R154 DS length and spline specs

ratpick63

ratpick63

detroit iron defector
May 4, 2006
62
0
0
Glendale, CA
Never heard anything bad about using one piece, other than with less weight it won't be as smooth a drive as the stock super-heavy unit.

I had a shop make me a one piece aluminum and just gave them the stock one to copy. Seems like my new one could've been 1" -1.5" longer, like he over compensated for live-axle plunge that's not there anyway. I haven't noticed any problems with it though. Of course I don't make enough power, or have enough traction if I did, to twist any splines.

My somewhat unrelated question: Will I need to change length or front yoke when I swap from W58 to R154?
I haven't checked to see if they're different, and planning to swap as soon as I find a good deal on a decent trans.
 
I

IJ.

Grumpy Old Man
Mar 30, 2005
38,728
0
0
62
I come from a land down under
This has been covered many times before and it's just a personal peeve of mine with many people reporting no issues with using a 1 piece....

At certain shaft speeds above critical you get shaft whip as the Uni joints oscilate and not travel in circles, with low diff gears and high OD ratios in a trans and high road speeds it's quite easy to land in this zone.

It will hammer the shaft diff and trans to death quite quickly.

My feeling is that the improved performance people report after changing to a 1 piece shaft is 95% placebo and 5% replacing a worn shagged 2 piece that possibly has the bonded section out of phase and is robbing power.

The PMoI of a 3" diameter shaft is so low I can't see a performance advantage removing weight there sorry.
 
I

IJ.

Grumpy Old Man
Mar 30, 2005
38,728
0
0
62
I come from a land down under
BCG: Nah I "feel" given my driving habits that a 1 piece will hammer ANY Diff and Trans to death in very short time and just can't understand the reasoning behind people fitting them and thinking it's an upgrade ;)
 
F

figgie

Supramania Contributor
Mar 30, 2005
5,225
16
38
50
Twin Cities, Minnesot-ah
B

physics, i talked to you about this man. The rotating mass of the DS is no where near the flywheel weight, so as Ian stated, mostly placebo. Stick with the two piece.

<-- This coming from the hypocrite running a 1 piece CF DS ;)
 
jawsgear

jawsgear

Undergoing Construction
Jan 29, 2006
465
0
0
Sactown
www.jawsgear.com
Measurement for a1 piece shaft should be from the end of tailshaft splines to the face of the differential flange. Do NOT subtract any dimensions off this measurement as it will cause length issues when it is being built. We will account for the proper amount of travel on the driveline. MK3 + R154 + Turbo we have the measurement for. We ask for meaurements because most individuals ordering are not sure what they have. R154 Transmissions and Auto Transmissions have a 23 Spline Output Shaft and W58 Transmissions have a 21 Spline. Why is a 1 piece better or worse than a 2 piece........

Check previous threads as I am not wanting to debate today. LOL

Hope this helps.:icon_bigg

Jeff
 
You must log in or register to reply here.
Top Bottom