My wife has a 93' 940T wagon with 110K miles. With all the snow/ice we have had in Charlotte, I was wondering if this car came with a limited slip diff. I heard that the later 940T's had this as standard but I have never confirmed. If

Volvo is nebulous about this. They say 92-95 have them, and then some 96- 960 and 90 series cars.

Who knows about which cars actually have them. Every single 740/940/960 for model year 1992 was supposed to have them, but someone, somewhere, found ONE car that didn't have it, so of course someone couldn't wait to get me on that one...

A lot of 1993s have it, but it looks as if it once again became optional in 93. At least it isn't the same as the other locking diffs that I have in 940s. The one in my 940 wagon is a really raucous device when there is a snow/dry-pavement combination with one wheel on snow and the other on dry pavement. The locking diff is very noticeable in the rain. If you rip the inside wheel on a slow corner, the outside wheel locks up and you're fishtailing. Also noticeable on snow and ice, where you usually hear a muffled clunk and that's all. I got to really watch it work last weekend when I got stuck in some depressions in the ice, and could actually watch it kick in with the door open. Doesn't take much to make it happen either.

I removed an Eaton locking rear end (Volvo 1041) from a 1991 940T, and helped my son install it in his 1984 760T. He lives in Pullman, Washington, and there has been plenty of ice and snow there this winter. Evan feels the locking rear end has really helped getting around Pullman's slick streets this winter, but he has had to learn about both rear tires breaking loose at the same time.

The only issue left to resolve is the speedometer. The non-ABS rear ends use a 12 slot tone ring, while the ABS rear ends use a 96 slot tone ring. Volvo used an ABS signal convertor to make the speedometer work correctly in the 1987 and 1988 modle year ABS cars. I have the signal convertor, but we ran out of time to get it correctly hooked up in Evan's car. He now uses the tach to compute speed, and has no cruise control until we get the speedometer working correctly. If you have any other suggestions on the speedometer, I'd like to hear them.
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john

What about a 1989 or 1990 ABS speedometer? Is there a reason that those don't work? I don't doubt there may be some differences betweeen 1984 and 1990 model years, but maybe there aren't.

That is a great suggestion, and we have considerered that. I even have a 1990 turbo instrument cluster. The catch is making the gas gauge and temperature gauges work. To make the temperture gauge work should only require the later temperature sender, and I seem to remember there was a problem with the gas gauge and sender. There are probably a couple of wiring issues, too. I have high skills on the electrcical stuff, but Evan does not understand (or want to) how long it can take to do that kind of work.

Evan will be home this weekend, and we may even try the 1990 instrument cluster if we don't go skiing.

Thanks for the suggestion.
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john

Very interesting!

I'd be interested in hearing if that works. I wish I knew more about what parts work with what cars. I'm limited to engines and transmissions for the most part. The ancilliary parts are a mystery to me in many respects.

I was definitely wondering about the other gauges being compatible. I know, that kind of thing can take a long time to do properly. Unfortunately there is no other way, no shortcuts (no need to fry a cluster!). Good luck with that.

By the way, I noticed a goofy behavior of the locking diff. We finally had some snow here this year, so I've had some testing time.

I don't remember anyone mentioning it, but I figured it out after a few times. I ran into a few occasions where I was on very icy surfaces right before making a tight turn onto dry pavement. The differential does the appropriate thing, apparently, which is to lock solid between the two sides. The problem arises when you turn onto dry pavement when it is still locked. The difference between the outside wheel distance traveled, and the inside wheel distance traveled, is quite significant. As a result, I've had a few occasions where I felt a strange, obvious struggle--almost a skip--in the rear of the car. Simple answer when I figured it out. THe diff was locked like a 4wd axle, after I had spun one of the rear wheels. Because of that, it never unlocked, dragging the outside wheel or spinning the inside wheel to match the distance traveled by the other. Very strange, pronounced 4wd-type behavior. It had me worried for a while until I figured it out. Now I expect it when pulling out from my parking garage.

Have fun skiing, if you go. Otherwise, enjoy working on the car!

Your car should have a locking differential -- different from a limited slip differential.

Copy and paste this link into your browser... it has the info you're looking for:

http://www.brickboard.com/FAQ/700-900/Driveline.htm#AutomaticLockingDifferential

Good luck.

Jeff Pierce
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'93 945 Turbo ( one kickass family car ! ), '92 Mercedes 190E (my daily driver), '53 Willys-Overland Pickup (my snow-plow truck/conversation piece)