Gear thread, hooray!

BurningRubber

10 Year Member
Dec 6, 2004
1,865
24
58
Thinking about asking for gears for Chirstmas.

But, I know EVERYONE AND THEIR BROTHER says go 4.10 at least. But 95% of the people saying that have the T-3650 trans with a better suited OD gear for cruising.

Im stuck with the T-45, and with 4.10's at 60mph id be turning 2,157.3 RPM.

With 3.73's id be turning 1,962.6 RPM.

3.90's are inbetween at 2,052.1 RPM.

Motive is really the only reputable company that sells 3.90's though. I do a whole lot of highway at 65-75mph, and I dont really want the car to be taching really high (100k +) when im cruising down the highway.

I think 3.90's would suit me really well, inbetween 3.73's and 4.10's... kind of the best of both worlds.

Ive decided that I wouldnt be doing the install by myself (lack of tools, and workspace) so if a shop is installing them are Motives any less reliable than FRPP gears? Id also be getting the t-lok rebuilt aswell as fresh bearings.

So is 3.90's still "wearing a dress"? Or is that sufficient amount of gear for a T-45 that tachs a little higher on the highway. As long as im right around 2k @ 60mph im cool. 3.73's and 3.90's are the only that fit that bill.

The car is a DD of course, and track time is limited. I want them to help with ET's but everyday driving is more of a priority. 3.73's might even suit me best, I just dont know.

Comment away ladies and gents.
 
A reputable gear installer in my area said Motive used to be good, but they switched their operation to somewhere overseas, and he flat out refused to sell or install them on anyones car.

That's his opinion.

My opinion is, they wouldn't probably still be in business if they had a reputation for failure. There are I'm sure thousands of people using their products. If you do the installation correctly, the only problem you may face is a little more gear noise than if you'd used a 4.10 FRPP or FMS ring and pinion. Now, this is only going by what people in the mustang community have said over the years. Motive tends to end up being louder.

If I were you, I'd get FRPP 4.10's. The difference between that and 3.90 is negligable, and you'd know darn well you'd have a quality product in there. I have FMS/FRPP 3.73's, and they rock, but if I had actually paid for the gears or installation, I probably would've been dissapointed. I'd go with 4.10's if I didn't have plans to have FI in the future.
 
If your going to rebuild the entire differential, and your buying the gears, why don't you buy a 31 spline set up? If you have the money, I would definetely go that route. Considering your paying someone to do the install. No sense in messing with the rear end twice.

As far as what gear to go with: you need to think about future plans for the car. Do you plan to supercharge? If so, 4.10's and a kenne bell SC would be no bueno for traction. hell, Even 3.90's and a KB would be rough. BUT 4.10's would be good for a centrifugal charger. If you plan to stay NA, slap some 4.30's on that b1tch. Hell I would go for more gear than that. But the choice is yours. Also, FRPP gears are NOT more "reliable" compared to motives. If the gears are installed correctly, they will NOT whine. period. So find someone that knows what they are doing.
 
Well a buddy of mine works at the shop doing the install. Oddly enough its a GM oriented performance shop, but they do killer work and work on all makes an models.

The 31 spline setup gets too expensive for me right now. Rebuilding the differential wont cost much, and the bearings need to be done anyway. The $ for a 31 spline differential and 31 spline shafts gets up there. Maybe one day if I bust the stockers.

For future plans, sure forced induction would be nice, but I dont see that anytime soon (college = no dinero for big stuff)... But the main reason im thinking a lower ratio like 3.73 or 3.90 is because the highway driving I do.

I rode in my buddies 99 GT with 4.30's through an auto, and that thing pulled insane... but crusing at 60mph it was taching pretty high. And if I had a 3650 id go 4.10's without a doubt.
 
you gotta decide what you are doing with your car after getting gears. You gonna get the rest of the bolt ons and cams or a blower? I'm at most doing long tubes and maybe cams, but thats it. So 4.10s for me
 
Well a buddy of mine works at the shop doing the install. Oddly enough its a GM oriented performance shop, but they do killer work and work on all makes an models.

The 31 spline setup gets too expensive for me right now. Rebuilding the differential wont cost much, and the bearings need to be done anyway. The $ for a 31 spline differential and 31 spline shafts gets up there. Maybe one day if I bust the stockers.

For future plans, sure forced induction would be nice, but I dont see that anytime soon (college = no dinero for big stuff)... But the main reason im thinking a lower ratio like 3.73 or 3.90 is because the highway driving I do.

I rode in my buddies 99 GT with 4.30's through an auto, and that thing pulled insane... but crusing at 60mph it was taching pretty high. And if I had a 3650 id go 4.10's without a doubt.

Well you know you money limits, I don't.

I think if you do A LOT of highway driving and you don't see the track that often, you should get the 3.73 gears. That leaves room for a Kenne Bell too:nice: