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  • 1979 - 1995 (Fox, SN95.0, & 2.3L) -General/Talk-
  • Fox 5.0 Mustang Tech

Speedo Gear

  • Thread starter Thread starter Turkey Sammich
  • Start date Start date May 18, 2007
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Turkey Sammich

I can't fap normal. I cracked a rib, then my ankle
Jul 12, 2006
0
59
154
May 18, 2007
#1
  • May 18, 2007
  • #1
My T5 recently went in without the speedo gear. Why it was removed is beyond me

How difficult would it be to put it back in, Estimate of start to finish, and where to install the gear at?
 

CRASH7772

Member
Apr 27, 2003
401
1
16
NH
May 18, 2007
#2
  • May 18, 2007
  • #2
Takes about 5-10 mins to install.

Here is some info to help decide which gear to get...

Figuring gear ratio with different size tires.

Divide the old tire diameter by the new tire diameter and then multiply by the current ratio. So a stock 87 tire is 225/60/15 or 25.63 diameter and say we put a 255/60/15 or 27.04 on.So 25.63 divided by 27.04=.9461 then multiply by the stock 2.73 gear and get 2.588 which is definitley not a drag gear.
This is a good site for comparing tire sizes http://www.1010tires.com/TireSizeCalculator.asp .

Manual Transmissions with 7 Tooth Drive Gear
# 1983-1989 T-5 OEM
# Pre 1993 T-5 Aftermarket
# 1996-1998 Cobra T-45 OEM
# All Tremec Transmissions
2.73 Gear Ratio / Maroon 16 Speedo Gear
3.08 Gear Ratio / Yellow 18 Speedo Gear
3.27 Gear Ratio / Pink 19 Speedo Gear
3.55 Gear Ratio / Black 20 Speedo Gear
3.73 Gear Ratio / Red 21 Speedo Gear
4.10 Gear Ratio / White 23 Speedo Gear

Manual Transmissions with 8 Tooth Drive Gear
# 1990-1995 T-5 OEM
# 1996-1998 T-45 OEM Except Cobra
2.73 Gear Ratio / Yellow 18 Speedo Gear
3.08 Gear Ratio / Black 20 Speedo Gear
3.27 Gear Ratio / Red 21 Speedo Gear
3.55 Gear Ratio / White 23 Speedo Gear
3.73 Gear Ratio / White 23 Speedo Gear
4.10 Gear Ratio / White 23 Speedo Gear
Automatic Transmissions with 7 Tooth Drive Gear
# 1983-1989 Automatic Transmissions
2.73 Gear Ratio / Blue 16 Speedo Gear
3.08 Gear Ratio / Gray 18 Speedo Gear
3.27 Gear Ratio / Tan 19 Speedo Gear
3.55 Gear Ratio / Orange 20 Speedo Gear
3.73 Gear Ratio / Purple 21 Speedo Gear
4.10 Gear Ratio / White 23 Speedo Gear

Automatic Transmissions with 8 Tooth Drive Gear
# 1990-1998 Automatic Transmissions
2.73 Gear Ratio / Gray 18 Speedo Gear
3.08 Gear Ratio / Orange 20 Speedo Gear
3.27 Gear Ratio / Purple 21 Speedo Gear
3.55 Gear Ratio / White 23 Speedo Gear
3.73 Gear Ratio / White 23 Speedo Gear
4.10 Gear Ratio / White 23 Speedo Gear
 

Turkey Sammich

I can't fap normal. I cracked a rib, then my ankle
Jul 12, 2006
0
59
154
May 18, 2007
#3
  • May 18, 2007
  • #3
Thanks

Will I need to pull the T5 back out of my car?
 

CRASH7772

Member
Apr 27, 2003
401
1
16
NH
May 18, 2007
#4
  • May 18, 2007
  • #4
Turkey Sammich said:
Thanks

Will I need to pull the T5 back out of my car?
Click to expand...

