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TR3650 transmission gear ratios

  • Thread starter Thread starter stangg01
  • Start date Start date Mar 6, 2007
S

stangg01

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Mar 17, 2006
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Mar 6, 2007
#1
  • Mar 6, 2007
  • #1
I recently had my transmission rebuilt. Now my 5th gear ratio is .62 when before it was .67. What happened? Did the transmission place replace my transmission with another kind such as a T-45, or a T-5?

The receipt states "REBUILT TREMEC 3650 UPGRA".
The transmission shop guy told me that the transmission is a new 2003.

Any ideas on what happened?
 

Tim2002GT

Founding Member
Apr 10, 2002
635
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29
Tulsa, Oklahoma
Mar 6, 2007
#2
  • Mar 6, 2007
  • #2
I think the 2003+ 3650's did have the different 0.62 5th gear.
 
S

stangg01

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#3
  • Mar 6, 2007
  • #3
By the way,
My car is a mid 2001 Mustang GT
 
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stangg01

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#4
  • Mar 6, 2007
  • #4
Thanks Tim2002GT
 
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GettinThere

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Mar 7, 2007
#5
  • Mar 7, 2007
  • #5
stangg01 said:
I recently had my transmission rebuilt. Now my 5th gear ratio is .62 when before it was .67. What happened? Did the transmission place replace my transmission with another kind such as a T-45, or a T-5?

The receipt states "REBUILT TREMEC 3650 UPGRA".
The transmission shop guy told me that the transmission is a new 2003.

Any ideas on what happened?
Click to expand...

Awhile back I tried to find out what the 5th gear ratio was. I was never able to get a definitive answer. From reliable sources I got both 0.68 and 0.62 so I still don't know what it is.

You still have a Tremec 3650 transmission, not a T-5 or T-45. Perhaps early 3650 transmissions had 0.68 and later ones had 0.62 ratios.
 
S

stangg01

New Member
Mar 17, 2006
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Mar 7, 2007
#6
  • Mar 7, 2007
  • #6
From my reasearch, I believe that:
.62 was for the Mach 1 and Bullitt Mustangs because they have 3.55 axle ratios.
.68 was for GT and v6 Mustangs.

Thanks GettinThere
 

stangman

15 Year Member
Jul 10, 2003
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in a 3 bed, 2 bath
Mar 8, 2007
#7
  • Mar 8, 2007
  • #7
stangg01 said:
From my reasearch, I believe that:
.62 was for the Mach 1 and Bullitt Mustangs because they have 3.55 axle ratios.
.68 was for GT and v6 Mustangs.

Thanks GettinThere
Click to expand...

that is correct
 

Nater

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Sep 5, 2003
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Mar 8, 2007
#8
  • Mar 8, 2007
  • #8
GettinThere said:
Awhile back I tried to find out what the 5th gear ratio was. I was never able to get a definitive answer. From reliable sources I got both 0.68 and 0.62 so I still don't know what it is.

You still have a Tremec 3650 transmission, not a T-5 or T-45. Perhaps early 3650 transmissions had 0.68 and later ones had 0.62 ratios.
Click to expand...

stangg01 said:
From my reasearch, I believe that:
.62 was for the Mach 1 and Bullitt Mustangs because they have 3.55 axle ratios.
.68 was for GT and v6 Mustangs.

Thanks GettinThere
Click to expand...

Take a look at Tremec's website. I know in my 2000 GT my engine was turning over 2000rpm at 70mph and now in my 2002 GT I'm doing 75 at 2000rpms. I noticed it right away when I shifted into 5th for the first time that the engine seemed to be turning less.
 

Give Me TP

Member
Jun 17, 2004
936
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Republic of Texas
Mar 8, 2007
#9
  • Mar 8, 2007
  • #9
Thus, those who have the 0.62 5th gear ratio NEED 4.10's

I have to be going 90 mph in 5th with them before I reach 3000 rpm.
 

tag4car

Member
Nov 21, 2005
0
0
16
Birmingham AL
Mar 14, 2007
#10
  • Mar 14, 2007
  • #10
if you don't mind my asking what was the final bill on your rebuild, i need to have new synchro's on 3rd and rev.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,249
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224
Massachusetts
Mar 14, 2007
#11
  • Mar 14, 2007
  • #11
stangg01 said:
From my reasearch, I believe that:
.62 was for the Mach 1 and Bullitt Mustangs because they have 3.55 axle ratios.
.68 was for GT and v6 Mustangs.

Thanks GettinThere
Click to expand...

2001-2002 GT's and 2001 Cobras get the version with the 0.68 5th gear


2003-2004 GT's and Mach 1's get the 0.62 5th gear.


The dropoff is very noticable. When i drive my car, every gear drops about 1000RPM's when i upshift, so it's nice and smooth. However, when i upshift to 5th, the drop is very large, about 1500RPM. It's nice though since i have stock gears, and i'm only doing about 2000RPM at 80MPH. There isn't any passing power, but that's what 4th is for.


An interesting observation, the 2003-2004 Cobra's 6-spd has a 6th gear ratio of 0.62 as well.
 
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