. Equa Lock V Locking Differential

[x-codegtcs]

OK - looking at Steve's wonderfully exotic find in Reno has me wondering what the difference is between a "locking differential" as stated on Steve's Marti Report and the Equa-Lok (lock) Differential stated on my 67 GTA? Was it just marketing lingo differences between 67 and 68? Or are there other differences?

 

[gt/csj4]

If I'm not mustaken (see what I did there) posi trac is a chevy name and Ford has dubbed theirs as 'equa lock' but all that I've seen on reports as; conventional, and equa-lock which essentially is a limited slip with a fancier name. I'm sure there's more to it then that however I've never really dug deep into rear ends...on mustangs anyways :wink: Anyway from what I do know limited slips are basically one wheel supplying power up until the other wheel slips in which it will then lock both wheel to evenly distribute power onto both. Whereas, a posi-track, is a constant locked diff supplying power to both wheels, which is why many people complain of the noise that is omitted thru the rear end because of the harsher angled ring and pinion gear and the locking section within the 3rd member, but if you own a locking diff ford you know the limi-slips are noisy as hell around corners (lovely clicks) A conventional is basic in that it supplies power to just one drive wheel all the time and the other wheel spins in forward motion with it, and if the drive wheel slips, it wont lock the other, hence the 'one wheel spin special' when guys burn out

Is there other offered diffs thru Ford? I know there are, not sure the names, but I am certain someone else can chime in on this. I think I heard a while ago that early mustangs with 9'' rears the had limi-slips were 28 spline whereas the later mustangs (67+) that were equipped with them, received a 31 spline. Is this confirmed? Nope, but it's worth mentioning

 

[x-codegtcs]

So would the Equa-lock be a limited slip and the locking more of a Detroit Locker?

 

[gt/csj4]

I believe the "detroit locker" is derived from the stance of the "posi unit" ergo; continuously locking diff. I don't exactly know where the name is from, but I know that GM has in some shape or form name-plated that to their vehicle monocle,but, I could be wrong here. I think in a lateral form, depending on vehicle manufacture, they make up some variation of different rear end names, to which have and serve the same purpose. detroit locker, posi track can be submissive at best, but in essence are just that; locking differentials.
Equa lock as I said, is merely a unit in which one wheel drives one singular wheel until it begins to slip in which the locking mechanism automatically locks the other wheel to help aid in traction, which does not require any driver control ( like air lockers and such do) the pros? Great, better forward motion traction in a straight line. The downside? Somewhat adverse oversteer, and a greater premature tread loss. Either way you cut it, it is better to have a purposeful "locking differential" then not at all. Better performance overall, but does helm a greater loss in other areas, which may, or may not , be a concern for most (simply cause it's just funner haha)

 

[RU_SPCL2]

Some background on the difference between limited slip differentials and Detroit Locker rears is available on Wikipedia. They essentially perform the same function but use different approaches in locking/unlocking.

http://en.wikipedia.org/wiki/Limited-slip_differential

http://en.wikipedia.org/wiki/Detroit_Locker

The Detroit Locker is a branded product of Eaton Corp., who is the leading maker of differential units for OEMs (i.e. the auto manufacturers) and the aftermarket. Eaton also produced the Posi-traction unit for GM and later purchased Detroit Locker.

http://www.eaton.com/Eaton/ProductsServices/Automotive/DifferentialsLockingDifferentials/index.htm


Ford used both Equa-Lock and Traction-Lok as brand names for their offerings. I don't know if they were Ford proprietary designs or OEMed from suppliers such as Eaton or Dana. They appear to be differ internally as noted in the following post quoted from VMF.

"Equalock™ and Traction-Lok™ are very different things, the E has a preset clutch pack, while the TL has a torque-sensing clutch pack.

Either way, it is possible to have one wheel spin under hard acceleration, although much more difficult with the TL. Clutch packs never truly lock.

It's "limited slip", not a locker. A locker, such as the Detroit Locker™, actually has a mechanical lock that freezes the differential solid when activated.

If you have an Equalock, you'll have to deal with a specialist. The E clutch pack is getting hard to find, and the Belleville spring was discontinued decades ago."

Hope this helps.

 

[gt/csj4]

great info i'll have to read up on it later :smile:

 

[Forsche]

OK - looking at Steve's wonderfully exotic find in Reno has me wondering what the difference is between a "locking differential" as stated on Steve's Marti Report and the Equa-Lok (lock) Differential stated on my 67 GTA? Was it just marketing lingo differences between 67 and 68? Or are there other differences?