You might need to jack it up or put it on ramps. Right about where you drivers side seat is (under the car) you'll find the speedo cable. There should be a screw/bolt holding that into the trans. Take that out and the cable should pull right out (assuming it's there to begin with), the gear will slide onto the end and there is a clip to hold it on to the cable. Just reverse for the install.
 

bobbyd

New Member
Sep 8, 2004
312
0
0
San Antonio/Los Angeles
May 19, 2007
#5
  • May 19, 2007
  • #5
CRASH7772 said:
You might need to jack it up or put it on ramps. Right about where you drivers side seat is (under the car) you'll find the speedo cable. There should be a screw/bolt holding that into the trans. Take that out and the cable should pull right out (assuming it's there to begin with), the gear will slide onto the end and there is a clip to hold it on to the cable. Just reverse for the install.
Click to expand...

will it be the same for a AOD? same location and everything?
 

CRASH7772

Member
Apr 27, 2003
401
1
16
NH
May 20, 2007
#6
  • May 20, 2007
  • #6
bobbyd said:
will it be the same for a AOD? same location and everything?
Click to expand...

You know I have actually never ever seen an auto up close on a 5.0 but I would imagine that it would be very similar.
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,170
17,870
224
Massachusetts
May 20, 2007
#7
  • May 20, 2007
  • #7
Which gear are you talking about??


The drive gear that mounts on the output shaft of the t-5, or the driven gear that goes on the speedo cable??
 

Turkey Sammich

I can't fap normal. I cracked a rib, then my ankle
Jul 12, 2006
0
59
154
May 20, 2007
#8
  • May 20, 2007
  • #8
The drive gear that mounts on the output shaft of the t-5.

View attachment 385036
 

Mustang5L5

That is…until I whipped out my Bissell
Mod Dude
Feb 18, 2001
43,170
17,870
224
Massachusetts
May 20, 2007
#9
  • May 20, 2007
  • #9
You can install it with the trans still in the car, but it will be tough. You need to take the tailhousing out and if you do it in the car you will need 2 people.

Easier to pull the trans out and do it on the bench
 

Turkey Sammich

I can't fap normal. I cracked a rib, then my ankle
Jul 12, 2006
0
59
154
May 20, 2007
#10
  • May 20, 2007
  • #10
Mustang5L5 said:
You can install it with the trans still in the car, but it will be tough. You need to take the tailhousing out and if you do it in the car you will need 2 people.

Easier to pull the trans out and do it on the bench
Click to expand...

That's what I was afraid of. Thanks for the advised
 

Chuckman

GTFO you fat, heavy bastard
15 Year Member
Oct 21, 2005
1,604
1,002
173
st. louis, mo
May 20, 2007
#11
  • May 20, 2007
  • #11
i did it before i put the trans in my car, very easy, should take about 10-15mins. pop off the shifter, pound out the rollpin, unbolt the tail, slide it off, gear is held on with a clip, then put it together like you took it apart. getting that little spring on the detent ball was the hardest thing for didnt, bastard didnt want to stay still long enough to get it engaged right.
 

CRASH7772

Member
Apr 27, 2003
401
1
16
NH
May 25, 2007
#12
  • May 25, 2007
  • #12
Turkey Sammich said:
That's what I was afraid of. Thanks for the advised
Click to expand...

My bad for not asking that. I couldn't imagine why anybody would pull that out????
 

Darkwriter77

Resident Ranting Negative Nancy
5 Year Member
Jul 1, 2005
314
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134
Apache Junction, AZ
May 25, 2007
#13
  • May 25, 2007
  • #13
Kinda weird that the 3.55, 3.73, and 4.10's all take the same 23-tooth speedo gear for the 90+ T-5's. I'm guessing the 3.73's would be the only halfway-accurate gear ratio with that speedo gear, then...?

Also got me to wondering how I'd know if my T-5 was a 90+ unit or a pre-90. I stuck a 21-tooth gear in there a couple years ago (closest I could get to 4.10's at the time) because I figured mine was an 89 or older, and I didn't want to deal with changing out the other internal gear ... but now I'm kinda wondering if maybe I do, in fact, have a 90+ T-5. Hmmm...
 

90_Red_LX

Member
Sep 29, 2003
668
5
19
Asheboro, NC
May 25, 2007
#14
  • May 25, 2007
  • #14
Darkwriter77 said:
Kinda weird that the 3.55, 3.73, and 4.10's all take the same 23-tooth speedo gear for the 90+ T-5's. I'm guessing the 3.73's would be the only halfway-accurate gear ratio with that speedo gear, then...?

