correct speedo driven gear

[Bill W.]

This question is a result of Wayne's post . What is the correct tooth count on the speedo drive gear and the speedo driven gear for a 65 close ratio transmission with a 4.56 rear ?. I have seen a couple of different numbers posted on other websites .

[Wayne M.]

Re: correct speedo driven gear

This question is a result of Wayne's post . What is the correct tooth count on the speedo drive gear and the speedo driven gear for a 65 close ratio transmission with a 4.56 rear ?. I have seen a couple of different numbers posted on other websites .

Here it is: 6 teeth on the tailshaft gear, 20 teeth on the steel driven. The latter might have gone to 21 teeth for the 1967 model with 7.75 tires.

[Bill W.]

Re: correct speedo driven gear

Thanks Wayne . I wonder why that gear is steel ? Long Island says it should be a 25 tooth . One transmission sales place says a 6 tooth & 23 tooth or a 7 tooth& 24 tooth . A rebuilder says a 24 tooth with a GM part number of 3860347 fits 370 to 456 . Very confusing . My replacement transmission has a plastic 24 tooth and I dont know about the small gear yet . Good picture , is that a new gear ? The machine work looks rough .