Ford specifications on front and rear lube

Status
Not open for further replies.
Joined
Oct 10, 2017
Messages
725
Location
Northeastern Vermont
Hi folks. On my 2010 mountaineer 4.0 AWD ford spec the rear diff 75w140 Synthetic and for the front 75w90 conventional. Gear ratio is 3.55 open front and rear. What is your opinion on why ford would spec two different weight lubes. Thank you.
 
My only guess would be a class 3/4 tow package. No other reasons come to mind why a heavy lube like that would be needed in a grocery hauler.
 
Originally Posted By: MolaKule
Replacement fluids could be:

Rear Amsoil SVG 75W140

https://www.amsoil.com/lit/databulletins/g2043.pdf


Front Amsoil SVG 75W90

https://www.amsoil.com/lit/databulletins/g2042.pdf
Yes; and if I may suggest 75W-110 for the front axle
smile.gif
 
Sport Trac rear differential?
Take a peek at the rear axle. The Sport Trac (Limited Slip?)
will have a tag on it stating Syn 75w140.
Some have a 1/2" drive fill/drain plug vs 3/8" and no drain.
If it's a Sport Trac diff, change the fluid.
I'd bet it's black in color.
 
Originally Posted By: littleant
Hi folks. On my 2010 mountaineer 4.0 AWD ford spec the rear diff 75w140 Synthetic and for the front 75w90 conventional. Gear ratio is 3.55 open front and rear. What is your opinion on why ford would spec two different weight lubes. Thank you.


Are you certain other models require the same fluid for front and rear? Maybe this is normal.
 
I believe ford has this split spec for the front and rear diff on most SUV AWD. Dyusik yes it does have tow package with the small receiver hitch (1 1/4 or 1 1/2
 
Originally Posted By: littleant
Hi folks. On my 2010 mountaineer 4.0 AWD ford spec the rear diff 75w140 Synthetic and for the front 75w90 conventional. Gear ratio is 3.55 open front and rear. What is your opinion on why ford would spec two different weight lubes. Thank you.

Rear axle typically carries higher load than front axle.
Ford engineer specifies 75W140 for rear axle stronger wear protection ....... and had his way ...
over fellow finance guy albeit at the 'expense' of CAFE credit, where applicable.
 
It’s such a small quantity and you don’t change very often, so just get what they recommend. It’s been too many years since I worked with Ford AWDs, but there may be a couple reasons for the lighter weight. If the system is on-demand or significantly rear-biased, the front axle will not produce as much heat. If it is demand-based, likely the only time it will truly be working all the time is in the snow, and the temps are cold enough the lower weight won’t impede fluid life. The rear axle may be doing the brunt of the work all the time, including high temp summers. That’s my take. It’s much easier when your AWD is 50/50 all the time, rain sleet or snow. Both my AWD transaxle and rear axle take 75w90. Easy peasy!
 
Also be aware there is nothing like a 75w90 conventional. Don't lose sleep and use synthetic.
 
Status
Not open for further replies.
Back
Top