Rear Differential Fluid
 

One of the last things I have on my list for maintenance on my Volvo was the rear end fluid. I figure after 30 yrs. (most likely) on the same fluid it is time for some fresh stuff.

My research shows that there was some random limited slip differentials sprinkled out there. How do I tell if mine is/isn't?
How much do you usually use of the stuff on a change?
(trying to not buy that 3rd jug if I can get by, stuffs not cheap!)

never seen a 240 with a LSD, AFAIK those were pretty much only in higher end 740/940, like turbo models, plus 760, 960's (and the 1991 940SE thats really a 960 turbo).

they aren't 'true' limited slip, they are simple lockers... if you're going under around 20mph and one rear wheel slips too much, both rear wheels are locked together. if you get out on some dirt/mud/snow, go to full lock turn, launch from a stop and give it enough gas to spin a wheel, you'll feel it klunk when it hooks up.

Pierce:

I don't mean to hijack this thread, but what rear end is in my 1987 760 Turbo? I can't find anything in the owner's manual, and the dealer has no idea if it is a LSD or a locker.

I am gong to be changing the rear diff oil with synthetic, and it uses a lot of oil, so my suspicion is that it is a locker.

From what I can see, you have a far greater knowledge of Volvos than I do.

(Do you have any questions about SAABs or Brazilian Puma autos...maybe my knowledge on those might be greater than yours... :-)


David Riedle

there should be a sticker on the rear axle, usually just left of the pumpkin (differential), and facing rear. 1030 is the regular one, 1031 is the locker. AFAIK, Volvo never used true limited slip, although there are aftermarket options for this, $$$.

edit: oh yeah, this sticker is typically buried under 1/4" of road grime and undercoating, I had to wipe it off with some paint thinner to read it on the one car where I bothered... and be careful not to wipe the printing off too.

Pierce:

Thank you! Unfortunately, the car has gone away for the winter...although it was 62 degrees here in Michigan today...

My guess that it is a locker as well.

Dave Riedle

the easy test is, when the road is wet and slippery, when you're at a stop at a left turn full crank the wheel, and as you accelerate give it enough gas that a rear wheel spins at low speed, if its a locker, the whole rear end will suddenly klunk and lurch.

Finally changed the fluid. Old stuff wasn't really that bad for being 30yrs old. But it's done took a little more than one bottle (32fl. oz.) of gear oil.
Thanks as usual Pierce and co.

I am going to change my differential oil in the spring, since the car is away for the winter.

I know the oil is fine, since the car only has 40,000 miles on it, but the synthetics are so much better than the old dino oils of yesteryear. My thoughts are that using modern oils should make the car virtually indestructible.

Of course, maybe it's just me...


Dave Riedle