Buick 37 Four Or Five speed modification

[Guest Maggie37]

Has anyone ever fitted a four or five speed overdrive gearbox to a straight eight Buick and retained the original torque tube and rear axle. Adapting the box to the engine is relatively simple and there are several companies making adaptors but I can't find anything to adapt a later gearbox to the torque tube. They are available for model A fords so it can be done but I just can't find any info at present.

I know you can put an overdrive unit in the torque tube but I don't want to do this..Any help appreciated

[Taylormade]

Different strokes for different folks. To me it's hideous.

[Curti]

If the 4 or 5 speed is not over driven,which most are not, what is the point?

[joe_padavano]

If the 4 or 5 speed is not over driven,which most are not, what is the point?

 

I think most five speeds you will find ARE overdriven, which IS the O.P.'s point...

 

To the O.P.:  You'll likely find that you'll get useful comments on a site like H.A.M.B. or Hotrodders.com. The majority of members here are dedicated to stock restorations and are unwelcoming to modifications (as the first two responses may have hinted).  As for your question, the T5 is a popular swap behind older engines, however most simply convert to an open driveline. I'm not aware of any easy (or difficult, for that matter) swap that retains the torque tube.  Good luck.

[Ben Bruce aka First Born]

  Maggie37, welcome.

   Joe is right. Also, you might scroll on down to the Modified forum in the Buick forum. Perhaps some help there. For sure a better reception.

  I ,too , would be interested in the answer.

 

  Ben

Edited October 4, 2015 by First Born (see edit history)

[Matt Harwood]

I might recommend reviewing Las Vegas Dave's recent posts about installing an overdrive in the torque tube of his 1938 Buick Special. It is a big job, but it accomplishes what I suspect you're looking for: more speed, fewer RPM. And it doesn't require re-engineering the entire driveline, although a lot of folks would now call that car "modified." It's a way to get what you want without killing the car's originality.

[joe_padavano]

One other option to consider is a torque-arm suspension with a T5.  The third gen Camaro/Firebird used a torque arm and a T5.  The torque arm is just a long steel channel that runs parallel to the open driveshaft.  It is bolted rigidly to the front of the rear axle housing and pivots at the back of the trans, so functionally it works exactly the same as a torque tube.  The only difference is that the driveshaft is exposed instead of being inside the tube. The F-body T5 transmissions have the mounting provision for this torque arm pivot.  You would need to convert the rear axle to an open driveshaft.  Speedway Motors sells kits to convert some torque tube axles, but I suspect those are primarily for Ford axles. 

 

Yes, this is a lot of work, and it requires a fair amount of fabrication, but it doesn't fundamentally change the rear suspension.

[Guest Maggie37]

Thanks for the suggestions. I live in New Zealand and travel long distances to events. Most roads here just two way with the odd passing bays. I find I can keep up with other cars doing the speed limit 60 mph but the poor old Buick is screaming her lungs out. If you go much slower traffic builds up behind you and creates a problem. I have a Studebaker that has a factory overdrive and is so nice to drive at 60mph compared to the Buick. While the purists might struggle with the idea I have to drive it and would keep all the original parts should I ever decide to part with her

[Guest]

I installed an electrically actuated Gearvendors overdrive in my '31 Cadillac for similar reasons. I'm very glad I did.  You can see a thread about it in the technical section.

Edited October 4, 2015 by Guest (see edit history)

[LAS VEGAS DAVE]

The original Borg Warner overdrive as found in the old Studebaker is not to hard a modification to install in your 37. I had many posts and pictures about it a few months ago and would be glad to answer any questions you might have. Its a great mod for the driving conditions you describe. Although it was not common It actually was available in the late thirties from some independent garages. Many guys with Ford model A's here on the west coast of the US have done this mod.

[Rusty_OToole]

If you want a Camaro why don't you buy a Camaro? If all you want is lower RPMs @ 60 you could install bigger back tires or a different gear ratio.

[Spinneyhill]

You could install a BW overdrive, as in the Studebaker, but your diff. would be too tall then. The factory installation came with a lower ratio diff. to make it more tractable. Remember you only have 85 or 90 hp to push you along and on our hills you will be changing gears a bit. Unless you are in Canterbury...!

[Aaron65]

If you want a Camaro why don't you buy a Camaro? If all you want is lower RPMs @ 60 you could install bigger back tires or a different gear ratio.

