All,

I replaced the rear differential seal this past weekend as it was seeping very badly.

I removed all of the gasket material and cleaned both mating surfaces and then reinstalled everything with a brand new Volvo gasket.

I looked under the car today and it is leaking once again on the drivers side near the top of the pumpkin. the exact same place.

I tightened the bolts a little more in hopes that this will fix the issue and I also checked to see that I have a clear passage way coming out of my rubber tube on top of the rear axle.

Any thoughts as to what to do next if this does not fix the issue short of replacing the seal yet again????

UGH!!! This has been the summer from car repair hell. I'd like to catch just one break, please!!!

End of rant!

Matt

Much like a thin metal valve cover, over-tightening the bolts can draw the sheet metal in such that the bolts feel tight yet the span between the bolts is not pressing against the gasket tight enough. The thicker and mushier the gasket is, the damage over-tightening can do. When you pull the cover back off and lay it on a flat surfaces, run around the entire perimeter with a thin feeler gauge in order to search out areas of poor contact. Or shine a flashlight into the filler hole and look for light coming out from under the cover lip. You may need to peen the holes outward ever so slightly to assure adequate contact BETWEEN the holes.
--
Current rides: 2005 Volvo S80 2.5T, 2003 Volvo V70 2.4NA, 1973 Volvo 1800ES (fixed the ignition - now back to the brakes again)

??

Hi,

I wish to post about checking the vent tube...but then you've done that. Since I'm already posting here..

Its a bit unusual for it leak from the top as we all know the fluid level is only about halfway across the cover. Just ensure the rubber vent hose is tight on its diff nipple attachment and not blocked or kinked when the car is lowered down (ensure nipple not blocked also). Then I would check the flatness of the diff cover by laying it on a flat surface. Check the mating surfaces for any left over old gaskets. Then with a new gasket, smear some RTV on both its surfaces and install back the cover. Refill as usual.

Regards,
Amarin.

You must use a sealant on the bolts threads and on the gasket surfaces.

Hypoid Gear oil is a far different animal to contain than motor oils. Smell is not the only unique thing about it.

I suggest this Hylomar blue product first.

http://www.newmantools.com/chemicals/hylomar.htm

You might find this stuff easier? But it may not be as good as above unless the above makes it for them. Both work with in similar principle.

http://www.permatex.com/products-2/product-categories/gasketing/gasket-makers/permatex-gear-oil-rtv-gasket-maker-detail

Phil

So are you recommending not using a gasket at all or in addition to the sealant?

Thanks,

Matt

Well this is the second rear diff seal that I've replaced.

The first one I did was two years ago and I did not use any type of sealant and it has yet to leak.

Thus I'm finding this very hard to believe, but then again, I just want it to been done with.

I will look at seeing if I can get either of the ones you suggest and then take it from there.

Thanks,

Matt

have you verified your cover is not deformed or bent such it does not lie flat against the axle surface WITHOUT being tightened

if it is the old style steel cover (as opposed to the aluminum) are there any tiny rust through holes

I have not verified if it lies flat, but since I have to remove it to fix it I will then check.

The back side is a little rusty, but from what I recall the inside looked pristine, but I will verify once again!

Nothing is easy is it?

Its quite late for me and I hope Im answering this correctly. There’s several nuts/bolts to tighten in a 'circular manner‘, right? be sure you tighten them in opposition to each other. In other words don’t just go around tightening the ones right next to each other.

Did you know that improperly tightened/over tightened differential bolts can lead to that 'howling' differential sound? It has been known to be tightened incorrectly even on the assembly line by a careless worker; well 'way back when' anyway. I would think by now modern improvements have rectified that issue.

I did not tighten the bolts in a circular pattern but more like putting on a tire.

Being drummer I usually tighten bolts like I tune a batter head on a drum, so no worries there.