wearing speedo gear

[mike gaines]

The teeth on the outer part of my speedo gear , ie the part of the gear nearest the cable have worn flat. I have had endless problems keeping the speedo working and it has now stopped again. The teeth on the front part of the gear are ok but this only covers about 40% of the total gear surface and this part seems to be engaging in the gear in the gearbox because I cant turn the cable by hand at the speedo end of the cable.When I remove the cable from the speedo and drive the car , the cable does not turn.The cable is not broken nor snagged.I have noticed that the retaining bracket (ring ) that holds the cable end mechanism into the gearbox seems to be exerting pressure on the upper part of the mechanism and could be lifting the speedo gear inside the gear box , could this be partly diengaging the speedo gear from the gear in the gearbox ? and causing the wear I am seeing ? I have a 58 Silverhawk with a 3 speed overdrive manual gearbox and the speedo gear has 22 teeth.I havnt opened a gearbox yet so dont know the inner workings.

[StudeRich]

Sounds to me like the Pinion teeth have the wrong pitch and or tooth count to match the speedometer drive gear on the output shaft.
The highest tooth count pinion listed in the Chassis Manual is a 1544758 with 16 teeth. It is for 4.27 ratio axle with 6.70X15 or 7.50X14 tires and 3 speed O.D. The drive gear is 1544698 with 5 teeth. 22 teeth would be for about a 4.88 ratio which was not available with 289 Engine.

StudeRich
Studebakers Northwest
Ferndale, WA

[blackhawk]

quote:Originally posted by mike gaines

The teeth on the outer part of my speedo gear , ie the part of the gear nearest the cable have worn flat. I have had endless problems keeping the speedo working and it has now stopped again. The teeth on the front part of the gear are ok but this only covers about 40% of the total gear surface and this part seems to be engaging in the gear in the gearbox because I cant turn the cable by hand at the speedo end of the cable.When I remove the cable from the speedo and drive the car , the cable does not turn.The cable is not broken nor snagged.I have noticed that the retaining bracket (ring ) that holds the cable end mechanism into the gearbox seems to be exerting pressure on the upper part of the mechanism and could be lifting the speedo gear inside the gear box , could this be partly diengaging the speedo gear from the gear in the gearbox ? and causing the wear I am seeing ? I have a 58 Silverhawk with a 3 speed overdrive manual gearbox and the speedo gear has 22 teeth.I havnt opened a gearbox yet so dont know the inner workings.

I think it is unlikely that the end of the cable housing that fits into the transmission case is cocked sideways. As I recall this is a real snug fit and there is a lip on this piece that seats flush with the case. All the bracket does is keep it from backing out.

As Rich says, you can only push the difference between the speedo pinion and gear just so far. Beyond that, the mismatch will be too great leading to excessive wear on the fiber pinion.

One other thing comes to mind though. I wonder if the pinion gear is being pushed too far in since the wear is all on one end of the teeth. The only way I can see this happening is if the end of the cable housing that the pinion fits into comes in different lengths for different applications and someone has replaced the cable assembly with one not intended for your transmission. Just a thought. I don't have any way to know for sure if there were different ends on the cable housing for different applications. It seems to me that there will be less tendency for the teeth to wear down or break off if the mating point between the pinion and the speedo gear occurs more in the center of the pinion.

Dale

[mike gaines]

Thanks for the replies , I think both issues could be relevant. Starting with the number of teeth on the pinion gear , how would I establish what the correct pinion gear should be.I assume I will need to know the diff ratio , how do I establish this ? , I have a three speed manual overdrive box and a 259 motor , without opening the box , how do I work out the correct matching pinion gear ?

[Dan White]

When I read the thread title I thought maybe one of the vendors was making new Studebaker swimwear available! Just imagine Speedo swim trunks with a Lazy "S" on them!!!!!

Dan White
64 R1 GT
64 R2 GT

[dynolou2]

There should be a tag on tha diff rear cover,secured by one of the cover bolts. My auto equipped Hawk reads 3.31. If tag is missing, pull rear cover,draining fluid, count number of teeth on ring gear and pinion gear. Divide # on ring by # on pinion to get rearend ratio. For a gasket, jeep CJ models dana 44 will do the trick, years 50's to early 60's. Hope this helps Lou [8D]

[MagikDraggin]

quote:Originally posted by dynolou2

There should be a tag on tha diff rear cover,secured by one of the cover bolts. My auto equipped Hawk reads 3.31. If tag is missing, pull rear cover,draining fluid, count number of teeth on ring gear and pinion gear. Divide # on ring by # on pinion to get rearend ratio. For a gasket, jeep CJ models dana 44 will do the trick, years 50's to early 60's. Hope this helps Lou [8D]

Why not simply jack up the back end, place a mark on the driveshaft and another on the rear wheel and rotate the wheel by hand? With the tranny in neutral, count the number of revolutions the driveshaft makes to one rev of the wheel and you have a close proximation of the gear ratio.


1962 GT Hawk 4sp

[Anne F. Goodman]

That's too easy.

Mabel 1949 Champion
1957 Silverhawk
1955 Champion 4Dr.Regal
Gus 1958 Transtar
Fresno,Ca

[53k]

quote:Originally posted by mike gaines

Thanks for the replies , I think both issues could be relevant. Starting with the number of teeth on the pinion gear , how would I establish what the correct pinion gear should be.I assume I will need to know the diff ratio , how do I establish this ? , I have a three speed manual overdrive box and a 259 motor , without opening the box , how do I work out the correct matching pinion gear ?

A '59-'64 Chassis Parts book has a chart showing the speedometer gear and pinion gear parts numbers (and numbers of teeth on the pinion). You more than likely have a 3.73 rear end ratio so you would need a 22-tooth pinion.


[img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/R-4.JPG[/img=right][img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/64L.JPG[/img=right][img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/64P.jpg[/img=right][img=right]http://www.frontiernet.net/~thejohnsons/Forum%20signature%20pix/53K.jpg[/img=right]Paul Johnson
'53 Commander Starliner (since 1966)
'64 Daytona Wagonaire (original owner)
'64 Daytona Convertible (2006)
Museum R-4 engine