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Hey guys I need some advice on the fluid in my rear differential. It is a 1973 f100 4x4 with a 3600 traction lok. I removed the fill plug and could not feel the level
Can I add some of the valvoline 80/90 gear oil with friction modifier already mixed in to what is in there now which I believe is the original oil
The truck has been in family since new and has only 66000 miles
Thanks
Ok I will add some and see what happens
If I decide to change it do you think I will be able to pump it out? Then what fluid would you recommend putting back
Thanks again
Buy a new gasket and pull your 3rd member to drain, best way, clean out the diff, clean the mating surface, torque nuts down and fill, the old diffs do not take additives, pick your poison of 80-90/120 and fill.
To be able to 100% drain, clean out and insp it out, yes you need to pull the 3rd member...but that is AFTER you pull the axles. 9" rear ends are like that. And you really need to replace the outer ring row of copper crush washers.
Drive it and get it warm and then try to pump it out. If it is 80/90 now you are going to need as large a hose that will fit the fill hole and a great vac system.
Pulling the third member to replace the gasket is a bigger project. As mentioned, gotta pull the axels. While I was there, decided to replace the axel bearings and seals. Had to cut the collars off and find a shop to press on the new collars on. If you can pump out the old fluid, you’d be better off. These projects have a way of snowballing out of control. Ask me how I know.
Yea buddy I hear what ya saying. At my age I have definitely been down a couple of those roads over the years.
I am going to pump it out, if at all possible. What is the biggest diameter hose you think I can use?
Thanks
Sorry I guess 3/8 or 1/2" to get started and get the big amount and the chunks out. Then step down to a 1/4 to give it some real clean out power. You can always make a clean out tank. U tube has all sorts of free ideas. I think this one came from a fellow FTE member.
No worries that is why we are all here to help each other out, and make fun of chebby guys. Once you get the big stuff pumped out, put a little clean back in and then get down deep with a smaller tip hose. You want to get as much sludge/gunk out the bottom. This turned into.....playing u boat commander in the deep drop off ahead.
This, and....
This. Followed by....
Draining the milk shake....
I almost has serial numbers on the chunks/gunk in the bottom. You do NOT want to be setting down when the 3rd member comes out.
All clean now.
Back to fun.
