37-38 Buick trans with early olds gears etc

Read alot of threads about this setup.LOTS of info.Some I get some I dont.So.... I have both a 37 and 38 Buick 3spd.Also have a couple early 50s 3spds.Thinking of putting behind a 324.Need contact info for the right people to talk to to find out exactly what I need to do or what my options are.Also have a 41 Lasalle side shift to work with.Nothing for sale yet till I get my setup together.I would rather talk direct with someone that knows exactly what the skinny is here.Thanks.

 

Wow, you really need ol timers to chip in here.
I wonder if Don Montgomery knows????

 

The only 37 Buick floor shift transmission thats worth anything is from a big Buick not a Special. Good for Buick nailheads, 389 Pontiacs. Back in the day I don't remember anyone using a 38 Buick trans. The Olds transmissions you have may be worth something if they are 1950's and have open drive tail shafts and be just what you need for the 324. Its important to know what bellhousings and tail shafts you have. The Buicks are torque tubes and need to be converted to open drive.

 

Ok, I will do some pics and text in multiple posts with thumbnail pics. Then the pics won't be red x's in the future.

First thing is to explain why to use a Buick case instead of the 51-up Olds Selector case. The Buick will give you a top shifter trans like a 37 LaSalle or 39 Ford. The Olds trans would have to use a rare aftermarket side shifter that operates the unusual in-out/back and forth main shift lever.

The reason you can't just use an entire complete 37 Buick trans is because the Buick input shaft is too small and too short. It is also a closed driveshaft type.

What years of Buicks? I am not sure. I am positive the 37 big series will work, and 37 has a case casting number that is 37 only, according to Hollander. The old 1956 HotRod magazine article says 37-38 I think, but I don't know if 38 will work (never had one). I do know that one or two gears are different in a 38 trans, so that could be why the 38 case number might be different.

The 37 number on the trans case is: 1298438-2
The 37 top shift cover number is: 1289505-2

Let's start the first pic showing what bell housing is needed. Look at the trans and bell on the far left. The trans is a converted 37 Buick. The bell is Olds 51-up. If you expand the pic to huge size, you should see the TOB snout/front bearing retainer already stuck into the bell center hole. You will need that stocK Olds piece.

The 37 Buick snout was a bolt-on, and won't work. The Olds snout has no bolts, it's held in place between trans and bell. NOTE: you must use a full face gasket between the trans and bell face surface, just like Olds did, or it will leak.

The Cad/LaSalle TOB snout/bearing retainer won't work either, because the OD is wrong. You can see one sitting on top of the center red transmission. The Olds one looks almost the same, except for diameter.

 

Tips on taking the transmissions apart:

Basic steps;

Take off the rear external parts;

On the Buick, you take out the u-joint to get at the yoke. Remove the yoke, then remove the rear bearing retainer/tail piece. On the Olds, remove the tail housing.


First pic shows the 2/3 syncro ass'y. The Olds is a symetrical syncro that can fit backwards. I marked an arrow on it to show how it was, so it will be re-installed to match the old wear patterns. The Buick is non-symetrical, but you won't be re-using it anyways. After you pull the rear shaft back a bit, you can pull the syncro out.

2nd pic of the snap ring and thrust washer on the rear mainshaft. This is for 2nd gear. There a 2 snap rings that need taking off to be able to pull the shaft out to the rear.

3rd pic shows the 2nd snap ring which is a stop for the first/reverse sliding gear. Shown with a small thin screwdriver to get under/ and lift up an edge to be able to get it off the groove.

With the 2 gears and their snap rings off, you just pull the rear shaft out the back.

Now, with the cluster laying on the bottom, you can now push the front input shaft rearwards into the case, and then out.

EDIT: I have found out that you can remove/install the input shaft without dropping the cluster gear. If you remove the the small snap ring at the front of the input, you can sneak the front main bearing out of the case, as it is not a press fit. Once the bearing is out, you can sneak the input backwards and up/out of the case, by moving the rear mainshaft off to the side.

 

Removing the reverse idler gear and shaft. That's the small gear on the lower driver side of the case, towards the rear.

