Question about gear lubricant

I'm speechless. Sounds like going in circles. Most likely the friction plates are worn out anyway at 105K and it won't matter what you put in it. I'd just put the stuff you've got in without putting the additive in. If you hear funny noises, then put the additive in.

This kind of stuff makes my brain feel like it's made of cold oatmeal. I

*think* I've used 85W90 because I couldn't find 90W. I've only used the stuff with no friction modifier already added and just bought a bottle of modifer and added it myself. I just bought the brand they had at Pep Boys and never had any problems. I have a '91, '92, and '97 all with the same LS rear end and they all appear to be locking up properly with 230K miles, 280K miles and 160K miles respectively. I don't know about the friction plates that Ashton refered to because so far my differentials have not caused me problems.

For something more complete (and, quite probably, more accurate) you can refer to the American Petroleum Institutes (API) documents regarding gear lubes...

In the last couple of years, Ford re-spec'd their rear differential oil to

75W140 - do not get alarmed... this more for fuel mileage considerations than anything else (FWIW, front differentials on 4X4s are still spec'd at either 80W90 or premium front axle lube, depending).

Oddly, the Motorcraft catalogue online shows only 75W90 as a a gear oil... no other gear oils listed... really odd is that we have been unable to get Motorcraft branded 75W90 for a long time... FWIW, this oil is listed as a GL-4 gear oil...

While I am unfamiliar with your GL-5 oil, I don't foresee any concerns using it...

Now... the limited slip additive... this additive simply changes the co-efficient of friction as the friction surfaces approach "lock up" (and I use the term advisedly). Without the friction modifier, you will get a stick-slip-stick-slip action that results in the noise/shudder we associate with limited slip diff clutches "going bad" (another term I'm using advisedly). If you have the diff apart and especailly if you are installing new clutches, you will want to soak the fibers in friction modifier (skunk oil is a term I use often). As far as refill is concerned... if you are using Castrol oils (little known factoid... Castrol used to make engine oil from the oil of the castor bean - bean oil was a staple in Formula racing and carried into prototype racing, the old group 7 cars like the Chapparal and even trans Am racing before being replaced by more modern lubes - race tracks that had bean oil lubricated engines on the card had a distinctive and pleasant aroma). I would follow Castrols instructions... Why? you might ask.

If Castrol tells you to do stuff with their oil and you do it and something goes wrong... Castrol is on the hook (obviously, this is not their intent). If I tell you to use their oil in a certain way and something goes wrong... let's just say that my intention is to stay off that hook, too.

As for the efficacy of your rear diff clutch packs... you can use a torque wrench and the workshop manual procedure to measure the break-away torque of your clutch packs - no need for guessing. Disclaimer.. this method isn't found in current WSMs... Ford, in all their wisdom, now tells readers to put one rear wheel on dry pavement and the other on ice and see if the car moves (I can see where ice on the roads is going to be a unique commodity in say.... Miami...).

Thnaks everyone.

Based on everythign written here, I guess I'll use it and ad the additive too, since I have it. Doesn't seems like adding it unnecessairly will hurt anything.

I did find a very interesting discussion on gear oil designations here:

Here's the difference on GL-4 vs GL-5

"API Category GL-4 designates the type of service characteristic of spiral-bevel and hypoid gears in automotive axles operated under moderate speeds and loads. These oils may be used in selected manual transmission and transaxle applications. API Category GL-5 designates the type of service characteristic of gears, particularly hypoids in automotive axles under high-speed and/ or low-speed, high-torque conditions. Lubricants qualified under U.S. Military specification MIL-L-2105D (formerly MIL-L-2015C), MIL- PRF-2105E and SAE J2360 satisfy the requirements of the API GL-5 service designation"

I guess either would wok and both are meant for hypoid gears. If I eve take my Explroer about 60 mph I'm all set :O)

Tanks everyone as usual.

Regards,, Anthony Giorgianni

For every> For something more complete (and, quite probably, more accurate) you can

The Fords do not "lock up". All they have is a handful of friction plates, like the clutch pack in an automatic transmission, sandwiched between the side gears. They are designed to slip, not lock. When you go around a corner they slip. And as they slip they wear. They are marginally helpful in low traction situations but nowhere near as good as the Chevy TracLok rear end which does lock. I don't know why ford keeps using them, no serious off roader would waste their time with them but would swap them for some form of locker or true limited slip like the Torsen, etc. I'll have to assume Ford likes them because they are cheap to make and it's almost impossible to notice that they are basically worn out plus they don't make the "clunk" noise like the Chevy system. Same thought process that leads to using "gauges" that only have two needle positions - it keeps people from complaining under warranty.

The Torsen isn't as great as you think it is... good - yes... but everything is a trade off in this life.

The very first thing is to wake up, smell the coffee and notice that it is called a LIMITED slip.... It works quite well for normal circumstances... and, quite honestly, most any truck you buy is going to be built for "normal circumstances" . If you are looking for anything nthat will deal with "extraordinary" circumstances, you will pay extra...

And, in the end, "paying" is what it is all about....

I am sure I could offer you a truck that will NOT get stuck... it WILL last

750,000 MILES.... it WILL be EASY to repair.. IF you CAN afford it, you will NOT pay the price... Because that's the way people are...

"But only want much for a similar truck...". It ain't rocket science... a spool is out of the question... a locker would add considerably to the cost of each vehicle... adding one more option increases production costs....

