Rear end overhaul - fluid question

[riotwarrior]

For every day use, in an open differential, the regular 75/140 will be fine. If you are planning some good towing of weight and high loading on hills, I'd bump up to Synthetic.

Ford specs syn for a diff with posi that much I do know, but open I'm not sure one.

If it was mine and I had the new toy cover and was doing full rebuild, I'd be like full on syn for sure, just because it's superior lubrication over conventional lube. You may even pick a point or two in mileage. You will never worry about if its doing it's job or anything.

ONE TIP...

You mention new Scottseals. Thus the axles are being pulled. You can lightly pack bearings with grease...again syn preferable..and when you top your axle off go do some side hills to get your fluid out to the bearings and full the bearing cavities. Once you've got it worked in a bit side to side, check fluid top it off again and do some more side hilling. If fluid remains ok your golden if it's dropped when parked level you can add more.

I like driving side hills as opposed to jacking one wheel up then the other...it works the lube into the crevices better when traveling on side hills.

JM2CW

Al

 

[cpdenton]

Lots of great info and advice. It looks like I can get some castrol synthetic for about 10 bucks a quart. That isn't too far out from the regular fluid, so I think I am going to use that.

I do tow an 8000 pound camper with this truck fairly regularly. I think the added capacity and good gear oil will help keep heat in check. There isn't much else you can do to control heat in a rear end.

Any of you installed the scottseals before? Anything I need to know about using them?