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Discussion Starter #1
At the local Pull-a-Part, I walked past an aluminum Police drive shaft that someone had already taken out and went ahead and grabbed it. I know it is too long, but figured with the magical interwebbernets, I could find what I needed...
Turns out that Spicer makes a slip yoke that is 1 inch shorter from the center line of the u-joints to the surface that would bottom out against the transmission if the driveshaft is too long. So, the driveshaft is 1 inch longer, but the yoke is 1 inch shorter. The Spicer part number for the yoke is 2-3-4911x and the best price that I found was from Autoplicity. Ford used 1330 u-joints in some shafts and 1350 in others. Mine had 1350, so I grabbed a Moog 348 that adapts the 1350 to the Spicer yoke's 1310, and a Moog 447 to adapt the rear 1350 to a S44 with the internal snap rings. See pic's for a comparison and installed view of the trans output.
 

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How do I know if I have the 1330 or the 1350. It is a police drive shaft. I am assuming the police drive shaft has the 1350 because it is probably a little larger.

So you can have the aluminum drive shaft installed for about $100 in parts. The front yoke $66.99, and universals for about $15.99 each. Plus the drive shaft of course.
 

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The only thing to contribute to the respectable write-up is that when researching a replacement yoke I was made aware of a GM spec called the "GTO Yoke" or something similar that sounds like it matches the 1" shorter length you found.

Even with my extended UCAs I had to search for a fix when installing my MMC shaft. With the known correct replacement U-joints I physically could not get the rear U- to slip into the pinion. I learned during this time my brand of quote, "3/4" extended" are not all a full 3/4", and therefore when I "ASSUMED" it was due to this issue. So, I had 3/16" milled off the end of the yoke, which still provided more than ample engagement with the tranny output shaft. Well, it turns out (counter-intuitively to me up til then anyway) that the driveshaft would push more into the tranny as the suspension compresses from fully relaxed. Well, I was wrong, and had I put a jack under the pumpkin then the U- could have slipped home and still had sufficient clearance with suspension fully relaxed after it was seated.

The point of all this is to mention that the real critical part for me was to confirm that the end the yoke would not compress too far forward at full travel and run out of machined spline on the output shaft thus putting the two in hard bind (and presumed high potential internal damage). My test for play through the travel range after installing showed this was not an issue, and it's apparent the the OP got the research right.
 

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Discussion Starter #4
How do I know if I have the 1330 or the 1350. It is a police drive shaft. I am assuming the police drive shaft has the 1350 because it is probably a little larger.

So you can have the aluminum drive shaft installed for about $100 in parts. The front yoke $66.99, and universals for about $15.99 each. Plus the drive shaft of course.
The 1330 has 1.062 bearing caps and the 1350 has 1.188. I 'think' the earlier aluminum shafts had 1330 and the later had 1350. Most info about u-joints, I found here-
https://www.dennysdriveshaft.com/c130_universal_joints_.html
 

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How much is the driveshaft itself?

I'm interested in doing this mod but I don't even know where I could source a Crown Vic shaft locally. With ordering parts and time spent trying to find one....I'm trying to decide if it's worth the effort. I remember pricing a new one from Denny's a while back and iirc it was ~$400. Which isn't unreasonable.
 

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I paid $100 or $125 to a friend who combs JYs for them, along with other parts for his projects and high moving pieces for our cars. Considering the extraction effort involved, and the cost of alternatives, I consider that fair. Of course you're also in for at least new u-joints, and extended U- and LCA/s, or Old Coot's yoke.
 

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Discussion Starter #7
How much is the driveshaft itself?
Around here, it depends on who is working the counter at Pull-a-Part. If they don't know what they are doing, it is $25 for a driveshaft. If they are paying attention, they will charge for the driveshaft and the slip yoke which adds $11 to the price. I did not bring the tools to take the yoke off mine, so I paid about $40 for it by the time they add the environmental fee and tax.
 

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Yeah...you guys are lucky. Around here even the junkyards charge ridiculous prices. They don't let you pick yourself either. So if you go in there looking for a specific part...like a driveshaft from a police car...I feel like they just charge you more.

