AWD Wagon-Bevel Gear Oil or Angle Gear

**rep** · 08-21-2007, 07:33 AM

I'm new to this forum and I greatly appreciate some help.

I'm a first time owner of a 1998 V70 AWD Wagon and I have been going through it and doing all sorts of maintenance on it. One of the items I'm looking for help on is the AWD system. I've heard it called a bevel gear or an angle gear.

Which terminology is correct?
How often truly should this be serviced?
How to tell if it has ever been serviced before?

All I've been able to find out from the Dealerships is a part number of 1161648. This does not tell me much. I've seen it called Gear Oil or Manual Transmission Fluid. Which is it?

After calling 5 different Volvo Dealerships only one was able to give me the following additional info. In there notes it was called a 75W90 Gear Oil.

In stead of buying this directly from Volvo is there an aftermarket mfg of this fluid?

I look forward to the responses. Thank you.

**mrscullini** · 08-21-2007, 10:14 AM

the bevel gear and angle gear are synonymous. the first gen xc uses 75-90 gear oil in this gear box as well as the rear diff. i use mobil 1 syn fluids. the bevel/angle gear is kind of a front diff, but instead of being driven, it drives the drive shaft to the rear diff.

the awd system in the first gen xc is a viscous coupling system. it is important to keep your tires rotated so that they wear evenly. uneven wear causes the tires to rotate at different speeds, which puts extreme stress on the viscous coupling system.

**BillAileo** · 08-21-2007, 12:51 PM

Because of the temperatures involved in operation of the bevel/angle gear the specified gear oil is a full synthetic. Any replacement fluid should be a full synthetic. Volvo gear oil, and Mobil 1 gear oil, and other full synthetics of the correct rating are appropriate gear oils. There is a posting on the resources portion of this website that describes replacing the oil in the bevel gear,

The bevel gear is not really a differential (which has one input and two outputs); but rather the bevel gear has one input and one output and consists of a set of beveled gears that mesh at a ninety degree angle in a way intended to provided quiet transmission of power to the rear.

Bill

**8pack** · 08-21-2007, 01:42 PM

I just changed the Oil in my Angle Gear or Bevel Gear, or Transfer case...all are the same. Look under the car and see if there any leaks or oil collecting on the case. also do a search on here for angle gear and bevel gear. Someone has already done a good job of positng pics and a description. If it is leaking, you will likely see the leak at the seal in the area where the axle comes in.

If there is evidence of leaks, I strongly recommend you change out your fluid and top off. If the gear oil gets low...........................

and $2500 later....

There is a single bolt to undo. You need to draw the fluid out with a suction device (MightyVac or similar) and then pump fresh fluid back in.

You can buy the fluid at your Volvo dealer for about $20 for a litre. Just ask for gear oil for the angle gear and say the "75/90 stuff)...they'll know what you want. Volvo calls it Transmission Oil but it is GEAR oil! I think it is just a linguistic difference like lorry and bus. you can use any GL-5 gear oil as I understand it including synthetic like royal purple. I stuck with the volvo stuff.

There are gradations on the bottle. Pump 700ml-750ml back in accounting for what gets caught in the tube (thick stuff).

Hope this helps...make sure you do a search and don't use my reply as your definitive answer

**tranmkp** · 08-22-2007, 07:51 AM

Too much fluid will create pressure and will blow the seals.

**rep** · 08-23-2007, 05:34 AM

First off Thank you for the replies...

mrscullini - from your posting you mention a rear diff. Upon my initial review the rear axle does not seem to be a solid axle type. So I'm confused a bit here. I'm unaware of a rear axle fluid for this vehicle. I see no mention of it in any of the Volvo owners books as well. Which Mobil 1 product did you use?

BillAileo - I'll check the resources portion of the site for info on replacing the bevel gear fluids. Thanks.

8pack - how long of a process was it to change over the fluids? I'm thinking of doing this on an upcoming free weekend.

tranmkp - understood as far as the fill goes to much is never a good thing here.

Any other info would be greatly appreciated. Many thanks.

**RedXC** · 08-24-2007, 10:20 PM

I had mine topped off on my 02, did not know it was a bit low until I did the 30k service. topping off was a bit hard since I didnt have any pumps. Just got a long hose and sure enough I got some in.

**8pack** · 08-27-2007, 06:32 AM

It takes between a 1/2 hour and an hour....the only real time is laying on your back and pumping the mighty vac to get the fluid to drain and then fill. it is thick stuff and it just takes a while to get it pumped in and out...it really is as simple as undoing the bolt...draining, refilling and replacing the bolt....just remember to get a fresh crush washer from volvo....ask for one at parts, they know what it is...

Good luck and let us know how it goes....

**volvoman9** · 10-16-2007, 08:05 PM

I have had a Volvo tech install a drain in my "98 XC by drilling into the case from a lower bolt hole. I believe this is a factory sanctioned procedure and can be done without removal of the unit. Costs about 50 bucks.