3-on-the-Tree

[D Yaros]

I am looking for a source for online info (pics/specs/repair manual/etc.) on the manual transmission used by Buick in the 50's - 60's. Am interested in such as I have "all but" determined this tranny was also used by Oldsmobile and Pontiac, and I had one in my 1960 Olds. See pic:

Appreciate it.

[Guest DinoBob]

This transmission is commonly differentiated from the earlier manual by the amount of bolts in the top cover. It's known as the 6-bolt, as opposed to the 5-bolt made from '36-55. I'm just learning about this transmission myself, as I have one in my '60 LeSabre.

The '59-'60 LeSabre with what Buick called the "Synchromesh" transmission was equipped with a special "performance-matched" 364 2-bbl with only 210 HP and 300 lb.-ft of torque. This is 40 HP less than the next mildest engine. I always assumed that this indicated an acknowledged weakness in the transmission's build by Buick. Not so, according to a site I read about vintage Pontiac racing. The writer cites the transmission as one of the most bulletproof 3-speeds ever built, due to its nearly straight-cut gears, and states that he ran one successfully behind a 450 HP engine.

My car has a 3.91 Positraction rear. The gearing in this trans, combined with that rear, does perhaps explain the HP. If I had the 325 HP and 445 lb.-ft of the big 401, I could spin the tires for a block. :-)

Here's a link:

Pontiac Manual Transmissions

I'll follow this thread.

[MrEarl]

thanks for that great info DinoBob as I have been wondering if I was on the right track in planning to use a Buick 6 bolt behind a supercharged 322 and in front of a 4.11 rear end. I had started considering and searching for an adapter for a Ford top loader but from the information you referenced I should be OK stay with ALL BUICK. WoooHooooooo

>>>>> the 1956-57 Pontiac H-D three-speed was stronger than any other 3-speed ever mass produced, with the exception of the Ford "Top Loader". A T85,although much stronger than a T10,is not quite as stout as the big old Buick unit <<<<<<<

Actually DBob, Buick used the 6 bolts starting in 1953 with the 322 cu. in./164 HP engine. In '54 the 40 series (Specials) with the 264 cu in/143 HP engine continued with the 5 bolt but the Super and Centurys with the 322 cui in /177&195 HP engines received this heavy duty 6 bolt top syncromesh. (The 54 Century, called by many the bankers hot rod, with 195 HP 322 backed by a 6 bolt 3 speed was one bad ass street car for it's time). Same in '55 but with even increased HP in the 322's. In 1956 only the 40 series with it's 322 cu in/220 HP engine was still offered with the 3 speed syncromesh and it was the HD 6 bolt. In ALL the syncromesh engines they kept the compression ratio lowered over that of Dynaflow engines by using pistons with two different dome heights and thinner/thicker head gaskets.

Edited September 28, 2012 by MrEarl (see edit history)

[D Yaros]

Well, the 6-bolt tranny in my 1960 Olds was connected to a 394 c.i. engine, putting out 315 h.p and 435 lbs. of torque. As for being indestructible, I can state I had to replace the sychronizer for 2nd gear more than once! But then I was, shall we say, pushing the drive train to its limits!

Still hoping someone can direct me to online info, manual, specs, etc. for this tranny.

[sean1997]

Read this thread and follow all of the links:

http://forums.aaca.org/f162/1957-buick-oddball-model-not-308745.html

[sean1997]

I should have also mentioned that you should buy a factory chassis service manual if you don't have one already. It should have a section on the manual transmission (at least the Buick manuals do) and it is really the best manual I've found. Hot Rod Magazine had a Technical Library publication called "Clutches Transmission Rear Ends" that has some info on the Buick/Olds trans, but not much.

[D Yaros]

The Olds FSM is, shall we say, more than a bit sparse when it comes to info on the standard trans. There is in a fact a section on the "Synchro-Mesh" transmission. No specs of any kind. Hardly a page or two.

Edited October 5, 2012 by D Yaros (see edit history)

[sean1997]

Maybe the Buick manuals might help. I think the older ones might have more info, but here is one for 1960:

http://www.teambuick.com/reference/library/60_chassis/files/4-a.pdf

http://www.teambuick.com/reference/library/60_chassis/files/4-b.pdf

and here is one for 1957:

1957 Buick Chassis Manual, Group 4, Clutch, Transmission, Universal Joint

Here the main pages:

1957 Buick Chassis Manual, All Series

Team Buick Forum

Some of the links are missing for other sections for 1957 and 1960, but you can guess what they are following the patterns above (like I did for the second file for 1960 above):

Emploded view power brakes delco moraine 1957 Buick

Wild About Cars (wildaboutcarsonline.com) also has some factory Olds service manuals for 1961-964. Oldsmobile used the 6-bolt trans for 1951-1964, so you could try those too.

Edited September 29, 2012 by sean1997 (see edit history)

[D Yaros]

Thanks a bunch! Finally, the type of info I have been seeking for what seems to be forever! Appreciate it!