Bevel Gear Adjuster Nut Leak? Topic is solved

[xHeart]

FWIW:
The adjuster nut is threadless so it doesn't screw into AG rather pressed into, here is a pix:


Tool and seals:

MVS_V70XC_0840.jpg (183.16 KiB) Viewed 1090 times

[Skymongrel]

It's even cleaner now per your suggestion I clean the heck out of it after this pic. I would like to stop this leak as it drips through belly pan onto driveway. I already replaced the inner seal the other day, a pain, it was in there pretty good. Tell me more about outer seal...more difficult? Can I grab an outer edge of seal if pre-load adjuster nut is out? Or am I looking at drive a screw throught it and pull?
Thanks again.

[Skymongrel]

Hmm...I was responding to Jimmy's post but it got added to xHearts. Anyway, this is a nice picture of the adjuster nut and those are the exact same parts I ordered! Even got another inner seal even thought I just replaced it (case something goes wrong).

I suspect there are some thread on that small inner lip. I read somewhere thats how you pre-load the bearing just beneath it. But this pic help me understand the anatomy of this area. Thanks!

[jimmy57]

I use screws or drill two holes and use a seal hook I have had for years. If the adjuster is removed the back side is accessible so seal could be pushed/drive out with a screwdriver.

That part is threaded, the threads are in the photo. Tabs, O ring groove, threads is the order foreground to rear. The O ring is visible when you clean it as there is a small depth of aluminum on outer edge of O ring groove.
I have done full bearing replacements on many of these of this version with diagonal split case. I'm in TX and most were easy but the few I ran across that were cars that spent time in salty areas are the ones I issued the alternate clean and externally seal suggestion. I have one running around that has teflon plumbers sealant on the threads with RTV on outisde. Perfect internals but the area the O ring would seal against was corroded.

[Skymongrel]

My parts arrived this morning and with another heat wave in WNY, I changed the adjuster nut o-ring and outer seal! I heeded your warning and cleaned the snot out of the angle gear area before opening it up. The new adjuster nut tool worked wonders!

I found that the outer seal was actually fine, nothing wrong that I could see. The o-ring was harden but not damaged. I removed the adjuster nut using the tool and it took 9 revolutions to remove it. When I put it back I used a torque wrench to 50 nm ( 36 ft lbs) and it took about 9 1/2 turns. Fresh Mobil 1 syn 75-90, fill til it spills and removed 100ml. Everything buttoned up (except the dust shield for wheel! doh!).

I'm gonna call this resolved for now...frankly I don't want to know if it still leaks I'm so tired of crawling under the car. Thanks for everyone's help!

[Skymongrel]

Thought I'd post an update regarding my bevel gear leak. Been driving for a couple days and I no longer have oil in the driveway. Although I replaced both RF axel seals and the adjuster nut o-ring, I'm convinced it was just the o-ring. However since I was in there I suppose it was a good idea to replace the seals. But frankly they look very good (160K). Also, I highly recommend the special adjuster nut removal tool, because not only was I able to remove the adjuster nut easily but I was also able to use it with a torque wrench on installation. Thanks again for advice on this problem!

[- Pete -]

Skymongrel,
Thank you for posting this thread.
Is your bevel gear still showing a lack of wetness?
Reading back, I get the impression you re-sealed your BG "adjuster nut" with it still bolted up to the trans, or have I got that wrong?
Either way, I was glad to see you were amongst the dry undercarriage fellows

Being locked down now in MN, I'm going to be tackling some long put-off & not so fun jobs; 284k XC70 BG leak is going to be resolved at long last.
Last time I had it on the hook I was almost certain I had zero'd in the leak's source(s) to the adjuster nut side of the equation. I believe I may have been wrong, but only in part. I do think I have a leak there, but also at the "rear" output flange seal.

2CBDA2CD-3AA8-4C4A-8C61-231D03C8F3E1.jpeg (168.08 KiB) Viewed 1006 times

Like Jimmy57 said, I'm sure I'll see pitting on mine given the miles & salt exposure.

If you don't mind, I'm going to add some photos to your thread of some seals that may also need to be replaced when doing the adjuster nut o-ring. I'll also try to add seal clickable links.

The above 5 pictures are of the rear/driveshaft/output flange BG seal. They are taken from one of my spare BG’s which has already been re-sealed.

Volvo part number 30684243

It has measurements of 45x65x10/11.4



Below is the passenger/right side BG (inner) CV shaft seal.

It has measurements of 28x38x7mm.

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52558F4C-1334-4A65-BD43-186A4683B186.jpeg (130.04 KiB) Viewed 1006 times

Above is passenger/right side inner BG CV shaft seal.

Volvo part number 9143885



Also here is the large outer seal on the passenger/right side, Volvo part number 30735126 measuring 48x65x8/9.4, link below.

Right/passenger BG large outer seal

FEBA50A7-B2FA-4E3A-A18F-B2CC11EAB257.jpeg (176.42 KiB) Viewed 987 times

Volvo part number 30735126


Editing...

[Skymongrel]

Nice pics. I should have taken some but my iphone battery was shot and couldn't get any good ones.

I think its important to really really clean and scrub with a copper wire brush the Bevel Gear and surrounding area to track down the leaks. I did not want to remove the BG so I went after the little things first. I think the big take away from this experience is that the o-ring behind the adjuster nut can leak! And this isn't the most common google search result when troubleshooting the problem. I was an easy job ONLY because I bought the removal tool ($33).

BTW with a 160k miles I believe both my RH axel seals were actually in great shape and didn't need to be changed.

Still dry!

[Skymongrel]

It's been almost a month, so while changing my engine oil today I snapped a shot of my dry bevel gear. Looks like the o-ring fix was the right call.