 

Although Rusty's comment is perhaps a bit overreaching, he's right about the gear ratio.  As far as I know, later Buick center sections SHOULD (you'll want to double check this before buying one) swap into your housing.  Later Buicks had gear ratios up to 3.40:1 or so.  You'll lose a bit of acceleration, but should then be turning around 2500 RPM at 60 (maybe even less).  Just another thing to consider, although I'd rather the OP USED his car as intended on today's higher speed roads than having it sit in his garage because s/he's disgusted with it or nervous out on the road.  It's not like he's dropping in an LS3 and painting it fuschia.

[dictator27]

What rear axle ratio does the car have in it?  Changing to a numerically lower ratio will improve the cars cruising speed at the cost of slower acceleration, but it is the simplest way to do it.  A friend of mine found a high speed crown and pinion for a 1926 Studebaker Dictator and raised the cruising speed from 80 kph to 110.  (Before anyone asks, yes the cars mechanical brakes are up to the job. )

 

Terry

[Guest Al Brass]

Most Buick's produce quite a lot of torque so I suspect a higher geared diff may not affect acceleration too much at all.

 

Al

[Rusty_OToole]

Buick straight eight is a low RPM high torque engine, capable of slowing down to a walking pace in high gear and accelerating up to top speed without bucking or faltering. The last thing it needs is a 5 speed transmission. They are for small, revvy motors with no power band.

 

Overdrive is a good idea but not easy to install with the Buick torque tube drive (putting it mildly). I know they do some miraculous mods down under but, a simple gear ratio swap would be a lot easier if you can find a suitable gear set.

[DavidAU]

"They are for small, revvy motors with no power band"

 

I dont think that is at all correct. 

There are thousands of flathead Fords and other old style engines around the world running very well with 5 speed gearboxes fitted behind them and I wouldn't  call them small revvy motors.

 

Try asking on the HAMB because someone somewhere will have already done it or at least tried.

 

Thinking about it a bit further though,  the main problem as I see it would be that the 5 speed box would be a lot longer that the Buick 3 speed and even if you make an adaptor for the torque tube, the tube will have to be shortened which will defeat your purpose of trying to keep original so it can be returned to stock if required.

 

You may have change it to open drive shaft like they do with the Ford V8 conversions.

Edited January 1, 2016 by DavidAU (see edit history)

[Ben Bruce aka First Born]

Buick straight eight is a low RPM high torque engine, capable of slowing down to a walking pace in high gear and accelerating up to top speed without bucking or faltering. The last thing it needs is a 5 speed transmission. They are for small, revvy motors with no power band.

 

Overdrive is a good idea but not easy to install with the Buick torque tube drive (putting it mildly). I know they do some miraculous mods down under but, a simple gear ratio swap would be a lot easier if you can find a suitable gear set.

 

 That "'walking speed in high gear' " only works with a low speed [ high numerically ] rear end gear. My '50 came with a 4.10. I changed to a 3.36. I really like it. About 650 RPM lower in high gear. BUT, whereas before , "walking speed" was about 500 RPM it would now be minus 150 RPM.  Way cheaper than an overdrive , though. But has limits.

 

  Ben

[Rusty_OToole]

Can you tell us if the 37 Buick can use gears out of a newer rear axle with higher (lower numerical) ratio?

[Ben Bruce aka First Born]

Can you tell us if the 37 Buick can use gears out of a newer rear axle with higher (lower numerical) ratio?

 

 

  I do not know from experience, but think not.  1940 through 1955 will exchange with each other.  I would hope someone from the '37-'38 group would chime in on this.

 

  Ben

[Spinneyhill]

According to The Hollander, there were three differentials used in the Buicks of 1937: 90 after #2897268, 40 and 60, and 80 series. I don't know the Buick series, so you'll have to tell us which one you have.

 

The Federal Catalog "S" of 1944 shows:

60 had a Standard ratio of 39-10 and a Power ratio of 44-10;

80 had either 39-10 or 38-9;

90 only had 37-8; and

40  either 39-10 or 44-10.

 

So which does your car have?

 

'38 80 Roadmaster 46-11;

'38 90 Ltd 41-9;

'38 60 and 40, 39-10 or 44-10;

 

'39 80 and 90, 46-11 or 41-9

'39 60 39-10;

'39 40 40-9;

 

'40-42 80 & 90, 46-11 or 41-9;

'40-42 40, 50, 60, 70  39-10 or 47-13 or 44-10.

 

So there is a bit of choice. Tell us what model you have and which diff. and maybe the Hollander will help choose a more tractable diff.

[Spinneyhill]

It looks like you need the later axle if you want to put post war gears in. See attached from National Service Data 1950.

 

Note the 3.6:1 C. & P. Gear set - that is the 47-13 introduced in 1940.

 

Edited January 3, 2016 by Spinneyhill (see edit history)