Speedometer reduction ratio gear and housing
 

Guys, I need a little help, I've gone through Les Andrew's volume 1 and the trouble shooting guide and can't locate an answer. I just got my 96 year old grandfather's 1928 model A roadster and I'm trying to learn the car and go over it for problems before I start driving it around.
I noticed the speedometer reduction gear housing was split. I ordered a new one with a gasket, when I remove the old housing and pulled the speedometer cable out I dropped the gear. I was not sure which way it was set in the housing, I tryed it both was and it fits with the keyed slot going in from either side. So does that mean it can be set in the housing from either side? The other obvious question is why did the housing split, I'm hopeing that it is something simple like over tightening of the bolts. I looked up at the speedometer drive shaft gear and it looks fine. Thanks

Re: Speedometer reduction ratio gear and housing
 

I don't know the answer but thought maybe a picture from the Brattons catalog would help?

http://www.brattons.com/product.asp?...=any&PT_ID=all

Re: Speedometer reduction ratio gear and housing
 

The gear housing is installed so the cable leads off to the right side of the car, then is fastened by a clip and bolt to the top rail of the frame. This keep the cable away from the muffler.

Make sure the gear doesn't bind on the driveshaft gear when you install the housing. Also make sure the driveshaft gear is in the proper location, and is secured by the wire ring. Someone posted a good picture of this recently, so hopefully it'll show up again.

Re: Speedometer reduction ratio gear and housing
 

Tom this maybe the pic you mentioned
it was posted by 1930 coupe

Re: Speedometer reduction ratio gear and housing
 

Thanks, I finally located the old string you were referencing, I had look earlier and did not find it. The old string is great with a lot of pictures. So now I need to go back and check for the proper cable end and play on the speedo end first. I had already checked the gear end of the cable and its keyed and seems to be ok on that end but I need to make sure the gear is turn freely in the housing. I'm concerned that there is an issue with the gear or cable and maybe that is what cause the housing to split??

Re: Speedometer reduction ratio gear and housing
 

Welcome! Where did the cover split? It is only made of pot metal so am almost positive that it was either bolt tightening or it developed a crack due to casting. Did something hit it by chance?

Mike

Re: Speedometer reduction ratio gear and housing
 

I don't think it hit anything, no morks on it and there is a metal running under and it doesn't have any maks on it. It split cross ways starting almost centered from the side closest to the engine and traveled arcoss to the rear side but closer to the bolt on that side but not into the bolt post area. I really do hope it was a bolt over tighenting issue. I am goimg to recheck the speedo cable at both ends and try to make sure they both move and have the correct ends.

Re: Speedometer reduction ratio gear and housing
 

Sounds like the gear wasn't meshed when it was installed and then tightened down, causing the crack.

Re: Speedometer reduction ratio gear and housing
 

I was thinking same thing.

Also possible that someone put a 21 tooth gear for a 4.11 rear end into a 9/34 housing and tightened it down too much breaking the housing.

It has been many years since I dealt in this but as I remember it may be possible to put the 21 into 9/34 or other housings ...

but the gear shaft "center" inside the housing is in a different position so it will break housing

OR if a 17 or 18 or 19 is put in a 21 (4.11) housing the gears will not mesh.

As I remember the 3.70 housing is close in size to the 3.78 housing ...

Re: Speedometer reduction ratio gear and housing
 

thanks again, for the information. It is/was a 9-34 housing. The gear in it I neglected to check it out. I started the car started with the rear wheels jacked up a little noise but the speedo still doesn't work. But did check the cable end at the speedo and it does not look like the picture in the older thread about this issue. So I m have multiple problems, the good news is the housing did not split so maybe it is the right gear but how do you make sure they mesh? I hope I m not messing up the drive shaft gear.

Re: Speedometer reduction ratio gear and housing
 

did you try removing the speedo cable from the turtle to see if it is turning when you spin the wheels? work forward from there to find the problem... it would take alot to screw the driveshaft drive gear up, its pretty heavy duty..

Re: Speedometer reduction ratio gear and housing
 

A lot of speedometers get tight on the magnet shaft, so I'd make sure the speedometer turns freely before you snap a cable or worse.

Re: Speedometer reduction ratio gear and housing
 

Could you post a link to the string location?
I'd like to check all that out myself. (pics)
With Winter coming...more information equals more projects