Dana vs Salisbury LSD behaviour?

E-Type
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Michael: Here are the three different carriers, you judge. This is a photo I bet you won’t find anywhere else. The 3.54 one is in the middle.

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Tony: I’m not going to argue what you saw or did because I wasn’t there and can’t inspect your diff, but emphasizing ZERO in upper case doesn’t make it true.

It’s perfectly possible that the clutches were worn out, or assembled with a very few plates and low torque configuration. It certainly seems to have been the case that the torque transferred to the driving wheel was insufficient to move the vehicle, where a locker would have. But the way you check for fitment of an LSD is precisely to jack it up with both wheels in the air and the trans in neutral.

If you turn one wheel and the other one turns the same way it is an LSD. Why? Because the half-shafts are linked by the clutches.
If you put one wheel on the ground, the free one will only turn once you overcome the break away torque setting of the clutches, Why? because the half-shafts are linked by clutches.

This linkage is permanent and non-negotiable, so there is ALWAYS (see what I did there? :slight_smile:) torque at both wheels. However, the real heavy-duty locking happens under power and good traction, where the ramp action presses the clutches tight. With one wheel spinning free, it is possible no ramping will occur unless you put some brake on, , which will leave you only clutch torque and that was/is not enough to shift your 4WD by the sound of it. Just don’t argue that clutch LSDs never deliver toque to a wheel, when that is the entire function of the clutches. Which doesn’t mean they are as good as others for off-roading - they’re not - but they are not totally ineffective either.

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Pete,
I didn’t know there were 3… I thought there were two. 3.73 and down and another for the shortest gear sets.
Most will be going down from the 3.54 or maybe an early north american 3.8 with a 3.31 going down to a 3.07 That doesn’t require a different carrier does it?
Has anyone who has gone from a 3.54 to a 2.88 had to change their carrier?
Quaife is making new 3.07 sets with the correct 10 spline pinion. They only offer one ATB diff AFAIK with the correct 19 spline config… so that’s the market. The eaton truetrac is made for 30 spline drive shafts whereas the Quaife and Thornton powr lock is 19 no? …and I think the truetracs are made in China.

I doubt most powr loks are working correctly

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??
Aren’t you referring to an open diff?
The powr lok transmit power to the wheel(s) with traction

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Some believe because they see but blessed are those who have not seen yet believe.

:slight_smile:

1.2,3 = 3
2.88 & lower (2.69?)
3.07-3.54
3.77-4.10 & higher

May be out a tooth here or there, but that’s the basic grouping.

3.54 can’t swap to 2.88 without other components swapped. Hope Dick can confirn.

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what Jag refer to as a powr lok is a clutch pack LSD, not a locking diff

with a clutch pack LSD, it MUST have at least SOME torque on the spinning wheel…if it has NO torque…ie the wheel of a 4wd is in the air, it will not work AT ALL.

This is absolutely proven

An auto locker such as a Detroit Locker WILL auto lock the axles when a differential speed occurs.

ARB or OX are manually actuated and lock the axles

Eaton Truetrac is somewhere in between.

http://www.eaton.com/us/en-us/catalog/differentials/eaton-detroit-truetrac-differential.html?wtredirect=www.eaton.com/Eaton/ProductsServices/Vehicle/Differentials/detroit-truetrac/index.htm

According to their literature, they will operate in a situation with zero torque on one wheel, but not as positively as a Locker, that is why they are somewhat favored in front diff of 4wd, altho the hardcore guys will elect a manually-selected locker

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You’re getting mixed up Tony. I’d advise to stop digging.

  1. What Jag do you have and have you got a shop manual so I can show you where to read Jaguar’s explanation of the Thornton LSD?

  2. What do you believe is the function of the clutches?

  3. If it is “absolutely proven” that clutch LSDs transmit “ZERO” torque and do not work “AT ALL” then I look forward to reading any serious publication or web link that you can provide that says anything of the sort.

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You mean collapsible, right?

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ok gents, better respond before an outbreak of shortshaft jokes :blush:

Firstly, thx Peter for availing me new learning…edit…I did not see your earlier response where you show pictures and detail the ramp action, so thanks for going to the trouble of doing that, I was not trying to argue against that post!

