Fix Speedometer

[StarFox07]

When I bought my car from the previous owner, the speedometer was and still is reading wrong as I havnt bothered to fix it yet. The car has (i THINK) 3.73's installed now instead of the factory 2.72's (?) so is there any easy way to recalibrate the speedometer?

Also I got one of those UPR brushed aluminum gauge plate kits, how do I get around taking out the plexiglass part in front of the gauges?

 

[PJB]

You need a speedometer recalibration gear.
I got mine from www.cjponyparts.com

 

[Roland69]

Manual Transmissions with 6 Tooth Drive Gear

Not found in OEM applications

Item Number
Description
N/A
3.08 Gear Ratio / Not possible

C0DZ-17271-A
3.27 Gear Ratio / Maroon 16 Speedo Gear

C3DZ-17271-C
3.55 Gear Ratio / White 17 Speedo Gear

C0DD-17271-B
3.73 Gear Ratio / Yellow 18 Speedo Gear

C0DZ-17271-B
3.90 Gear Ratio / Pink 19 Speedo Gear

C1DZ-17271-A
4.10 Gear Ratio / Black 20 Speedo Gear

C4OZ-17271-A
4.30 Gear Ratio / Red 21 Speedo Gear



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



Item Number
Description
C0DZ-17271-A
2.73 Gear Ratio / Maroon 16 Speedo Gear

C0DD-17271-B
3.08 Gear Ratio / Yellow 18 Speedo Gear

C0DZ-17271-B
3.27 Gear Ratio / Pink 19 Speedo Gear

C1DZ-17271-A
3.55 Gear Ratio / Black 20 Speedo Gear

C4OZ-17271-A
3.73 Gear Ratio / Red 21 Speedo Gear

Jeep Part #j3167393
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



Item Number
Description
C0DD-17271-B
2.73 Gear Ratio / Yellow 18 Speedo Gear

C1DZ-17271-A
3.08 Gear Ratio / Black 20 Speedo Gear

C4OZ-17271-A
3.27 Gear Ratio / Red 21 Speedo Gear

Jeep Part #j3167393
3.55 Gear Ratio / White 23 Speedo Gear

Jeep Part #j3167393
3.73 Gear Ratio / White 23 Speedo Gear (Not 100% accurate. This combination will offer the best accuracy without changing the drive gear. Change drive gear to a 6 tooth for complete accuracy. See 6 tooth table.)

Jeep Part #j3167393
4.10 Gear Ratio / White 23 Speedo Gear (Not 100% accurate. This combination will offer the best accuracy without changing the drive gear. Change drive gear to a 6 tooth for complete accuracy. See 6 tooth table.)



Automatic Transmissions with 7 Tooth Drive Gear



1983-1989 Automatic Transmissions



Item Number
Description
D0AZ-17271-A
2.73 Gear Ratio / Blue 16 Speedo Gear

C7AZ-17271-B
3.08 Gear Ratio / Gray 18 Speedo Gear

C7VY-17271-A
3.27 Gear Ratio / Tan 19 Speedo Gear

C8SZ-17271-B
3.55 Gear Ratio / Orange 20 Speedo Gear

D0OZ-17271-B
3.73 Gear Ratio / Purple 21 Speedo Gear

Jeep Part #j3167393
4.10 Gear Ratio / White 23 Speedo Gear



Automatic Transmissions with 8 Tooth Drive Gear



1990-1998 Automatic Transmissions



Item Number
Description
C7AZ-17271-B
2.73 Gear Ratio / Gray 18 Speedo Gear

C8SZ-17271-B
3.08 Gear Ratio / Orange 20 Speedo Gear

D0OZ-17271-B
3.27 Gear Ratio / Purple 21 Speedo Gear

Jeep Part #j3167393
3.55 Gear Ratio / White 23 Speedo Gear

Jeep Part #j3167393
3.73 Gear Ratio / White 23 Speedo Gear (Not 100% accurate.)

Jeep Part #j3167393
4.10 Gear Ratio / White 23 Speedo Gear (Not 100% accurate.)



Now if you really want to change the internal drive gear of your manual tranny you can match it according to the table below. Be aware that the 6 tooth will offer the most combos for numerically higher gear ratios and offer the greatest degree of accuracy. The 6 tooth gear selection table for a manual tranny is the first in the page.


Item Number
Description
E3ZZ-17285-B
6 Tooth Internal Drive Gear / Black

E3ZZ-17285-A
7 Tooth Internal Drive Gear / Yellow

F0ZZ-17285-A
8 Tooth Internal Drive Gear / Green

 

[86bluecobra]

basically you need the 23 tooth speedo gear. It won't be 100% accurate but it will be close.

 

[TRWXXA]

Also I got one of those UPR brushed aluminum gauge plate kits, how do I get around taking out the plexiglass part in front of the gauges?

I don't think you can "get around" removing the cluster lens in order to put in the gauge plates.

To get the lens out:

Remove the covers from around the steering column (2 phillips head screws in the holes below the bottom cover).

Unmount the hood release handle from under the dash (2 bolts -- I forget the size... maybe 10mm ).

Remove the lower dash panel (a couple of 8mm hex screws on the bottom edge, and then it pops out).

Remove the lighting switch assemblies from the instrument cluster bezel and remove the connectors (this is the fun part -- use a flat blade inserted on the sides of the switches to carefully pop them out).

Remove the instrument cluster bezel (a couple of 7mm hex/torx screws at the top near the windshield, and a couple of various sized bolts that you'll see when you get the lower panel removed).

The lens is held in by approximately six 7mm hex/torx screws.

And, as the Haynes manuals all say... "Installation is the reverse of removal."

I think I covered it all.

 

[PJB]

basically you need the 23 tooth speedo gear. It won't be 100% accurate but it will be close.

The one I bought from CJ Pony Parts was better than the TCI one I ordered from Jeg's. It has the longer tail than the TCI one and hasnt fallen off the shaft like the TCI one did.
Its also gray or black instead of white, even though its listed as white on their website. It is the right gear because the speedometer isnt way off like it was with the stock gear.

 

[5.0 Nostalgia]

To get it almost 100% accurate you have to change the drive gear in the tailshaft. With the 23 tooth gear in my old AOD, it registered about 1.1 miles for every 1 mile instead of 1.4 miles for every 1 mile with the stock gear.

 

[PJB]

On the AOD the gear is part of the tailshaft. It doesnt come off like the T5.