The Jalopy Journal

tommy

I realize there won't be a lot of interest in this but it could come in handy for other makes as well. Apparently Studebaker aligned every stick shift bell housing to it's respective engine as it was assembled with no locater dowels like Chevys and others. Some after market blow shields recommend this procedure also. I'm no machinist and I was a little intimidated by the process but I've been able to most anything else so I gave it a go. What follows is how I did it.



The whole point is to get the transmission input shaft aligned with the engines crankshaft. To do that the hole in the bell housing has to be centered with the crank. You do that with a dial indicator as shown here. The shop manual says this hole should be concentric with in .004 of an inch.



Here is the fixture I made to hold the indicator. It's about as simple as it gets.



With the bolts lightly snugged, I set the indicator to zero and turned the crank with a wrench 90* took a reading, another 90*, another 90* and a final 90* to get back to where I started. It had to go up and over some. I tapped on it with a hammer and repeated the process. It was pretty damn close but I used a tapered punch in one of the bolt holes to lever it over the last little bit. It was easier to control the small movement needed. When I repeated the process this time one quadrant was out .001! So now I have to keep it there. I have to pin it in place.



The factory hole above the bolt head is where it gets pinned.




After the bolts were all tightened and I rechecked the dial indicator I drilled the holes to slightly smaller than the 3/8" dowel pins that I will be using.



Then the hole is reamed with this reamer to exactly 3/8"



The ratchet makes the job easier.



Here's the pin driven into place. The heavier flange on the engine block holds the pin in place when the bell housing is removed. Now every time the bell housing is R&Red it will be in alignment with the crankshaft.

Being raised on Chevrolet's and Pontiac's, I'd never seen this process before. Probably something a first year machinist apprentice would do in a machine shop but I'd be a piss poor first year apprentice.

__________________
Quote...You are hereby Knighted...'Sir Asseth of Hole' Tommy... 3W Larry.
Quote...It's called "HOT RODDING", not paint by numbers....Fab32

I Drag

One thing I've never understood about this procedure: How do you initially align the centerline of the dial indicator with the centerline of the crank?

__________________
I am always thinking about cars.
John Kosakowski
'58 Biscayne
"Purple Reign" Nostalgia altered

Hudsonator

Good article. Thanks.

I remember reading on Tom Langdon's site once that even the chevys can be out as much as .020".

This is one of those things I've neglected in the past.

Hud

BJR

It's not necessary as it spins in a circle with the crank no matter where it is positioned from the center.

tommy

I had a hard time getting my head around that one too. The answer is you don't have to. When the indicator is bolted on it will stay a constant distance from the crank centerline as it rotates around that center line. The indicator will show any change in that distance. Since the indicator doesn't move any from that center line, any change has to be in the part you are reading. The indicator doesn't need to be on center.

I was initially worried about making some kind of precise machined fixture to keep everything centered but my crude little angle iron fixture did the job.

__________________
Quote...You are hereby Knighted...'Sir Asseth of Hole' Tommy... 3W Larry.
Quote...It's called "HOT RODDING", not paint by numbers....Fab32

dare-to-be-different

You don't have to center the dial on the crank if you use a rotating crank to spin the dial indicator inside the bellhousing.

Rotate the crank to move the dial indicator.

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Some people like to relax in a leather recliner,
but to others there is nothing better than cardboard
...on concrete. Valvoline commercial.

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flt-blk

My S2D came with the factory 4sp so I have never done this. I wonder how far out it is stock.

I'll probably double check it when I go for the 5sp conversion.

Thanks Tommy

__________________
THEM TX "Nomad"

dare-to-be-different

We did a lot of these in the early 1970's and several in the 80's.

You can use a Lakewood OLDS scattershield on a Stude with some mods.

If you are going thru the trouble of dialing in a bellhousing, you might as well go a few steps more and do it on a safety shield that can contain a clutch explosion, AND give you the option of mounting whatever trans you want to install.

