Click on image for the lowdown. 
====
| | | Forums66 Topics128,076 Posts1,055,924 Members48,430 | | Most Online14,466 Apr 26th, 2026 | | AD Chevy Trucks Over 6,000 pictures Brad Allen has an awesome collection of Chevrolet factory pictures that he has set up from film strips. Check them out!
Lots of work on Brad's part ... pure enjoyment (and references) for you!
| | THANKS!
For helping keep this great
old truck web site
on the Internet for over 30 years! and not clogged down with Ads! Again, thanks! | | | | Joined: Dec 2013 Posts: 224 'Bolter | | 'Bolter Joined: Dec 2013 Posts: 224 | My 3 speed floor shift is very sloppy. The travel distance is 10.5 inches. (I measured it!) It shifts into all gears and is a daily driver. The distance is so great you end up playing with the persons knee sitting in the middle! ;-) Oh, to be clear, this is a floor shift. I'm not going to tear this down in the near future as summer is time to enjoy my driver. Can anyone give me some idea what I may be facing and what might be necessary to repair this? I'm new at this and I've certainly benefitted from many pearls of wisdom given by many. BTW, this is a '47 3100, with a 1949, 216 engine AND I "THINK" a '49 tranny????? | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | "BTW, this is a '47 3100, with a 1949, 216 engine AND I "THINK" a '49 tranny?????"A 1949 truck 3-speed transmission with a floor shift? That type of shifter would not be original 1949 equipment. You might want to post a photo of the shift linkage on the transmission - someone might ID/recognize what it is. However, 1947 3-speed transmission was a floor shift, with a parking brake handle near the transmission. What is the casting code on the transmission? | | | | | Joined: Dec 2001 Posts: 1,248 'Bolter | | 'Bolter Joined: Dec 2001 Posts: 1,248 | Didn't the first '47 3100's still use the floor shift from the previous trucks?? 1947 was sort of the change over year between the 1946 style trucks and the new AD style trucks?
John | | | | | Joined: Dec 2013 Posts: 224 'Bolter | | 'Bolter Joined: Dec 2013 Posts: 224 | Well it is listed on the title as a '47. PO told me a '49 engine was installed. I ASSUMED the orig. tranny bolted to it. Yes, it is 3 on the floor with the emergency brake handle to the right of the floor shift. Not sure where to look for the casting #, but I will look. BTW, the data panel was removed so I have nothing to go by for chassis info. Engine casting # was GM 19 3835849. That correlates to a '49 engine, which agrees with what the PO told me. Seems the 3100 was a '47 but who knows what parts were actual carry overs? From my little knowledge, it seems many of the parts from '47-53??? were compatible--i.e. engine and tranny for 216 at least? I'm pretty new to all of this so I'm reaching out for any bits of info I can. I'm not trying to [censored]-U-ME too much I hope!! Just trying to learn about component parts that need immediate or future attention. BTW, this is not an Art Deco truck, it's definately AD. I'll try to figure out the picture thing. | | | | | Joined: Mar 2002 Posts: 9,115 'Bolter | | 'Bolter Joined: Mar 2002 Posts: 9,115 | Well if you were asking about changes, the rods and crankshaft changed in 48. I would think your 47 would have the gas tank under the frame and not behind the seat. | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | If you want to ID the engine, here are locations of the codes. Post the following if you want to ID the engine: - block casting code - block date casting code - head casting code - head date casting code - engine serial number An Internet search might show your block casting code 3835849 being used from 1942-1953. Most show it for 1952-53 216 block. If you want to know the date of the transmission, post the transmission code: the location and interpretation for 1947 is given here (same link as I gave above - look at the bottom of the link/page for the location) | | | | | Joined: Dec 2001 Posts: 1,248 'Bolter | | 'Bolter Joined: Dec 2001 Posts: 1,248 | I wonder about the differential in your truck? If I remember right someone said the 3 speed transmissions on the floor were shorter in length than the column shift transmissions later? Your truck does have an enclosed driveshaft?
John | | | | | Joined: Dec 2001 Posts: 1,248 'Bolter | | 'Bolter Joined: Dec 2001 Posts: 1,248 | To your original question about slop in the shifter. if it is like the 4 speed I have in my 1953 truck, it was mostly the pins that were worn on mine where the collar holds the shifter in the top of the transmission.
John | | | | | Joined: Mar 2005 Posts: 155 'Bolter | | 'Bolter Joined: Mar 2005 Posts: 155 | The 'slop' you describe is common when the parts (interlock & yoke) at the bottom of the shifter is worn. The shifter in my '47 was exactly as you describe. I was able to remove the shifter and fabricate shims to tighten the interlock/yoke mechanism up. The 1947 truck is a one-year only longer torque tube (62.5 in.) and does not have the SM420 transmission. However, the 3-speed floor shift transmission and bell housing in the 1947 will bolt up to a later 216 or 235 engine. You may well have a 1949 engine, but it sounds like you have the original '47 transmission. RdsLessTaken/Don http://s1291.photobucket.com/user/R...rucks/3speedGM37-47_zpscdb719f5.jpg.htmlhttp://s1291.photobucket.com/user/R...%20Trucks/IMG_20385_zps7803e014.jpg.html | | | | | Joined: Mar 2012 Posts: 240 'Bolter | | 'Bolter Joined: Mar 2012 Posts: 240 | The shifter on my '47 had the same symptoms (from the day my older brother first bought it). The 4.022 housing (see Don's picture above) was replaced along with the interlock, cover and the shift lever (the pin had huge "slop" through the ball). The shifter motion improved immensely. IMHO the NOS housing helped more than the interlock, but on any given truck, the wear could be worse on either.