On the Buick, the shaft is locked in place with a special bolt from the outside. It has a hex and has a long pin machined on it to fit deep into the case and right through a hole in the idler shaft. Easy with a wrench. You can see the wrench in pic 2.

But the Olds has no bolt. It has a straight soft steel pin rammed into a deep hole. You need to get a bit that fits perfect in the hole to drill right through the entire pin, then you can use a drift inside the case to bang the idler shaft out towards the rear.

 

Now the case is empty, we need to back up and locate and drill a hole in the bell housing. The Buick right side shift rail protrudes forward into the bell, so you need a hole.

Put the input shaft and bearing back into the case, then place the trans case on the bell, start the 4 trans bolts, then scribe a line down through the hole in the case for that rail. Shown with a yellow thing to show which hole I mean. I scribed with a very thin sharp detail file.

If you decide you need to drill right through the bell, if your bell is too thin to make a pocket, then you should use an o-ring there. You'd need to 45* a chamfer either on the trans face or bell face to fit an O-ring. Don't forget there will also be a full surface gasket covering the entire trans face, while you test fit the o-ring into your beveled hole.

If you drilled right through the bell, and did not use an o-ring, oil will travel past the shaft and into the bell.

 

Just the rear tail housing mods left now:

The 4 bolt pattern is slightly wrong to use the Olds tail on the Buick case.

The Buick used studs... but take them out so you can fit the housing up. Put the Olds rear shaft and rear bearing back in the case. Now hold the Olds tail housing so it centers itself on the bearing. Now rotate the housing to see through the top two holes. When it looks like they are both "evenly off centered", mark one hole edge where the housing needs to be filed about 1/16" or so more, outwards.

When you keep filing and test fitting, just put that one stud in. Stop filing the hole when the housing slips on fine. Now do the same amount on the other top hole, and now you have 2 studs fitted.

The lower passenger side needs about a 1/4" slotting to be able to get the stud in.

The final hole on drivers lower, needs relocating. Cut off a bolt that used to hold the Olds tail on. Then slot it for a screwdriver. Then when the case is cleaned, clean the new plug and threads with brake clean, then locktite the plug in the old hole.

Now scribe down through the Olds tail housing to find where to drill/tap the last hole.

By the way...The 4 tail studs have one short one. Make sure the short one goes back where it was. That's shorter so it won't hit the Idler gear inside.

 

The last thing I can think of is the difference in the cluster thrust washers.

You will be using all the gears, all the shafts, from the Olds. The only related part to save from the Buick is that rear cluster thrust washer.

The Buick washer is flat. The Olds washer has a locating "dent" in it to keep it from spinning in high torque events. The Olds case has a divot or hole casted in, where that dent is on the washer.

If you want the locked washer setup, you'd have to use a grinder bit to make a hole in the Buick case... or just use the flat Buick washer.

That's all I can think of worth saying. I may at some point if I see a mistake or if I left out something important.

 

Thanks Frank!!!!!

 

Great tech! I`m looking for some better 37 Buick gears like the ones removed in this tech.
I would be interrested in buying if in good condition.
Please PM if selling. Thanks.

 

A lot to read and learn here ..... Thanks .
I have a 263 with a 3 speed ...

 

My son sent this pic at 5pm yesterday with no text... It's a 37 Buick

I finally recognized the yard, so I got there at 10 am.

It was already cut up and in the pile, but the motor/trans off to the side.. bummer... it was the small series trans. I never saw a small series 37 trans before and nothing can be used from it.

 

in case someone uses this thread for future 37 Buick case swaps with Olds gears....

I have had a few Olds selectors apart in the last few days and have found many differences that I never knew about.

My best advice if swapping Selector guts into a 37 Buick case, is to find a good donor Selector to use "all" of the parts from. I have been trying to piece together 2 more 37 cases with random Selector stuff; here are a few things new to me:


-I am finding differences in gear face tooth angles on: -clusters, -1st/rev sliding gear, -rev idler gear. If you look at the older pic I put up, showing my 1955 cluster gear, you will see that the rearmost "gear" is all one piece and very wide.

