checklist 4 fitting an overdrive into an S1

[Cali_59]

Jim,

Here are the gear ratios for an overdrive (from the series 5 owner's manual). Regular 4th is just a little lower ratio than O/D engaged in 3rd.
Mike
~~~~~~~~~~
Thanks Mike and everyone for the ratio's and Info, still not sure which route I will go in regards to having accurate speedo.

Will this OD switch work for me, until I can find the proper one??

https://www.ebay.com/i/352166148339?ul_noapp=true

thanks Chris

 

[Jimjordan2]

Gosh, I thought/think I understood all this, but today I picked up that rear end from Warren (another post completely), and I'm completely befuddled. Came from what is reported to be a series IV automatic car. Anyway, the rear was not with the car, but the scuttle was there, and said Borg Warner on the tag. I was trying to determine the gear ration out in the field, with not too much luck, as things were just not adding up. With one axle tight against the ground, and turning the tire one rotation, the differential only turned about 2 1/8 rotations. Anyway, got it back home, and on the sawhorses, and still, holding one axle solid, rotation is the same, one rotation of the wheel turns the diff 2 1/8 rotations. Done many times over with the same results. I'm stymied. or just stupid.

 

[Jimjordan2]

Never mind, just found this answer on another post. I think.

 

[hartmandm]

Hopefully you are concluding 4.22

Mike

 

[65beam]

That series 4 had to be an early car since it has the same parking brake as a series 3. The parking brake set up was changed to the late style somewhere in November of 64. It may be a 3.89 since the 4.22 was used with the auto trans after car #2641 which was after the change of the parking brake. It's all in the parts book and this rear looks to be unmolested.

 

[hartmandm]

Turning the wheel one rotation and observing the shaft rotates approximately 2-1/8 turns should be a 4.22 ratio.

Mike

 

[alpine_64]

Turning the wheel one rotation and observing the shaft rotates approximately 2-1/8 turns should be a 4.22 ratio.

Mike

The autos should have had the 3.89 stock. Someone must have switched it to the shorter O/D 4.22.. Or being in USA the vast majority of SVs that ran a 4.22 with standard trans

 

[65beam]

If you have the VIN of the car then check it in the parts book and you'll see what gear ratio was originally installed in the car if sold in the states.

 

[Tom H]

I assume you are interested in knowing what you have, rather than any history. You have a 4.22 axle there. No doubt about it. Regardless of any VIN number or markings, or Series history, someone could have easily swapped axles or just the pumpkin.

Tom

 

[alpine_64]

I assume you are interested in knowing what you have, rather than any history. You have a 4.22 axle there. No doubt about it. Regardless of any VIN number or markings, or Series history, someone could have easily swapped axles or just the pumpkin.

Tom

Yup...thats why i was saying likely a swap out... Not many cars that haven't been messed with. Nothing is a given on them, have to validate everything to check

 

[Jimjordan2]

OK, like I said earlier, never mind, I found the information from before.
But that being said, I took my time after cleaning a few things and getting rid of parts. I taped it off and marked it and then cut the tape. No mistakes. With the other axle locked down, I turned the axle precisely, well, almost precisely, two full rotations, and came up short of 4 rotations on the shaft.
So, 3.89. Yes?
Sorry if so much time was spent on it.

 

[alpine_64]

Yup, 3.89...thats a great ratio.with the OD.. What wheels and tyres are you running?

I run the 3.89 with OD and 195/65/14 on the rear.. The tall gearing makes for a great long haul cruise in an alpine. Just remember you will need to adapt the speedo for the OD amd 3.89.. If you are going to make a converison box choose your wheel / tyres combo first

 

[65beam]

FYI, the sad part is that shops that can either rebuild, calibrate or build a conversion box for speedometers are very hard to find. The last known shop in this part of the world that did this work was Columbus Speedometer but they closed. The shop that was in Cincinnati doesn't answer their phone either. Does anyone know of shops elsewhere in the states that do this type of work? Companies such as Autometer have made GPS speedometers available for a reasonable cost. I called Nisonger awhile back about converting the speedometer for the RHD LeMans to a GPS unit. They do it and restore the face, etc. and would require elimination of the trip odometer but the cost would start around $750.00 and go up from there. They said to buy a Garmin for less than $100.00 and have an accurate unit that will give you your speed and isn't affected by gear or tire variance. Trying to maintain originality of an older vehicle is getting tougher as the years go by.