Has anyone out there had any experience with the Steffansson (www.samsteffansson.se) limited-slip differential (manufactured by AP Racing) for the S/V70 series? The U.S. distributor for S.A.M., Maximum Vehicle Performance (www.mvpvolvo.com), has told me they haven't sold a single one of these in the U.S.

The unit is supposed to be a geared system similar to a Quaife. I would think this would do wonders for us front-drive T5 owners who just can't seem to get that power to the ground and I'm curious why the LSD isn't popular.

-Dale

...you do know that the FWDs diff is inside/part of the transmision don't you? That being the case, it's no surprise to me that no FWD Volvo owner would want to pay the labor to have their trans removed and dissassembled for such a mod as it'd be very costly.
If the car was still under warranty, adding that part could void the warranty being that the trans didn't come that way from the factory (in the US) and thus if and when anything else related to internal trans parts failed, the customer would be out (IE:no coverage).
I can see adding the RWD MVP unit to a RWD Volvo (not multi-link however) as it's fairly easy to do and even if it didn't hold up, one can find a good used rear axle assembly for those (700s/940s) fairly cheap. The FWD trans diff is another story in itself and not anything that an amateur DIYer is likely to do himself IMHO, at least not your "average guy" with basic home tools.

> ...you do know that the FWDs diff is inside/part of the transmision don't you? That being the case, it's no surprise to me that no FWD Volvo owner would want to pay the labor to have their trans removed and dissassembled for such a mod as it'd be very costly.

Actually.. The diff can be removed from the transmission housing without having to remove the transmission from the car. Oil needs to be drained an refilled and the drive-axles have to be removed (and thus part of the front suspension). But a competent mechanic should be able to do it in about 4 hours or so.

I had a viscous-diff installed in my S40 T4, which also has the M56 gearbox used in the 850/S/V70's. Worked very well IMHO..

Bye, Arno.

It's rare to see any MY 850s/X70s in this area so I don't have a MT car in front of me but I checked the Volvo OEM MT manual (TP4101201) and from the pictures shown it looks like the case halves for OUR M56 MT are one piece case halves, the diff cannot be removed w/o R&Ring the trans and splitting the case halves.
The X40s, X80s are not available here with MTs so it's very likely then that what you have is not the same MT as what we're getting here.

I am aware of the complexity of this job. Considering that the unit itself is $1700, I can imagine that cost will drive many people away from this mod. I was just thinking that FWD with LSD would be a viable alternative over AWD for people who want a little more traction, especially since Volvo doesn't appear to have its act together on AWD implementation in the V70.
No -- definitely not a DIY job for the non technical and absolutely not recommended for vehicles still under factory warrantee.

It's also for MTs only and MTs are now fairly rare in the US these days. As for traction control, it's really not a problem if you think about it. If one takes off "normally" (even w/o TRACS, which most cars now have) you don't spin the wheels on any car, not even during rain or snow.
I have a modified RWD 745T (auto trans) and even with its 2,600 rpm high stall speed torque convertor (standard, stock rear diff) wheel slip isn't a major problem on dry roads or wet roads if I accellerate normally (not floored).

From what I'd gather about the FWD, MT unit, it's something that only a serious racer would consider, not your "average guy" who drives the car daily.

i would've snatched a lsd the first thing i modded. but alas, i have an auto...so, the lsd is for manual (if i recall correctly). manuals were not really offered on the turbo/t5 (in the u.s. that is)...only later in the s70/v70...

Steve,

I guess I've got one of the very few manual T5s in the U.S. I bought it through Tourist and Diplomat Sales in Germany. I'm now beginning to realize why every U.S. Volvo mechanic who sees the car asks me if I bought it overseas.

Was it actually difficult to get a T5 stick here or were dealers just discouraging buyers from ordering a manual so they could sell cars off their lots instead? It should be possible to order a car in any configuration you want and, in 99, the T5 was available in U.S. Spec with a manual gearbox.

Having driven both auto and manual T5s, I can't imagine getting an automatic on purpose.

-Dale

The biggest problem I had finding my 98T5M(anual) is one local dealership
was quick to trade any manual cars with other dealers. People did
not want them, I was told (I think they just did not have any at this one
dealership). Another dealer had one (still had the plastic covers on
the rotors and hood) and I purchased that one. While it was parked
in front, another guy wanted to test drive it (sorry, sold). I think
they just did not import too many and few people order cars since the
emotional appeal to drive it away is so great.

In Europe, the S70 T5R (yes, there is an R) has a viscous coupled
transmission (manual only) that was not offered here. That might
be a better route then limited slip since it is all OEM parts
(assuming you can get the parts).

I read (some car magazine) that Saab experimented with limited slip
on the Vigen and found it increases tourqe steer so they decided not
to use it. Guess that makes sense if you have more traction you get
more tourqe steer.

You're absolutely right; it does make sense that an LSD in a front-drive car should increase torque steer. An open differential guarantees that each half of the drive system experiences about the same torque and any torque steer is caused by component inertia, unequal shaft twist, or uneven pavement causing the torque "moment arm" to vary slightly from left to right (the last one is why moderately wide tires on a front-drive car can adversely affect handling). Add an LSD and this is no longer true. If one tire has traction and is delivering torque to the pavement and the other tire does not, you would think that the steering wheel would be pulled toward the tire with less traction.

For some reason, however, several front-drive applicable LSD manufacturers, including Quaife, claim that their LSDs actually reduce torque steer. I don't understand how this could be true, but they're making the claim.

Does anyone out there have more information on this?

-Dale

lucky u =). i don't think volvo brought any of the manuals over to the u.s. for the 850 turbo/t5 models, at least, not thru the dealers anyway. they started to have manuals only after the s70/v70 overhaul/facelift.