---------I have run into 2 this week that the rearmost gear resembles 2 smaller gears with a groove machined in the center of what would have been the "wide gear style". Each style of cluster requires the following matching parts: -1st/rev sliding gear, and a -rev idler gear. That's because each style of cluster has a different tooth angle on these rearmost gears. Try to keep these in sets, if you are salvaging pieces from several broken Selector donor transmissions.


-I also found a syncro ass'y, and a 2nd gear that I never knew about. The syncro I did use on mine, had symetrical " blocker rings", and front is same as back; both are "small syncro rings". This new one has a very large syncro ring for the rear, which is 2nd gear. So, that means 2nd gear is different, as it's mating surface for that ring is much larger.


- new problem areas to look at on Selectors. First is the rear tailhousing that you need to use on the 37 case. Seems like they had "casting shifts" on some. Look at the front face where there is a 2 step counter bore to hold the rear main bearing OD snapring, as well as the deeper bore "step" that holds the rear main bearing from coming backwards. I found 2 broken ones today, where that inner step that holds the bearing, was "pushed in" and cracked/broken. These 2 housings had almost "no meat" at the back of that step, and broke because either the gasket was too thin, or the gasket compressed over time. I did find 2 other housings that had a very thick step, and can't break. This is a casting shift defect, on the broken ones.

- talking about tailhousing swap; More casting shifts.. If you look at the forward driver side of the tailhousing, there is a bumped out shape that is the oil channel for the rear bearing and tailshaft area. On some 37 swaps that I have had here, there can be a slight misalignment of that casted "bump" which leaves a tiny edge of the oil channel hole open...and that will leak a lot when running. I suppose you should look at this before drilling/filing the Olds tailhousing to fit the Buick rear case stud pattern. You might be able to slightly rotate the housing to cover that oil hole completely. The tailhousing does not care if it is rotated, as there is no rear trans mount. Plan ahead,... meaning;.. pull all 4 studs out, leave the rear bearing & OD snapring in the case, then rotate the housing to see if you can cover that hole.


I'll try to go through some Olds parts books to find out why I am seeing different pieces.

 

I converted a '37 Buick Roadmaster trans to open drive back when you could buy parts reasonably from the dealers. (about 1959). I bought a Olds output shaft and rear housing and added them to the Buick box, using all the Buick gears except for the Olds output shaft. This was used behind a 1953 Buick standard shift bell housing, also bought from the dealer. Memory is not to clear on how the throwout bearing was set up but I definitely know the Buick gears stayed in the trans. I can't imagine how difficult it would be these days to find this kind of stuff.

 

There still is a lot of lost info on 37 Buick trans mods; The ones used behind a Cad/Old OHV use the Olds guts and need that longer input shaft.

The old 1956 HOT ROD article tells of using 40-48 Buick gears?..I think for using with a closed drive, not sure.


I am somewhat sure that the 37 1st/rev slider won't fit onto the Olds output shaft, because the inner splines were slightly different?


it's all lost history...


I just took one old time modded Selector apart today, to find a new 1st/rev slider, new 2nd gear, and new syncro, but never driven since. It was a Selector case welded and modded to use 37 Buick forks and top cover. Problem was that the top cover needed to sit higher to be able to shift without binding, because the mating surface height differs between the two types of transmissions. I need to try to make a 1/8" to 3/16" spacer, as the trans is worth trying to save.

I don't know if they ever thought of making a spacer, or just gave up. It has impressive welds and machining, and must have taken a lot of time to do.

 

There s a nice topic on Teambuick about using Jeep clutch behind a 248 or 263 and using a T5.
Too lazy to search.

 

I think thats the next Problem thats come to me,the hot 263 Engine will kill my original Gearbox.
I don't know what i do then,when it will sometimes broken...
I don't wanna change my original Car to a open Drivetrain.
I'm very carefull with my Box and hope its never happen.

 

I see you have a 1938 Special, and I assume that is the smaller transmission?

I don't know if you could adapt a 37/38 Roadmaster trans to your motor, but if you can, you won't break it.

