Angle Gear case covered in sludge

[DannyStringhamMarquis]

While doing a transmission fluid flush and motor oil and filter change this weekend, I noticed an oil pattern on the "shroud"/protective casing.

I followed where the drip/fluid loss must be coming from and discovered my angle gear was covered in sludge.

Anyone have thoughts on appropriate corrective action?

[pbierre]

I would clean all the sludge away, and then re-inspect it a few days later. The oil leak will be easier to pinpoint against a clean background.

[Pennhaven]

What year? Angle gear oil seepage is a common issue with earlier P2 XC70s.

There is a fix via an official Volvo service bulletin. It requires removing and disassembling the angle gear, chamfering the housing joint edges, and applying sealant. If you search here you can likely find the details. When expert member Astro14 did his he also added a drain plug.

Or you can just do what I've done for ten years, simply clean off the housing and drip tray at every oil change (aerosol brake cleaner works easily enough), check the level in the gear housing every change or two, and change the oil every 30 thousand miles. While the seepage looks messy, in my case it actually is very slight and I've never had to add gear oil between changes. Also note: The housing isn't supposed to be full to the fill hole. The spec is to fill and then remove about 100cc, so the fill level is actually about 1/2" below the hole. If you overfill it, it will only leak more.

That said, you could have a leak from the turbo oil line above the gear, so cleaning everything and checking is the way to go.

[Xfingers]

I agree with both posts. Clean it off and see if it returns. When these angle gears are overfilled/filled to the brim, I do think they weep fluid. Maybe someone overfilled it 5 years ago and that sludge has been on there for 4 years. I'd probly do a level check. If it's full, then just keep an eye on the level and see if you get more build up. If the angle gear fluid is low, then top it up and see if you keep losing fluid. If the car is new to you and you're unsure about the condition of the angle gear fluid, you may want to consider changing it. You'd need a MityVac-type hand pump and the right gear oil (different from the trans ATF).

There is the possibility it could be coming from the turbo above.

[DannyStringhamMarquis]

It's an '05. I've had it since 2012. I suppose it's possible it's been there for years and I haven't noticed because I've not really been trying to look when I did the oil change.
Now, as I attempt to be a much larger DIYer than I've been, I suddenly understand what components are and that they shouldn't look like that.
Thanks for the advice, I plan to check it again on Friday. Probably need to drain about a half quart of fluid from both transmission and motor, so I'll be under there again anyway.

Last year, I discovered my rear diff has a slow leak which I've been topping off at oil changes. Glad to know the angle gear may have a similar issue.
We gotta love the quirks of these P2s right?!

[Xheart]

It is normal for seals to give a little after a 12 year run -- great family car.

It could just be an overfill of AG fluid and never cleaned cause it doesn't look wet. OR the copper seal at filler was reused, never replaced (common oversight).

I agree! Clean and maintain, check fluid level during oil change or often for happy motoring.

[Astro14]

It is normal for seals to give a little after a 12 year run -- great family car.

It could just be an overfill of AG fluid and never cleaned cause it doesn't look wet. OR the copper seal at filler was reused, never replaced (common oversight).

I agree! Clean and maintain, check fluid level during oil change or often for happy motoring.

That’s what I would do: clean it up. Drain. Refill. Watch.

A while back, I carefully removed all the old oil. Then added 700ml. Then used a bent piece of wire to determine the fluid level. I marked the wire and now have a “gauge” for checking fluid in the angle gear.

[Pennhaven]

That’s what I would do: clean it up. Drain. Refill. Watch.

A while back, I carefully removed all the old oil. Then added 700ml. Then used a bent piece of wire to determine the fluid level. I marked the wire and now have a “gauge” for checking fluid in the angle gear.
I use a bent pipe cleaner. Super easy to see the oil level on it.

[Xheart]

Any update?

[DannyStringhamMarquis]

Any update?

This was one of many longitudinal problems with my beloved '05 XC70.

In late September, I was doing the relatively standard front Lower Control Arms, Ball Joints, and Sway Bar Links. I had been observing what seemed to be unusually high Motor Oil consumption.

When we got the vehicle as apart as is required to do the suspension work, I noticed that there was oil sort of everywhere.

I suspect it's in need of PCV service and one or more seals had been pushed out under pressure.

However, that did it. I was done. I traded it in for what will hopefully be a vehicle which requires less garage time. The XC70 was my daily driver, and that's all my lifestyle can afford right now -- 1 daily driver. It's been a good run with the car and the forum, but this will most likely be my last post. Thanks for all the advice everyone! I truly appreciated having your insights and support with this great vehicle