Drivetrain Rear end gear swap

V-6Pony

New Member
Dec 10, 2019
10
0
1
67
Keene NH
2000 V-6 Automatic convertible want to change gear ratio. Has 3:27 with a 7.5 ( I think its a 7.5 have to take a look) running 17 inch tires. Wanted to go with Yucon 3:73 but a mechanic recommended 4:11 any opinions. Not a daily driver just for fun and shows. Not sure what it will do to my MPG, but should give me more speed out of the gate.
Thanks
 
  • Sponsors(?)


wmburns

SN Certified Technician
Aug 14, 2009
5,810
499
164
Houston Texas
It seems to me that IF you have any concerns about MPG's, then 4.11's are not for you. Stick with the factory ratios.

I also believe that 4.11's are too low for an automatic. It will reduce the life of the automatic transmission.

There are many people on the forums that are serious fan boys for the 4.11's. I suspect that most do not take extended trips with their 4.11's.
 

V-6Pony

New Member
Dec 10, 2019
10
0
1
67
Keene NH
Thanks for the reply. Not really concerned about MPG. Car is not really a daily driver. Just weekend trips and car shows. Why you think it will reduce the life of the transmission? Car only was 64K on it. Will at least go with 3.73 for a little more low end get up and go
 

kiddiccarus

The first widely accepted Tranny
15 Year Member
Dec 24, 2003
1,080
559
133
30 Mins from a Ragged GT
www.angelfire.com
my .02 here...... Before you do this, look into what it will cost you to swap to the 8.8 rear with LSD. In my case I have a 95 vert with a 5 speed. Came with 2.73:1 in a 7.5. I found an 2004 gt 8.8 which had 3.27:1 inside with LSD for $250
 

wmburns

SN Certified Technician
Aug 14, 2009
5,810
499
164
Houston Texas
Why you think it will reduce the life of the transmission?
The 4R70W is a PCM controlled transmission. The programmed shift points are based upon how long it take the transmission to actually change gears and at what RPM the gear change should be completed. When too low of a gear is used this causes the RPM's to rise faster than stock. The net effect is it still takes the transmission the same amount of time to change gears. However the RPM's have risen more/faster due to the lower gear. For this reason it's sometimes necessary to adjust the shift points so that the gear changes have completed at the same RPM.

Also look up "critical speeds" with how it relates to U joints.
 

V-6Pony

New Member
Dec 10, 2019
10
0
1
67
Keene NH
The 4R70W is a PCM controlled transmission. The programmed shift points are based upon how long it take the transmission to actually change gears and at what RPM the gear change should be completed. When too low of a gear is used this causes the RPM's to rise faster than stock. The net effect is it still takes the transmission the same amount of time to change gears. However the RPM's have risen more/faster due to the lower gear. For this reason it's sometimes necessary to adjust the shift points so that the gear changes have completed at the same RPM.

Also look up "critical speeds" with how it relates to U joints.
Thanks for that information. I will run it by my mechanic and see what he thinks. Going to go with 373's I think the 411's are to much for that car and how I am going to drive it.
 

silversmith82

Member
May 2, 2005
67
1
9
4.10s... 4.11s are a chevy gear.


Get the 4.10s, people swap to 4.10s all the time with no ill effects. Its one of the best mods to do for an auto to get it off the line quicker. Reduce the life of the trans... lol no. As long as the trans cooler is doing its job it'll be fine.

I also would just find a 8.8 with 4.10s already installed and do the 8.8 swap.
 