The only flaw in using an unmodified 37/38 Roadmaster trans, is that they use a cork O-ring on the input shaft to seal the oil inside the front bearing retainer tube. That O ring sits in a very deep 1/4" wide groove in the shaft, so that groove makes the shaft weaker. I used, what I believe is, later Buick 6 bolt type Selector input shaft, that does not have that groove, but is the correct length to match the 37. It looks as beefy as the Olds Rocket V8 shaft, but it is 1" shorter for the Buick motor applications.

I'll try to take some pics in a day or so.

 

I don't know enough to comment, other than to say that this gentleman used a '37 Buick trans with '52 Buick gears behind a stout Nailhead, and adapted it directly to the Ford torque tube (no tailshaft.) This was all done in the early fifties. I wish I had gotten his name!

 

I have found some info that those buick style trans were used in olds up to 1964, but not many were used, by then automatics had taken over. for info on adapting later open drive transmissions to straight 8 buicks, google --- jyrki,s buick site, ---- he has a good buick build sheet.

 

Frank the 1956 Hot Rod article is right about using the gears from a 40- 48 Buick in a 37 case. What was not mentioned is it had to be from a Century, Road Master or Super. Back in the day we ran a Buick 55 Special with a 58 Road Master 364 engine and a 37 Transmission. The Buick had a torque tube and we used the late forty Buick transmissions to replace blown gears. They were plentiful and cost $5 from the local junkyard.

 

Great information once again from the H.A.M.B. I had a 53 Oldsmobile with a 37 Roadmaster trans in the car I loved the way it shifted from first to second it was spring loaded to assist the wealthy people in the old days shift the car.
The transmission was a great conversion.

 

Anybody have more on the Buick case with Olds gears/input shaft, and adapting it to the Ford torque-tube?? Frank? Any ideas?

 

From what I have read on the 37 trans, the rodders swapped in "40-48" Buick gears as they must be stronger than 37.

I do know the 37 input shaft has a groove cut into it for a cork O-ring to keep oil off the clutch. That makes for a really weak spot on the input IMO. I have one if you need a pic.


Now, if you use a flathead Ford engine, with closed drive rear; you want to stay away from Olds guts for 2 reasons; One is that the Olds input is too long for the old aftermarket adapter bells to do the swap (like Offy 3648)

The other reason is Olds is open drive.

So, you stay with Buick input and guts to get shorter input and closed drive. The thing I never checked out, is comparing the Buick closed rear spline to Ford closed rear spline. I have a 37 shaft here to measure, but don't have a Ford trans apart to compare.

Ok, so say you want Olds/Cad motor, but with closed drive Ford setup; This could get messy. The guts to all these GM trans look so similar, but there are changes that make things not fit. One is the spiral spline for the 1st/rev sliding gear. The 37 Buick slider won't slide onto an Olds mainshaft. So, I suppose it is possible that those "40-48" or even newer Buick Selectors might have a 1st/rev slider that will work, and then hopefully, the Olds input will mesh with the Buick 2nd gear and mainshaft.


Another thing that I ran into, is the angle of the teeth on 1st/rev sliders are different on some GM's. That means the cluster tooth angle needs to match.

You'd have to experiment. I screwed up a few years ago and gave away a later Buick closed drive Selector trans with the later, better, short input. (1950s I assume) If I still had it, I could have tried to fit the longer Olds input in it. I almost would bet it would.

 

BTW, I have a car coming in this week, and it has a very cool welded transmission, which is a clone of a 37 Roadmaster/Olds open drive. It's a piece of artwork. I will take some pics; it's going into a 32 5w with a 49 Cad motor

top that

 

In the mid 1940 model run Buick changed the pitch on the teeth.

 

Here is the Cad trans I bought last week. It was welded up to take a Ford top plate. I posted about it several days ago. Passed on a selector trans with open drive line at the Monroe, Wa. swap meet last week. (I now wish I hadn't). The tag said he wanted $55. I also have a floor shift Special trans. It looks fairly stout. What breaks on them? Neat thread. Really like the old school mods.
Norm