I have a muncie M-21 that I need a speedo gear for........ Does anyone have one? Or know where I can get one? Thanks, Rob
reply Scott, Im a little lost here as to which gear I need. I have 3.23's in the rear and 295/50R/15's. I dont know what I need. When I look at the side of the trans, I can see the casing where the speedo cable screws into, and there is nothing in there. I cant really see into the hole to see whats in there. Im not sure what I need. What do you think? Rob
reply... ok, I crawled under the car last night and removed the set screw that holds the housing in the trans. The housing doesnt have anything in it, Im guessing thats where the gear I need goes ou: When I look into the trans all I see is a white, or neutral colored gear. It doesnt really look like a gear, it looks like a bolt....and it looks to be made of nylon or plastic. As far as I can see there are only 6 groves on it. Because of the trans crossmember, I cant see any more than that. I tried to take a picture but couldnt. :rant: Im really confused, can somone help :af: Rob
Rob, If you put the trans in neutral, and rotate the driveshaft, can you count the number of teeth on the gear? If you give me that, your tire size, and your axle ratio, I can tell you what driven gear you need. The speedo drive gear is a helical gear, like a distributor or cam gear. If you mark one of the teeth and rotate the driveshaft, you should be able to count the teeth.
reply.... I have 3.23 gears and the tires are 295 x 50 x R15's ( yes they are huge ) :3gears: As far as I can tell there are 6 teeth on it. I must be looking at the right thing becuase, I would agree it does look exactly like a distributor gear. It appears to be made out of nylon, and white or neutral in color. Rob
Rob, based on the info you supplied above, I calculate you need a 15 tooth driven gear. Problem is, the smallest driven gear I see is a 16 tooth gear. If you change to a bigger drive gear, it should work. Check this site out: http://www.tciauto.com/tech_info/speedo_gears.htm#400 This is for automatics, but the gears may be the same. If you moved up to an 8 tooth drive gear, you could use a 19 or 20 tooth driven gear.
reply.... Yes....thats is exactly whats in my trans...it looks just like that.....how do I change the dive gear? Or if thats exactlt whats in there, do I need to change it? From my viewpoint it was very hard to see, it is very possible that it had 8 teeth and I only saw 6. Was 8 more of a common thing than 6? I know my trans came out of a 69 chevelle and its pretty stock, other than that I dont know much ( bought it on e-bay ). Would it help at all if I had the casting numbers or no? Rob by the way scott you are the man :beer
Rob, You have to know, not guess how many teeth were on the gear. I know it's hard to see, but if you have to unbolt the crossmember, than do it. The gear is easy to change. It's held on by a spring clip (The clip is pictured next to the gear) The clip fits into the output shaft, and the gear slides over it and snaps into place. To remove the gear, you depress the clip, and the gear slides off. Of course you have to remove the tailhousing, and all that entails.
reply... I have installed a blue gear. It seems to be correct. I will be testing it shortly and will report back. Thanks for all of the help... Rob
