Crown victoria trans & rear end synthetic change

[KJack]

hello everybody. i have a 1997 frod crown victoria. i want to do a complete flush of the transmission & rear end and replace with full synthetic fluids. the car has 90k miles on it.my questions are.

Are 90 k miles too many miles to do a trans flush and change to synthetic fluids? some auto mechanics have suggested that i stay with regular fluid. the tranny runs great and has had fluid changed every 40k

what would be a good fluid to go with. reline, amsoil, BG etc

also whats a good fluid for the rear end?

other notes. my drving style is pretty good. 70/30 highway and city. warm climate in texas. it has a 4.6 engine and sorry i dont kno what kind of trans is in it but it is the factory 4 speed.

 

[Falcon_LS]

Motorcraft Mercon V is an excellent fluid. I would just use that and add 2 bottles of LubeGard Red or Platinum if you're not going the synthetic route.

As for the rear end, again I would go with Motorcraft Premium Rear Axle Lubricant 80W-90, or if you want to go synthetic, Motorcraft 75W-140. Might want to add some MoS2 in the differential for added protection.

 

[SZR48207]

Crown Vic w/ V8 most likely has the 4R70W.

I did a writeup on performing a coolant line fluid exchange on this transmission. I used Castrol Mercon V and it has done well so far. Still a very bright red/pink with little sign of heat deterioration.

http://sites.google.com/site/fordf150p0171p0174fix/4r70w-fluid-change-procedures

 

[Falcon_LS]

Thanks for sharing your article!

On his '97, it should still have a torque converter drain plug.

 

[unDummy]

90k is not too many miles to do a flush. You'll need to start with a pan drop and filter change 1st. Do not use any solvents. After that pan drop/filter change, refill ATF and perform a cooler line flush. Any of the full synthetic boutique brands will work fine. Amsoil, Redline, BG, Mobil1, Wynns, RoyalPurple, Amalie, Eneos, ... are easy enough to locate.

For the rear-end, any synthetic 75w90, 75w110, or 75w140 can be used. Mobil1 should be easy to find locally.

 

[KJack]

thanks for all the advice and info

 

[ChuckBerry]

I bought a 99 crown vic CVPI in June, and since I did not know if the differential had ever been serviced I got the fluid changed with Valvoline 75w-90 full synthetic for the ever so slight fuel savings the small viscosity difference will make. If you never intend to do regular, heavy towing with your Crown Vic, the 75w-90 full synthetic or 80w-90 dino diff fluid will be ideal. But if you will be doing regular towing, especially at highway speeds, the 75w-140 would be a better choice.

 

[CROWNVIC4LIFE]

The stearlership changed my rear end at 100K miles and put in 75w90 synthetic Motorcraft...I generally due the trans fluid every 30k miles using Motorcraft Mercon V

 

[DreamerGT]

Originally Posted By: Reddy45
Crown Vic w/ V8 most likely has the 4R70W.

I did a writeup on performing a coolant line fluid exchange on this transmission. I used Castrol Mercon V and it has done well so far. Still a very bright red/pink with little sign of heat deterioration.

http://sites.google.com/site/fordf150p0171p0174fix/4r70w-fluid-change-procedures


good write up, I need to change the trans fluid in my vic.

 

[FL-400S]

I was looking for some pointers like this, thanks! I might add...I think you can get an aftermarket trans pan with drain plug and maybe added capacity. Next time you guys drop the pan it might be worthwhile to swap it out.

Looks like ford makes one too.

http://www.p71interceptor.com/tranny/uhaul/oilpan/pictures/

Not sure if the dipstick would still be accurate...

 

[RF Overlord]

Changing the pan won't affect the dipstick reading.

I have the so-called "U-Haul" pan on one of my Marauders. It is identical to the stock pan but with a drain plug added at the factory.