Thread starter Similar threads Forum Replies Date
5 Rear end gear noise 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 3
C Drivetrain Rear Differential Noise 1994 - 1995 Specific Tech 6
C For Sale Moser 8.8 Rearend Drivetrain Parts 0
A Limited Slip Rear End Grinding and Whining 1996 - 2004 SN95 Mustang -General/Talk- 1
T 2008 Mustang GT Vibration in Entire Car 2005 - 2009 Specific Tech 5
Roger Dixon Need Advice on Rear End Gears 1996 - 2004 SN95 Mustang -General/Talk- 2
K Rear End/differential SN95 V6 Mustang Tech 6
F Rear End Gears 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 7
78mIIman Drivetrain 78 Ii 8" 3.80??? 1974 - 1978 Mustang II Talk & Tech 8
G Speedo Calibration SN95 4.6L Mustang Tech 5
S Expired Rear End Gears Drivetrain Parts 0
U 1999-2004 7.5 Rear End In 1994-1998 V6 SN95 V6 Mustang Tech 0
Old Yeller Update Rear End Gear Setting? 2005 - 2014 S-197 Mustang -General/Talk- 13
M 2014 Mustang Rear End Gear Change V6 Auto - Whine And Vibration 2005 - 2014 S-197 Mustang -General/Talk- 1
O Best Rear End Gears For 4.6 V8 2005 - 2009 Specific Tech 3
smkshw New Rear End Gear Choice? Fox 5.0 Mustang Tech 13
GoldenEagle91 Drivetrain Vibration From The Rear End In 5th Gear Fox 5.0 Mustang Tech 17
tacomatrx450f 8.8 Rear End Spider Gear Shim Spining? Any Idea Why Fox 5.0 Mustang Tech 4
jon1475 What Was Your Cost To Install Rear End Gears? 2005 - 2014 S-197 Mustang -General/Talk- 11
delmo408 Drivetrain AOD require new rear end gear ratio? Classic Mustang Specific Tech 7
Angelv23 Expired 3.27 gears for 8.8 rear end Drivetrain Parts 0
2E151 Rear End Gear Ratio Swap: Shop Cost 2005 - 2014 S-197 Mustang -General/Talk- 8
J Rear end and gears ...... 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 4
P Rear End Gears 2005 - 2009 Specific Tech 3
J Expired mustang rear end pinion and gear set Drivetrain Parts 1
J Ribbed rear end pumpkin, 3.50 gearing, brand new posi Drivetrain Parts 3
JonezySN95 Rear end gear help 1994 - 1995 Specific Tech 20
Kdubslugga Installing rear end gears. Gotta question. Fox 5.0 Mustang Tech 1
8 Who makes the best rear end gears? Fox 5.0 Mustang Tech 18
rclifton 3.73 rear end speedo Gear??? Fox 5.0 Mustang Tech 2
L HELP WITH 8.8" REAR END GEAR PATTERN SN95 4.6L Mustang Tech 10
L Suggestions on rear end gears.. SN95 4.6L Mustang Tech 6
9 rear end gearing Fox 5.0 Mustang Tech 13
foxforce33 Rear End Gears: 3.55s or 3.73s? Fox 5.0 Mustang Tech 13
1 Rear end gears? Classic Mustang Specific Tech 21
I I need some rear end gears ASAP 8.8 Drivetrain Parts 4
M new rear end gears 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 16
9 rear end gear oil 1996 - 2004 SN95 Mustang -General/Talk- 12
shoguun where to buy rear end gears 1965 - 1973 Classic Mustangs -General/Talk- 8
9 what weight gear oil for rear end? 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk- 2
9 what grade gear oil for rear end? Fox 5.0 Mustang Tech 1
Y 2003 4.6 Rear end gears SN95 4.6L Mustang Tech 45
9 how do i find out what rear end gears i had stock? 1994 - 1995 Specific Tech 7
H Can anyone help me with 7.5" rear end gears? Fox 5.0 Mustang Tech 6
tims 86 rear end gears Fox 5.0 Mustang Tech 4
E rear end gear ? 2005 - 2009 Specific Tech 10
boosted68stang rear end gears Fox 5.0 Mustang Tech 11
D Steep rear end gears (4.10s) compensated by replacing overdrive in a T5? Fox 5.0 Mustang Tech 32
9 Best rear end gears for 03 GT 5 speed 1996 - 2004 SN95 Mustang -General/Talk- 17
T rear end gears Fox 5.0 Mustang Tech 6
Similar threads