I'd have to find someone in PA to pick one for me and then either ship or drive to meet them. Which I really don't have time for.

Sigh..
 

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At the local Pull-a-Part, I walked past an aluminum Police drive shaft that someone had already taken out and went ahead and grabbed it. I know it is too long, but figured with the magical interwebbernets, I could find what I needed...
Turns out that Spicer makes a slip yoke that is 1 inch shorter from the center line of the u-joints to the surface that would bottom out against the transmission if the driveshaft is too long. So, the driveshaft is 1 inch longer, but the yoke is 1 inch shorter. The Spicer part number for the yoke is 2-3-4911x and the best price that I found was from Autoplicity. Ford used 1330 u-joints in some shafts and 1350 in others. Mine had 1350, so I grabbed a Moog 348 that adapts the 1350 to the Spicer yoke's 1310, and a Moog 447 to adapt the rear 1350 to a S44 with the internal snap rings. See pic's for a comparison and installed view of the trans output.

Does nobody grasp the fact that a 1310/1350 combo joint is very weak compared to a straight 1330 or 1350 joint? The whole purpose of the 1330 and the 1350 is to make it larger and stronger so how is mixing a 1310 which is small and weak with a 1350 which is large and strong ever going to be a good idea? There will be serious issues with that joint snapping if it is used on any vehicle that gets abused and beat on. Am I the only one to realize this or am I just overthinking this?


Mike--94MSP9C1
 

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For anyone who stumbles onto this thread wondering what we're on about …
According to this website, the 1999-2001 P71's metal matrix composite driveshaft is the most desirable.
(considerably edited/trimmed for brevity)
MMC/MMX DRIVESHAFT:

Near mid 99, Ford introduced the Metal Matrix Composite (MMC/MMX) driveshaft, equipped on the 99-2000 model years, with many earlier 99 models and some early 01 models receiving the MMC driveshaft as part of a TSB service. The original part number for this driveshaft was “XW7Z-4602-AA.”
What makes the MMC driveshaft unique is that it is a special blend of aluminum and steel that is 30% STRONGER than the aluminum-only driveshaft, this allows the MMC driveshaft to absorb more driveline vibrations, thereby producing a better balance at higher speeds. The unique composition also allows the shaft to absorb “twist” much better, making it ideal for high performance applications.

Looking at the cross-section of the driveshaft, the inside is lined with a perfectly sized piece of looped and layered cardboard.
Although not confirmed, it is thought that this piece of cardboard helps reduce some driveline harmonics by attempting to absorb any resonance within the hollow driveshaft.

Ford also defined the critical speed estimation to identify driveshaft and gearing requirements for production.
Maximum critical speed w/ 16″ wheels states:

————————————–
CVPI Aluminum Driveshaft 4.10 = 116MpH
CVPI Metal/Matrix Driveshaft 4.10 = 133MpH
CVPI Aluminum Driveshaft 3.55 = 132MpH
CVPI Metal/Matrix Driveshaft 3.55 = 154MpH
CVPI Aluminum Driveshaft 3.27 = 145MpH
CVPI Metal/Matrix Driveshaft 3.27 = 167MpH
CVPI Aluminum Driveshaft 3.08 = 154MpH
CVPI Metal/Matrix Driveshaft 3.08 = 177MpH

Note: An MMC/MMX driveshaft can be identified by one of a few different ways based on feedback from several CrownVic.net members:
– MMC/MMX has pink and green stripes running around the shaft while all others have pink/blue/orange stripes.
– Large letters “POLICE” with small black print with the letters “MMC”
car-part.com [as well as several other jy websites] list several p71 driveshafts available, some as low as $35 (before shipping), within 100 miles of Queens NYC.
However, it's fair to strongly suspect that they are specifying the 98-02 aluminum P71 driveshaft, and not the 99-01 MMC/MMX P71 driveshaft.
 

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Yup. The last piece be mighty important as the guy who sold me mine only picks the much rarer MMC version.
 

