Hot Rods AD_NAPCO's 39 GMC Rocket 324 Build

In comparing the 56 Pont shaft to the 57 Olds I found that the rear bearing is the same od. The shaft however is 1.156 on the 56 as compared to 1.364 on the 57. The 56 has 16 splines while the hd 57 has 31. No swapping yokes here Frank. Much beefier for sure. Haven't torn into it yet but will before we leave for CA in Sept.
I found a guy in southern NY that is or has been building 37 Buick trannies with the selector gut. I am going to reach out to him tonight to see if I can persuade him to let some parts go

 

That's super good info on the shaft dia sizes.

We should update Fedcospeed Buick/Olds thread on the "57-up differences" at some point. IMO

It would be useful info for posterity

 

So interesting news out of the wrecking yard. He has two transmissions there...

One of them, has a case with the number 1298438-2, and he says "but I don't think this tailhousing was made for this case because the holes have been kind of hogged out' Holy crap... 37 Buick conversion! He said the cover was off of it, the synchro assembly had been taken, and 2nd gear looked dodgy... Hmmm... He said the rear bearing surface was good but what he gave me for a casting number was bunk. He said it was '112-15'... I asked him to look again and call me back in the morning. He said the tail housing measured about 8 3/4". The only thing I worry about is whether or not that bearing surface is really good considering 2nd gear is hammered.
He gave me one other tail housing number, supposedly off a complete trans, of 173988-2. I asked for the case number too but that didn't materialize.

I just wish the yard were closer... It's about a 4.5 hour drive from me.

 

Worth persuing IF it has the top cover w/shifter, as well as the internal shift rails and forks in the main case. If any of that is gone, you'd be hard pressed to find the individual pieces.. IMO

Here is a tail number from my 1957 J2 stick trans. I forget if it was a late or early build date on the engine serial number...if that even matters? I think he misread that tail number, as it should be one more digit? Mine: 1173968-1

If others here could post their later tail numbers before he calls back??

But, let's say it is a post 56 tail housing...what about the bigger shaft? that would mean a larger bore and bushing inside the housing, and likely a bigger seal bore ID?

There is a visual difference on my 57 tail housing; the very end of the casting by the seal.....the pre-57 is like a very flat one inch wide collar. The 57 is kind of shaped more like a soda bottle neck top "knob"..if that makes sense

 

Guys, my 57 tail # is 1173968-2. I believe that is what he has and he has misread the 88. On mine you have to look real close to see that it is really a 68. That tail has a beefy support for the bearing thrust as compared to the others and the larger shaft. I took pics of it but I don't know if I can post tonight as the net is running real slow.

 

here ya go

 

Holy cow... that is a MUCH stouter tail housing!! Hmmm...

I will do two things. First thing is I'll call NW trans and run these numbers and see if his number is real or not. If not, I'm going to assume he misread it and it's the 57 trans. If it is, I assume it's pretty well worthless to me without a rear yoke and the front bearing retainer 'candlestick'. So I'll make sure that those parts are included. Next, I'll ask if there's any way he can find the top cover and shifter for that Buick case, as well as the slip yoke and bearing retainer for it. My biggest problem at the moment is that the war chest is looking pretty darn dry .

 

I just spoke with Rusty at NW trans and he confirmed that the number they gave me, which was 173988-3 does not exist, and if you add another 1 to the front making it 7 digits, that doesn't exist either. He said he believes it's the 1173968 as well. The wrecking yard said that the tail housing on this tranny measured about 9.5" long. Does that square with what yours pictured above measures? I'm sure he's just pulling a tape and eyeballing it. The other number he gave me was 112-15 which was attached to the Buick case, which again, I've confirmed is bunk. Probably a casting date.

 

My 57 tail is approx 9-1/8" not counting the seal sticking out...so maybe that explains his 9.5?

here is the main case number on the 57 trans body, it is upside down numbers on the passenger side; 1175493-2

now, here are two Buick case numbers; they are right-side-up, but on the drivers side of the main case:
1289500-2
1298438-2

I know I've seen more different Buick case numbers, maybe posted on Fedco thread, and I believe that poster had them figured out with a Hollander book as to what years from 36 to 38? Same case as far as we could tell, just different numbers?

I have more selector cases and one more buick trans I can try to get to...

As far as costs/money; A lot of us buy in bulk and then resell what we have left over, to end up with "free" parts for our build. Just be careful, as sometimes it can go bad if you later find damaged things in your pile.

 

I was away all day today visiting with family a few hours away in the Santa Rosa area. Just got home. Long day.
I did not get a call from the yard today so I'll follow up with him tomorrow and at at least get some prices. Thanks again for the help!

 

Ok... Just spoke with the guy at the wrecking yard. I got the actual tail housing casting number from the converted trans.

I asked about the slip yoke and the TOB collar. Both missing. He said zero odds of finding the top cover/shifter. So I don't want that trans. The casting number he gave me on the tail housing is 1165430-1, which Rusty at NW trans said matches 54-56 Olds 88 in his book. That is a radically different number than I've had thus far. I do wonder what the difference is. I suspect, since it's so much closer to the 57 number, is that it may have a beefier casting in that rear bearing area... Just a wild ass guess. Anyone have a tail with that number? The price on this tail housing is doable... I may call back and see if one of them has a way to send me pictures of it to make sure the bearing surface is in good shape.

