Drivetrain T5 5th gear options

bwest

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Oct 25, 2005
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Hey all -

Any of you guys swapped the OE 5th (.68) with either the .73 used in the 2005+ v6 T5's or the GM .72? I'm having a hard time digging up the spline/countershaft gears (like via a spec sheet or someone that has actually done it). The gap between 4th-5th is too wide for my liking w/ a 1.00-.68 and it would be much more useful if .72-.73 was an option.

Thanks!
 
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Can’t use the GM gears on a Ford t5. The mainshaft spline counts are not the same. GM is 27 spline and ford is 28.


So there are three main 5th gearsets for the T5 that I am aware of not including the aftermarket offerings.

27/59
25/51
33/53

I think there is a 31/55 but not so much info on that.

The 2.95 gearset came with the 25/51 set which gave you 0.63. With the 27/59 you got 0.59

The 3.35 gearset comes with 27/59 which gives you 0.68. Some of the 94-98 V6 cars came with the 25/51 which gives you 0.73 which is probably what you are looking for.

The 33/53 set came on a few early 2.95 trans and is hard to find. It gave you 0.80 in a 2.95 trans and 0.97ish in a 3.35 trans. Lots of aftermarket 5th gears are similar to this one and give you 0.80 only with the 2.95 box. You don’t want this for obvious reasons.


Sounds like you want to find a 25/51 gearset from a 94-98 v6 trans. I am not sure what gearset came in the 99-04 and 05-10 trans so count the teeth and compare.
 
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good to know on the different main spline counts between the GM and Ford boxes - thanks for that.

With that info looks like I have the search narrowed down a bit - this is something of a winter project as I need to drop the tranny to fix a leaky RMS, seems like the right time to figure this out as well. The 4th -> 5th jump is so damn wide it really makes general road gearing a major PITA to make all 5 gears useful (limiting compromise between them).
 
I can't see too many scenarios where this should really be an issue.
Highway racing, which at those speeds would be pretty risky.
Road racing, but i think you would have said that's what you are doing.
Or if the car doesn't make any low end power.
My TKO has a pretty steep drop, but in 99% of real world driving it really doesn't matter.
 
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