I'm looking to upgrade my 1991 940t with a locking or limited slip rear-end before I skin the right rear tire.

Does anyone have some straight up details on the Powerlock vs. TrueTrac diffs for the Dana 30 rear end? I've been thoroughly confused by previous posts on the forums.

Eg.

Weight
locked torque transfer bias (50/50, 30/70, etc...)
Max Torque rating
Reports of harshness, clunks, ratcheting, etc...
Durability (wear)

Also, can anyone tell me whether or not a 1991 940t would have the electronic speed sensor in the diff?

Thanks,

Lare

I'd be surprised if you didn't have an Eaton locking diff already (supposedly "all" 1991MY 940 Turbos and maybe even naturally aspirated cars had that). There might be differences.

It will allow some wheelspin but usually cleans it up by 10mph.

The unit is fairly reliable and long-lived. Use LSD-ready axle lube for best results. It can live on standard rear axle lube, but the takeup of the unit is more severe and noticeable, as the clutch slippage is much less.

If you DO have the locking diff but it isn't locking, suspect a problem. I really like the function of that unit vs. an LSD unit.

The Eaton unit is used in a lot of high performance cars and trucks, so a Volvo application is very "light duty" with respect to unit longevity, compared to some of the higher horsepower ones. If you don't have the eaton unit (no LSD/Locking diff at all) I'd say, get one. They are very slick.

Chris,
How much do one of those puppies cost?. As you may remember, I discovered that my 'southern' V90 has no ALD. WIth a slight 1+ inches of snow here in Bal'mer, an not a plow or salt truck in sight, I was slip-sliding away, and had trouble backng into my parking pad after a trip to home depot.
--
John Shatzer, '97 V90 @ 92K; 92 965 @ 106K

Contact Brian Leppin at Brian@Volvousedparts.com.

Since your car is a 1991 turbo 940, it may already have the Eaton locker. The Eaton locker is a 1041 rear end, and can be identified by the tag on the rear of the left axle tube. It could be a 1031 axle assembly since the Eaton locker was introduced as a running change in the 1991 940 turbo cars.

Yes, your car has the electronic speed sensor for ABS and speedometer in the rear end.

I have the TrueTrac and prefer it to the Dana Powerlock.

I thought the Detroit Locker was the hot new LSD and favorite of the Brick crowd.