 

" NW trans said matches 54-56 Olds 88 in his book. That is a radically different number than I've had thus far. I do wonder what the difference is. I suspect, since it's so much closer to the 57 number, is that it may have a beefier casting in that rear bearing area... Just a wild ass guess. Anyone have a tail with that number? The price on this tail housing is doable... "

My computer is acting up so I can't quickly find out what number my silver tail housing was... is that closer? But anyways, what kind of money are they talking on a used housing?..sounds pricey in your cryptic wording

I zoned out with my shop cleaning and sorting... I need a break from that....found my last empty 37 case, cleaned it mild acid overnight, and must now decide which donor Olds I should use... Only have 2, one is for the J2, other is 1953. If I can decide, I might have the silver one left over, not sure though

But that brings up the fact that my silver one, and the one you found, have both been slotted for a 37 case...so, are the slots all done in the right directions, to fit your 37? Think about it for a bit; one stud is relocated on any modded 37, and it was up to the modder, to decide which directions to slot the other 3 holes on the tail. So, will it work with your relocated oil hole???

I bring this up after years of making judgement errors when buying modded pieces. You don't want to add more grief IMO.
..

 

Ok so I spoke with the guy at the bone yard. They are going to send me pictures, probably in the morning, of this 1165430-1 housing. I want to see what the bolt holes look like where they modded it for the Buick case, and I want to verify that bearing seat is good. He said they ship every day so I may have located a good tail housing to put this thing back together again after all!

 

Frank, what mild solution have you used to soak that tranny to clean it?

 

This bare case was empty for years at Mikes in Mass, so it also had a bit of rust inside and on all machined surfaces. I soaked overnight in 5 gallon bucket of Oxyalic Acid mixed with water. You can find those dry crystals at hardware store; made for bleaching wood.

That cleaned the rust off with a bit of wire brushing of the residue, leaving a blackish coloring on machined surfaces. A few minutes of scrubbing with vinegar, and rinse.

Stronger acids like Muriatic can eat up cast iron and cause envasive porousity.
.

 

First off, I hope you don't think you need the 57 up trans...because you don't. Those cars weighed so much compared to our builds. I have a 57 trans here, and I'm trying to decide if I will convert that one to topshift, or use a 53.

If I thought there was any point in swapping out the 55 one in my car, heck, now would be the time....but there is no gain, only losses, with the required 2-piece driveshaft with integral slip joint. I probably have a doner slip to make one, but there is no sane reason to put the 57 in my car. Slicks, posi, and bracket racing might be a reason...and I'd bet the 55 would hold up the same in such a light car...

The pics: I think they tried to slot the upper holes to rotate the tail a bit, to correct the oil hole alingment deal? Hard to tell, but could be. WoW, that must have been in a rod for a long time, by all the crud buildup on the white paint. ...and you can see crud buildup in the vent hole, so it maybe was run without a vent cap.

I've been messing with a 37 case here, checking rear main bearing fit, etc.. I was trying to figure the loads on the rear bearing outer part. Going by theory, when most of the thin casting breaks away, you still have a big chunk that will never break..it can't. So, the only things that could happen, is strain on the big snap ring, trying to shear it like a punch press. I doubt if the ring can shear that way, like a circle within a circle..

So, I think the bearing OD race tries to get crooked in the case bore, as the OD race is firmly supported in just one spot, and springy support where only the ring supports. But I checked the fit on this 37 case...it's super close fit, needing a very light hammering to get it in, so it would take forever for the bearing OD race to wear the bore crooked. IMO

I'd wait for a mint one IMO

.

 

Well, I was leaning toward the 57-up just because they appeared to be much more stout, and at least lately, more available? Don't get me wrong. Now that I know the 134 (light duty) is a 303 tail, and a 116 (heavy duty) is a 324 tail, I'd be thrilled to just go with a good 116. I certainly don't want to spend money I don't need to at the moment. For now, I'll be running the tail that I just cleaned all the potential shrapnel out of and waiting for a good 116 trans or tail housing to show up. Thanks!

 

I have to agree with Frank on the wearing of the bore deal. In our applications I doubt that there would be an issue unless we were hammering the hell out the drive train all the time and even then it would take quite a bit of time for anything to show up. I would run what you got and wait to find a 116 tail down the road.

 

That is definitely the plan now! Thanks, Walt. Hopefully I'll have my rebuild parts in hand soon.
Now to do some research on speedo gears!

 

So my current speedo gears are a 7 tooth drive, and an 18 tooth driven. Based on a 3.23 rear end, and a 32" tire height, the calculators I've found are giving me a 14.3 tooth driven gear required. Anyone know if that's typically how it works? Leave the drive gear alone and find a driven gear to work with it? Otherwise it'd be a total pain to have to wait for everything to be in place only to find I need to tear it apart again to change the drive gear. If all I have to do is change the driven gear then it's no sweat. Just gotta find one. Hopefully Northwest Trans can help with that.

