1998 2.5l 2WD, 145k miles, time for some service. One of the things I want to change out is the oil in the diff. Had it pumped and filled at 75k at a lube shop. This time I'm pulling the cover and cleaning it out.
Any opinions about the "FORD Rear Differential Lube Additive" that my owner's manual reccomends? Is this actually important or am I just throwing more money into the dealer's pocket?
I'll be draining and filling the 5 speed trans at the same time. Is Slick 50 worth the money or just another gimmick?
Curious,
CB
:+

 

> 1998 2.5l 2WD, 145k miles, time for some service. One of
>the things I want to change out is the oil in the diff. Had
>it pumped and filled at 75k at a lube shop. This time I'm
>pulling the cover and cleaning it out.
>Any opinions about the "FORD Rear Differential Lube
>Additive" that my owner's manual reccomends? Is this
>actually important or am I just throwing more money into the
>dealer's pocket?
>I'll be draining and filling the 5 speed trans at the same
>time. Is Slick 50 worth the money or just another gimmick?
>Curious,
>CB
>:+

I think it's a good idea to do. I think the additive you are talking about is for a posi rear, if you have it, it's required, if you don't don't put it in. NO NO NO slick 50.

 

Basic lube 101;
additive are typically "friction modifiers" and are used for clutch or slip operations in a tranny or rear end unit, like the posi trac as previously stated.They will wear out over time as well.
Most important is to clean off the magnetic patch on the cover when disassembled, this will give you an idea of wear particles generated by your operation. when changing products you must ascertain the properties you want. If you have temperature extremes in either direction, a synthetics properties can be used.
Careful research from trusted sources can make available the wear particle inhibition of specific products.
As for additives, the first recommendation is to follow the OEM specs, the reputable oil manufactureers make their products to the specs requested by the vehicle manufacturer. Additive makers do not typically give the technical info about products, even simple stuff like viscosity, or ASTM test results.
Stick to the five R's of lubrication, right temperature, right time, right frequency, right viscosity and right amount; typically any lubrication failure is a result of missing one of these marks. If you can can follow this discipline you will have a great understanding of lubrication and more importantly will not have to tidy up any failures as a result of lube deficiency.

 

I used to put Slick 50 in my engine and the last time I put it in my 94 Ranger differential. I did some research on the internet and couldn't find one positive remark about these Teflon products. However, there is a wealth of positive data on synthetic oils and gear lubes. I always used Castrol GTX and now I put in two or three quarts of it and then two or three of the Castrol full sythetic to create a blend. Even two or three quarts of synthetic along with regular oil will drasticly reduce engine wear. However, might switch to Castrol's new high milage oil instead of the GTX and then add the synthetic to this. Any thoughts on this new high milage oil or blending synthetics with normal oil? On the differential...Mine is due for another change (I change mine every 100,000 miles and I just hit 200,000) and I plan to use a full synthetic gear lube and get rid of that Slick 50 crap. It's a pretty easy job. clean up the different with a hose and towel first to remove the dirt. Loosen the bolts around the diff. cover and allow the old lube to drain out, then remove the cover completely. I used clean towels to clean the inside of the diff. out and then cleaned the metal shavings off the filler plug. Then i used RTV copper silicone to put it all back together. Anybody have any ideas on something I can spray into the differential to clean off the gears, and is RTV OK for a gasket maker? Didn't leak last time.