverBullet00]

I did this and it makes the trans really noisy, has anyone else experienced this? It shifts a ton smoother, but fifth gear especially sounds really loud and makes a clunky grinding sound??? Any ideas? should I add more, I have 3.2qts in now....

 

[40th GT]

I did this and it makes the trans really noisy, has anyone else experienced this? It shifts a ton smoother, but fifth gear especially sounds really loud and makes a clunky grinding sound??? Any ideas? should I add more, I have 3.2qts in now....

My trans is a bit noisier than before but it's not that loud. The only thing that was fixed after my flush was that the 1-2 clunk is gone.