 

Quote: "Now to do some research on speedo gears! "


oh jesus...

really pushin it eh? lol

Well there may be some hope on finding NOS or? I found a NOS driven gear with the metal screw-in piece, all together in a MUCH newer Buick box...really modern Buick logo etc. Roadsir has that one now...but as far as getting interchange numbers between GM brands??

I did do some research and I "think" I have the correct NOS driven gear for my tires and the 3:23 axle. I've got no clue what else I have that could fit...maybe nothing.

.

 

HA! I guess that's just how I do it! I find new ways to push it even when I don't know I'm looking for them. Well, maybe there's an adapter that can be had to correct the difference. I'll call the trans shop and see what they say and really worry about it when I actually have a truck that moves under it's own power. How's that? I was mainly concerned with whether or not I needed to worry about changing the drive gear because it has to be pressed off and then back on along with the rear bearing and didn't want to have that done for practice. I will get another press at some point but it's not in the cards anytime soon.

 

So we can close the file on the speedo gear diversion.

http://www.speedometershop.com/ratio.html#ADAPT

I'll get an adapter when the time comes.

 

Parts book is somewhat confusing on speedo driven gears; They changed the number for 54 through 56, compared to 51-53. But mainshaft number is the same, so is this a gear tooth ratio change? IDK ..there is only one gear per year range unless I missed something.

Then go to the back of the book for driven gear charts/vs/tire and axle ratios; they seem to show more that just one tooth count choice on the DRIVE gear?? I must be missing something in the drive gear part number section.

I would count the teeth on your drive gear and the driven gear, and write it down, in case there might be a driven gear that will fix your error when you test drive it.
.

 

Yup. Got it written down. 7 tooth drive, 18 tooth driven. Supposedly 14 teeth driven would be right, dependent on how many RPMs my speedo need to turn to run up 60 mph, which, I don't know.

 

from the back of the book I think F&J referenced,

sorry these images are not displaying right side up,
'tried for fifteen minutes, and I am no computer dummy..

 

I tried again this morning to figure out where the heck the "optional" numbers are for the "drive" gears ..

I simply gave up; Lets look at 1954 for example, this above chart shows on the "ratio" column, that there is 8 and 9 tooth drives? That must be what the 8 and 9 are..

..but go to the trans section, look up drive gear for a 54 88/S88 stick trans, and I only see one gear listed...unless I am missing something.

If there is an 8 and a 9 tooth drive gear for 1954 for example, what group number, or where in the book, is it?

I don't need to know, I just wanted to know

Maybe I should go back and do page to page, in the back of the book...maybe I missed that group section?

.

 

Brown truck came today with my trans rebuild parts. I took my output shaft over to the driveline shop to have the rear bearing pressed on. Supposed to have that back before they leave tonight. Fingers crossed. I would like to get the trans assembled this weekend. I also left my top cover with him to have the shifter retention pins converted to a threaded type rather than the staked over type, and the broken ear repaired. That'll take a bit more time, I'm sure, but at least I'll have the trans back together and waiting for the new top. Then I can finally bolt up the trans to the motor and see where the stick shift lands when the whole mess is in the frame. Hoping I'm not too far off of where it would be in stock form... Not sure I could get that lucky.

 

Well... Shit. Waited all that time for the Northwest Transmission shipment and the parts are wrong. At lease partially.

1) I only received three bronze thrust washers. The large one for the front of the countershaft, in flat Buick form, which is correct, I got. I got one for the opposite end of the countershaft, which is the correct ID, but the OD is too large for the recess in the back of the countershaft. The third washer, I assume, is half of the pair I should have gotten for the reverse idler, but the ID is too small on it anyway.

Here's my first question. Both of the illustrations below show only one bronze thrust washer, and one steel thrust washer at the rear of the countershaft, and figure 11-22 shows two small roller bearing retaining washers at each end of the bearing spacer. My assembly came out with a small, and large retaining washer at the front, behind the large bronze thrust washer. The larger retainer washer fits perfectly in a machined space which leaves it flush with the face. At the rear, there was only a small retainer washer. No large one, and no machined place for one to fit. Is that normal? Secondly, at the rear, my countershaft had four thrust washers. Steel, bronze, bronze, steel. So two bronze washers sandwiched between two steel washers. Again... Is that normal? Should my parts kit have come with three bronze washers for the counter shaft and two for the reverse idler?

I want to be sure I have my facts right before I call the trans parts place.

 

Josh, as these cases get worn over the years it is quite possible that the end play can become greater than originally spec'd. I have a 37 lasalle case which must of been used for racing and the end play is a lot more than the 12-25 thousands suggested by John at NW. Guess one would have to change out the case or shim with added spacers which is what I am doing. 11-22 appears to be correct for what I have seen in these trannies but I have never found the inner roller bearing washer, only the outer.?????
Frank will chime in as he has had many more years experience with these than I but my take on the extra washers would be for tightening up the end play.