99 S70 AWD system
 

All,

I am new to this forum and am looking for info. Hope you can help... Got a 1999 S70 AWD in our family. This is our first Volvo, and fell in love with the beast. Since I work on my own cars, I was able to get things done like suspension rebuild, ATX flush! (thanks to this site) heater core replacement and other small repairs.
I live in Seattle and last year we had a pretty suckey winter. Our steep driveway was covered with snow and to my surprise, the car had a hard time making it to the top of the road. It almost seemed like it was 'stuck' in FWD mode only. Then my ABS lights came on along with the Engine light. Turns out, the ABS ECU was bad. Thanks to Victor in CA, he was able to repair it for me for less than $150 including shipping. The stealer wanted 1050 from me..
Since the car now has 140k miles, I want to make sure the AWD system is in order. What do I need to check on the system? Do I change fluid in the Haldex diff? Where is it located? Is it part of the transmission? Thanks, f

RE: 99 S70 AWD system
 

Greetings from Narita, Japan.

I'm not privy to the S70's AWD system, but I would check the owner's manual to see if there is a scheduled services for the diff. If so, replace it with the specified diff oil.

Also, make sure that the timing belt has been done at every 70,000 miles or within the last 5 years.

Wait till S70 owners wake up.

I wish you luck,


JPN

RE: 99 S70 AWD system
 

My question is how fast were trying to move in the car when the AWD system didn't seem to work?

Because the AWD system does stop working after 30MPH. It disingages and becomes FWD.

RE: 99 S70 AWD system
 

there should be a way to turn that off, i have all wheel drive, i want it all the time :)

RE: 99 S70 AWD system
 

Hi there
The VOLVO AWD system is not a real AWD, in a normal (Dry condition) Only 5% on the Torque is being transfer to the rear, so generally you are driving a FWD. However if the system (Slip differential) detect a slipage it's able to transfer up to 95% of the Torque to the rear. It means that you don't have a really AWD system unless the car start slipping! ( it's not like BMW, Audi or Infiniti)
Anyway I have the same car and I have lot's of noise coming from the transfer case ( They also call it Bevel gear OR Angle Gear) Expensive to repair ( Around $2,000 CAN) I am still thinking if I want to do this repair.
You have to check the AWD oil and make sure it's clean.
The other issue with this system is the Bevel Gear does not have any Drain plug, the only way is to suck it up and refill it (it need close to 1000 - 1100 cc, Please double check). Some people drill a hole into the casing and install a plug, I don't like it becuase you are not sure if you can get rid of all debris.
Please make sure to use Volvo AWD oil ( Kind of expensive $60 for 1 Lit.
Let me know if you found anything else, I need to gather more info, to make my mind whether to repair the bevel Gear or just take it out and convert the car to a FWD.

Best

RE: 99 S70 AWD system
 

thnks for the replies. I was trying to get out of the driveway very slowly, easily under 5mph. I was't getting tracktion at all in the rear, but hopefully this will be solved by hte new ABS module. BTW my 1990 Audi coupe quattro is unbeatable in conditions like these, so that's why I was kind of surprised about the volvos performance. Especially since it's a newer car. (1999)
Unfortunately I don't have the owners manual but will check the diff fluid and replace\refill if needed. Tnx,