Aluminum driveshaft swap

[honestabe]

Swapped out the steel driveshaft for an aluminum one from a mark 8. I used a driveshaft from a 93' mark 8 but looks like the same 2 piece shaft to me. It was a fairly easy swap, just got to swap ends off from the old steel shaft which was no big deal because I was going to replace the u joints anyways. One of the reasons I did this was because my old shaft had a bit of vibration, which could have just been from the worn u joints. The other reason I did the swap was because of the weight savings. I dropped about 9-10lbs from the swap so maybe gained 2hp and 1mpg. The length is nearly the same only like 1/8" shorter over the original either that or I suck at measuring. I spent probably 3-4hrs because I'm slower than molasses, but shouldn't take more than 1-2hrs for most people I would imagine.

 

[slowmkviii]

Cool swap never thought of this
Now I need to find another 93 shaft

 

[honestabe]

This was removed from a 93' but it doesn't look like 1 piece to me because of that gap or am I wrong? It looks the same from what I recall I had on my 97' mark 8

 

[no0c]

Swapped out the steel driveshaft for an aluminum one from a mark 8. I used a driveshaft from a 93' mark 8 but looks like the same 2 piece shaft to me. It was a fairly easy swap, just got to swap ends off from the old steel shaft which was no big deal because I was going to replace the u joints anyways.

2 piece shaft? Looks like a one piece prop shaft to me.

Swap ends off the steel shaft? Did you cut them off?

The other reason I did the swap was because of the weight savings. I dropped about 9-10lbs from the swap so maybe gained 2hp and 1mpg.

I wouldn't hold you breath waiting for either one of those phenomena to happen.

 

[chris2523]

i had no idea they were the same length...
but anyhow, hard to tell from the pic, but if there is a gap, that makes it a 2 piece drive shaft. still lighter though.

 

[driller]

Swap ends off the steel shaft? Did you cut them off?

Probably swapped the slip yoke and/or pinion flange.

 

[honestabe]

2 piece shaft? Looks like a one piece prop shaft to me.

Swap ends off the steel shaft? Did you cut them off?



I wouldn't hold you breath waiting for either one of those phenomena to happen.

The yolk and the rear coupler (I think that's what it's called), the town car's yolk is longer and has a bigger coupler. I don't expect major difference but I felt it was worth the upgrade for $100 w/ new u joints.

i had no idea they were the same length...
but anyhow, hard to tell from the pic, but if there is a gap, that makes it a 2 piece drive shaft. still lighter though.

Yeah I did a little research prior which was good because I was going to use a crown vic shaft but that was too short, I guess town car is something like 3" longer. Yeah I'm pretty sure it's 2 piece probably got swapped before the car was taken to the bone yard.

 

[no0c]

The correct nomenclature are slip yoke (transmission end) and Ford's nomenclature for the rear is also a yoke which bolts to the flange. Sometimes they are referred to as a companion flange.

Nothing to do with an egg, any part of it.

10 lbs from a 4000+ lb car (.25%). I'm not sure that's really a significant change.

I'm still confused as why you call it a 2 piece shaft. Please fill me in. Thanks.

 

[honestabe]

The correct nomenclature are slip yoke (transmission end) and Ford's nomenclature for the rear is also a yoke which bolts to the flange. Sometimes they are referred to as a companion flange.

Nothing to do with an egg, any part of it.

10 lbs from a 4000+ lb car (.25%). I'm not sure that's really a significant change.

I'm still confused as why you call it a 2 piece shaft. Please fill me in. Thanks.

Because of the obvious gap on the rear of the shaft, may be hard to tell in the pics even though it came off a 1993 according to the yard. Also not really weight savings in a whole, but less rotational mass slightly less drivetrain loss.

 

[chris2523]

the 94-98 mark viii shafts are one shaft inside another with a rubber coupling.
was supposed to help with drive line vibration, didn't work.

 

[honestabe]

the 94-98 mark viii shafts are one shaft inside another with a rubber coupling.
was supposed to help with drive line vibration, didn't work.

You know it has reduced rear end hum or growl from around 40mph. I remember reading somewhere they went with this design to combat low speed harmonics instead of high speed. Honestly I don't think this car will ever see 100mph the fastest I recall going is probably 85mph for fun at a track. A quick 16.8 in the 1/4 lol

 

[slowmkviii]

In the pic it does look like a 2 piece.
Do we get some pics of said car?

I just picked my newest tc from your area too
We could have done lunch

 

[KStromberg]

Because of the obvious gap on the rear of the shaft, may be hard to tell in the pics even though it came off a 1993 according to the yard. Also not really weight savings in a whole, but less rotational mass slightly less drivetrain loss.

I wouldn't put a lot of weight on what the junkyards say. I don't think most of them even know that a one-piece driveshaft is specific to the 93 Mark8s only. With that said, it is obvious that you do not have the 93 driveshaft because of the seam on the end of the shaft, but that's old news. We've established that. Regarding the weight of the shaft, I would surely not be surprised with some slightly better throttle response with that shaft. 9-10# is huge in terms of rotational mass which has a greater effect on performance than that of dead weight. Drag racers take advantage of this concept and it works. Technically, your crankshaft is not working as hard now.

 

[honestabe]

I wouldn't put a lot of weight on what the junkyards say. I don't think most of them even know that a one-piece driveshaft is specific to the 93 Mark8s only. With that said, it is obvious that you do not have the 93 driveshaft because of the seam on the end of the shaft, but that's old news. We've established that. Regarding the weight of the shaft, I would surely not be surprised with some slightly better throttle response with that shaft. 9-10# is huge in terms of rotational mass which has a greater effect on performance than that of dead weight. Drag racers take advantage of this concept and it works. Technically, your crankshaft is not working as hard now.

Yeah, I know it's quite the weight savings in those terms but I only expected to free up a couple ponies. Too early to tell as far as gas mileage, the biggest felt benefit is less vibration and no more whine/hum from around 35-40mph, I should mention I also have 3.73 gears.

 

[Markviiiedrea]

One piece vs two piece.