I have a 1984 242 Turbo that is not running. It has the M46 trans. How can I tell if the rear end is a limited slip version ? Thanks, & Happy Holidays ! Bruce.

Bruce,

Though they're a lot of fun, you don't need to do any tricky burnout rituals to know if yours is an LSD diff or not: Bill's first suggestion, of raising the rear axle and spinning one tire, is the simplest; and it's failsafe. If both tires turn the same direction, it's LSD as Bill says. If one doesn't turn, or they turn in the opposite direction, it's an open diff.

If you find that you do have an LSD diff and you want to give the clutch packs a quick field test; (if you do this, please be more than careful): jack up one rear wheel and leave the other firmly on the ground. Put the gearbox in neutral and do not engage the parking brake. Use a torque wrench set to 40 foot lbs and rig it to the center of the elevated rear wheel. If your LSD clutches are okay, the elevated wheel will not turn with less than the 40 ft/lbs' force. Again: more than careful! It would be very easy to turn the 'grounded' wheel and roll the car right off the jack. Falling cars can be real nasty. Careful careful careful please.

Hope this is of interest.

Best,

Cam

Cameron, thank you for the info. It is greatly appreciated. Bruce

Easy way to id a limited slip in the wrecking yard whne both wheels are off the ground. Turn one driven tire and watch the other one. if it turns in reverse direction you have a standard rear end. if it rotates in the same direction you have a limited slip rearend.

]Bill D.

Bill, thanks for the help. It is greatly appreciated. Bruce

I have also been confused about how to tell if it is a limited slip. I always thought my car was (always leaves 2 equal ruts if i get into the boost on a dirt road), but when the car is jacked up, the wheels spin opposite directions. I guess no LSD for me, but it would be nice to have. Maybe once I replace the U joints and Trans\Engine mounts I can try a pavement burnout to find out for all if it is LSD. In the condition it's in right now, I'd be afraid t obreak something if I dropped the clutch.

Zack, hope it turns out to be an LSD. Bruce

In a parking lot put one drive wheel on dry pavement. The other wheel is in a drainage triugh area with a little soap and water in it. or try ice and dry pavement. Stand on the brakes rev up the engine then pop it into gear and let go of the brakes. if the car moves on in a straight line you probably have a LSD if the wet tire just spins you have a standard rear end.

Not sure if I have this right so if I'm wrong anyone feel free to jump in here. I believe if the rear end is off the ground and the transmission in gear or park. With regular you can turn a wheeel with someeffort. A LSD the wheel will not turn at all?

Bill D.

If someone were to try your test on dry pavement/ice they could well injure themselves. All one has to do is accelerate moderately and the car will not go straight, but will turn away from the side with the dry pavement, because that side has traction. The icy side will not have traction regardless of how much power is being put to the wheel, and will spin.

A better test is to put both wheels on a slippery surface; ice, snow, or mud. Try to pull ahead from a stop quickly. If the rear jerks to one side and the rear wheels feel like they want to be the front wheels, you've got posi. Anyone who's lived with a posi for a while knows that feeling on a wet curve when the car suddenly wants to swap ends. It would be hard to have a posi for any amount of time and not know it, unless you drove like grandma.