I have a 2003F150 with a 8.8 rearend that Ford "fills for life" with a 75W140 gear oil. Those 8.8's in the past used a 75W90 gear oil & I was curious if you could switch to a Schaeffer's 267 or Amsoil series 2000. I've heard of guys doing this & improving their fuel mileage 1-2mpg. I think Ford put a 75W-140 synthetic in there to help get vehicles through the warranty period. Maybe Ford has changed the rearends internals but does anyone know?
Can you change your Ford rearend fluid viscosity?
- Thread starter BruceB
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Bruce, My '97 F-150 came filled with syn. 75w-140. I changed it to Amsoil Series 2000 75w-140 a couple of years ago. If you have a limited slip dif, be sure to add Ford's friction modifier as well. I know Amsoil claims you don't have to with the Series 2000 gear lube, but my dif was " hanging up" slightly on slow corners. The $3 additive cured that little problem.
MolaKule
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FYI:
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=16;t=000319
I wouldn't change GL viscosity; stay with the 75W140 synthetic. If you don't haul loads or pull anything over 500 pounds, you may not need to change the diffy fluid for 60,000 to 90, 000 miles. The Ford synthetic GL is impressive.
The 75W140 is there because of the needed film strength at high temps and high torques.
[ May 13, 2003, 01:58 PM: Message edited by: MolaKule ]
http://theoildrop.server101.com/ubb/ultimatebb.php?ubb=get_topic;f=16;t=000319
I wouldn't change GL viscosity; stay with the 75W140 synthetic. If you don't haul loads or pull anything over 500 pounds, you may not need to change the diffy fluid for 60,000 to 90, 000 miles. The Ford synthetic GL is impressive.
The 75W140 is there because of the needed film strength at high temps and high torques.
[ May 13, 2003, 01:58 PM: Message edited by: MolaKule ]
Most of the later model 8.8 truck rear ends have been filled with 75W-140 synthetic.
On my 2003 E-250, it came from the factory with SAE 90 and I changed it at 500 miles to Redline 80W-140. The 80W-140 will provide better low temp flow but also provide better high temp protection not to mention possibly augmenting lockup performance from the thicker oil. I don't see how using a thicker oil would HURT the Dana 60!
On my 2003 E-250, it came from the factory with SAE 90 and I changed it at 500 miles to Redline 80W-140. The 80W-140 will provide better low temp flow but also provide better high temp protection not to mention possibly augmenting lockup performance from the thicker oil. I don't see how using a thicker oil would HURT the Dana 60!
I have never noticed an increase in gas mileage using syn oils. I have used syn oils in every possible place a syn oil can be put in on my cars and p/u trucks .
Hello ,
I myself have a Ford 2000 E250 Conversion Van . The rear end on this has 373 gears and uses 80W90 non synthetic according to the owners guide manual .. I pulled the cover off and am now draining , I am going to go with the 75W90 synthetic Castrol as that is what autozone sells for about $4.50... Mobil 1 is $8.50 a quart , Can it be that much better ... Larry B.
I myself have a Ford 2000 E250 Conversion Van . The rear end on this has 373 gears and uses 80W90 non synthetic according to the owners guide manual .. I pulled the cover off and am now draining , I am going to go with the 75W90 synthetic Castrol as that is what autozone sells for about $4.50... Mobil 1 is $8.50 a quart , Can it be that much better ... Larry B.
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