Greetings from New Jersey, I like the idea of finding NOS parts for a complete rebuild of your 1947 crashbox 4 speed transmission.
Maybe just finding a good used box is a viable option ?
How do you know what actual condition it is in ?
Maybe just replacing bearings would get your old crashbox
working well ?
My method of restoration would be to replace everything inside the tranny case if possible.
It's had 40 - 50 or more years of use.
Isn't it about time to refresh the old trans ?
My 1954 Chevy truck has a SM 420 4 speed trans.
It took me ( 7 ) month's of searching to find EVERY SINGLE
PART GM NOS inside the gearbox case.
The only parts I will re-use are: The case - Top Cover - PTO Cover - Drain & Fill plugs.
Everything else is GM NOS !!!!!!!!!!
NOVAK wants over $1,500.00 for a used SM 420 4 speed trans with a $215.00 rebuild kit installed.
So, I ask, What's my SM 420 worth with ALL NEW PARTS 100% ???
I personally would not want a 1947 crash box trans.
But.....it interests me that you would like to keep it & find parts to rebuild it.
I looked on ebay, and I was surprised to find a number of 1947 crashbox parts for sale: see my 1947 Chevy Transmission ebay parts album on photobucket below.
http://s669.photobucket.com/user/glp0329/library/1947%20Chevy%204%20Speed%20Transmission I've taken a little more than an hour to check out people that sell new GM NOS parts.
I have found the following parts GM NOS.
Albeit, you could find nearly every single part for a rebuild.
Here's what I found that's available.
1.) 4.309 - 590518 - Reverse Shaft
2.) 4.421 - 590501 - Countershaft 2nd. Gear
3.) 4.421 - 590502 - Countershaft 3rd. Gear
4.) 4.421 - 590503 - Countershaft Reverse Gear
5.) 4.421 - 590504 - Countershaft Driven Gear
6.) 4.409 - 590486 - Pilot Bearing Spacer
7.) 4.433 - 590496 - Reverse Idler Shaft
8.) 4.429 - 590333 - Countershaft Keys
9.) 4.303 - 590515 - Reverse Shifter Yoke
10.) 4.309 - 590516 - 3rd. & 4th. Gear Shift Shaft
11.) 4.431 - 590236 - Idler Gear Bushings
12.) 4.309 - 590517 - 1st. & Reverse Gear Shift Shaft
13.) 4.351 - 3847311 - Main Drive Gear
14.) 4.355 - 954373 - Bearing
15.) 4.374 - 590479 - Maindrive Gear Bearing Retainer
16.) 4.422 - 121888 - Bearing
17.) 4.423 - 590496 - Washer
18.) 4.408 - 954390 - Bearing
19.) 4.409 - 590483 - Inner Rear Bearing
20.) 4.415 - 590484 - High Speed Sliding Gear
21.) 4.417 - 605555 - 1st. & 2nd. Sliding Gear
22.) 4.422 - 142260 - Countershaft Front Bearing
23.) 4.422 - 121856 - Countershaft Rear Bearing
24.) 4.374 - 590479 - Oil Slinger
25.) 4.403 - 605023 - Mainshaft
My guess that another 10 - 15 parts would give you a very substantial rebuild.
I personally like all new nos bearings & all new nos shafts.
All new gears are a bonus.
I'm sure hunting down some of the small parts will nearly drive you nutty !
You've got to check ebay nearly every day for parts.
When you see it .....grab it !
Make a list of what you need with part #'s.
Get a blow up diagram of your crashbox.
My SM 420 cost me a $1,000.00 in NOS Parts.
But.....I now have a new NOS gearbox 100% .
This is nearly unheard of !!!!!!!
My SM 420 is not some used SM 420 box with new bearings & a few small parts like I would get from NOVAK. No knock on Novak intended. They serve a purpose & need to make a profit. I'm glad they are out there doing what they do.
You can be sure if Novak was selling my SM 420 the price would be $$$ astronomical $$$.
I'd be glad to let you know where & who has the parts listed above. Just email me.
Hope this gives you some inspiration.
I do believe this 60 plus year old gearbox can be rebuilt.
I think it's going to cost probably around $1,000.00 , maybe a little less maybe a little more.
I'd checkout the gear pre 68 Dave has before it's gone.
It sounds like a nice rare part.
Whatever you do good luck.
George
in
New Jersey
