tom4416

Sorry if this has already been answered (I did search but couldn't find the procedure). I'm no mechanic but can usually handle most maintenance chores but the front diff has me stumped. I haven't removed the belly pan but it looks to me like there isn't a drain plug under there. I did see a side plug when I took the left front wheel off that isn't a bolt but rather an allen head plug. It looks like the fill area. Is there a separate drain plug or does it need to be sucked out this fill area or am I way off base. Also, while I'm on the topic, is Amsoil the preferred choice for synthetic gear lube and if so, what is the difference between their formula 2000 and the regular synthetic lube? One other question - is it wise to keep lubbing the front propeller shaft if I don't use 4WD (no off road use, no water wading). It doesn't turn unless 4WD is engaged so I'm not sure how it would "use" grease and I don't want to overfill and blow some seal out. I've been doing all the zerks on all the shafts each time I do the oil (every 3K) but am thinking maybe I'm overdoing it. TIA for any help.

bulldog-yota

SOrry can't answer your question, but here's a bump.

I will get the factory manual soon and hopefully have more answers, as I need to do this soon. I will just use good old Mobil1 Synthetic gear lube. I will also need to lube the driveline as I doubt the dealer has ever done it. I prefer Mobil 1 as I'm more familiar with the brand. Probably just my ignorance, because a lot of people on the board is into Amsoil products. I think both are probably far superior to what the dealer will put in anyhow.

jimbo74

if there is too much grease in it, it will just gush it out somewhere... not a big deal... its better to have overfilled the susp with grease than to ever run it dry.... be careful however, if it gushed out, and wasnt wiped up, it will then start attracting dirt....

superjoe83

Unless Toyota did something stupid, there should be a drain plug for the front diff, take off the skid plate and it "should" be there, my Tacoma has a Allen fill and drain plug, which is 10mm but may be different on the new 4runners, I'm not sure of the differences in the types of amsoil, i just use non-synthetic in the front diff and synthetic in everything else, mainly because it leaks and its expensive topping it off with synthetic all of the time . Now about the u joints, when you grease them you should "pop" the seals, all four of them per joint, they are made to do this and will not hurt them, make sure all 4 seals pop, if one is stubborn try rotating the drive shaft 180 degrees and try again, i would just give the front shaft u-joints a pump or two to make sure they are full every time you do the rear.

The Dutch Man

Hey bozy,

Lefty posted his "15K service" only a few weeks back. He said that the front diff has to be pumped out and filled through the side filler hole. My last GM vehichle was the same way. Too funny because I'm going to do my this weekend because the dealer didn't do it when I brought mine in for the 15K service. I'm using Valvoline Synthetic blend 80W-90 per the manual. I haven't removed the skidplate, so don't know if there is bottem drain plug or not. Oh, the plug is a 10mm hex. Had to go purchase one last night at Sears. Have everything else in my tool box except that one! Will let you know after this weekend.

Dutchman

tom4416

If the drain is also a 10MM plug instead of a bolt, it would explain why I can't easily see it so I guess it's time to drop the pan and take a look. I do have a 12V oil pump which is how I'm going to refill it so I could always pump it out instead of having to drop the pan each time. I'm not going to the dealer because I'm almost positive they would "forget" to do the front diff since it looks like a PIA and they probably figure it gets so little use that there is "no harm done" in not changing it. Plus, I would rather get some synthetic products in there in case I have to extend the change intervals for one reason or another. Thanks for all the advice so far.

Lefty

Yep, there's both a drain and a fill plug on the front diff. Both should be 10mm hex (don't ask me why Toyota went hex on the front and bolt on the rear). I didn't need to pump the diff out, just drained it after making sure the filler plug was loose. You WILL need either a pump or a long filler tube to fill that diff back up, however. You will not be able to get the fresh gear oil close enough to the filler plug to fill the diff again if you don't. I used a filler tube I bought at Checker for $5 to fill it back up.

As for what oil to use, I used Amsoil 80w-90 synthetic. I don't think it makes much difference what type of oil you use (mobil, Amsoil, Redline, etc), as long as it's the right viscosity and fills the diff.

For more details on the 15k Maintenance, do a search for a thread I started a couple months ago on that topic. Some useful info in there...

Good luck with the work and let us know how it goes !

Steve