ForbTheStang

why is the 3.90 more expensive then the 4.10? should i go with motive prefourmance? i herd that they make noise? is this true? or should i got with the frpp but they dont make a 3.90.

mrtstang

They really are just as good as the ford racing gears! I've had my 3.90's for about 2 years now, and have no problems.

They do make a little noise at certain rpms, but nothing bad at all.

ChalknCover

Motive is fine, they actually make the FRPP now. If the part# has a M on the end, then motive made those FRPP gears. At least that is the way on Summit. The gear whine comes from a bad install, not bad gears. Motive is just fine for the 3.90. Also, it isn't as common of a gear choice which may be why they are higher priced, they aren't machining as many as say 4.10's and 3.73's.

Because you have such a short 1st gear, it can get annoying. Though I am an auto, so I may be incorrect.

ForbTheStang

if i got with the 3.90 gear how much is my speedo gonna be off?

Sxynerd

With stock tire height you run out of gear before the end of the 1/4

devongarver

[quote=BlueBloodedPony;6320952]Motive is fine, they actually make the FRPP now. If the part# has a M on the end, then motive made those FRPP gears. At least that is the way on Summit. The gear whine comes from a bad install, not bad gears. Motive is just fine for the 3.90. Also, it isn't as common of a gear choice which may be why they are higher priced, they aren't machining as many as say 4.10's and 3.73's.



Motive gears are junk IMO. They are not the same as FRPP. Atleast not as of 2 months ago when i had mine installed. Big SHOT Dyno installed mine, and they refuse to use anythign but FRPP gears, and they even had a motive set laying on the floor that a customer brought in, they refused to install it. Also, motive gears state right on the outside of the box "NOTE: Requires break in period"

There is no break in period for FRPP gears according to Ford. So, something must be different there.

And for the reason i feel that Motives are junk, is because i have heard several accounts from different installation shops about gears breaking, and noise from them. This is why my shop doesnt install anything but FRPP now. Just my 2cents.


EDIT: i did a little more research. Heres some info i gleaned from another forum.
http://allfordmustangs.com/forums/4-...de-motive.html

It appears that motive began making FRPP in 11/05, but FRPP gears are now being produced by Ford again as well. They are more expensive, but they are there. The part number ends in A for the real FRPP gears, or M for the motive junk. The motives have a different "back cut" on the teeth than FRPP. They also require different installation methods than FRPP. Im searching for evidence of this now, but motives website is pitiful...

ForbTheStang

are u talking about the 4.10?

im 90% sure im gonna go with the 3.90 any body know what brands are in the 3.90 and if so could u link a website.

i baught my car used and at 70 mph my rpm is just a hair above 2k is that normal or does it all rdy have a gear in it. might be 2100k

Sxynerd

Yes, 4.10's. I will let some of the true track drag racers chime in on the tech of it...

ForbTheStang

but i love your words of wizdom!

Sxynerd

Stock gears more than likely.