Also got me to wondering how I'd know if my T-5 was a 90+ unit or a pre-90. I stuck a 21-tooth gear in there a couple years ago (closest I could get to 4.10's at the time) because I figured mine was an 89 or older, and I didn't want to deal with changing out the other internal gear ... but now I'm kinda wondering if maybe I do, in fact, have a 90+ T-5. Hmmm...
Click to expand...

For 3.55s it is dead accurate. 3.73s its around 5-10mph off. 4.10s is way bad, just they say use the 23 toother for the 3.73s and 4.10s because it's the highest tooth count offered. This applies for the 90+ t5s. Pre 90 the 23 toother is accurate up to 3.73s, and the 4.10s are a few mph off.
 

JustA5.0

Member
May 12, 2007
148
0
16
Toronto, ON
May 25, 2007
#15
  • May 25, 2007
  • #15
Darkwriter77 said:
Also got me to wondering how I'd know if my T-5 was a 90+ unit or a pre-90. I stuck a 21-tooth gear in there a couple years ago (closest I could get to 4.10's at the time) because I figured mine was an 89 or older, and I didn't want to deal with changing out the other internal gear ... but now I'm kinda wondering if maybe I do, in fact, have a 90+ T-5. Hmmm...
Click to expand...
You could purchase the 23 tooth white gear and see if it's accurate (= 89 older) or still off (= 90+). Also, not sure what tire size you have, but it will play a small factor in accuracy.
 

JustA5.0

Member
May 12, 2007
148
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May 25, 2007
#16
  • May 25, 2007
  • #16
90_Red_LX said:
Pre 90 the 23 toother is accurate up to 3.73s, and the 4.10s are a few mph off.
Click to expand...
I'm fairly certain the 7tooth drive gear needs a red 21 for the 3.73s and a white 23 for 4.10 gear ratio. So a 23 tooth speedo gear should be quite accurate on the pre-90 OEM T-5.
 

90_Red_LX

Member
Sep 29, 2003
668
5
19
Asheboro, NC
May 25, 2007
#17
  • May 25, 2007
  • #17
JustA5.0 said:
I'm fairly certain the 7tooth drive gear needs a red 21 for the 3.73s and a white 23 for 4.10 gear ratio. So a 23 tooth speedo gear should be quite accurate on the pre-90 OEM T-5.
Click to expand...

Hmm. You may be right on that one. I know 90 and up though the 23 tooth is not accurate for 3.73 gears though for a fact.
 

JustA5.0

Member
May 12, 2007
148
0
16
Toronto, ON
May 25, 2007
#18
  • May 25, 2007
  • #18
^^ Correct, due to the 8tooth drive gear in them
 

Darkwriter77

Resident Ranting Negative Nancy
5 Year Member
Jul 1, 2005
314
281
134
Apache Junction, AZ
May 25, 2007
#19
  • May 25, 2007
  • #19
I was told that you had to swap out the internal gear to use the 23-tooth speedo gear, however, because a 7-tooth internal gear would just eat the thing up...?

Hell, just for giggles, I may as well put the thing up in the air and verify for certain that it's got 4.10's, anyhow. It certainly pulls, drives, and cruises with the higher RPM's in a way consistent with 4.10's, which is what the prior owner claimed that had been installed. The speedo still reads 10 to 15 mph high at 65 mph, though, with the 21-tooth gear, so either I've got a 90+ T-5 with 3.73's (or 4.10's?), or I've got a pre-90 with 4.10's and I'm one step down in gear teeth count.

As far as higher-count speedo gears ... weren't some guys running a speedo gear out of a Jeep for 4.10's? Or was that the same white 23-tooth gear already recommended?
 

Mr Grim

New Member
Dec 29, 2006
58
0
0
May 25, 2007
#20
  • May 25, 2007
  • #20
Darkwriter77 said:
I was told that you had to swap out the internal gear to use the 23-tooth speedo gear, however, because a 7-tooth internal gear would just eat the thing up...?
Click to expand...

I have heard about the 23 gear getting eaten up too. Is that because it isn't compatible with a 7-tooth drive gear? Does it work with an 8-tooth drive?
 
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