Engine and Transmission Tech

Has anyone modified a 3-speed bell to accept a 4-speed? After a lengthy search and some miscommunication, I got a 198 V6 bellhousing with three-speed holes. I have a friend who is an ace fabricator and could no doubt sew on some aluminum plate with the correct pattern....

If you get the holes right, does a factory 3-speed otherwise work--e.g., size is otherwise the same to accommodate shaft length and clutch--or should I sell this one and keep hunting?

By the way, here's the bellhousing:



Kris



Edited 1 time(s). Last edit at 11/21/2007 10:31PM by motormouth.

For the fabricators in the house, here's my exact plan to take the above 3-speed bell to 4-speed specs....

1) Place a 4-speed mounting-face template on top of the 3-speed face (treating it as a 2D image).
2) Mark the "missing" 4-speed-surface metal on the 3-speed bellhousing.
3) Cut out those areas and file all edges to be perpendicular to the transmission mounting surface.
4) Fashion (cut, file) the missing pieces from a suitable block of aluminum. The bottom two pieces will be easier because the flange-side face is flat (straight). The pieces to widen the top two holes will either have to be filed in a semicircular fashion around the original bolt-hole area, or that area cut out too.
5) Set the new pieces in place to replicate a factory four-speed mounting surface.
6) Weld from the inside and outside, grind the welds for acceptable esthetics, then make a light pass on a surface grinder for a dead level mating surface.
7) Mark, drill and tap mounting holes.

Will post photos of this effort. Kris

Kris,

D & D makes an adapter for a 215 3speed bellhousing (looks like yours) that works with a Ford T-5.

Thanks Carl. I'll check that out. Kris

Problem solved. Got myself a 4-speed bell with some close attention to Craigslist and a quick email. Put it on my blog, if anyone's interested.
[nc.startribune.com]

Some folks might benefit from seeing the distinction between the 3-speed and 4-speed, so here's a shot of both. (Four-speed is on the right obviously--this is the version with the 3-speed holes as well.) Kris




Edited 1 time(s). Last edit at 12/18/2007 01:02PM by motormouth.

I think I might bring my bellhousing over, if you've got time to see if they are different. I "special" bellhousing was listed on the old D&D documentation from back in '76. It would be interesting to see if they are different at all.

Sure he didn't just mean Special? I'm sure Special and Skylark have no difference. Not sure if Olds cast their own or used the Buick, but it must be very similar if not identical.

Here's an interesting discovery: the flywheel cover holes on my "new" 4-speed ballhousing have never been tapped, which means this has never been mounted to a car, at least not by a GM dealer or mechanic, as they wouldn't put it on without the cover. And it's super clean as though it's just been sitting in an NOS parts pile. This thing is spotless.

The part number stamped into it is 1355746.

WOW! That could be about the "Special" bellhousing. The implication is they were making their own... I'm hoping that's not the case... You around next week?

Transdapt makes an aftermarket Buick 215 bellhousing that Dan LaGrou sells.

My 3/4 speed bellhousing must have been bolted to a 3 speed tranny, cause the 4 speed mounting holes were not threaded.

I'm assuming your bell is bolted up.... Do you remember what year it's from? Another unexpected attribute of my 3/4 is that it's stamped "64." Everything I've ever read about the 215 says it was in production from '61-'63 (with development years previously of course).

Whence comes a 215 bell cast in '64? Buick had moved on to the 300 by this time, which doesn't share engine-side bolt pattern. Was GM still knocking out a small number of bells as parts stock? Were they produced for some other purpose--e.g., for some suitor (prior to Rover) interested in buying the freshly abandoned 215? Was a stickshift 215 a forgotten option in the (early?) '64 Skylark/Special?

Curiouser and curiouser....

motormouth Wrote:
-------------------------------------------------------
> I'm assuming your bell is bolted up.... Do you
> remember what year it's from?

Yes, it's in the car. It was the first part I ever acquired for the swap. I don't remember even checking the date code.

The BOP 215 3-speed bolt pattern goes back into the late 1930s or 1940s It is the same as the T-84 warner trans cases used on Willys and Studebaker champs.(which had OD available) The 215s and V-6 198s have been installed in 1940s and 1950s Jeeps quite easily. I hooked one up years ago. I required a 1/4" thick aluminum spacer plate to get the to get the input shaft the correct length and slightly longer bolts. At that time the 4 speed bellhousings were quite rare. Most were in Olds F-85s. The Buick Specials were mostly Automatics, some 3 speeds and very few 4 speed models. Sometime in the early 1970s Buick Division re-did their parts books. Somehow they dropped the 4 speed parts number. AND the 3 speed stick bellhousing number showed up as working for 4 speeds. I bought one from a noted Buick salvage outfit that advertised in Hemmings. We went round&round about his (Buick specialist) knowlege after I had talked to a long time Buick Dealer partsman. I paid a re-stock fee and shipping just to recover some of my money. I had a good 3 spd one off an early 1961 Olds (1960 casting date) that was just the same as the Buick one he sent. Later on I did find a 4 spd Olds one. I think they were all from 1962 or 1963 4 bbl cars. GM divisions sell parts to each other. Very likely Olds made the 4 speed bellhousing, creating the parts number and sold them to Buick since Buick need so few of them. The genuine Olds 215 4-spd bellhousing has the same bolt pattern as used on 55 Chevy cars on into the 1960s era Saginaw box pattern. It looks to me as though the 3-spd housing works better with a Ford T-5 since it requires a thicker adapter plate. I don't think I would try to hook a GM 4 or 5 speed to the 3-speed 215 bellhousing (the bolts are just to short to get enough threads) when assembled. Thats my 2 cents worth + I don't trust aluminum welding on die-cast unless it is heat treated after. then have ???s