It is a 98 AWD with 125k miles. Based on the records, the last owner always took it to dealer for oil change since new till 10k ago. If I want the engine last another 100k, shoud I stay will what Volvo recommended, or switch to syntheic like "Mobile 1". What about the tranny & transfer case, should I stick with Volvo or change them all to syntheic.

A North American Volvo tech, trained in Sweden, told me a trick which allowed me to get over 300k on 960. Every other oil change, drain the warm oil, and replace it with ATF (any type) right to the full mark. Run the car for 15 minutes at idle, let it cool, and drain the AFT and refill with your choice of oil. This way, you will remove a vast majority of the varnish and deposits from your engine.

Synethic is suppose to reduce the sludge too. I swear by regular Castrol 10W40, 10W30 in the winter.

it's not too late to use synthetic. BUT, I have a 98 S70 and have been running it with Walmart dino oil and changes at 6K and Walmart tranny fluid at 30K changes. I have 257K on mine and it runs like new still. No oil leaks either BTW.

I do believe that synthetic is a superior oil, I just don't believe we generally drive in conditions that require its higher standards.

Your car has good 'Genes' too..My85.245T sold at 275mi I like SYN oil I use Mobil 1 runs cooler and cleaner..I know it is not a cure all.

It is never "too" late to switch to synthetic 10W30. If enough gunk piled up to keep oil from the RMS or other seals, they might leak after 2 or three oil changes, but the gunk only masked what would have been a terrible situation.
Your engine parts will enjoy the synthetic oil and live longer. Change it now and again in 2-3000 miles, then wait every 5-7K miles to change the oil and filter.

The tranny needs a flush. It only takes 30 minutes to do it properly, you can use mobile1 ATF synthetic in your car.

The bevel gear oil needs to be changed as soon as possible. Every 50K miles is a good rule of thumb. Use the oil reccomended by Volvo, about 1 liter.

Klaus
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Volvoless. Sold the R. There is now a void...

What is the bevel gear, where is it located & what kind of oil does it need. What kind of oil does the transfer case need.

Bevel gear is only on AWD cars, and is located behind the engine, basically right underneath the stereo. Where the transmission would be on a RWD car. It is easy to identify because it has a long drive shaft coming out of it going to the rear of the vehicle to drive the rear wheels.

There was a discussion about the bevel gear oil recently:
HERE

there was also a recent discussion about the rear diff oil:
HERE

PS: Please try to do a little searching on the forums before posting a question. It's arguably better to revive an existing thread on a particular topic if there are additional questions.


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1998 V70 AWD Turbo 180k+

What does the owners manual specify? In the manual for the 1999, Volvo recommends synthetic oil for rough duty operation, such as towing or hot locations. This should apply to 1998, too. Even the 1995 940 manual recommends synthetic.