Transmission tailshaft housing question

[Chayton]

Okay guys...getting very close to putting this darn thing back together. Here is my dilemma: I need to replace the transmission. I have a 4r70w out of a 2002 Crown Victoria sport. However I noticed the tail shaft housing lengths are slightly different. Can I simply swap housings and be good to go? I sure hope so!

[crownvic05]

Yes, swap tail housing.

[RF Overlord]

I think there will be an issue, but PM 88grandmarq first. He's the expert.

[Comin' in Hot]

No.... the answer is no. I probably have more experience with this issue than anyone here. Which transmission has the shorter tail housing? The one you’re going to install or the one you’re taking out?

[Chayton]

No.... the answer is no. I probably have more experience with this issue than anyone here. Which transmission has the shorter tail housing? The one you’re going to install or the one you’re taking out?

Well ****. I did some more research online and apparently I should be able to???? The transmission I’m installing has the shorter tailshaft housing.

[crownvic05]

Crown vic sport has the short tailshaft housing. Either use one from a p71 or the marauder

[Comin' in Hot]

The Crown Vic guys will tell you this is OK. But let’s face it, they do things you should never do to your vehicle.

The Issue : The driveshaft is too short, causing improper spline contact. You could install the longer tail housing and use your current driveshaft, but the problem is your yoke has recessed splines. This means there is 1” less spline contact. When I bought one of my marauders it had the shorter output shaft and tail housing with a standard marauder driveshaft. The splines twisted the inside the yoke just enough that the yoke would not slide correctly, but not enough to see easily.

Solution #1: Get a driveshaft that is the correct length. Marauder length +1 inch.

Solution #2: Get a 1” spacer mounted between the pinion flange and the driveshaft flange.

[Comin' in Hot]

There’s also a third solution, which involves tearing apart the transmission and changing the output shaft to the longer one, but it’s not at all practical.

[Comin' in Hot]

When I say the Crown Vic guys, I’m referring to the guys that take a car with a steel driveshaft and put in a P 71 aluminum driveshaft that is 1” shorter. They are the guys that tend to change the tail housing and think it’s OK without changing their output shaft. I’ve had this argument with them and gave up. They think there’s nothing wrong because once it’s installed it looks like it’s right, but none of them think about the spline contact. Or they don’t have enough horsepower to destroy the yoke/output shaft.... i’ve also heard of the tailhousing bushing failure with this mod but nobody understand seems why it happens lol.

[crownvic05]

I havent had an issue with my set up on my 05 sport. 5 years running strong with 3.73, marauder drive shaft and extended tailshaft housing. Over 40k miles and ive pushed it hard on occassions. Just speaking from personal experience.

Comin' in hot does have a point though but omce again, i havent had no issues and i know lots of crown vic members with same set up with no issue either.

[crownvic05]

So now you have me wondering if my set up is right. I dont have the horse power to worry about it but its good to know

[Comin' in Hot]

So now you have me wondering if my set up is right. I dont have the horse power to worry about it but its good to know

Sorry. Lol.

[Chayton]

Well shoot sounds like I’m :censor:

[88grandmarq]

yep, the issue is the output shafts are different and the slip yokes are different to match the output shaft.

marauder, town car and CVPI use the long output shaft, which is not splined all the way up and has an o-ring to seal it. the slip yoke matches this and is smooth in the first half and splined at the end.

you can use the shorter output shaft with this slip yoke, but you end with only a 1/4" of spline contact because the inside of the slip yoke is not splined all the way.

[Chayton]

yep, the issue is the output shafts are different and the slip yokes are different to match the output shaft.

marauder, town car and CVPI use the long output shaft, which is not splined all the way up and has an o-ring to seal it. the slip yoke matches this and is smooth in the first half and splined at the end.

you can use the shorter output shaft with this slip yoke, but you end with only a 1/4" of spline contact because the inside of the slip yoke is not splined all the way.

So but if I use a 1” spacer I’ll be fine ?

[Comin' in Hot]

So but if I use a 1” spacer I’ll be fine ?

As far as I could tell it’s slightly over an inch difference. I had custom biliet spacer made, that I no longer need. Shoot me a PM if you were interested.

http://i22.photobucket.com/albums/b335/Witman40/5c44d574.jpg

[crownvic05]

As far as I could tell it’s slightly over an inch difference. I had custom biliet spacer made, that I no longer need. Shoot me a PM if you were interested.

http://i22.photobucket.com/albums/b335/Witman40/5c44d574.jpg


Can you please post a pic of the other end if you don't mind. This would be where it goes into the tailshaft.


If our friend don't buy it off of you, I might be interested.

[Comin' in Hot]

I don’t have a picture of the longer tailhousing with the shorter output shaft.... I would think it would look like nothing is wrong. You wouldn’t be able to tell until you removed the driveshaft. The output shaft wouldn’t be sticking out of the tailhousing at all.

[Zack]

Here's a thought:
Install the correct transmission.
The end

[crownvic05]

I don’t have a picture of the longer tailhousing with the shorter output shaft.... I would think it would look like nothing is wrong. You wouldn’t be able to tell until you removed the driveshaft. The output shaft wouldn’t be sticking out of the tailhousing at all.


pm me your price

[justbob]

Here's a thought:
Install the correct transmission.
The end



LOL Quote of the week.


Sent from my iPhone using Tapatalk

[Blown3.8]

Here is a short housing over a long shaft.

Just had to completely disassemble a built TBird trans to install the long marauder output shaft so we could get back on the road quick.:beer:

1st pic short housing over long shaft
2nd marauder equipment
3rd surgery table

[justgod]

https://adtr.net/kb/crown-vic-driveshaft-swap/

Used this on my Freddy Brown 4STBE trans:
https://adtr.net/product/ford-crown-victoria/fabtech-driveshaft-spacer/

[Chayton]

Here is a short housing over a long shaft.