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I was doing a little more research, and A NEAPCO N3R6081X or AAM 7812557 may be a better fit. The AAM 7812557 has a non vented plug

This is listed as stock

AAM 7848635

OEM transmission slip yoke with Long barrel length for Impala SS with 700R, 4L60, 4L65, 4L70
Manufactured by AAM American Axle
Fits 27 spline 700R, 4L60, 4L65, 4L70 transmissions
Replaces OEM slip yoke that utilized injected plastic to lock OEM U-Joint in place.
Replaces Neapco N3R-3-12051X, OEM GM 07848635, 74088635
DIMENSIONS:

Length to center of u-joint... Dimension #1 = 6 3/4 inches
Barrel Diameter... Dimension #2 = 1 1/2 inches
Barrel Length... Dimension #3 = 4 7/8 inches
Dimension #4 = 1 1/8 inches
Dimension #5A = 2 9/16 inches
Series... GM 3R
Spline count... 27
VENTED plug
COUNTERBORE DEPTH....3/8 inch
INSIDE "C" Clip Style lockup

___________________________________________________

NEAPCO N3R-3-6081X

GM 3R Series Slip Yoke 27 spline Powerglide, Turbo 350, 700R, 200R and 4L60 Transmission Slip yoke.

Also fits Muncie M20 & M21, Saginaw, Borg Warner T-5 T-10 & T-56 27 spline manual transmissions and other GM automatic transmissions with 27 spline output. Inside snap ring General Motors 3R series

Length to center of u-joint... Dimension #1 = 5 1/2 inches
Barrel Diameter... Dimension #2 = 1 1/2 inches
Barrel Length... Dimension #3 = 3 5/8 inches
U-joint cap diameter... Dimension #4 = 1 1/8 inches
U-joint width... Dimension #5A = 2 9/16 inches
Series... 3R
Spline count... 27

or

AAM 7812557

OEM transmission slip yoke with short barrel length for Impala SS
Manufactured by AAM American Axle
Fits 27 spline Powerglide, Turbo 350, 700R, 200R and 4L60 Transmission Slip yoke. Also fits Muncie M20 & M21, Saginaw, Borg Warner T-5 T-10 & T-56 27 spline manual transmissions and other GM automatic transmissions with 27 spline output.
Replaces OEM slip yoke that utilized injected plastic to lock OEM U-Joint in place.
Replaces Neapco N3R-3-6081X, OEM GM 07812557, 74082557, 26042557
DIMENSIONS:

Length to center of u-joint... Dimension #1 = 5 1/2 inches
Barrel Diameter... Dimension #2 = 1 1/2 inches
Barrel Length... Dimension #3 = 3 5/8 inches
Dimension #4 = 1 1/8 inches
Dimension #5A = 2 9/16 inches
Series... GM 3R
Spline count... 27
NON Vented plug


The one that I would say is stock has a 6 3/4 inch end to universal center, and the other two have 5 1/2 inch dimension. This is 5/8 inches longer than the 2-3-4911X, but 1 1/4 inches shorter than the "stock" length. Both of them take the larger 1 1/8 inch (s44) size) caps, vs. the 1.064 1310 joint.

You can also get a pinion yoke that takes the 1350 universal.
3-4-8681-1, and MW 39003 for a chrome moly unit.
 

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Does nobody grasp the fact that a 1310/1350 combo joint is very weak compared to a straight 1330 or 1350 joint? The whole purpose of the 1330 and the 1350 is to make it larger and stronger so how is mixing a 1310 which is small and weak with a 1350 which is large and strong ever going to be a good idea? There will be serious issues with that joint snapping if it is used on any vehicle that gets abused and beat on. Am I the only one to realize this or am I just overthinking this?


Mike--94MSP9C1

I honestly would only consider this mod a factory replacement for a car that requires an extended driveshaft. The shaft itself will be stronger than a stock shaft, but it is only ever as strong as the weakest link (U joint). If you were planning on doing a shaft for a high power/built engine/forced induction car, personally I'd just have an aluminum shaft built with 1350 joints and use a 1350 pinion yoke. The Vic shaft is a great/cheap way to address the extended shaft needed for extended control arms on a stock/bolt ons car though. I don't think you'll see many guys popping U joints with bolt on cars on drag radial launches. Making some steam and on slicks though, would probably be a good idea to upgrade.
 

