1998 Volvo V70 XC Bevel Gear

pgalli92 · Post by **pgalli92** » 17 Feb 2013, 10:48

Well I'm back once again. About a week ago I noticed a slight humming noise from the front end and it has progressively gotten worse getting louder especially at 70mph+ and when slowing down to a stop it sounds like sloppy/grinding gears. I recently had my rear differential replaced and the noise is similar to when that started to go, only this time its in the front. The engine runs fine and I believe the tranny is sound, as it shifts smooth (most of the time) and the fluid looks good. Now I believe it is the angle/bevel gear starting to go as I see black fluid on the bottom of the bevel gear. My driveshaft is removed so it is currently a FWD and I have no plans on putting it back in. I have read that you can remove the bevel gear and just drive it without it and you don't even need a new cv axel on the passenger side as it just slides right through the BG. I was just wondering though, if the bevel gear completely fails, will I still be able to drive it? From what I've read its only an AWD part and transfers power to the driveshaft. Any help is greatly appreciated, Thanks!

pgalli92 · Post by **pgalli92** » 18 Feb 2013, 12:06

Anybody?

pmortv70xc · Post by **pmortv70xc** » 18 Feb 2013, 15:57

Hello - yes, once the driveshaft and bevel gear is removed, you can still drive FWD only with no problems. You will need to ensure that the collar gear is reinstalled to prevent transmission fluid leakage. There are numerous posts on this site about the process. I've been driving my 2000 for several years as FWD only and it's just fine but I miss the AWD in the snow.

Post by **jimmy57** » 18 Feb 2013, 17:59

Or you replace the existing RH trans seal where collar inserts with the seal for FWD car and a RH front axle. The OD of the trans where seal fits is the same AWD or FWD. The ID is either for angle gear sleeve or on FWD it is a smaller ID for axle. AWD RH axle is not finished for seal in the right place so a FWD RH axle will need to be used. When you run with AG removed and collar fitted you have to concoct a way to keep sleeve in place and the RH axle will rust and never be useable for a convert back to AWD.

SwedishMadeFunBrick · Post by **SwedishMadeFunBrick** » 19 Dec 2023, 22:15

jimmy57 wrote: ↑18 Feb 2013, 17:59 Or you replace the existing RH trans seal where collar inserts with the seal for FWD car and a RH front axle. The OD of the trans where seal fits is the same AWD or FWD. The ID is either for angle gear sleeve or on FWD it is a smaller ID for axle. AWD RH axle is not finished for seal in the right place so a FWD RH axle will need to be used. When you run with AG removed and collar fitted you have to concoct a way to keep sleeve in place and the RH axle will rust and never be useable for a convert back to AWD.

Finally, confirmation!!!! My 98 V70R AWD had a sound similar to(or perhaps the same as) above. There was no play in the output shaft of the bevel gear, so I opened assembly and everything looked to be in surprisingly good condition. The splines on the collar and the bevel gear showed next to no wear. I did find that the outer pinion shaft bearing looked like it had been warped by heat as well as there being some sludge gumming everything up. Replaced the bearing and race/cup after cleaning everything up and excitedly awaited some new seals. When they arrived the bevel gear went on, but the noise not only remained but is now more frequent! I peeked at the trans side splines when the bevel gear was off, but since it still sounds like skipping teeth I am wondering if I maybe didn't look too thoroughly there and missed some spline damage on trans side.

In any case, I thought about it and figured the fwd trans should be the same as the AWD, despite reading the opposite on a couple of occasions. So why couldn't I just get a seal for fwd and not worry about securing the collar in the transmission and having to get a new axle since I do want to fix the AWD in the future? I'm going to take this as confirmation and go ahead and use fwd seal and axle as a temporary solution until I can get the bevel gear properly repaired.

Any chance someone can confirm that I have the correct seal? From what I can find it appears to be Volvo part number 6843112.