Secondly, even though it may seem that way, (including after this reply) I am not confusing open diff operation vs LSD

Proceeding more carefully, without capitalisation, and bearing in mind thread diversion, so in summary,

The way I worded what I meant to say was incorrect & something I was missing as well

My Daimler VDP has Powr-Lok, which I broke and replaced, MKX Powr-Lok diff to go into my 420G,
and my GMC 6x6 had Thornton Powr-Lok in the front diff, which I swapped into another axle housing

Technical & other literature states the Thornton Powr-Lok LSD differs from other clutch plate LSD by having an alternative pinion mate gear & cross-shaft arrangement etc, facilitating the clutch plate operation with ramping etc

This is stated to be the most aggressive type of LSD

As to the question of whether a Powr-Lok can be induced to effectively act as an open diff under any circumstances, from the literature and your (Peter) respected automotive knowledge, presumably never

In the instance of whether factory LSD D44 equipped 4WD, such as Isuzu, Jeep etc can be induced to act effectively as an open diff under any circs, ie one wheel off the ground…to avoid being covered in mud, I can only suggest people do their own research

had a bit of a squizz at Truetrac online info, diametrically opposed statements, what to believe?

in any case does seem like the Powr-Lok is hard to beat for a Jag

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fwiw, the Jeep Dana 44 (that accepts a Truetrac) has a 30 spline, 1.30" OD axle

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No sweat Tony. Happens to us all. Had to laugh at several errors in that Daze Mustang IRS article as well.

Not the cheap shots like pointing out the Jag IRS did not debut in the 1960 3.8S (there being no such car in 1960, nor E) but his statement that early Mustangs had a 58” wheelbase. I know little about pony cars, but if that were true, there wouldn’t be room for doors between front and rear wheel arches! Wheelbase/track are hardly interchangeable terms…

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Thanks Tony I’m on the road this weekend , but will look at the E Type size on getting home tonight.

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This one might be close to 58"

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His strangest claim is that the E-type IRS was designed AND manufactured by Spicer in the US, and was shipped over to Jaguar as a complete assembly.

I’ve googled that claim to find a possible source, and I’ve never found a mention of that claim elsewhere.

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Thanks Tony. I measured the clutch plate out of a Jaguar diff, as I don’t have a diff opened to actually measure the spline, and it’s 25 tooth 2.18" dia. That dia. measure may not be totally accurate but I suspect it’s within a tenth of an inch at worst.

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not wanting to flog a dead horse, but genuine curiosity

the other day, I changed a wheel on a Jeep Cherokee with LSD.
I know the LSD works, as it not only rotates accordingly with 2 raised wheels, but I have felt it operate (usually upon gassing it on a wet slippery corner)

only lifted one wheel 1/2" off ground, got distracted…forgot to remove jack

wont drive off bottle jack under axle tube on level ground!

this is as I have come to expect after 40+ years of 4wheeling…lift a wheel on LSD, and you have minimal traction on other wheel…not zero, but bugger all.

that is why a multi-hundred million dollar industry exists pulling out perfectly good LSD carriers and replacing them with locking diffs in 4WDs

I cannot personally replicate this test, as my V12 is off the road, and my 420G doesnt have LSD

It is entirely probable that the different mate gear/cross-shaft initiates an action in a similar way to a Detroit Locking diff, which has a Cam action to automatically lock and unlock the axles, and are aggressive to use on-road

Not quite so easy to replicate my test, as the Jeep has a solid rear axle, so no way to damage anything, but I would be very interested to see if a Powr-Lok equipped vehicle can drive off a jack, with one wheel in the air…some idiot surely must have tried to do so accidentally , like I did

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Well, maybe the UJ’s in the IRS were made by Hardy / Spicer and that was enough “evidence”. :smiley:

I am very sure the IRS cages were welded in England. And the whole development of the IRS incl. testing with prototypes (E1A, E2A and a D-type) was most definately done in England (ask Norman).

But the “fact” (untrue) heard much more often is that the Jaguar AJV-8 engine would be based on the US Ford V8 or Buick V8, which is complete nonsense too. Yet it has been published in print many times. Or the myth that Mercedes (Daimler-Benz AG) would own the Daimler brand in North America which has been on Wikipedia several times is also completely untrue. (There is a registration for the Daimler trademark in North America by Jaguar Cars Ltd.)

Cheers!

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May I join your discussion regarding limited slip rear axles. In the “0ld FORUM” I posted a series of pictures of a 1959 Ford F150 Dana 44, 19 spline axle with a Ford TRAC-Lock LSD. Call it what you want it is still a Dana and similar to what Jag used BUT NOT A THORNTON. Not the same animal. Look at the pictures and draw your own conclusions. THE TRUTH IS OUT THERE. Pete

The pictures are on old forum April, 6 2013 Guys please if you are only repeating hearsay THEN LABLE it
as HEARSAY, RUMORE, URBAN LEDGEND and not fact
a lot of this info will be referred to later by people working on their own cars.

