Speedo DRIVE gear
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Speedo DRIVE gear
Hi, I have a problem with my trucks' speedometer. It's a '65 F100 with the NP435 4 speed. I'd been having problems with speedo driven gears not lasting long and being irratic. The slightest wear of the driven gear and no speedometer. Anyway, I took a look in that hole that the speedo cable goes into for the first time today and it looks like it has a plastic drive gear in there that is all but worn to nothing! Has anyone ever changed one of these and if so, is it accessable without taking apart the whole tranny? Can you just drop the drive shaft and unbolt the rear end of the tranny and get to this gear? I'd like to change the rear seal while I'm at it anyway since it has a bit of a leak anyway.
Thanks,
Mark
Thanks,
Mark
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Joined: Dec 1999
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From: NC
Mark, While searching for info on speedometer drive gear sources, I found this thread. I have a 66 F100 Cruise-O-Matic which now needs a new speedo gear because I changed the tires and the rear end ratio. I'm told that this transmission has a 7 or 9 tooth drive gear, driving a 17 tooth speedometer gear, (not sure which type or color).
Anyway, I was told that all I need to do is take off the tail shaft to access this drive gear held on by a keeper of some sort. There was no mention of disturbing or changing a seal.
Doubt if this helps on yours, but was wondering if you've learned anything since your post in June.
Dave
66 F100 Cruise-O-Matic 390
Anyway, I was told that all I need to do is take off the tail shaft to access this drive gear held on by a keeper of some sort. There was no mention of disturbing or changing a seal.
Doubt if this helps on yours, but was wondering if you've learned anything since your post in June.
Dave
66 F100 Cruise-O-Matic 390
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Dave,
Thanks for the reply, it is helpful. I'm glad to know that the speedo drive gear should be easily removed from the shaft and that it is held on by a (hopefully) easy to remove keeper. I guess once I get it apart and get the part in my hand, I can then begin the probably more difficult task of rounding up a new one!
Mark
Thanks for the reply, it is helpful. I'm glad to know that the speedo drive gear should be easily removed from the shaft and that it is held on by a (hopefully) easy to remove keeper. I guess once I get it apart and get the part in my hand, I can then begin the probably more difficult task of rounding up a new one!
Mark
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No, haven't gone that route other than to look on EBay. I imagine even that is going to take awhile since I don't know what the part number for my particular set up is and even though I've seen several speedo gears on EBay, they all have separate part numbers. I guess I need to come up with a parts diagram for my 4 speed... In the meantime, I've installed a tachometer on the steering column and I just approximate my speed from the RPMs. I have a feeling that even though it doesn't sound like this is going to be difficult, it's going to be time consuming. I've even looked on the web for rebuild kits for my tranny and they don't appear from the descriptions to come with the speedo drive gear. Strange, the thing appears to just be plastic...
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Joined: Jun 2002
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From: Atlanta GA
Yes, but, from the ones I have seen the transmission/transfer case gear is usually a hard white plastic and the speedometer gear is a softer green/red/blue plastic. So the easier to change one wears much faster. I think if you got a Ford number you could probably pick one up at the Ford dealer.
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