I'm in sweden but surely you have some authorities that make sure your vehicles are safe for the road in the us as well.


So, i have a -88 F150 with AOD and a limited slip diffirential rear.
The previous owner said that every time he took the truck to the annual inspection he had to bitch and whine at the inspectors in order to clear the rear brake test because the limited slip diff would make the brakes perform differently depending on where the wheels are placed on the brake test rollers. And by differently i mean that the braking balance (dunno what its called in english) would alternate between the left and right wheel upon repositioning the truck on the brake test rollers.

My english is poor when it comes to techical terms but i hope you understand it anyways

 

Hi there, your english and spelling is about equal to our college kids on this site. I'll let you determine if I am complimenting or slamming you. In the state where I live, dynos are not used, in California they are for emmisions testing but quite frankly, I am not familiar with its other uses.

In my understanding of the previous owners description, I would have to agree with him 100%. The limited slip function of the rear end has no bearing on braking, unless the rolling resistance is different on each side. What in the world do they say with anti lock brakes, which brings up another issue, is the dyno 4 wheel or two wheel?

Good luck and Welcome to the forum!

 

I'd have to say it's probably better than the texting influenced half-english most 20-somethings use.

I know it doesn't answer your question, but welcome to the forum. My wife's family is Swedish and every year I have to go the St Lucia festival... in Florida! Oh well, the price I pay for beautiful daughters. Again, welcome to the forum.

 

Geese! That's got to be a near perfect "Apples vs. Oranges" argument. Limited slip relates to traction during acceleration & ABS relates to traction during deceleration, specifically during braking. The only thing they have in common is, the two rear wheels are involved. So America has yet to corner the market on incompetence! That's a good thing, right? Do they know how the second hand on a "Rolex" is supposed to behave? If not, I can get them a great deal on one. Imported from "Mexico"!

 

When I was a kid I used to pray every night for a new bike. Then I realized that the Lord doesn't work that way, so I stole a bike and asked him to forgive me.
The bike story was very insperational! .....Wait a minute!............. and "The Lord helps those, who................" It's all starting to make sense now! ...I get it! It took 52 years, but better late than never, right?

 

What ymeski said...the braking "issue" as your inspectors call it is just the Anti-lock Braking System (ABS) doing the job it was designed to do.

 

Limited slip has NOTHING to do with stopping....only aids in traction for taking of....hence the term slip....

Brakes take care of just that...I am afraid to tell you that the previous owner was an idiot....

 

If he was braking on individual rollers with a limited slip the brake input would tend to equalize the torque going to each tire. Depending on what they were measuring the transfer of torque could be mistaken as a bad brake on one side or the other. Riding the brakes is a good way to equalize traction with a limited slip and is taught by most off road instructors to help traverse gulches or areas with only one tire having traction.

 

Thanks, a nice ego boost at 7 in he morning.

Yeah, the rollers are individual

 

I heard a saying once...."If you cant dazzle them with Brilliance...Baffle them with Bullcrap..."

this is definitely some baffling going on here...

all brakes are applied and the same time...only separation is the front to back NOT side to side....

only time there would be is when one side is allowed to slip and the ABS or Anti-Lock kick in...

that goes fine for the front and back unless you have Limited Slip or Positive traction....

when you have an Open Differential you can have side to side braking as the Spider Gear will alow plenty of slipping so to speak..but even in a straight line the spider dont move and traction is equal..only time the spiders move is if the wheel is over powered by torque or the brakes lock unevenly...as in one side tighter than the other...or road surface not holding traction...

this will NOT happen in a limited slip...both rear wheel are tied together...they have even traction so Individual braking in the rear mostly will not happen unless the clutches in the rear are shot to the point the differential acts as it is an Open Diff...

if it is within spec there will be no separation except when turning so individual braking of the rear can an will ruin the clutches...