Have fun,
Bill
1947 3100 Advanced Design
Never, never, never, never give up. - Churchill | | | | | Joined: Nov 2011 Posts: 1,611 'Bolter | | 'Bolter Joined: Nov 2011 Posts: 1,611 | 47PUJim,
There should be a casting date on your transmission. I am not familiar with the 3 speed transmissions; but on 4 speeds, there is a casting date on the drivers side of the housing and on the top cover. If it is a 1947 transmission, it should read something like:
A 15 7 = January 15, 1947
Paul | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | 1947 3-speed and 4-speed transmission ID codes and locations are given at a link provided in both of my posts above.
| | | | | Joined: Dec 2013 Posts: 224 'Bolter | | 'Bolter Joined: Dec 2013 Posts: 224 | Thanks guys. I am going to try to find time to crawl under my truck today and find those casting numbers. :-) | | | | | Joined: Dec 2013 Posts: 224 'Bolter | | 'Bolter Joined: Dec 2013 Posts: 224 | Hmmm...crawled on my belly like a reptile and scraped/washed away 67 years of crud on my tranny and came up with: 591195 below it GM 41 and in small letters: K 120. Now I gotta find out if this is from a '47 or '49 tranny..3 Speed. Wonder if they were interchangeable? The mystery conttinues......"Elementary, my dear Watson." | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | Was that code on the case, at the rear edge of the cover?
Might the code be QM 41 K 120?
| | | | | Joined: Dec 2013 Posts: 224 'Bolter | | 'Bolter Joined: Dec 2013 Posts: 224 | Just checked. No. There is NOT a "QM" before the K120. I took a pict. with my phone but don't know how to post it anywhere. I've got it real clean and there isn't anything else EXCEPT was looks like a blank raised space before the K and after the 0. They certainly are not legible.Wonder if they were for later stampings in the production?? | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | It is probably "GM"
Where is it located?
Click on my username to the left and you will find my email address in my Profile. Mail the photo to me and I will host/post it.
| | | | | Joined: Dec 2013 Posts: 224 'Bolter | | 'Bolter Joined: Dec 2013 Posts: 224 | It's coming your way!! :-) | | | | | Joined: Sep 2001 Posts: 29,269 Bubba - Curmudgeon | | Bubba - Curmudgeon Joined: Sep 2001 Posts: 29,269 | Is there a code on the rearward edge of the transmission's top cover?
| | | | | Joined: Apr 2008 Posts: 11 New Guy | | New Guy Joined: Apr 2008 Posts: 11 | My SM 420 had the same problem White Lightning talked about. Pins at the top of the tower were real loose. In addition the ball at the bottom of the shift lever where it pushes the gears around was also badly worn. I fixed these two issues and it is like new.
The three speed may have similar issues. | | | | | Joined: Nov 2011 Posts: 1,611 'Bolter | | 'Bolter Joined: Nov 2011 Posts: 1,611 | From the date casting it looks like a November 12, 1940 or 1950 transmission. | | | | | Joined: Dec 2013 Posts: 224 'Bolter | | 'Bolter Joined: Dec 2013 Posts: 224 | Tim, I got after the top of the transmission today. Was caked with years of grease. The top flat cover of the tranny measures about 5x6 inches and is held on with 4 corner bolts. In the middle of that is the gearshift which is bolted (4 bolts) to the top of the cover. I cleaned this mess pretty well and did not find any #'s on the top of the tranny cover. Those casting #'s quoted earlier have been all I've found. You were more successful than I with an internet search for a bushing. Thanks. Interesting to see how confuzzling these trucks can be! | | | | | Joined: Dec 2013 Posts: 224 'Bolter | | 'Bolter Joined: Dec 2013 Posts: 224 | Dan, Thanks for the info on '47 tranny. Is your '47 original? the running boards and splash shield were unique to '47? I've never seen picturesshowing that OR 2 piece running boards. Were those options for the vehicle? | | | | | Joined: Dec 2013 Posts: 224 'Bolter | | 'Bolter Joined: Dec 2013 Posts: 224 | Sorta feel like Archimedes today..."Eureka!" Tim asked for a # on the back of the tranny top cover. Dumb me, I was looking AT the top cover and ignoring the area of the body adjacent to the rear of the top cover. The stamping is: J 6131407. I will try to Google using that info. Do I win the lottery? ;-) | | |
| |