My above post has the wrong link. Correction: http://www.mobil.com/USA-English/Lubes/P...-90_80W-140.asp
owners manual states rear diff lubed 4 life
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Originally Posted By: INDYMAC
Unless Ford clarifies for you that the differential is warranteed for life, than get that garbage out of there.
Exactly! The whole idea of lubricated for life is for people who throw cars away at 100,000 miles. Put a good syn oil that meets the correct specs in and run it another 80k.
Unless Ford clarifies for you that the differential is warranteed for life, than get that garbage out of there.
Exactly! The whole idea of lubricated for life is for people who throw cars away at 100,000 miles. Put a good syn oil that meets the correct specs in and run it another 80k.
Originally Posted By: artificialist
I have worked on plenty of rear axles that were factory filled "for life" with 75w90 or 75w140 synthetic. That didn't stop the bearings from wearing out and scarring the shafts.
That is why I always check out gear oil for RWD and and 4WD vehicles, and recommend replacement every 50,000 miles.
That is my regimen. Every 50k is cheap insurance. You can easily go 80-100k but my trucks get severe service so its a drop in the bucket compared to an AWD diff, tcase or front diff rebuild.
I have worked on plenty of rear axles that were factory filled "for life" with 75w90 or 75w140 synthetic. That didn't stop the bearings from wearing out and scarring the shafts.
That is why I always check out gear oil for RWD and and 4WD vehicles, and recommend replacement every 50,000 miles.
That is my regimen. Every 50k is cheap insurance. You can easily go 80-100k but my trucks get severe service so its a drop in the bucket compared to an AWD diff, tcase or front diff rebuild.
I've got the fully synthetic Valvoline 75w90 for it ready and waiting.
I did make one mistake, I forgot the tube of limited slip friction modifier. Should I take the Valvoline back and get the kind with friction modifier in it?
I did make one mistake, I forgot the tube of limited slip friction modifier. Should I take the Valvoline back and get the kind with friction modifier in it?
Keep the Valvoline and just go to your local Ford or Mercury dealer and get the correct additive from them. Does the Valvoline say it has the limited slip additive in it already? Maybe you local autoparts store carries an equivalent additive, though it might be better to stick with Ford's additive
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Whimsey
Whimsey
It may have the additive.
Tell me what you think.
http://www.valvoline.com/pages/products/product_detail.asp?product=58
Tell me what you think.
http://www.valvoline.com/pages/products/product_detail.asp?product=58
That will work fine. It's the same fluid I put in the wife's Explorer limited slip and I never used an additive. No chatters or groans of any kind.
Originally Posted By: SubLGT
I think "lubricated for life" actually means "lubricated for life of the warranty"!
Bingo, we have a winner!
The same thing applies to any fluid in any car which is labelled "...for life". It's nothing more than a marketing trick.
I think "lubricated for life" actually means "lubricated for life of the warranty"!
Bingo, we have a winner!
The same thing applies to any fluid in any car which is labelled "...for life". It's nothing more than a marketing trick.
Oh yeah, BMW is into that "lifetime" fluid [censored] and it usually produces disasterous results.
I emailed Jim Blanton, a noted European drivetrain rebuilder about this and he recalled that under BMW's old regimen of 30k oil changes, the boxes he rebuilt usually had mileage exceeding 250k.
With the advent of lifetime fluids he started seeing under 100k mile boxes and diffs that needed total rebuilds, and many times all that survived were the case pieces - the innards were too worn to use in the rebuild.
And I'm talking about manual transmissions here - the slushboxes with the lifetime fluids are really a joke as far as durability is concerned.
Bottom line - service the driveline with good quality, owners manual recommended fluids and enjoy your truck for many miles. Cheers!
I emailed Jim Blanton, a noted European drivetrain rebuilder about this and he recalled that under BMW's old regimen of 30k oil changes, the boxes he rebuilt usually had mileage exceeding 250k.
With the advent of lifetime fluids he started seeing under 100k mile boxes and diffs that needed total rebuilds, and many times all that survived were the case pieces - the innards were too worn to use in the rebuild.
And I'm talking about manual transmissions here - the slushboxes with the lifetime fluids are really a joke as far as durability is concerned.
Bottom line - service the driveline with good quality, owners manual recommended fluids and enjoy your truck for many miles. Cheers!
Doug has done the ideal thing with gearboxes- drain out the unit somewhere very early in life at 3-5k miles, perhaps, and then add a top quality synthetic of the rec spec. This should give you a very long life unit (if not subsequently abused or recieved defective from OEM). This gets most of the break-in wear metals out early, before they have a chance to wear out the bearings and gears prematurely.
I bought Valvoline synpower gear oil because it specified that it was suitable for limited slip. That and the fact that is easy to find.
The service manual for mom's Jeep Grand Cherokee states to use an 80w140 gear oil in the open diff, or a 75w140 synthetic with Limited Slip additive in the "Trac lock" model. Since there was no way to tell the 2 types apart, I just stuck some limited slip 75w140 in there, and it works just fine.
The service manual for mom's Jeep Grand Cherokee states to use an 80w140 gear oil in the open diff, or a 75w140 synthetic with Limited Slip additive in the "Trac lock" model. Since there was no way to tell the 2 types apart, I just stuck some limited slip 75w140 in there, and it works just fine.
Originally Posted By: bmwtechguy
Doug has done the ideal thing with gearboxes- drain out the unit somewhere very early in life at 3-5k miles, perhaps, and then add a top quality synthetic of the rec spec. This should give you a very long life unit (if not subsequently abused or recieved defective from OEM). This gets most of the break-in wear metals out early, before they have a chance to wear out the bearings and gears prematurely.
Wish I would have known this 6 years and 82k miles ago! Makes perfect sense, but oh well.
Doug has done the ideal thing with gearboxes- drain out the unit somewhere very early in life at 3-5k miles, perhaps, and then add a top quality synthetic of the rec spec. This should give you a very long life unit (if not subsequently abused or recieved defective from OEM). This gets most of the break-in wear metals out early, before they have a chance to wear out the bearings and gears prematurely.
Wish I would have known this 6 years and 82k miles ago! Makes perfect sense, but oh well.
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