Installing new axles (drive shafts)
 

Here in the UK we call them drive shafts but I believe in USA you call them axles - basically I'm talking about the two shafts that come out of the diff and go to the wheels.

I recently removed the stock shafts and installed some stronger ones from The Drive Shaft Shop, but now the diff is leaking oil out of the part where the shaft goes in to it (but only on one of the shafts). So I'm wondering if we haven't got them in far enough and if there's any way to actually know when they're properly "in".

We basically just slid the new shafts in to the diff side, then knocked them in with a rubber mallet until they wouldn't move any further. There was no definitive point of knowing they were properly in, and they come out about 50-100mm again very easily if I pry them with a flat head screwdriver. Is that normal? Seems to be the same on both sides, yet only one side is leaking.

Also, someone told me to make sure the gap in the C clip is at the bottom when you insert the shaft in to the diff but that doesn't make much sense to me because surely the entire part that we're inserting the shaft into can rotate 360 degrees... so how would you know to tell someone a certain point will always be at the bottom for the C clip gap to fit around? We tried our best to keep the gap at the bottom but in all honesty once you've let go of the C clip and started pushing/twisting the shaft to get it to slide in to the splines in the diff properly, there's no way of knowing what angle it ended up at.

Our plan at the moment is to drain the oil out of the diff and lower it, then take the back of the diff housing off so that we can see what we're doing when we take the shaft out and re-insert it. But if anyone has any suggestions for other things I can check or try before resorting to this, I'm all ears.

A friend who's got more experience with this kind of thing said he's 90% sure it will be the rubber seal around the edge of the opening in the diff that you insert the shaft into. Maybe we accidentally damaged that as we put the new one in. I guess I'll go see if I can get a replacement seal from my local Toyota dealer

I bought and installed DSS axles too and had two issues. First one, the axle itself was leaking grease from inside that when hot, seemed like oil so I thought oil was leaking from the diff but it was not, it was the axle. Grease was sprayed axially from the axle onto the suspension, gas tank, etc...

Second issue was the rubber seal on the diff. It has a metal ring on the rear (looks like a circular spring), and it got bent on a very little spot, making a really small leak on the diff.

DSS warrantied the axle, I replaced the seal and no more leaks after that.

I bet your issue is the rubber diff seal.

Yeah after speaking to a few other people we all agreed that was the most likely thing, so I've just been to my local toyota dealership and ordered a replacement. Also ordered the crush gaskets for the diff filler and diff drain plugs because I think enough oil has come out now to warrant topping it up - so may as well just drain it and replace it with some Motul 300.

I'll give an update once the new seal is in just in case anyone else finds this thread and has the same problem

Oh and when you replaced the seal yourself, what did you use to get it out and install the new one? I notice the toyota service manual says we need to use some special tool but everyone I've spoken to says we could probably do it with a screwdriver (to prise it out) and a large socket to evenly press the new one back in

Wait, so if you call the axles the drive shafts, what do you call the drive shaft, the axle?
Don't get me started on tyres, boot, bonnet, etc. (J/K, but really, what do you guys call the drive shaft?)

Yup, screwdriver to pry it out, a bit of grease on the lip and a rubber handle of a hammer to push it in place

lol we call the main drive line that goes from the transmission to the diff a "prop shaft"

You'd think that I've seen enough episodes of Wheeler Dealers to know that...

OK so we got the oil seal out today and sure enough, the small metal spring that goes around the inside of it was wrecked. Put the new oil seal in (and changed the diff fluid while I was there) and so far so good. Will see if it leaks at all over the next couple of days