What about 3.90 gears?

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07-12-2006, 03:04 AM

#11

David_K

5th Gear Member

Join Date: Mar 2005

Location:

Posts: 3,967

RE: What about 3.90 gears?

3.90s are awsome im getting ready to switch to 3.90s from the 3.73s i have in my cobra right now

07-12-2006, 03:14 AM

#12

03sonicgt

5th Gear Member

Join Date: Oct 2005

Location: Berkley, Michigan

Posts: 2,751

RE: What about 3.90 gears?

Because ford racing does not make a 3:90 gear, only motive and richmond do. And I personally wouldn't buy any other brand of ring and pinion.

07-12-2006, 07:44 AM

#13

geetee03

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Join Date: Oct 2005

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Posts: 2,023

RE: What about 3.90 gears?

Quote:

ORIGINAL: 03sonicgt

Because ford racing does not make a 3:90 gear, only motive and richmond do. And I personally wouldn't buy any other brand of ring and pinion.

+1

took the words out of my mouth.

07-12-2006, 01:54 PM

#14

spederman

2nd Gear Member

Join Date: Feb 2005

Location:

Posts: 378

RE: What about 3.90 gears?

Here is my experience with 3.90's. I have had two set installed and have delt with a nightmare. 3.90's are made by motive or Pro 5.0. I had motive's. The first set i had installed they whined like a bitch. The installer i used has done hundreds of gear installs, but unfortunately all FRPP. I had them replaced under warranty with another set. This time i went to a different performance shop. The result was the same. They whined even worse then the second set. This guy also is a Ford certified master tech and has done hundreds of installs. I couldnt handle it anymore and just put in FRPP 3.73's because i just bought a vortech. Finally peace and quiet. The problem with the 3.90's is that Motives tolerances are so freaking tight that the gears have to be setup PERFECTLY. Even though ford recommends a certain range for the backlash, motive's have to have PERFECT gear tooth overlap. Even if they are slightly off, they will whine. FRPP there is a lot of room for slack and they will still be quiet. The motive's have to be a trial and error process where you have to put them in and check the tooth overlap and if not perfect re do them with different shims. Well, a lot of installers are lazy and just call it good enough because FRPP's you can do that. But not with motive's. So unless you are positive that your installer is great, i wouldnt risk it. Just my 2 cents

07-12-2006, 01:56 PM

#15

Miliock

3rd Gear Member

Join Date: Jul 2004

Location:

Posts: 770

RE: What about 3.90 gears?

I thought the same company made motive and frpp gears?

07-12-2006, 02:15 PM

#16

40thgtfl

3rd Gear Member

Join Date: Apr 2006

Location: Florida

Posts: 782

RE: What about 3.90 gears?

Quote:

ORIGINAL: MustangChris04

Finally! Somebody on mustang forums understands that we need more top end than 4.10's.
I could understand why they like them because they all go to the track. But I went to moroso once and I hated it, they didnt prep the track and the later it got the more dew there was on the track. I can see why so many people in south florida like to street race because there is nowhere else to do it.

i feel your pain. 4.10s would never cut it around here. moroso is a joke, i cut a 2.4 second 60' there once.

as for the gear choice i am going to try the pro 5.0 3.90