944 Question

[LWB250]

Maybe this sounds silly, but...

I'm trying to grasp the setup on the 944 with the use of a torque tube for transmitting power to the final drive/differential. Since I've never worked on one of these, it's a mystery to me other than having seen some photos and diagrams. I understand the concept and have seen it on other cars, like Corvettes.

So as I understand it, there's a torque tube that is attached to the engine/flywheel that runs the length of the car. It is attached to the transaxle, which is in the rear of the car. The shift linkage runs the length of the car and goes to the transaxle, of course.

What I'm trying to understand is where the clutch is located? Is it at the rear of the engine, mounted on the flywheel, like a traditional clutch? If so, I presume the torque tube is bolted or attached to the pressure plate in some manner?

Thanks for filling me in. I'm still seriously considering a 944 for a fun/project car in the future, and just trying to learn as much as possible by following some groups and vacuuming up as much reading material on them as possible.

Dan

 

[Glen]

The clutch is in the normal location at the back of the engine but to get to it, the torque tube needs to come out...which means the transaxle comes out too.

 

[LWB250]

The clutch is in the normal location at the back of the engine but to get to it, the torque tube needs to come out...which means the transaxle comes out too.

That sounds unpleasant.

Dan

 

[Glen]

That sounds unpleasant.

Dan

I bought a 924 Turbo when I was 19 in the mid 80's, had it for about 7 years but thankfully never had to do a clutch! Pretty slow by today's standards but still fun for a kid in college.

 

[LWB250]

I'm still toying with the idea of getting a 944 for a "fun" car. Haven't quite convinced myself.

Thanks!

Dan

 

[dionphaneuf]

Dan you should drive one! I've been noticing that it seems now possible again to get a solid Turbo for <$20k which is right. As you mentioned, they can be annoying to work on but nothing an adventurous mechanic can't solve as mr @Duh_Vinci has shown. I miss mine a lot

 

[a777fan]

@Duh_Vinci is a true vintage Porsche salesman. I have been lusting for a 944 after his resto thread, and I don’t even remember giving the neighbors a second look while growing up!

 

[asultan]

Dan you should drive one! I've been noticing that it seems now possible again to get a solid Turbo for <$20k which is right. As you mentioned, they can be annoying to work on but nothing an adventurous mechanic can't solve as mr @Duh_Vinci has shown. I miss mine a lot

i've heard enough motor out necessary horror stories for basic service interval items to keep my 944 obsession at bay - affordable fun at a cost of lots of annoyances

 

[skikrazey]

Always liked the 944 Turbo & the 968, was considering picking one up a after selling my modified 85 Ur-quattro. Bought a 1990 B3 Coupe Quattro that is modified to RS2 Avant specs. A what could have been car! Best part, I can drive it all year long!!!

 

[Duh_Vinci]

Maybe this sounds silly, but...

I'm trying to grasp the setup on the 944 with the use of a torque tube for transmitting power to the final drive/differential. Since I've never worked on one of these, it's a mystery to me other than having seen some photos and diagrams. I understand the concept and have seen it on other cars, like Corvettes.

So as I understand it, there's a torque tube that is attached to the engine/flywheel that runs the length of the car. It is attached to the transaxle, which is in the rear of the car. The shift linkage runs the length of the car and goes to the transaxle, of course.

What I'm trying to understand is where the clutch is located? Is it at the rear of the engine, mounted on the flywheel, like a traditional clutch? If so, I presume the torque tube is bolted or attached to the pressure plate in some manner?

Thanks for filling me in. I'm still seriously considering a 944 for a fun/project car in the future, and just trying to learn as much as possible by following some groups and vacuuming up as much reading material on them as possible.

Dan

Cheers Dan, long time, sorry, I indulged myself into a little "reset from the world" time... looks like you questions have been answered. Definitely interesting system.



From what I've read is not entirely hateful, but not a simple few hours job either. My brother had his clutch replaced by a Porsche enthusiast/engineer while back (86 944), he also wanted to do the belts, water pump, etc. It was "easier" for them to remove the engine to do all the work, on the bench, while everything was out.

Always liked the 944 Turbo & the 968, was considering picking one up a after selling my modified 85 Ur-quattro. Bought a 1990 B3 Coupe Quattro that is modified to RS2 Avant specs. A what could have been car! Best part, I can drive it all year long!!!

