Hi Guys, just swapped out my 3.23 rear gears for a set of 3.9 and was using a chart to install new speedo gear, (m21) BUT it looks like the new gear is larger than the old gear by approx .080", is this normal, had 20 tooth in it and was going to put in a 24 tooth part number 3860347. Is this correct?? Has 245/60/15 rear tires.
Found my own answer, there is 2 drive gears available one is 1.760 and the other is 1.840 both with 8 teeth. Guess I'll be pulling the trans this winter to install a new speedo drive gear, YUK
Found my own answer, there is 2 drive gears available one is 1.760 and the other is 1.840 both with 8 teeth. Guess I'll be pulling the trans this winter to install a new speedo drive gear, YUK
I though you could change the speedo gear, in the "bullet" at the cable thread on . I never heard, of having to change the gear inside?
Yes when changing from a 20 to a 24 u must change the internal gear to the smaller one.
When I pulled the old gear out it look like it was smaller in diameter than the new one, I figured I had the wrong gear, only the 23 and 24 tooth gears require removing the extension housing to change the inner gear. I have a 20 tooth right now so I must have the larger internal gear for it to work. Oh well another winter project, LOL.
And of course my muncie is the early style with the steel press on gear, hard to get off and on without damaging it. Oh well I think the trans was leaking back there anyhow.
I can't guarantee it since it was many years ago, but I thought when I put the TH350 in my Acadian I had gone from a 19 tooth to a 25 tooth without changing the drive gear.
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1966 Strato Chief 2 door, 427 4 speed, 45,000 original miles
1966 Grande Parisienne, 396 1 of 23 factory air cars (now converted to a "factory" 4 speed)
I went lookin online for info and found a muncie part suplier that listed speedo gears, stating that the use of 24 tooth driven gear must use the 1.760 drive gear. This is the site http://www.dandltransmission.com/muncie.html
