Bevel Gear Oil Leak By Output Shaft For Rear Driveshaft

tidewater21 · Post by **tidewater21** » 12 Apr 2013, 08:49

I've been tracking down an oil leak in my '98 V70XC. I have finally narrowed it to the shaft seal coming from the bevel gear where the rear driveshaft attaches. I removed my rear driveshaft a few years ago because of the gear failure. It has been running fine until this leak started and it is now really leaking when driving the car. It may have run a little low on gear oil as I had other oil leaks I have now fixed including a new PCV system, rear cam seal etc. before I realized it was from the bevel gear.

Anyway the car runs fine but I have to top off the bevel gear after a short run so I have to do something. The car does seem to develop a hesitation or jerky motion for a few seconds when gear oil low. Symptom is almost like water in the gas or something or a fauly Mass Air Sensor. I did replace that about 1 year ago. I'm thinking it's from the low oil level in the b gear, not sure. I've searched the forum bevel/angle gear threads but don't see much about changing the seal where the driveshaft connection occurs. Am I just better off taking the bevel gear right out of there or is the seal replacement easy enough to avoid all that? The car has 223,000 miles. Just finished PCV system, Secondary air pump and check valve replacement. Other engine oil leaks seem fixed.
Thanks for any insight.

Post by **JDS60R** » 12 Apr 2013, 10:31

Remove center shaft from bevel,
Mark relation between pinion nut and pinion shaft.
Use impact gun to remove pinion nut.
Pull off yoke.
Replace old seal with new (Victor Reinz if possible)
Repalce yoke
Retighten pinion nut so mark on nut and pinion shaft align.
Replace bevel gear fluid with synthetic and a new crush washer if not done already.
Replace center shaft to bevel after making sure all caked/dried grease is removed and high quality grease is in center shaft cv
Enjoy

tidewater21 · Post by **tidewater21** » 12 Apr 2013, 10:59

Thanks JDS60R,
I was hoping not to have to remove bevel gear completely at this point. Do you think that Victor Reinz seal is going to be available from online Volvo part suppliers or is my best bet to get an original Volvo part from the dealer? I got my rear cam seal from the dealer per MVS recommendations.

I appreciate your info, thank you.

Post by **JDS60R** » 12 Apr 2013, 11:20

I would guess the current Volvo replacement is going to be a VR so you are safe either way. Just an issue of getting it in your time frame and budget. Probably faster to buy OE 9183891

tidewater21 · Post by **tidewater21** » 12 Apr 2013, 13:02

Thanks again, I saw the part number on a schematic of the angle gear and wondered if that's what I need. I'll go for it and try to get back on the road ASAP.

Hopefully I haven't further destroyed the unit running it low on oil. It wasn't until I cleared up some other leaks that I was able pinpoint the bevel gear. The oil had that strong, distinctive odor of gear oil vs. engine oil. Sadly the bevel gear hadn't received the proper maintainence the rest of the car got over the years. Thanks for your help.

tidewater21 · Post by **tidewater21** » 16 Apr 2013, 09:01

Anyone have an idea of the size of the nut at the end of this shaft from the bevel/angle gear? It holds the flange on the shaft for driveshaft to rear diff. I need to get the seal out on bevel gear. It's bigger than 27MM but I don't want to buy a bunch of sockets, just the one I need.

Thank you

Post by **JDS60R** » 16 Apr 2013, 09:58

Local auto parts stores will rent ( with money returned on return of kit) a CV axle nut kit that has 30mm and up in it. I am sorry but I do not know the exact size. I am hoping the 30mm and up sizes will help

tidewater21 · Post by **tidewater21** » 16 Apr 2013, 11:38

Thanks a lot. I'll check it out at the parts store. That's a great idea to get a number of sockets and see what fits. Never thought of it. That seal was really worn out. I got a good look under there and you could see where the oil was coming out. It may be my last leak (knock on wood), for awhile anyway. Other engine repairs seem to be holding up.

Thanks

Post by **matthew1** » 16 Apr 2013, 11:41

tidewater21 wrote:Anyone have an idea of the size of the nut at the end of this shaft from the bevel/angle gear? It holds the flange on the shaft for driveshaft to rear diff. I need to get the seal out on bevel gear. It's bigger than 27MM but I don't want to buy a bunch of sockets, just the one I need

Just measure it with a metric ruler, tape measure or caliper. It's 30mm, 32mm or 36mm. I bought a 36mm socket from Sears for around $9.

tidewater21 · Post by **tidewater21** » 26 Apr 2013, 09:45

Thanks for the help and advice on this project. The job is completed and I thought I'd share the experience in case anyone else does the work. The size of the nut on the shaft in 30MM. I picked up a set of 10 impact sockets ½" drive at a local (stores nationwide) tool store and with the impact wrench got the nut off easily. There was room for the wrench to fit in the tunnel where the driveshaft would run. A puller was used to get the flange off the shaft. The hardest part was getting the old leaky seal out. I drilled some holes to weaken tight fit and finally it popped out. I cleaned up the area inside the housing good and installed a new Volvo seal from the dealer. It cost about $14.00.

I drove the seal in using a PVC pipe coupling from a plumbing store that fit the diameter of the seal well. It distributed the force evenly around the seal.

Some photos below show the view inside the housing on the bevel gear where the shaft comes out without the seal and with the new seal installed.

Hope this helps anyone trying to do this job on a 1998 V70 XC.