In the grand scheme of things... if you are smart enough to realize you are stuck and avoid spinning one rear wheel for the sake of frustration.... if you do not spend all of your time making tight figure 8s in the Walmart parking lot, there is no reason that the limited slip differential cannot be of some small modicum of assistance in NORMAL conditions....

If you are in search of a mud bogger... build a mud bogger...

Ford Charges around $250 for their nearly useless limited slip. Chevy charges the same amount for an excellent locking rear end.

You pay the same, you don't get the same.

Wrong. Cost is the same.

Sure, it's of some help sometimes but get a rear wheel off, or nearly off, the ground and you are screwed. Do the same in the Chevy, for the same price, and you hear the "clunk" and the truck just pulls on thru. It's particularly helpful for trucks that were not set up for hard off roading and don't have great articulation, you can leave a wheel in the air and still get traction.

More a case of if you want the most for your rear end dollar get a Chevy.

I don't know how effective the Ford limited slip is. But some years ago, I was four-wheeling after a big snowstorm out in the woods. One of those small Jeeps was plain out stuck. All the power was going out one spinning wheel. My Explorer had no problem going through. I wasn't even using low range. I can't say for sure it was the limited slip that helped. But the other guy sure could have used it. I had no slipping at all, not off the rear anyway (Didn't pay attention to the front). And with low range, I had even more tricks available to me. In the 17 years I've had my 92 (mostly in Connecticut), I've never even gotten close to getting stuck. And I like driving in blizzards, when no one is out on the roads. Those Michelin LTX ATs (recommended by folks in this group) are really good for snow too!

I don't know if the limited slip still is working. I'm pretty gentle with the truck. Incidentally, I'm doing my winter prep now, painting the surface rust on the bottom with Rust-Oleum - and the inside of the bumpers. Next it's time to shampoo and Scotchguard the interior! - and I'm ready for the deep powder.

Regards, Anthony Giorgianni

"TonyG" wrote in message news: snipped-for-privacy@11g2000yqp.googlegroups.com... I don't know how effective the Ford limited slip is. But some years ago, I was four-wheeling after a big snowstorm out in the woods. One of those small Jeeps was plain out stuck. All the power was going out one spinning wheel. My Explorer had no problem going through. I wasn't even using low range. I can't say for sure it was the limited slip that helped. But the other guy sure could have used it. I had no slipping at all, not off the rear anyway (Didn't pay attention to the front). And with low range, I had even more tricks available to me. In the 17 years I've had my 92 (mostly in Connecticut), I've never even gotten close to getting stuck. And I like driving in blizzards, when no one is out on the roads. Those Michelin LTX ATs (recommended by folks in this group) are really good for snow too!

I don't know if the limited slip still is working. I'm pretty gentle with the truck. Incidentally, I'm doing my winter prep now, painting the surface rust on the bottom with Rust-Oleum - and the inside of the bumpers. Next it's time to shampoo and Scotchguard the interior! - and I'm ready for the deep powder.

Regards, Anthony Giorgianni

Judging from what I've read here and there Jeeps seem to be considered to be more capable off-road than the early Explorers. I don't know because I've never driven anything but an Explorer off-road but it *seems* like, as long as I have traction on three wheels, that it will go through most nasty conditions. Ashton's description of how the LS works sounds like it should not lock up the rear wheels but if, for example, I'm driving up a steep dirt hill and it can't quite make it the both rear wheels will spin and dig equal holes. Is this not the same as "locking up?" As for the front end it appears to me that it is an open differential and one wheel can still slip. So far I have not gotten into a situation in an Explorer that I could not get out of under it's own power except the time I was driving between two deep ruts and the ground collapsed under me and left me with four wheels off the ground. But I doubt if any similar vehicle could have done better under the circumstances. If there is something better I would sure like to know what it is so I can buy one. I have an old Mitsubishi Mighty Max ('88) with manual trans and transfer case and it does not seem to be as capable as my Explorers but it also does not have nearly as much power and I have not really tested the rear end to make sure it's "locking up" or "not slipping" or whatever it's called. One thing I really, really like about the Mighty Max is the manual shift lever for 4WD. I hate the servo motor on the Fords.

On Oct 13, 12:27 am, Ashton Crusher wrote:

Get on a dirt road, driveway (not a friends, however) and lightly spin the wheels. That should answer teh question. My (non-Ford) big truck will chirp the tires on the white lines marking pedistrian walkways at intersections if I give any gas to speak of when turning. Very noticable.

Come up to NH, we'll give you snow and mud! Free, too.

>

Emailing:

ck this out this will take cars of all your questions plus never never use GL1 oil ,this is for old trucks and tractors

Based on everythign written here, I guess I'll use it and ad the additive too, since I have it. Doesn't seems like adding it unnecessairly will hurt anything.

I did find a very interesting discussion on gear oil designations here:

Here's the difference on GL-4 vs GL-5

"API Category GL-4 designates the type of service characteristic of spiral-bevel and hypoid gears in automotive axles operated under moderate speeds and loads. These oils may be used in selected manual transmission and transaxle applications. API Category GL-5 designates the type of service characteristic of gears, particularly hypoids in automotive axles under high-speed and/ or low-speed, high-torque conditions. Lubricants qualified under U.S. Military specification MIL-L-2105D (formerly MIL-L-2015C), MIL- PRF-2105E and SAE J2360 satisfy the requirements of the API GL-5 service designation"

I guess either would wok and both are meant for hypoid gears. If I eve take my Explroer about 60 mph I'm all set :O)

Tanks everyone as usual.

Regards,, Anthony Giorgianni

For every> For something more complete (and, quite probably, more accurate) you can