Front & rear differential fluids

[Fifty150]

Ford Dealership will provide labor at market rate. Ford Warranty will apply to labor for 1 year/12,000 miles.

Now the big decision is whether to go with Royal Purple or Lucas Oil.




1997 Mercury Mountaineer

Transmission:Automatic
Fuel:Gasoline
Cylinders:8
Drivetrain:AWD
Driving Condition:Severe

• transmission - Automatic 4R70W (2WD and AWD) | 13.2L (13.9 qts) | manual calls for Motorcraft MERCON ATF, Ford part # XT-2-QDX, Ford Specification Mercon.
• [DC] RP MaxATF (part #01320)
• tranfer case - Borg Warner AWD transfer case | 1.25L (2.64 pts) | manual calls for Motorcraft MERCON ATF, Ford part # XT-2-QDX, Ford Specification Mercon.
• [DC] RP Synchromax (part # 01512) 1st Choice, alternative - RP MaxATF (part#01320)
• front differential - Dana 35 front axle | 1.7L (3.5 pts) | manual calls for 4X4 Gear Oil, Ford part # FITZ-19580-A, Ford Specification WSL-M2C191-A.
• [DC] RP MaxGear 75W90 (part #01300)
• rear differential - Ford Traction Lok 8.8 | 2.6L (5.5 pts) | manual calls for Motorcraft 75W140 Premium Synthetic Rear Axle Lubricant, Ford part # XY-80W90-QL, Ford Specification WSP-M2C197-A.
• [DC] RP MaxGear 75W140 (part #01301)

Royal Purple Inc
1 Royal Purple Lane
Porter, TX 77365
281.354.8600
281.354.7600 fax


1997 Mercury Mountaineer

Transmission:Automatic

Fuel:Gasoline

Cylinders:8

Drivetrain:AWD

Driving Condition:Severe

• transmission - Automatic 4R70W (2WD and AWD) | 13.2L (13.9 qts) | manual calls for Motorcraft MERCON ATF, Ford part # XT-2-QDX, Ford Specification Mercon.
  
• 
  
• http://lucasoil.hodgsoncorp.com/catalog/product_info.php?cPath=32&products_id=101
  
• 
  
• 
  
• tranfer case - Borg Warner AWD transfer case | 1.25L (2.64 pts) | manual calls for Motorcraft MERCON ATF, Ford part # XT-2-QDX, Ford Specification Mercon.
  
• 
  
• Same as above
  
• 
  
• front differential - Dana 35 front axle | 1.7L (3.5 pts) | manual calls for 4X4 Gear Oil, Ford part # FITZ-19580-A, Ford Specification WSL-M2C191-A.
  
• 
  
• Find out the gear oil weight range, see below
  
• 
  
• http://lucasoil.hodgsoncorp.com/catalog/index.php?cPath=27
  
• 
  
• 
  
• rear differential - Ford Traction Lok 8.8 | 2.6L (5.5 pts) | manual calls for Motorcraft 75W140 Premium Synthetic Rear Axle Lubricant, Ford part # XY-80W90-QL, Ford Specification WSP-M2C197-A.
  
• 
  
• http://lucasoil.hodgsoncorp.com/catalog/product_info.php?cPath=27&products_id=261

Enquiry from Hodgson Corporation - Lucas Oil Store

 

[Harb]

hey guys, just changing my axle seals in the rear of my 97 explorer and have everything apart. What type and viscosity of oil would you recommend for refilling the rear diff. I drive mostly city and highway. We have hot summers (90's) and it can get very cold in the winters (-40).

also not sure if I have a limited slip. the tag on the axle says: 15 S614B on the top and 73 88 7D03 on the bottom.

Thx for the help

 

[Fifty150]

I used Lucas Oil 75W140.

Refer to my post above for all the fluid specs.

 

[moexplorer97]

If "rear axle fluid" is the same as "differential lube" then Ford needs to decide on whether or not it needs changing. Why do I bring this up? Because after looking in my owners manual, both paper and online, it says;

"The rear axle is filled with synthetic lubricant and will not require a lubricant change during the life of the vehicle unless the rear axle has been submerged in water. In addition, rear axle lubricant quatities need not be checked or changed unless a leak is suspected or a repair is needed."

However, when I go here, www.genuineservice.com , and look up my Ex on the site, it says that at 100k miles, I am to replace "rear axle lubricant".



Regardless, I'm going to change it, I just thought I'd point out the conflict.


