Packard Forum Index » Post-War (1946-54)

Hello all.
Does anyone know how many teeth on the speedo cable drive gear should have for relevant diff ratios?
My 49 has a 3.9 diff and 19 tooth gear, speedo works fine and is quite accurate. I found a 17 tooth gear in my hoard, what diff would this suit?
Cheers,
Gary

Depends on both axle ratio and whether the trans had an OD. Some of the gear tooth count stayed the same for several combinations over several years but others changed a tooth or two which might have something to do with tires fitted on a particular model. Some also had a different part number for the same tooth count, the difference being in the shaft and cable connection end and what cable to trans adapter it needed to fit into.

Click on the factory parts list at the left menu and then type in 3.257 in the group number box. A list of all years and models will come up and you can see which combinations and years used the same part number and tooth count.

There should be 2 numbers stamped in a recessed band in the shaft near the drive end of the gear, one for the Packard part number and one for the Stewart Warner number.
This will give you a positive identification.

If you find the Stewart Warner number, can you please tell me what it is on your 19-tooth gear along with the part number? I’m looking for one just like it.

Well thanks for that Howard. I do have non-original tyres (15 in light truck), but somehow it all works for my car.
The 17 tooth gear has SW106317 on it, as far as I can see. The 19T gear is in the car, wait out on that one.
Gary

Further to the previous: the 19T gear on my car has two numbers, SW347537 and 101919. I am guessing the 19 on the latter refers to teeth, or is that too logical?
Gary

The SW347537, or at least the 347537 part of it, refers to the Packard part number which is apparently the same as Stewart Warner once the SW is added! Yours is apparently 19 tooth but for the R9 overdrive.

The one I'm looking for has 412444 so that must mean that it is SW412444 and is for certain R11 overdrives.

Just a quick revival of this old post. I found a drive gear in my own stock which has Stewart-Warner number 99283 on it. Does anyone have a SW book to cross-reference it? It's the proper tooth-count for my 1951 but I believe there were different gears driving them on various models. I need a 19-tooth type but not sure if this is it or not!

I also need a 412444 for my 51 200 Deluxe with overdrive. That is what came out of the parts list. I am also having trouble finding one, however, I have only been looking for 2 days!

The 51 should have the Borg Warner R11 overdrive which was also used in some Fords, Jeeps and other makes. Reason I bring this up is almost all the literature has the R10 and R11 service instructions together in the same manual. While the R10 won't fit in a Packard, I wonder how similar they are internally and what parts might interchange because there are repro gears made for the R10 since it was in lots of mid 50s Chevies. Summit even has a couple of Chevy gears made by aftermarket company OER that look a lot like the Packard gear.

Modern Driveline Inc also has a few of the same aftermarket gears and while they look similar to Packards gears, I have no idea if they would fit the Packard adapter or if an adapter for the aftermarket gears also available at Modern could be made to fit the Packard case.

A few years back Packard people were able to get some R11 parts from Herm, the overdrive guy. He has gone fairly modern now so no idea if he still has anything for old car units but I wonder if it would be worth getting in touch with them to see what they say about parts interchange or to maybe get a lead on what other brand car vendors who used the R11 it might be worth contacting.