Just had to completely disassemble a built TBird trans to install the long marauder output shaft so we could get back on the road quick.:beer:

1st pic short housing over long shaft
2nd marauder equipment
3rd surgery table

is there a reason you chose this route instead of going with a spacer?

[Chayton]

Here's a thought:
Install the correct transmission.
The end

But that would make too much sense....

[Blown3.8]

is there a reason you chose this route instead of going with a spacer?

Didn't know they made spacers for that. Mostly time constraints, its what I could do quick enough to get back on the road to race. And its worked all these years as is, the trans internals not so much.

I thought about using the longer GM driveshaft I have here, but wasn't sure if it would start wobbling at 140mph and break something else. And like said before the yoke splines don't go all the way to the end to use the MM shaft on the short housing.

Tear down and reassemble isn't that difficult. Just needed some help with some seals installed, cause I dont have the tools for that.

[Chayton]

Didn't know they made spacers for that. Mostly time constraints, its what I could do quick enough to get back on the road to race. And its worked all these years as is, the trans internals not so much.

I thought about using the longer GM driveshaft I have here, but wasn't sure if it would start wobbling at 140mph and break something else. And like said before the yoke splines don't go all the way to the end to use the MM shaft on the short housing.

Tear down and reassemble isn't that difficult. Just needed some help with some seals installed, cause I dont have the tools for that.

Gotcha. Thanks for sharing all this information, very helpful.

[Chayton]

Update: I went with the fabtech spacer route. 50 dollars later my car is up and running perfect; just as it did before. So in summary:

I saved $1000+

The car functions just as it did before, no issues whatsoever. In fact days after I drove it down to SoCal for the Panther Mafia tour (it was awesome)

I guess you can call me crazy! lol.


And best of all, now I’m forced to 5 speed swap my crown Vic Sport like I’ve been saying I want to!!! :D

[massacre]

Couldn’t you just remove the u joint and swap yokes? I swapped a wr70w slip onto my aode driveshaft.

[BUCKWHEAT]

Here's a thought:
Install the correct transmission.
The end

If the P71 shares the 'correct' transmission, get a used trans out of the salvage yards.
We have buckets of P71's in the yards around St Louis, and that should be true generally.

[massacre]

I must not be understanding, if you have the slip that matches the output shaft you can use any shaft in theory by choosing the proper u joint(s). Slip is not permanently attached to driveshaft.

[Chayton]

I must not be understanding, if you have the slip that matches the output shaft you can use any shaft in theory by choosing the proper u joint(s). Slip is not permanently attached to driveshaft.

Yes that is what I did. I swapped the slips and then used this product:

https://adtr.net/product/ford-crown-victoria/fabtech-driveshaft-spacer/

[Chayton]

If the P71 shares the 'correct' transmission, get a used trans out of the salvage yards.
We have buckets of P71's in the yards around St Louis, and that should be true generally.

while not a bad idea for worst case scenario, that would cost hundreds of dollars and involve removing another tranny that has an unknown history. I knew for a fact this trans shifted great and wasn't worn. All I had to do was buy a $50 spacer and change the slips, which was fine because I added fresh Moog u joints while I was in there.

[justgod]

The P71s have a shorter output shaft and shorter tailshaft housing than the Marauder 4R70(5)W.
If you use the stock length Marauder driveshaft on a P71 trans, there won't be much spline holding it all together.

[Chayton]

The P71s have a shorter output shaft and shorter tailshaft housing than the Marauder 4R70(5)W.
If you use the stock length Marauder driveshaft on a P71 trans, there won't be much spline holding it all together.


Not true




.

[MyBlackBeasts]

Not true.


4R70W transmissions come in long tail shaft versions like in the MM and short tail shaft versions like in the F150 and other vehicles.


If you replaced the trans with another 4R70W Long TS, why would you need the spacer?


Did you lift the car needing more DS length?


Is the DS you have shorter than OEM?


Please provide details.


TY!

[Chayton]

4R70W transmissions come in long tail shaft versions like in the MM and short tail shaft versions like in the F150 and other vehicles.


If you replaced the trans with another 4R70W Long TS, why would you need the spacer?


Did you lift the car needing more DS length?


Is the DS you have shorter than OEM?


Please provide details.


TY!

If you read through the previous postings you will see the reasoning for the spacer and that the issue has been resolved. I had to point out that his statement was untrue to avoid confusion for anyone who views this thread in the future.

Here is a great article with the technicalities that also shows why that was false/not true:

http://adtr.net/kb/crown-vic-driveshaft-swap/

[MyBlackBeasts]

Not true.


I read the original posts but that was nearly 2 months ago.


I thought I remembered you using a short shaft which is why you confused me when you replied "Not True".


I now realize you were referring to the "P71" in the post. He was incorrect as the P71 has a long shaft with aluminum DS, the CV Sport has the short shaft with a steel DS.


Thank you for clearing up my boggle.

[Chayton]

I read the original posts but that was nearly 2 months ago.


I thought I remembered you using a short shaft which is why you confused me when you replied "Not True".


I now realize you were referring to the "P71" in the post. He was incorrect as the P71 has a long shaft with aluminum DS, the CV Sport has the short shaft with a steel DS.


Thank you for clearing up my boggle.


Yes! No worries I just wanted to make sure there’s no confusion.

[massacre]

Yes that is what I did. I swapped the slips and then used this product:

https://adtr.net/product/ford-crown-victoria/fabtech-driveshaft-spacer/

Oh ok
Gotcha