marko3xl3

Some months ago (when I didn't have time to do it myself), I went to a really reputable oil change place in my area so I could have the oil changed on the fly. They were really helpful and even gave discounts for bringing my own synthetic oil.

Anyways though, they also told me that the rear differential fill hole screw was very rough to come in and out which doesn't really bother me NOW, I am going to replace the current fluid with synthetic when the next oil change comes around anyways, but I am afraid that the thread won't cooperate with me and I won't be able to put it back in.

Especially since 4Runners already use big screws there, my choices are kind of limited. I could re-thread the hole the plain-ol-way or, the better solution, to re-thread it the helicoil way.

Now the problem I am having is that no matter which way I am going to re-thread the hole, what am I going to do with the shavings?

I already thought of methods like holding a strong shop-vac to the hole while threading it or using magnets, but what if some of those shavings will still get into the housing, what should I do then?

Any general advice on this type of problem (doesn't even have to involve a differential) would be greatly appreciated, and thank very much in advance for your knowledge,

Marko

4Crawler

iTrader: (3)

Usually just a problem of having grit and dirt on the threads of the plug itself. Get a wire brush and clean the threads well and possibly use a litte anti sieze compound on the threads and see if that helps. If the female threads and messed up a little, you could run a tap up into them, apply a liberal coating of grease on the tap to catch the shavings.

marko3xl3

Yeah, I will try that as soon as I have some time. Should I just use a regular tap or a helicoil?

Good advise,
Thanks

Marko

4Crawler

iTrader: (3)

I would try cleaning up the existing threads first, either a tap or find a bolt of mathing size, file a groove across the threads and then run that in and out a few times to clean up any burrs.

marko3xl3

Yeah, of course I am gonna do that first. I kind of had to jet out for a second, so sorry if I expressed myself wrong.

I will probably get around to doing it next week or so, I just wanna make sure I have peoples' opinion on it before.

Anyways, if all the cleaning doesn't work out (let's say some previous mechanic really drilled a screw bad in there) should I go with just normal tapping or helicoil?

4Crawler

iTrader: (3)

If you want the original plug to fit, helicoil. Otherwise go up to the next larger thread and just re-tap.

marko3xl3

Thanks for all the advice, I'll let you know how it comes along when I get to it .

TechWrench

Is the fill plug hole in the case casting, or in a steel cover plate. If it is a case casting, a heli-coil repair would be, IMHO, better than trying to drill and tap the hole to the next size (then you have to locate a larger drain bolt to replace the stock size. If it is in a stamped steel/aluminum cover, you probably don't have enough excess material to over drill it for the heli-coil insert.

marko3xl3

It's in the case casting, I was aware that I will have space for both, helicoil and re-tap, but I want the solution with the least metal shavings which would be helicoil (and most shops around here recommend the same thing, except they charge too much).

Also, I think the 4Runner plug is already the biggest standard plug available so going bigger might give me/other a headache later on (stock issues).

Thanks for the advice though,
Marko

4Crawler

iTrader: (3)

Actually the Toyota axle has no cast parts and no cover plate. The housing itself is formed of ~4mm thick steel and the rear cover (non-removeable) is thinner steel with a welded in bung for the fill plug. I really doubt the threads in the hole are so messed up that just re-tapping to the existing size would not work. I've helped remove stuck plugs that required welding a nut to the plug in order to remove it. None had any real damage to the hole threads. Usually the only damage is some of the plug thread that strips off inside the hole. Clean it up and it'll probably be fine.

marko3xl3

To be honest, I am not sure what all hose parts are called, all that I think I know is that the differential has a drain hole right in the housing itself and one fill hole right in the housing itself.

Thanks again and I will make sure to let you guys know how it turns out,
Marko