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I honestly would only consider this mod a factory replacement for a car that requires an extended driveshaft. The shaft itself will be stronger than a stock shaft, but it is only ever as strong as the weakest link (U joint). If you were planning on doing a shaft for a high power/built engine/forced induction car, personally I'd just have an aluminum shaft built with 1350 joints and use a 1350 pinion yoke. The Vic shaft is a great/cheap way to address the extended shaft needed for extended control arms on a stock/bolt ons car though. I don't think you'll see many guys popping U joints with bolt on cars on drag radial launches. Making some steam and on slicks though, would probably be a good idea to upgrade.

Not even so much as hard launches as it is the fact that the cars are so heavy and the torque alone can break a 1310. That is just such a weak size u-joint for such a heavy car. Why do you think GM did the larger joint on this car when it was stock?


Mike--94MSP9C1
 

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Mike, I guess I haven't re-read everything enough times to sink in, but 'splain me how the MMC mod weakens anything compared to stock. Without memorizing the part nos. I only remember getting the necessary adapter joints commonly called out by everyone else who did the mod. If one side fits the stock yoke and pinion, and the other fits the "larger" FoMoCo DS, then it would seem no weaker than starting out. So, how does this mod (or even -Coot's yoke) weaken the car from stock?



Unless you're saying the MMC shaft is the part using the "smaller" 1310 joint????? ::confused mojii::
 

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Mike, I guess I haven't re-read everything enough times to sink in, but 'splain me how the MMC mod weakens anything compared to stock. Without memorizing the part nos. I only remember getting the necessary adapter joints commonly called out by everyone else who did the mod. If one side fits the stock yoke and pinion, and the other fits the "larger" FoMoCo DS, then it would seem no weaker than starting out. So, how does this mod (or even -Coot's yoke) weaken the car from stock?



Unless you're saying the MMC shaft is the part using the "smaller" 1310 joint????? ::confused mojii::

What I am saying has NOTHING to do with the driveshaft mod. It is pointing out the fact that you are using a smaller diameter U-Joint when you use a 1310 and these vehicles are too heavy to use a joint that small. The quality of the mod or the MMC Shaft has no bearing on what I am unsuccessfully trying to point out is an inferior size u-joint. Old coot is using a smaller yoke which requires a smaller U-joint which in my opinion is too small for such a heavy vehicle. I guess I just need to keep my mouth shut again and step out! I really suck at trying to make such a simple point!


Mike--94MSP9C1
 

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What I am saying has NOTHING to do with the driveshaft mod. It is pointing out the fact that you are using a smaller diameter U-Joint when you use a 1310 and these vehicles are too heavy to use a joint that small. The quality of the mod or the MMC Shaft has no bearing on what I am unsuccessfully trying to point out is an inferior size u-joint. Old coot is using a smaller yoke which requires a smaller U-joint which in my opinion is too small for such a heavy vehicle. I guess I just need to keep my mouth shut again and step out! I really suck at trying to make such a simple point!


Mike--94MSP9C1
I got your point, and looked up a couple of other yokes that take at least the stock B body U joints.
 

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To try to simplify the issue:
Chevy stock ujoint cap 1.125 inch
Ford stock BEFORE 2006 1.062 inch
Ford stock After 2006 1.125 inch
So the newer ford shaft seems to have about the same ujoint as the Chevy.

From memory ford less HP and torque and a little lighter.


I grabbed the specs from moog parts off the net.


I have never found information on this forum about ujoints or driveshaft problems for the aluminum vic on a stock LT1 b-body.
 

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Chevy 1994

4449 Lb
260 Hp
330 Ft/Lbs
3.08 dif



Ford 2011 Police

4057 Lb
250 Hp
297 Ft/Lbs
3.55 dif


Ford develops it's Hp and torque at much higher RPM than the Lt1.


The ford shafts with the smaller ujoints handled 210-230 Hp and lower torque(270Ft/Lb?).
 

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So, just use the yokes that take the larger GM universal that are listed above. The NEAPCO N3R-3-6081X, or the AAM 7812557 both give you the GM universal size, and you can mate them up with the Ford drive shaft with 2 Moog 447s, one on each end of the drive shaft. That makes it really simple, and stronger.
 
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