P.S. Goes right along with my exhaust guy telling me that the stock catalytic converter was meant to last the entire life of the vehicle, even if said vehicle has 230,000 miles.

 

[GRNMACHINE]

This may be a stupid question but: I thought Motorcraft Premium Rear Axle Lubricant Ford Part No: XY-80W90-QL meant weight 80W90?? Also if it is supposedly Synthetic why does Ford recommend the LS additive?

I recently purchased Mobil 1 75W90 Synthetic and wondering if I need to get different weight???

 

[Tcfootball]

My truck is getting high on miles and Im not sure if this will help or hinder lifespan. I have a few quarts of this stuff laying around. Just seeing if this could save me from buying the 75-140 synthetic. Has anyone used or maybe raise a red flag against using Mobil shc 634 synthetic gear oil? From my understanding it is has a viscosity of 140. Any help? Thanks, Mike

 

[Tcfootball]

Any help?

 

[GRNMACHINE]

Any help?

Sorry I cant answer that one. I believe I am going to switch to Mobil 1 75W-90 synthetic and throw in some Ford LSD additive as well. Only problem with the Mobil Gear Oil is the stuff has an odor that is horrendous.

 

[GRNMACHINE]

I was able to find Royal Purple locally. Replaced the rear diff with it 75-140, also threw in the Ford Friction Modifier since I had already bought it. Also replaced the rear diff cover with a Mr Concepts cover which holds more oil, has a Drain Plug!, and Made in USA. Also looks great. Gave up on doing the front diff, spilled too much diff/trans oil on myself and the garage floor while replacing fluids on Pathfinder (pls no flaming..) Front Diff is also leaking a little and really do not want to drop the "pig" this year. Just finished ball joints and front hub assm. May go to Jippy Lube to have the front suctioned and replaced/refilled to get thru the winter. They dont carry 75w-90 synthetic they say, I am ASSuming 75w-140 synthetic would not be a good idea for the front?

 

[GRNMACHINE]

Ran out of time & patience to do the front, Jiffy Lube did have synthetic 75W-90 afterall. Total Cost $60.85 with tax. I can return 2 bottles of unopened Mobil 1 75W-90 & worthless hand pump at autozone for a total of about $32 as well. No noxious fumes, no spillage, and Done. Thanks to all for all the info on rear diff, transfer case, etc. Lots of money saved in comparison to dealer prices.

 

[GRNMACHINE]

Another question, beat a dead horse here. It appears the front diff leak is coming from where the diff connects to the front driveshaft. Anyone seen this before? It doesnt appear the diff gasket is leaking at all. Looks like the oil runs down to the bottom of the diff cover from the driveshaft. Havent done any searches yet but I am thinking it cant be good??

 

[GRNMACHINE]

Quick Search-pinion seal. Dont think I will be tackling that one.

 

[leon63]

I went with Mobil 1 synthetic --75w90 front and 75w140 rear with no additive. Rear is 3.73 limited-slip and there is no chattering/noise. I bought the oil at Schucks O-Reilly $9/qt for 75w90 and $17/qt for 75w140.

 

[DeadAWD]

Front and Rear Differential Oil change . . . & more

Hi Everybody!

OK, as usual, I did the research, talked to people, looked at the truck and all the manuals available (mine is a 1996 AWD 5.0literV8. I think it has 3.73 gears, Dana front diff and Limited Slip rear diff).

REAR DIFFERENTIAL: takes Full Synthetic 75W140 with friction modifier. There was a tag on the cover that reads "75W140FULLSYNTH". I first removed the drain plug to make sure that it wasn't stuck. I then removed the cover and perfect looking oil came pouring out (I do zero off road, my Explorer is strictly a street vehicle, and it has 142,000 miles). I wiped the inside of the cover out. Everything seemed to be covered in something that looked like a thin coating of moly lube. I bought an aftermarket gasket ($8, because I personally hate using silicone gasket stuff, I didn't want to have to wait to refill the diff, and because it would increase the capacity a tiny bit). I went to the local hardware store and bought a piece of clear tubing that fit on the bottle and also in the fill plug hole, cut it to a length so that I could raise the bottle over the drive shaft. I filled the diff with almost 3 quarts of Full Synthetic with friction modifier (2 quarts Redline and 1 quart Valvoline - because that is all the local parts store had). All put back together and back on the road I can't tell any difference than before I changed it. Only that I have more piece of mind.