Much appreciated

Post by **abscate** » 20 Dec 2023, 01:28

Volvo part numbers are documented most excellently here...

https://www.volvopartswebstore.com/prod ... 43308.html

Put your Vin in and have at it

For the fwd seal, just configure a new car in fwd only mode and pull the seal there

SwedishMadeFunBrick · Post by **SwedishMadeFunBrick** » 20 Dec 2023, 08:00

Thank you, but most excellently and most identifiably are somehow not one and the same, obscured or small/poor resemblance to the part, and even incomplete or cutoff descriptions can cause confusion and doubt. Especially when looking at multiple different diagrams trying to locate/identify/compare between models and or years. So, after having already looked up the part number I believe is correct despite that system never allowing me to actually specify my trim level (though the option appears there it is not clickable) and thus unable to configure a fwd only mode, I thought it couldn't hurt to throw out a request for some helpful consensus and/or reassurance.

SwedishMadeFunBrick · Post by **SwedishMadeFunBrick** » 20 Dec 2023, 21:14

Alas, the seal for the FWD is not the correct seal needed to allow me to run a FWD passenger CV axle without the need to have bevel gear collar to prevent leakage of ATF. Am I missing something? Looking at the transmission again now, and the seal that the collar rides in has a good deal larger OD. and the seal wouldn't be sealing against the cv axle anyway, it would have to be sealing against the splines on the trans output that the cv shaft passes through... Or is this output actually to be removed? If anyone can shed some light here it'd be very much appreciated.

In any case, it looks like my splines here are good afterall, so the issue of the original noise should be contained within the bevel gear itself I imagine.

Attempting to include photos. Fingers crossed.

: Trans output with current AWD seal.; 20231220_213721.jpg (591.24 KiB) Viewed 443 times

: Trans output splines.; 20231220_213613.jpg (392.65 KiB) Viewed 443 times

: AWD trans seal on left, FWD trans seal on right (used one just for purpose of comparison); 20231220_213947.jpg (679.8 KiB) Viewed 443 times

After reinstalling the bevel gear and the problem noise occurring more frequently, it looks like more wear than I saw initially, especially on the bevel gear side. What's the verdict, is the collar still useable, or has it done it's job and this is enough wear to cause my problem...?

: Splines on the bevel gear side of collar.; 20231220_214116.jpg (327.98 KiB) Viewed 443 times

Measurements for seals (both 8.5mm thick):

: 20231220_214852.jpg (424.02 KiB) Viewed 443 times

: 20231220_215008.jpg (340.66 KiB) Viewed 443 times

: 20231220_215603.jpg (347.82 KiB) Viewed 443 times

: 20231220_215109.jpg (456.77 KiB) Viewed 443 times

Again, any help greatly appreciated!

Post by **abscate** » 21 Dec 2023, 02:04

SwedishMadeFunBrick wrote: ↑20 Dec 2023, 08:00 Thank you, but most excellently and most identifiably are somehow not one and the same, obscured or small/poor resemblance to the part, and even incomplete or cutoff descriptions can cause confusion and doubt. Especially when looking at multiple different diagrams trying to locate/identify/compare between models and or years. So, after having already looked up the part number I believe is correct despite that system never allowing me to actually specify my trim level (though the option appears there it is not clickable) and thus unable to configure a fwd only mode, I thought it couldn't hurt to throw out a request for some helpful consensus and/or reassurance.

Once your car year and model is in you select one transmission for AWD and a different picture for Fwd , guided by the text on the picture. That should get you the part numbers.

Dimensions on seals are often given at skandix.de , found by part numbers

SwedishMadeFunBrick · Post by **SwedishMadeFunBrick** » 21 Dec 2023, 10:51

Well apparently it doesn't. I have the right parts, as both seals came off of cars they were installed on. Isn't the issue a bit more about how the core idea doesn't work? And I can't actually swap in a seal from a fwd and eliminate the collar afterall? If you're going to just tell me once again something obvious like how to find a part number when all I was doing originally was asking for verification to reassure... And continue to ignore anything else referenced or asked in the post, then you may as well just not even reply. That would be even more helpful to be honest.