Muse seeeeee!!!!! I've had 1991 in while pearl back in 1995, always wanted to convert it to S2 specs, but ended up as a total loos to a deer. Please, post few pics! Loved the B3 Coupe, still do, but imo, RS2 bumpers and the power is what the car needed!

Regards,
D

 

[Jlaa]

Thanks for the diagram!! Dumb question - why is the torque tube required to house the driveshaft? Why cant the driveshaft be exposed like a normal driveshaft driving the rear differential?

Why must this driveshaft, which drives a rear transmission, be enclosed in a torque tube?

 

[Duh_Vinci]

Thanks for the diagram!! Dumb question - why is the torque tube required to house the driveshaft? Why cant the driveshaft be exposed like a normal driveshaft driving the rear differential?

Why must this driveshaft, which drives a rear transmission, be enclosed in a torque tube?

I've asked myself the same question, and the closeted answer I found was Corvette related. I think the key is the small diameter of the torque tube vs drive shaft" that had to be encapsulated:

"torque tube is an alternate design for power delivery, in which a small-diameter shaft running from the trans to the rearend (or the engine to the transaxle) is fully encased in a tube, and in the case of coil-sprung cars like the Opel, a Panhard rod controls the rearend's lateral movement

"Why do Corvettes use torque tubes?

The purpose of a torque tube is to hold the rear end in place during acceleration and braking. Otherwise, the axle housing would suffer axle wrap, such that the front of the differential would lift up excessively during acceleration and sink down during braking.


Regards,
D

 

[Jlaa]

Ive asked myself the same question, and the closeted answer I found was Corvette related. I think the key is the small diameter of the torque tube vs drive shaft that had to be encapsulated:

torque tube is an alternate design for power delivery, in which a small-diameter shaft running from the trans to the rearend (or the engine to the transaxle) is fully encased in a tube, and in the case of coil-sprung cars like the Opel, a Panhard rod controls the rearends lateral movement

Why do Corvettes use torque tubes?

The purpose of a torque tube is to hold the rear end in place during acceleration and braking. Otherwise, the axle housing would suffer axle wrap, such that the front of the differential would lift up excessively during acceleration and sink down during braking.


Regards,
D

I learned a bit about the "torque tube" today. It appears the idea debuted at General Motors - in 1961 with the Pontiac Tempest and a rear mounted transaxle.

"The torque tube housing does not support the driveshaft in any way but only maintains the precise alignment between the engine and transaxle, holding the shaft in its curved position."

1961-1963 Pontiac Tempest

The 1961-1963 Pontiac Tempest was Pontiac's innovative entry into the compact car market. The story behind the development of the Tempest is one of divisional defiance and cost-conscious innovation. See pictures and read about the Pontiac Tempest.

auto.howstuffworks.com

Secrets of the 1961 Pontiac Tempest Rope Drive

The unusual driveshaft setup on the 1961 Pontiac Tempest has been called a “rope drive” and described as a giant speedometer cable, but how it really works is far more interesting. When General Motors unveiled the ’61 Pontiac Tempest … Continue reading →

macsmotorcitygarage.com

 

[Duh_Vinci]

I learned a bit about the torque tube today. It appears the idea debuted at General Motors - in 1961 with the Pontiac Tempest and a rear mounted transaxle.

The torque tube housing does not support the driveshaft in any way but only maintains the precise alignment between the engine and transaxle, holding the shaft in its curved position.

1961-1963 Pontiac Tempest

The 1961-1963 Pontiac Tempest was Pontiac's innovative entry into the compact car market. The story behind the development of the Tempest is one of divisional defiance and cost-conscious innovation. See pictures and read about the Pontiac Tempest.

auto.howstuffworks.com

Secrets of the 1961 Pontiac Tempest Rope Drive

The unusual driveshaft setup on the 1961 Pontiac Tempest has been called a “rope drive” and described as a giant speedometer cable, but how it really works is far more interesting. When General Motors unveiled the ’61 Pontiac Tempest … Continue reading →

macsmotorcitygarage.com

Great info, learn something new every day!

 

[Alphasud40]

In the Tempest the small driveshaft 3/4“ diameter on some was placed into a arc to cancel out oscillation. In the 944,968, and the 928 the torque tube provides support for the shaft via 2 roller bearings. I have owned and worked on 944‘s in the past. If you have use of a lift a clutch out is time consuming but pretty straightforward. actually working on the car is pretty straightforward relative to new cars. Cars are beautifully balanced. The only one I would stay away from is first series 83 to 85 1/2 and the 944S with the gutless 2.5 16V engine