FRONT DIFFERENTIAL: takes 80w90. It is preferable to use Full Synthetic, which usually comes in a 75W90. As long as the differential, front or rear, doesn't have any "slip" capabilities, or clutches, etc, then it doesn't need friction modifier. Though most new full synthetic gear oils DO have the friction modifiers. I obviously didn't want to remove the diff, since it requires dismantling the entire front half of the truck, so I opted for a suction machine to remove the oil. One local stealership wanted $150. Another local dealership charged me $45 and I provided the 2 quarts of Mobil 1 Full Synthetic 75W90. The diff takes 1.7 liters. They didn't give me any oil back. After the truck was done I asked the mechanic how he put the new gear oil in, and he said with a simple tube stuck on the bottle and he squeezes the bottle. I drove it home and noticed a whining sound. The only other thing I did was to rotate the tires. So it was one of those two things. At home I got under the Explorer and removed the fill plug. The front diff seems to be a little low, maybe 1/4 to 1/2 inch below the drain plug hole. I'll top it off soon.

Does anyone more mechanical than me, know if it would be bad to put in a little 75W140 in the front diff, other than possibly reducing the fuel consumption a teeny-tiny bit?

Thanks,
"Back from the Dead" Dave

P.S. Already ordered are 4 Monroe shocks (Sensa-trac load adjusting rears and Reflex fronts) and the dampener that goes between the rear diff and the frame, and one shock bellow (for that dampener on the rear diff.) They should be here in 4 or 5 days. I've got sagging rear springs, so I'm thinking about replacing them while I've got a little cash. I got a quote of $325 to remove the existing ones, re-arch them, add another leaf, and reinstall everything. I didn't think that was too bad. The only problem is that I don't want a firmer ride, id est- I don't want more leafs in there. I was thinking about removing the bottom most leaf as it is. I want a cushy ride. Right now, with 142,000 miles, the thing sways and bobbles like an amusement park ride. LMCtruck.com sells new 3/1 springs 2.5" side for $99 a piece. What do people recommend for new rear springs that are NOT hard or heavy duty off road things. Think Lincoln Town Car!

 

[my pos mounty]

I would buy the same oil that was used in the front diff already, and add to it.

The whine you mention, where does it seem to be coming from? Does the pitch change when cornering at all? Does it stop when you take your foot off the accelerator? Is it always present, but relative to speed?

As far as the leaf springs, since LMC has them for around 100 a side, why not get brand new ones instead of re-arching the bad ones? It would restore the ride of your truck back to the factory ride for a very good price. Ask that garage how much to just remove the leaf springs and replace them with the leaf springs you will provide.
You might want to look at the front/rear sway bar bushings and links if it is swaying in the breeze like that.

 

[GRNMACHINE]

Gettin seal done, sorry for double posting, but in a bind. Question I have is this: dealer claims he is putting in 75W140 Ford Synthetic in. I asked him if I could bring him Mobil 1 75W90 but he guarantees the 75W140 will be okay in front differential????

THANKS

 

[my pos mounty]

Gettin seal done, sorry for double posting, but in a bind. Question I have is this: dealer claims he is putting in 75W140 Ford Synthetic in. I asked him if I could bring him Mobil 1 75W90 but he guarantees the 75W140 will be okay in front differential????

THANKS

I thought that Ford issued a TSB saying that from now on it was their recommendation that the synthetic 75W150 was to be used in the front and rear differentials in the third gen trucks. (add friction modifier to the limited slip) I know you already have your answer in the other thread, just throwing this info out there. And, no that would not cause any issues. The synthetic is a better fluid anyway.

 

[Fifty150]

If there is a TSB, and you can find it as applicable, then go with the TSB. Talk to the tech. It's a dealership. They should have all the TSB information. If not, talk to the tech, and insist that you want the fluid weight recommended in the manual.

 

[GRNMACHINE]

Thanks for the responses & info mounty & fifty! Talked with the tech as well as the service manager. They both said that synthetic weight would be fine. Cost was $200 less 15% (still have the discount card from original purchase 15 years ago). Seems to be driving fine & no oil stains or dripping this morning. I am not sure about the TSB's for the 3rd gen's, didnt see the post in time before truck was ready. I am not as mechanically inclined as most people on this site, so I can honestly say I was very happy to get the work done by the dealer. Based on the time they started working on it and the time it was done, I would guess they worked on it for at least 4 hours. Thanks again guys.