bbull3t

Hi guys I've been thinking of swapping to a 6 speed transmission for my 07 GT and I've been looking online but prices are $2000 and up. I was wondering if it's possible to hit the junk yards and get a used 6 speed transmission from a 11-14 GT since most of these aftermarket transmissions are for 05-14.

jz78817

if you're going to spend the time, effort, and money to do this you definitely want to get something better than an MT-82.

Dino Dino Bambino

The only difference between the 5-speed and the 6-speed is that the latter has five closely stacked ratios instead of four, while both have a chasm between the 1.00:1 ratio (4th in the 5-speed, 5th in the 6-speed) and top gear.
Ideally I would have liked the TR3650 to have another ratio, say 0.83:1, between the 1.00:1 4th & the existing 0.68:1 5th gear. The only transmission that comes close is the Tremec Magnum XL 6-speed #TUKT12021 with the following ratios:

2.97 2.10 1.46 1.00 0.80 0.63

breathegood

I'm curious. Why do you want a six speed? Is your current transmission giving you problems? Are you unhappy with the ratios?

I would like a six speed in my '07 as well, but not enough to make the swap unless I had a mechanically advantageous reason to do so.

jz78817

in my own experience with my 2010 GT (3:31 rear) was that it always seemed to be in the "wrong" gear for what I wanted to do.

breathegood

Can't that be resolved [mostly] with new diff gears with a significantly less involved and less expensive installation?

If the transmission ratios are a problem, wouldn't you be more prone to looking at a custom spec unit anyway?

Norm Peterson

That would be my approach, starting with a thoughtful evaluation of what speeds I'd either want to be shifting at or (perhaps more importantly) where I would not. This would have to cover the entire range of driving circumstances, so there'd be some compromises involved - how useful do you want 6th to be or can you fit all of your driving except highway cruise into 1-5? There, I'd generally favor giving the track/autocross/dragstrip shifting demands priority over any street driving I can offhand think of.

That's also what OP should also be considering assuming the MT82, since the MT82's ratios are considerably different from the TR3650's ratios. If the MT82 is in decent condition, a 4.6L should go easier on it as long as the nut on the other end of the shift lever does his part in not abusing it.


All this has crossed my mind once or twice . . .


Norm

doctorpimp

Cheaper and less headache way is to trade in your 2007 for a 2011.