We used Super T-10's, Muncies, and Ford Toploaders with these scattershields on Studies. They fit like a cork in the firewall/trans-tunnel, but they do fit. The scattershields are already drilled and tapped for Ford and Chevy trannys.

If you want to use a scattershield, you will need a pilot bushing and new linkage, but the Stude clutch linkage is too delicate anyway. They had plenty of failures with stock clutches in stock cars. Eventually you will get tired of fixing the Stude linkages with slipping splines, bending rods etc that you will make a new linkage anyway, so now would be a good time to make a sturdy linkage setup.

Yes that is a real Weber aluminum flywheel. I bought a few new ones for $50 each long long ago. All gone. We used the stock Stude flywheels on most of the installations.
I preferred the stock flywheels anyway.
The aluminum Webers would swell up from the heat of a couple hours of driving and mess with the clutch adjustment. That is NOT something a kid wants to have happen with a 3200 lb Zoom clutch while driving 2-3 mph on the sand down Daytona beach during thong patrol. I switched back to steel flywheels.





The BEST way is to dial them in with the engine standing on end. We have found that if you try to dial in a bellhousing while in the car, you will be off by .004 .006 or sometimes more because of the dial indicator sagging from gravity no matter how sturdy the mount.

I suppose you could try to allow for the gravity-sag pulling the indicator down, but it is hard to tell how much error-correcting to use.

If you can possibly avoid doing it with the engine in the car, stand the engine on end for best accuracy or your bellhousing can be low by a few, or several, thousandths and still read zero. Stand it on end if you can.

__________________
-------------------------

Some people like to relax in a leather recliner,
but to others there is nothing better than cardboard
...on concrete. Valvoline commercial.

[SIGPIC][/SIGPIC]

tommy

That is precisely why I'm doing it. When my truck was built by someone else it had an adapter to a open drive early Ford trans. They replaced it with a Stude 3 spd.. It would chatter sometimes in first. The Stude guys said that it could be caused by misalignment. I have no idea if they did this when they changes bell housings. I know it will be right this time.

__________________
Quote...You are hereby Knighted...'Sir Asseth of Hole' Tommy... 3W Larry.
Quote...It's called "HOT RODDING", not paint by numbers....Fab32

I Drag

Tommy, BJR, and DTBD: I get it now, thank you!

__________________
I am always thinking about cars.
John Kosakowski
'58 Biscayne
"Purple Reign" Nostalgia altered

FritzJr

As long as you are doing a dial indicator sweep of the bore, you should also check the squareness of the face where the transmission will mate up. I have had some Chevy bellhousings that were quite a bit out of square, i.e. not perpendicular to the crankshaft. Sometimes you can fix this by thin shims where the bellhousing mounts to the block. Otherwise, the bellhousing needs to be remachine to get it square.

shpotty

My '53 Pontiac shop manual outlines the procedure for doing this on the old straight six and straight eight Pontiac engines too.

__________________
Bart (They call me Daddy at home.)

"Knowledge without imagination is nothing"
Albert Einstein

dare-to-be-different

That's a good idea about checking to see if the surfaces are parallel.

Here is a good word for LAKEWOOD about their scattershields...

When we suspected that the deep-drawn Lakewood scattershields may have been made with any "forgiving nature" about loose tolerances because they were intended for short use on race tracks, we took several to a machine shop to have them checked with a dial on one of those precision ground granite surface plates they use.
At the time I was sceptical of the acurracy of deep-drawing the "can". Hydro-forming they call it, but basically it was still pressed into shape.

Every single one of the lakewood shields was dead-on when checked on a surface plate. Even a couple shields that had been in use for several years were still dead-on.. So were the couple of Stude cast iron housings we brought in.

I have always been suspicious of any aluminum ones, but have never checked one.

__________________
-------------------------

Some people like to relax in a leather recliner,
but to others there is nothing better than cardboard
...on concrete. Valvoline commercial.

[SIGPIC][/SIGPIC]