Do not use a 23 tooth driven gear, it will probably not last more than a couple of months. The 23 tooth gear was originally designed for a Jeep and the thread pitch is wrong for a T5. I tried one and the results are in the photo.
Please post your rear axle ratio and tire size and someone will advise you on the correct speedometer gears.

 

Those 23-tooth driven gears don't hold up because the gear doesn't quite mesh with the drive gear.

What axle ratio are you running?

Sounds like you probably have an 8-tooth drive gear and need a 7. The tailshaft and shifter have to come out. I know I can't get my T5 shifter out without dropping the trans or cutting a hole in the floor.

 

Those 23-tooth driven gears don't hold up because the gear doesn't quite mesh with the drive gear.

What axle ratio are you running?

Sounds like you probably have an 8-tooth drive gear and need a 7. The tailshaft and shifter have to come out. I know I can't get my T5 shifter out without dropping the trans or cutting a hole in the floor.

The tailshaft and shifter have to come out ?
I need to unmount my gear box ?
Sorry , i'm french and sometimes it's difficult for me ....
i don't use google translate, perhaps i should


Thanks

 

Hello,
axle ratio 3.25
Wheels 225X60 R17
When i test my speedometer with a drill, no problem, no shake.

thanks

 

Yes, the tail shaft housing and shifter have to come out.
The easiest way to change the drive gear is to remove the transmission from the car. The gear shift handle must be removed, them the tail shaft housing can be removed. The drive gear is held on the main shaft by a spring clip. Depress the spring clip and remove the gear from the main shaft. The gear you need is a 7 tooth drive gear. A 17 tooth driven gear most closely matches your rear gear and tire size.
https://lmr.com/ probably has the best prices on speedometer drive and driven gears.

 

arghhhhhh
damned
i will be busy during the winter !

do you think, i can put a 23 teeth during some month ?
I saw the photo, but it solve my problem

thanks

 

I would advise against it. Not only does the 23 tooth gear shed its teeth, but you will end up with tiny plastic gear teeth through out the transmission. The gear teeth can block lubrication to the internal components of the transmission.

 

The speedometer bouncing is probably the drive cable. You could try to fix it by removing the inner cable from the sheath and adding some wheel bearing grease. Or just replace the cable

 

i dont' knowthis product
but i find i think an other,
speedo ratio adapter photos
i think is good ford my tremec, i saw a driven gear.

it's a good solution without remove the gear box

thanks

 

There are places that build custom adapters to change your speedometer gear ratio

Speedometer Ratio Adapter - Speedometer Cable Adapter

These high quality speedometer cable adapters are built to order with different ratios and different configurations to meet the needs of your speedometer cable and transmission. AC Delco OEM Replacement ratio adapters come pre-greased and made to fit your GM vehicle including Chevrolet, Buick...

recordtechnologies.com

On my street rod I ran into the same thing with my T5 needing a speedo gear they don't make. I used a 10% adapter that slowed my speedo down enough I could get a gear that would work.

 

I believe you're not supposed to use grease on the speedometer cable, only graphite.

 

The original cables on my '66 and '91 were greased, you just have to use the correct amount and type of grease.

 

hello,
i think, i'm going to need you.
this society speedo ratio adapter photos
has no email ...
only person to person
i think the cable at the bottom of the page is what i need.
https://www.a1electric.com/speedo/ratio3t.jpg
is someone can tel us for me to explain my problem.
It's easy for me to write, but phone is very hard for me, i do not understand or 1 word sometimes
If it's ok, we will have an other problem.
how a society without email will be able to send in france a product !!
but Each day has enough trouble of its own.

franck

 

hello
just a little up for a little help

Thanks