Which limited slip is best?

[lil_Blue_Ford]

Yes, but I don't mind. People like to weigh in. I didn't know there were so many different options for the Ranger.

I suppose there might be some thanks to the Jeep crowd since they really like the 8.8” Explorer axles to replace their junk rear axles. But it also helps that the 8.8” was used in Mustangs, Rangers, Explorers, F-150s, etc. So there’s a lot of options out there because of popularity

 

[Lefty]

I suppose there might be some thanks to the Jeep crowd since they really like the 8.8” Explorer axles to replace their junk rear axles. But it also helps that the 8.8” was used in Mustangs, Rangers, Explorers, F-150s, etc. So there’s a lot of options out there because of popularity

I had a couple Jeeps. I loved them. My CJ5 was tough as nails and pulled a lot of people out of some real hairy places. I really like that 8.8 with the 4:10 in the Ranger. It might not get the best mileage but it makes for a geared-like-a-mountain-goat feeling: downright fun to drive.

 

[gw33gp]

@gw33gp - your statements are getting more and more incorrect. A locked differential does NOT send 50% of the torque available to each axle all the time! A locked differential sends the same rpm to each wheel regardless of the torque, including cases where 100% of the torque goes to one wheel and 0% goes to the other.

What you are not understanding is my statement of "effectively locked" If you have a bolt that is torqued so that it takes 100 lb-ft to loosen it, if you only have 50 lb-ft available to attempt to loosen it, it is "effectively locked". Same thing with a differential - if the diff requires 500 lb-ft of torque bias to allow it to differential, and the tire can only provide 300 lb-ft of torque, the differential is "effectively locked."

If you have a Torsen diff axle with one wheel in the air, only that wheel will spin no matter how fast you spin it, because the Torsen diff will not "lock" when there is no torque on it. The only way to get the vehicle to move forward in your example above is to put your foot on the brake, so that there is some torque required to turn the wheel that is in the air.

Lefty's question has pretty much been answered and I believe he has pretty much decided on what he wants to do. I don't think it will hurt anything to continue the discussion on the Torsen.

You and 00t444e are correct about a locked differential making both axles turn at the same rpm. I was trying to come up with that but used the mindset that both tires had traction. My mistake was saying "all the time". Using equal torque was not a good example because it is true only in limited conditions.

I understand your effectively locked bolt example but that does not equate to a differential. Torque bias does not care how much torque is applied to the differential. It just applies a percentage of the torque (called bias) of the axle with least traction to the axle with the most traction. In order for it to be locked or essentially locked it would have to have a 100% torque bias. That is what lockers or spooled differentials do. I believe a T-2 Torsen has at most 50% torque bias and that would not come close to being locked. If your ""effectively locked" term includes 100 ft-lbs torque on one axle and 50 ft-lbs torque on the other axle, then I can agree. However, that is not locked. That is still differentiating.

If a Torsen did have the ability to be locked, the tires would be screeching around every corner.

You are right about using the brake when one tire is in the air to get some torque on the axle to transfer some torque to the other axle. That is not the only way to get some torque on a free spinning axle. When you accelerate a free spinning wheel, it requires force to increase the rotational momentum. That force comes in the way of torque from the axle. That torque can then be used to send some torque to the other axle. I use this method in surface conditions like moguls where diagonal tires can be lifted or have little traction. I have a manual transmission and I don't have three feet, so the acceleration method has worked well for me.

I am sorry if I have gotten to the point of boring anyone. The scientist in me just can't let it go.

 

[Lefty]

Lefty's question has pretty much been answered and I believe he has pretty much decided on what he wants to do. I don't think it will hurt anything to continue the discussion on the Torsen.

You and 00t444e are correct about a locked differential making both axles turn at the same rpm. I was trying to come up with that but used the mindset that both tires had traction. My mistake was saying "all the time". Using equal torque was not a good example because it is true only in limited conditions.

I understand your effectively locked bolt example but that does not equate to a differential. Torque bias does not care how much torque is applied to the differential. It just applies a percentage of the torque (called bias) of the axle with least traction to the axle with the most traction. In order for it to be locked or essentially locked it would have to have a 100% torque bias. That is what lockers or spooled differentials do. I believe a T-2 Torsen has at most 50% torque bias and that would not come close to being locked. If your ""effectively locked" term includes 100 ft-lbs torque on one axle and 50 ft-lbs torque on the other axle, then I can agree. However, that is not locked. That is still differentiating.

If a Torsen did have the ability to be locked the tires would screeching around every corner.