Interesting post and I admit I know nothing about rear-ends (of the car-type that is) and, I'm not even sure I understand the good posts below although I'll read them again. I did read through the previous thread on this subject. I have a related question. Mine is a 302 with 3.0 limited slip and lists locking differential in the option list. Is the reference to limited slip and locking differential two different things? Can you have one without the other. And is limited slip or locking differential by definition a 9 inch rear-end?

I saw the previous post discuss whether non-GT cars could have 9 inch rears and the eventual consensus seemed to be that non-GT's could be ordered with a 9 inch rear although it was believed that only 302's could be ordered that way. This seems to fit the description of my car.

Thanks,

Steve

 

[CougarCJ]

I wish that I could find the video clip of Marisa Tomei explaining limited slip. :grin:

Equa-loc, from what I have been told is very light duty, and is a 2 pin locker?

Traction Loc is a stronger system and 4 pin locker?

Detroit lockers are (forged?) machined rather than cast. They came out in 1970 on performance Ford products.

 

[gt/csj4]

seriously so glad we have a group of people we do on this website because everything I think I know I have no idea lol

 

[x-codegtcs]

I wish that I could find the video clip of Marisa Tomei explaining limited slip. :grin:

Equa-loc, from what I have been told is very light duty, and is a 2 pin locker?

Traction Loc is a stronger system and 4 pin locker?

Detroit lockers are (forged?) machined rather than cast. They came out in 1970 on performance Ford products.

So, let me ask as in the Marti Report terms - When a Marti report states "E Limited Slip" and then below in the options report states "Locking Differential" what form is that?

I just wonder since I would expect some consistency (I know, I know) from Ford on the names. Since my 390GT FB is a 67, I just was trying to separate function from marketing mumbo jumbo.

 

[x-codegtcs]

seriously so glad we have a group of people we do on this website because everything I think I know I have no idea lol

I have to totally agree! EVERY search I do regarding Mustang parts and for clarity, has a link to CS.com...Some real knowledgable people here! Thank you all for sharing your knowledge!

 

[x-codegtcs]

Interesting post and I admit I know nothing about rear-ends (of the car-type that is) and, I'm not even sure I understand the good posts below although I'll read them again. I did read through the previous thread on this subject. I have a related question. Mine is a 302 with 3.0 limited slip and lists locking differential in the option list. Is the reference to limited slip and locking differential two different things? Can you have one without the other. And is limited slip or locking differential by definition a 9 inch rear-end?

I think they are one in the same because either it is a "locker" or it is "limited slip". Neither of which would make it a 9" rear end. The limited slips came in 8 and 9" rear ends. Looking at the photo posted in your car inspection thread looks like an 8". The tell tale clues are the top and bottom of the pumpkin are flat and there are little "notches" on the perimeter of the pumpkin. The 9" were more round and didn't have these notches. I have attached some photos hopefully demonstrating what I am talking about. The green primered rear end is the 8".

Hope this helps!

 

[robert campbell]

I wish that I could find the video clip of Marisa Tomei explaining limited slip. :grin:

Equa-loc, from what I have been told is very light duty, and is a 2 pin locker?

Traction Loc is a stronger system and 4 pin locker?

Detroit lockers are (forged?) machined rather than cast. They came out in 1970 on performance Ford products.

Scott is correct. there is a 2 pinion (one axel in the posi center carrier, two small pinion, equa lock) which is common to 28 spline axels and a lighter duty. There is a 4 pinion (two axels in the posi carrier, 4 small pinions, trac lock) that was stronger with more clutches and came "normally” with 31 spline axel cars. Much more heavy duty that the equa lock. I do not think the 4 pinion trac lock was available in an 8 inch rear end. Only the equa lock was available to my knowledge.

The Detroit Locker was the ultimate posi and used no clutches. It has a ratchet mechanism that throws a group of dogs into a mating syncro hub. Going around a corner at slow speeds it lurches and has a LOUD audible click sound. It is either in or out and is designed to throw in under power. You will know instantly when driving slowly in a circle if you have a Detroit Locker. It is a serious racing piece and not a favorite of casual cruising people.

Rob

 

[x-codegtcs]

Scott is right about almost everything he posts! ( I would say right ALL the time, but I am not sure that is human.. ;P )

 

[CougarCJ]

Thanks for the kudos, I try to verify things as the truth, prior to posting. It is all part of that carchaeology thing. ;-p