1-pc Driveshaft?

Kumba

Kumba

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I'm looking to do an 8.8" swap and am really just not a fan of the 2-piece DS set-up. I understand how it lets Ford make a sloppier driveshaft in production that vibrates less, but I still don't like it.

But does anyone know if the tailshaft on the LS is shared with a Mustang tranny? Cause if so, I'll just replace that POS flex coupler with a regular yoke.
 
I believe the accepted way to improve on the guibo is to substitute one (BMW?) that's dimensionally equal but tougher. There's been discussion regarding this topic previously. If you look back at the original thread exploring the 8.8 punkin rework, I believe you'll find good information.

KS
 
I saw the 2-3+ year old threads about using the BMW flex thing, but I'm not sure I'm really sold on the whole concept. The thread was also inconclusive about if it worked or was even attempted. So that unfortunately leaves me at square-1.
 
Give me a couple days I have a 1 piece aluminum driveshaft coming. I can explain the details once I get it and can take a pic of the setup.
 
PMJJ said:
Give me a couple days I have a 1 piece aluminum driveshaft coming. I can explain the details once I get it and can take a pic of the setup.
Click to expand...

You are using the 3.9 right? And that would be cool! Also like to know what length DS you used :)

The more I can get done and sitting in the garage before the swap, the less likely I'll hate the car when the swap happens.
 
Here you go Kumba,

Yes, I have a 3.9L. Personally I wouldn't go with an aluminum driveshaft, couple reasons why,

1- The price for this shaft was: $632 shipped. Steel shaft would've been half that, or even just adapting to the stock one would be less money.
2- They can only make aluminum shafts in 2" diameter up to 57", this is like 4" or 4.5" due to the length. Thats partly why the stock one was 2 piece, to cut down on vibration and the lack of room in the tunnel to put a 1 piece in the length.
3- I had to modify stuff to get it in, which wasn't a big deal but it is still very tight in the tunnel.
4- It took a month and a half to get this shaft, not sure what was going on at the shop but whatever.
5-Had to cut and remove stock center support mount.

The output flange on the tranny is from a 2005 mustang. You have to cut the tit that sticks out from the output shaft coming from the tranny because it used to go into the stock driveshaft, and it will hit a normal driveshaft yolk flange.

The flange on the axle housing is just the one that was on it originally in a Lincoln Mark VIII.

As far as the length you need to wait and measure point to point just because it has to be exact like down to a 1/16th.

DS 1-Optimized.jpg


DS 2 OPTIMIZED.jpg


DS 3-Optimized.jpg


DS 4-Optimized.jpg


DS 5-Optimized.jpg
 
Hey, PMJJ---

A comprehensive write-up on the work necessary to do your install would be very valuable. Such things as an explanation of the fabricating necessary, sources for the parts special to your conversion, what items you simply had to discard, and substitutions required would all be of significant interest! Also, what's the function of the bellows/boot on the one end of the DS?

KS
 
cammerfe said:
Hey, PMJJ---

A comprehensive write-up on the work necessary to do your install would be very valuable. Such things as an explanation of the fabricating necessary, sources for the parts special to your conversion, what items you simply had to discard, and substitutions required would all be of significant interest! Also, what's the function of the bellows/boot on the one end of the DS?

KS
Click to expand...

The bellows covers a splined slip joint. Since the transmission side of the Yoke is no longer a slip-yoke like older cars, you have to have some flex in the driveshaft in order to be able to put it in/out of the car without dropping the rear end. The bellows covers that to keep dirt out. In theory on an IRS, it should see very minimal movement.

For a ballpark idea, what was the length of your DS? If you are using the Gen1 rear cover in the factory mounting position, and the tranny/engine are in their factory position, all swaps like this should be within 1/2" of what your set-up is. At least gives me a number to start with.

It looks to me like you have a good bit of room in the tunnel. I am curious to see the cross member and how bad the interference is though. Also, opinions on the 1-pc vs the 2-pc? I know the critical driveline speed is less, but I'm not really worried about doing 140+ mph any time soon. I'm just tired of the humm at highway speed (75-80mph).

Guess i'll wait for your follow-up with your impressions on it. Definitely what I had in mind though. A mustang flange on both sides, and a custom-length mustang DS.
 
DS Conversion

And, for what it's worth, I AM interested in the use of the combination to include speeds over 200 MPH.:D

KS
 
cammerfe said:
And, for what it's worth, I AM interested in the use of the combination to include speeds over 200 MPH.:D

KS
Click to expand...

I'd definitely go with a re-worked 2-piece setup. Reinforce the CSB, put in real u-joints not flex couplers, and make the shafts aluminum or some kind of carbon fiber composite. A 1-piece would be real difficult to make work at that speed. Can be done but a real pricey option.
 
Kumba said:
The bellows covers a splined slip joint. Since the transmission side of the Yoke is no longer a slip-yoke like older cars, you have to have some flex in the driveshaft in order to be able to put it in/out of the car without dropping the rear end. The bellows covers that to keep dirt out. In theory on an IRS, it should see very minimal movement.

For a ballpark idea, what was the length of your DS? If you are using the Gen1 rear cover in the factory mounting position, and the tranny/engine are in their factory position, all swaps like this should be within 1/2" of what your set-up is. At least gives me a number to start with.

It looks to me like you have a good bit of room in the tunnel. I am curious to see the cross member and how bad the interference is though. Also, opinions on the 1-pc vs the 2-pc? I know the critical driveline speed is less, but I'm not really worried about doing 140+ mph any time soon. I'm just tired of the humm at highway speed (75-80mph).

Guess i'll wait for your follow-up with your impressions on it. Definitely what I had in mind though. A mustang flange on both sides, and a custom-length mustang DS.
Click to expand...

The length was 61 3/8", flange to flange face. Again, they'll need an exact measurement, because once they build them thats it, it's a custom length driveshaft with no returns.

There is alot of room in the tunnel on the sides, and the bottom but the top is were it's tight, eliminated one problem removing the center support bearing mount so that free'd up some space but the gas tank is only a 1/4" from the shaft.

Personally I would just modify the stock shaft, just way to much money for a mustang driveshaft.

I have a 93 mustang drag car that has a carbon fiber shaft and that shaft was only $500.
 
PMJJ said:
The length was 61 3/8", flange to flange face. Again, they'll need an exact measurement, because once they build them thats it, it's a custom length driveshaft with no returns.

There is alot of room in the tunnel on the sides, and the bottom but the top is were it's tight, eliminated one problem removing the center support bearing mount so that free'd up some space but the gas tank is only a 1/4" from the shaft.

Personally I would just modify the stock shaft, just way to much money for a mustang driveshaft.

I have a 93 mustang drag car that has a carbon fiber shaft and that shaft was only $500.
Click to expand...

Ahh, the CSB support. I thought you were talking about some kind of subframe cross member I didn't know about. The CSB isn't structural so that's good. More weight shed.

They make a necked alum driveshaft just for that reason. It's tapered from 4" to 3" to allow for clearance around the tank and subframe.

And yeah, anything fox body is usually dirt cheap compared to anything custom. Plus, were you hitting trap speeds of 200mph? Cause if so, damn bro! That's not your average 500-hp dragstang for sure!
 
Yeah I pretty much passed on it cause it looked to be real tight and with 4.10 gears quick math by Frank at DDS suggested 5" diameter. Idk about removing the pilot shaft, just seems to be importamnt to centering and vibs.
 
Kumba, I'm Land Speed racing. One mile at Maxton. The record in the class I'll be bumping into is 184+. New engine---new class.

KS
 
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