You are right about using the brake when one tire is in the air to get some torque on the axle to transfer some torque to the other axle. That is not the only way to get some torque on a free spinning axle. When you accelerate a free spinning wheel, it requires force to increase the rotational momentum. That force come in the way of torque from the axle. That torque can then be used to send some torque to the other axle. I use this method in surface conditions like moguls where diagonal tires can be lifted or have little traction. I have a manual transmission and I don't have three feet, so the acceleration method has worked well for me.

I am sorry if I have gotten to the point of boring anyone. The scientist in me just can't let it go.

Yes, I like the Torsen too. I might even have one installed next week, depending on parts available here in town. I'm no engineer, but I've driven Jeeps and limited slips before. I've liked them all, found them highly road worthy and safer for the most part. Still it seems as though the Track Lock might be slightly better mannered for just driving around on the streets and require little or no change in my driving habits. I'm not going off road. I'm not pulling trailers, and, for the most part, I have given up on pulling other people out of the ditch.

 

[Lefty]

Yes, I like the Torsen too. I have some understanding about how it works. I might even have one installed next week, depending on parts available here in town. I'm no engineer, but I've driven Jeeps and limited slips before. I've liked them all, found them highly road worthy and safer for the most part. Still it seems as though the Track Lock might be slightly better mannered for simple basic stuff, just driving around on the streets or not getting stuck. I hope that it will require little or no change in my driving habits. I'm not going off road, not pulling trailers, and, for the most part, I have given up on pulling other people out of the ditch.

Some of you mentioned lockers. They are okay too. They can work well on the street but IMHO are better suited for off road. I would rather have a locker than nothing, It's a lot easier to install. I'm no mechanic, but a friend of mine put one in. He thinks I could maybe do it and offered to help if I got stuck.

Still, I prefer to have a limited slip, have a bonafide mechanic open the differential up, inspect it, and do the install. It's a subjective choice for the most part.

All of your comments have been formative in this decision. I will report back in a week or two when the installation is done.

 

[lowspeedpursuit]

This thread certainly went places. I think arguing about LSDs being "effectively locked" is semantics. If we said an LSD with higher bias is relatively "closer" to being locked, I don't think anyone would disagree.

"Effectively locked" isn't a practical consideration. Straight on-road, the driver doesn't care. Around a corner on-road, exact behaviour may differ, but either LSD will differentiate. When you have no traction, the differences from a locker are obvious.

 

[Uncle Gump]

 

[gw33gp]

View attachment 102054

Now that is some math! It would probably take me a lifetime to figure it out.

 

[Lefty]

This thread certainly went places. I think arguing about LSDs being "effectively locked" is semantics. If we said an LSD with higher bias is relatively "closer" to being locked, I don't think anyone would disagree.

"Effectively locked" isn't a practical consideration. Straight on-road, the driver doesn't care. Around a corner on-road, exact behaviour may differ, but either LSD will differentiate. When you have no traction, the differences from a locker are obvious.

Well said. Thanks!

 

[Uncle Gump]

Now that is some math! It would probably take me a lifetime to figure it out.

I'm just copying your answer...

 

[Lefty]

I'm just copying your answer...

You're the best Gump Thanks for your comments.

 

[2011Supercab]

View attachment 102054

It's obvious, the answer is 42

 

[Lefty]

It's obvious, the answer is 42

Isn't that the answer to life, the universe and everything?

 

[sgtsandman]

Yes, I like the Torsen too. I might even have one installed next week, depending on parts available here in town. I'm no engineer, but I've driven Jeeps and limited slips before. I've liked them all, found them highly road worthy and safer for the most part. Still it seems as though the Track Lock might be slightly better mannered for just driving around on the streets and require little or no change in my driving habits. I'm not going off road. I'm not pulling trailers, and, for the most part, I have given up on pulling other people out of the ditch.

Which leads me back to my original answer for the question you are asking. To me, the Torsen or the Eaton Tru-Trac would be the best choice for your application just because there is less to worry about as long as you change the gear oil to maintain proper lubrication. No clutches to worry about wearing out and no additive to remember putting in the differential when changing the gear oil.

A clutch system will do the job and will probably be just fine but in the long run, there will be more maintenance with them over a worm gear actuated LSD.

 

[Lefty]

Which leads me back to my original answer for the question you are asking. To me, the Torsen or the Eaton Tru-Trac would be the best choice for your application just because there is less to worry about as long as you change the gear oil to maintain proper lubrication. No clutches to worry about wearing out and no additive to remember putting in the differential when changing the gear oil.

A clutch system will do the job and will probably be just fine but in the long run, there will be more maintenance with them over a worm gear actuated LSD.

I'm meeting with a mechanic next week Monday. All of these are on my wish list. He's going to track down what's available. My options may be limited. We will take it from there.