oemoilleaks
Member
- Joined
- Mar 26, 2017
- Location
- SoCAL
I had to recently replace the m40 trans in my '68 142s. I had to swap over the old speedometer drive gear and housing from the old trans to the new. But for some reason when I finally started to drive the car, the speedometer was off... WAY off.
Like a ration of 1.269:1 off. Meaning when the speedo says I'm driving 50mph, I'm actually doing roughly 64mph. 70mph on the speedo = 89mph IRL.
This also screws up the odometer, and since my fuel gauge hasn't worked in 4 years I need that odometer to read accurately so I can gauge my fuel consumption.
My point to this ramble is this:
Does anyone know what could cause this shift? The final gear is the same as it was (4.10) the only thing that changed was the gearbox.
On that note, what is the correct drive gear for the 4.1? What's the correct one for a 4.3? How can I tell which one is actually in there? (once I pull it out...)
Like a ration of 1.269:1 off. Meaning when the speedo says I'm driving 50mph, I'm actually doing roughly 64mph. 70mph on the speedo = 89mph IRL.
This also screws up the odometer, and since my fuel gauge hasn't worked in 4 years I need that odometer to read accurately so I can gauge my fuel consumption.
My point to this ramble is this:
Does anyone know what could cause this shift? The final gear is the same as it was (4.10) the only thing that changed was the gearbox.
On that note, what is the correct drive gear for the 4.1? What's the correct one for a 4.3? How can I tell which one is actually in there? (once I pull it out...)