OLD CAR CLOSED DRIVESHAFTS 2

[bobo60]

hi,

ive heard of "closed driveshafts" that were used on early 40-50's american cars, but never had the oppertunity to actually see or work on one. i beleive the actual driveshaft is inside a torque tube. how do u get to the u-joints to remove the shaft, and what is the purpose of the tube?

thank you,

bob

 

[MikeHalloran]

I don't recall seeing one up close, but I think the tube is actually stressed in bending, and is intended to resist the axle torque, just like the pressed I-beam that rides alongside the driveshaft in recent Camaros. I.e., think of it as a single really long ladder bar, anchored near the transmission tailshaft.



Mike Halloran
Pembroke Pines, FL, USA

 

[bobo60]

thanks mike,

but the driveshaft actually goes through the tube, correct?

bob

 

[MikeHalloran]

Yes, I think it does, and no, I don't know how to get the driveshaft out. But it can't be terribly difficult; they were built on an assembly line.

It still may involve juggling heavy parts:

http://www.southernwheels.com/march-98Frame1Source1.htm

Mike Halloran
Pembroke Pines, FL, USA

 

[bobo60]

thanks again mike for the info, and link!
i always thought that those old closed type driveshafts would be alot of work to repair! wow!

bob

 

[GregLocock]

If you do a web search on Peugeot workshop manuals you should be able to find a good description of them, and how to disassemble them.

Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.

 

[Fabrico]

Mercedes Unimogs have a torque tube arrangement which is solid on the rear axle and pivots in a ball socket with U-joint inside at the front, and no U-joint at the rear. It is a beefy setup that absorbes the drive torque of the rear end, and serves as part of the suspension.

The Corvette has been using a cousin of the torque tube for the last several years. About the only difference is that the shaft goes from the engine flywheel, to a fixed transaxle in the rear, instead of a sprung live axle. The Pontiac Tempest had a very similar arrangement in the 60's. These systems do not use U-joints. Interestingly, a bow is used in the very long shaft instead of supports and bearings.

 

[firefrog]

Hello
I used to own two old Chevy pickup trucks with the closed driveshaft. As I remember the actual driveshaft was solid steel about 1.25". There were bushings inside the tube. One end of the tube was permanently attached to the differential. The other hooked up by a threaded casing to the transmission. It was a slip-joint type rig with leather seals. Once you removed the upper casing and pulled it back, you could just unbolt the u-joint. Purpose? I only heard stories. Back then, they used their trucks for tractors. (Chev 235 engine had a torque peak at 1200 rpm and the truck had a load rating of something like 6000 lbs.) The closed shaft kept out the grime, vegetation, and livestock. Seeing how strong they were and how long they lasted, the closed driveshaft may have something to do with it.

 

[bobo60]

firefrog,

cool! i thought that one of the benifits of the closed driveshaft would have been to protect the u-joints from water, dirt and so forth. i think it was truely "overkill" but in a good way! i was born in 1960, so its interesting to explore old designs. i was born and raised a machanic, but only did it for about 12 yrs, then went to work for a large computer company as a customer engineer, and worked on laser printers! alot of mecanical work there too, along with software. so i still got to do mecanical work, but came home from work almost as clean as i was when i left home to go to work!

bob

 

[EngJW]

I'm surprised no one has mentioned the Ford Model A, and all the Fords up to the late 40s. Any old timer out there who has fooled around with street rods knows about them.

 

[bobo60]

wow!

the model a fords had a closed driveshaft setup? i heard they were kind of confusing to shift, operate. throttle on steering coluum, floor pedals for some gears....

bob

 

[grnegg]

Bobo60,

you are thinking of the Ford Model T... This car actually has the torque tube driveline as well as a planetary transmission. This amazing transmission only needed addition of a control scheme and some actuators...which would have made it essentially equivalent to modern automatic transmissions!

Ford used the closed (torque tube) style from the early teens through the 1950s. It is a very robust system.

Dave

 

[evelrod]

Bob, ya gotta get out to the car shows more often.

Model T's had a three pedal arangement to operate the tranny because it was extremely simple. Most folks of the early 20th Century had no knowledge of cars and Ford wanted something that was "idiot proof"...He got it...Press the left pedal to the floor and advance the throttle (on the steering wheel) and away you go in 'low'. Let up the pedal all the way (half way is neutral) and it's in 'high'. That's all there is to it. When stopped, depress the center pedal and advance the throttle and your backing up. The right pedal is for the brakes.
A Model A has a conventional three speed non synchro gearbox and is driven like any modern car. Torque tube drivelines were used in early cars for, as has been pointed out, they are "bullet proof" and seldom needed service.

Rod

 

[bobo60]

thanks rod,

im ignorant about some old automobiles, but am willing to learn. thats why i ask questions on this forum,as dumb as they may seem, to someone with vast knowledge of classic cars...bob

bob

 

[jbthiel]

I believe that my Dad's '69 Opel GT has an enclosed drive shaft. As was mentioned above, it works as a axle locating member. Prevents wheel hop with the sloppy leaf springs.

 

[JayMaechtlen]

Buick also used torque tubes, at least thru 1956
ugly, heavy, but reliable.
cheers
Jay

Jay Maechtlen

http://home.covad.net/~jmaechtlen/

 

[SMOKEY44211]

Rambler used them until mid 60's ----Phil

 

[evelrod]

Actually, Jay, they are not 'that' much heavier than an open drive line. A bit, but not all that much. The reliability factor is the big deal here. "U" joints have not always been reliable exposed to the elements. My 37 Buick torque tube was original, as installed by the OEM in 1936 and still functioning perfectly when I sold the car in the late 90's. My Model A Ford (Mfg. date 11/13/30) is still as originally installed and functioning perfectly at a little over 130,000 miles and 76 years!!! Hard to beat that, even with modern technology. I think the reason you no longer see this setup is a combination of cost and ride quality in "normal" cars. Some sports cars, Ferrari, Corvette, etc. still use a variation of the torque tube.

Rod

 

[patprimmer]

Rod

I think the cars that still use torque tubes have IRS, so the tube becomes fully sprung rather than partially unsprung weight, and therefore has no effect on ride.

It effectively couples the reaction forces within the differential to the engine block and may allow for some weight savings elsewhere in the chassis.

Regards

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[GregLocock]

Mazda MX5 (Miata) being a current example.

It's a very neat solution, although I'm a bit surprised to see it on sportscars as opposed to GTs. It can't be light.



Cheers

Greg Locock

Please see FAQ731-376 for tips on how to make the best use of Eng-Tips.