Packard Forum Index » Pre-War (1899-1942)

TomB (or anyone):
If u can obtain an OLD JC Whitney cataloug from say the 1960's then take a look in it to see what kind of adapter plates were offered for Packard to alternate transmission conversions back then. Most likely look at the GM to Packard conversions since GM was very slow to change designs over many years.

Might be that some late 70's or 1980's ford,GM or MoPar 4 speed over drive transmission will fit to the packard bellhousing wwith somekind of adapter plate that could be modified slightly.

Just a good research topic to try different possibilities.

Thanks for that last bit OD. FYI, Yes I purchased and am running 700 x 17s as that is what the car originally came with.
QUESTION: Have you had much experience or heard much about the Mitchel Gear Splitter O.D. units ? Their name came up in a few of the conversations I've had lately.
Tom

Thanks Shinyhubcap. I will at least be able to talk to the shop with a little more knowledge and smarter questions and I'll find out just what condition those shocks are in, then take it from there. Before it went to the shop, I tried standing on the bumpers and sort of jumping up and down to see if the front end moved...it didn't. :(

Bye the way, have you heard anything about Mitchel Gear-Splitter Over Drive Units ? Made in Colusa, CA.

Regards,
Tom

As always, I just learned a couple of other invaluable tid-bits, one about the absence of the "traditional" "bell housing" on the '34 and/or prewar Senior Packards, and possibly who the "patriarch" is around here !! :)
I am definitely listening to both you AND Owen !!
Tom

Good Morning all...Just a humble comment. I would agree with O.D. that the only proper change would be an overdrive. I have an R11 in our 1949 packard Deluxe and it works very well.

I also have a 1931 Model A Tudor with a Mitchell Overdrive. It is a gear splitter that gives the Model A six speeds forward. In low overdrive, the car is a normal Model A that cruises at 40 miles an hour.

In overdrive, it sort of depends on how strong your engine is and how good your brakes are. Ours just has a lightly higher compression head and a Model B carburator, our mains and rods are babit, and in overdrive she is happy at 55 miles an hour.

The key is that the only change to the car, is the overdrive, and the car has not been cut up/changed so that the driving experience is not as it was when the car was built when not in overdrive.

Mostly, I go 40 to 50. I like to look at the flowers...If I want to go fast, then I drive the Packard or a modern machine...Ernie

I was under the impression the only alternative for that 30s era senior models was the add on OD because the later trans/OD combinations such the R11 will not bolt onto the early engines. Am trying to remember the owner (maybe 34PackardRoadsta) that did the addon OD. That was a fantastic job. IIRC, there were quite a few pictures of the installation on site and on his private website.

Correct, the 120 based cars with OD starting in 39 and all cars up to 56 units will not work on early classics.

Thank you Ernie. Appreciate the comments and info.
Regards,
TomB

Discussion about this topic are more meaningful if we compare miles per hour per 1000 RPM instead of just the drive ratio, as this does not take account of the effect of different wheel sizes. For example my 1929 model 633 has a 4.38 drive with 6.50 x 20" wheels. This gives about 22 mph/ 1000 RPM.
A 1934 Packard with 7.00 x 17" wheels and a drive ration of 4.69 would be travelling at about 20 mph / 1000 RPM. For a 3.05 ratio, as mentioned above, this would increase to around 30 mph / 1000 RPM which would obviously make a very significant change to the cruising versus hill climbing compromise.
It is a simple calculation:
MPH / 1000 RPM = (3.14 x outside diameter of tire in inches x 1000 x 60) / (12 x 5280 x drive ratio)
So for the 633: (3.14 x 33 x 1000 x 60) / (12 x 5280 x 4.38) = 22.4 mph/1000 rpm

Hi David - your figures are close to what Packard put out for the Seniors - at 60 mph with a 4:41 (standard in the Super Eight and Twelve, 4.69 for the smaller "Standard" Eight) the engine rpm was around 2800.

To put this into perspective, this is at least 1,000 rpm more than a modern car at that speed.

Or, to put it another way, if a modern car and a classic-era "Senior" Packard start out on a trip to cover 1,000 miles.the Packard will have to drive ANOTHER 550 miles in terms of engine use to cover the same 1,000 mi.

Or, to put it another way, at 60 mph, the Packard with its long stroke is beating its connecting rod bearings...heck...everything in the motor...harder than a modern car's drive-line would incur at 110 mph. MUCH harder in terms of inertial loads on the rod bearings, because of the much longer stroke.

Bottom line..LISTEN TO OWEN !