Speedo gear issues

[cobra-bit]

I pulled my tranny a couple weeks ago and noticed the speedo gears were all chewed up. I’ve also ran into an old post from the previous owner of my car that mentioned he constantly had this problem.

I’m just above the 400rwhp mark, does anyone else have this issue and what can be done to fix it? Do they make stronger gears?

Thanks,

 

[RDJ]

this is a VERY common problem in mustangs. The plastic gears get eaten up pretty regular.

 

[cobra-bit]

That’s why I’m kind of surprised there’s upgrade for these or at least not one that I’ve been able to find….anyone know of one?

.....although your avatar makes me feel a little better….

 

[TX93Cobra]

mine was chewed up as well. and i had to replace it.

 

[runin1320]

Sounds like you may have a discrepancy in the number of teeth(pitch) on the drive gear vs. driven gear. Looks like '83-'89 are different from '90-'98. Is the transmission stock, from a different year, or aftermarket?

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

Manual Transmissions with 8 Tooth Drive Gear
•1990-1995 T-5 OEM
•1996-1998 T-45 OEM Except Cobra

Automatic Transmissions with 7 Tooth Drive Gear
•1983-1989 Automatic Transmissions

Automatic Transmissions with 8 Tooth Drive Gear
•1990-1998 Automatic Transmissions

 

[Big Ben]

I just went through this. A VERY common mistake is using the wrong color speedo gear.

Here is a post from my Forum:

Well my speedometer took a crap some time ago and I did not make it a priority as I hardly drive the car and was pretty sure it was a faulty speedo gear at the tranny. My tranny also has been on it's way out over the past year with some bearing noise, whinny noise and reverse making a nasty clank. I took the car to my good friend and practically neighbor Jaime (Hannibal 302) to switch out the gear and also the gear oil in hopes of making my tranny last a little longer.

What we found out was the wrong speedo gear was installed (an 18 tooth instead of the 21). It is a common mistake but unfortunately a bad one because they get all chewed up and the little bits go into your transmission and potentially ruin it (which I believe contributed to mine). I shop that shall rename nameless (not an advertiser here) did the installation some time ago and like I said it is a common mistake. I always thought 3.73 on a T5 called for a white speedo gear but turns out there is a black and a red one that are all determined by the color of the gear inside the transmission. Mine called for red (yellow gears inside) and a white was installed. In addition, according to Pro Motion Performance (who I swear by) you should never put synthetic in a T5 you should only run Dexron Mercon III. This particular shop had installed Royal Purple.

Here is the chart:

http://www.ddperformance.com/PDF/SpeedoChart.pdf

 

[Liv4Spd]

Interesting - thanks for the info Ben :beer: