Do I need a new rear end?

[lsb532004]

Ok People.
I have a 2004 Grand Marquis-Black. Will post pix soon.
I have added a K&N air filter, PI zip tube and dual exahust.
I imagaine HP is up near 250HP from stock 224HP.
Have 30k miles on car. Tires are in great shape-Michilens.
When it is wet out, right rear wheel spins more now then b4 mods.
What should I do? New tires? Which ones? Different rear end? When it is wet out I do not get on it off the line. What is it going to be like when it snows?
What do ya'all suggest?
Lsb532004@sbcglobal.net
Thanks
Len B

[RoyLPita]

Len,
Your Grand Marquis does not have a limited slip axle. I would recommend one. Some of our members here have upgraded the rear ends on their MMs and may have one available. BTW, You could change the gears to either 3.27, 3.55, 3.73 or 4.10. Check the classifieds.

Just so you know, you would need a tune to compensate for the speedometer.

[Dennis Reinhart]

Ok People.
I have a 2004 Grand Marquis-Black. Will post pix soon.
I have added a K&N air filter, PI zip tube and dual exahust.
I imagaine HP is up near 250HP from stock 224HP.
Have 30k miles on car. Tires are in great shape-Michilens.
When it is wet out, right rear wheel spins more now then b4 mods.
What should I do? New tires? Which ones? Different rear end? When it is wet out I do not get on it off the line. What is it going to be like when it snows?
What do ya'all suggest?
Lsb532004@sbcglobal.net
Thanks
Len B


We now sell a complete 31 spline kit, I use the Ford heavy duty truck Posi this is a good carrier its easly rebuilt if it ever needs to be and it comes with the new Ford 31 spline axials

[djbruce26]

Sounds to me like you need a limited slip differential. DR (post above) does sell them at his site. There are other places to purchase them too if you wish... but I would suggest you talk to places about the install of this before you make a decision to buy anything. After making the decision on whether you could install it, versus having a shop install it, you would be able to make that decision.

Yes, tires are an alternative to fixing the tire spin. More grippy tires will prevent this from happening... but if you do lose traction (as you have experienced lately) you will still have a problem moving because you are only having one wheel try to power the car. A limited slip differential will use both rear wheels to power the car and therefore can make better use of your current tires or better ones.