Help needed (Gen 4) - Rear diff oil seaping out of nut?

Hi everyone! Hope you are well.

Few days ago i fitted a rear diff guard from jimnybits. All went well, except for when i took a nut out. Its the one on the right.



When it came out, a little bit of diff oil trickled out, and i thought that was just where a little bit of oil had been trapped behind the nut.

Went to look again today, and i could feel where a bit more had trickled out. No pools of it on driveway, so i assmume its no problem.

So can i ask, is the nut i taken off somehow daming up the diff oil? Whats behind the nut? And if the seal is broken will i be in danger of slooooowly loosing my oil??

Help massively appreciated chaps. Thank you.

Here's a photo of an (Gen 3) axle casing without the differential in...



When you take the two bottom bolts out of the diff those holes are opened up and the oil leaks out...

Ideally - when fitting the guards - you need to drop the oil out and replace it after fitting the guard... and the bolts need some mastic on them to ensure a good seal (before the new oil is added)...

HTH

Is there no mention of this in the instructions? Can't see anything on the item listing...?

Dave

Oh i see. Not been too impressed with jimnybits guard kits really. Big lack of instructions, non in the diff kits, and somewhat vague on the other guards. Guards are ace though.

Yes, when i took the nuts put, they had a white gummy film on them, so what is this stuff called again? Might have to get some and re-fit the nuts i think. Crumbs!! Hope i aint run my diff dry!!

Hearbeat increASING!

Diff guards are quite unnecessary on a Jimny. The bolts are put in from the factory with a dollop of sealant on the threads. Normally when you take them out you can see it on the tip of the bolt, like a smurf's hat.

Hey Andy - as others have said, that flange of bolts retains a cover plate which is removable. Usually fastened in place with a paper gasket or hylomar sealant of sorts between both mating faces (in the old days they used cork gaskets). Nip them back up tight, the leak shouldn't persist. As others have mentioned it's probably worth doing a job like that in future at the same time as an oil service.

I can't quite make it out from the photos, but what gauge steel is used for that diff guard? only reason I ask is that if its 3mm+ I'd be a little concerned about the grip length of those original fasteners. (I don't know how long they were to begin with) There's potential risk of stripping the threads in the diff if that's the case. Out of interest, do Jimny bits supply longer bolts?

Judging by X8GGY's photo (presumably a gen.3 diff), looks like you've only got about 5mm of threaded casing.

Thanks for your advice, and thanks for putting my mind at rest somewhat

When i removed the 2 bolts, the left side one didnt cause any leakage which was odd. And the 2nd one on the right didnt cause too much oil to come out, just a very sloooow trickle. The bolts were quite large in length, and a good amount was reinserted, even with the 5mm thick guard.

I concur with what you said about the oil stopping after it leaked a little, i have since placed some kitchen roll in the diff pan, and after a day no more oil has come out. I have now slapped a load of thick gloopy oil around the bolts too. Gonna keep sn eye on it though.

Perhaps time jimnybits added some instructions to their guards.

Thanks everyone, tomorrow im fitting the ARB breathers and fitting soeleys hand made step down pipe components.

Bring on the puddles!

P.s... No mate, no longer bolts were supplied unfortunatly.

P.s ..

Glad you got it sorted Andy, WD40 is an awesome degreaser. Clear the diff up with that and keep an eye out for future leaks.

Nice work on the breathers too!

Busta wrote: Diff guards are quite unnecessary on a Jimny. The bolts are put in from the factory with a dollop of sealant on the threads. Normally when you take them out you can see it on the tip of the bolt, like a smurf's hat.

This and Andy's oil leak problem were the reason I binned these style of guard off. I found that when they are bashed on a rock (as intended for) they would cause the bolts that Andy has leaking to leak worse. They were otherwise very solid, but the price you pay for it is leaking from those bolts after any impacts. Fine if you know about it, but the standard diff housing is a solid thing anyway and doesnt really need the extra "guard", or weight. Money would be better spent on weld-on bracing of the factory welded joints either side of the diff housing, the weaker point by design