I do not know if this is copy righted or not I do not have specific permission to use
Version:1.0 StartHTML:000000241 EndHTML:000005115 StartFragment:000000626 EndFragment:000005083 StartSelection:000000626 EndSelection:000005079 SourceURL:mhtml:file://E:\Copy (1) of My Documents\Jaguar Differential Build Dana 44.mht

Everything you need to know! Let me preface this article with a warning! If you have never set up a rear-end, used a case spreader, used a dial indicator or a pinion depth gauge, you have no business tackling this Dana 44/Salisbury Differential.

First, There are basically two versions of the Dana 44/Salisbury Differential easily identified by the side stub axle covers. One version has a 5 bolt retainer plate, the other has a triangular 3 bolt retainer. Another major tech spec you’ll need to know is the side axle spline count It will be either 19 or 30.

I will concentrate the information for this overhaul on a 19 spline Salisbury, since that’s what I have.

I purchased all my parts for a Dana 44. Word of warning! It’s OK to order your differential carrier and ring and pinion for a Dana 44, but you’ll want to buy your bearings, races and shims at a local 4wd store because a kit won’t have all the correct bearings and you’ll just be wasting money!

Other important decisions you need to decide before you start your rebuild; 1.What size gears will I use? That will determine which size carrier (or case) you’ll need. There’s a break at 3.73/3.92

Which type of carrier suits your purpose; limited slip, locker, air locker or possibly a spool! I used an Auburn Gear which was the best price for the quality! Note: There is NO spool (full or mini) available for 19 spline axles!

I won’t bore you with setup specs because those are readily available at all the gear manufacturers sites!

Another important note if you plan to use a new carrier with your Jaguar gears. The Jag gears use larger ring gear bolts. You’ll have to drill out your carrier holes and chamfer the edges for the Jag ring gear to bolt on to the carrier! It’ll work and it’ll be fine! The only factor you need to be aware of is, you cannot later buy different gears to install on that carrier because the bolt shoulders are smaller and your carrier will be drilled too large! You’ll need to purchase a new carrier or fabricate steel sleeves for the carrier (too much work, I’ve done it)!

I will let you know that backlash and carrier preload are adjusted using shims that are behind the pressed on carrier bearings. You will be removing and pressing these bearings on and off several times! A nice convenience is having an extra pair of side bearings that have the centers honed so they slide on and off the carrier easily allowing you to press on the new bearings only for final assembly.

Pinion depth is adjusted by adding or removing shims from behind the inner pinion race.

Both sets of aftermarket gears that I purchased did not use a crush sleeve, so we won’t go into it’s purpose or adjustments.

One last note regarding the Pinion. You will now have a 26 spline input shaft. You cannot use the Jaguar flange. Your local 4-Wheeler supply will have the Chevy yoke and U-bolts you’ll need! Spicer #2-4-8091X

Here’s my list of parts:

Bearings and Races

Carrier Bearings: 25590

Carrier Races: 25523

Pinion Bearing Inner: 31594

Pinion Bearing Inner Race: 31520

Pinion Bearing Outer: M88040

Pinion Bearing Outer Race: M88010

I have used 2 different Auburn Gear Carriers. I currently have the 5420111 Hi-Performance for Dana 44 3.92 up, 19 spline.

The input seal is a CR 15788

I’d also consider replacing the rear brake hose for about $12. Part # N7000-42133 or IN102467

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Sure. And I was not aware before that not all the internals are exchangable, but 3,54, 3.31 and 3.07 are. And the 2.97/2.88/2.69 where the 2.88 I believe was pretty common in XJS’s.

I have the 3.31 in the V12 and I am happy with it. I used to have the same in my ex Ser.1 2+2 but that also had an overdrive (auto to MOD conversion) and I thought I would like an O/D or 5th gear in the V12, but I don’t. Driving fast with the V12 OTS is fine the way it is, IMO.

Cheers!

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Finally an excellent essay of what works and what doesn’t by someone who’s done it and has first hand knowledge. Thank you!
A word of caution, it seems that on the forum, in trying to be helpful, incorrect information is presented as fact. If you haven’t the first hand experience, please indicate that.

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…happens in matters of science, too!!

On my old—~200,000 miles— LSD diff in Tweety, it would pull itself off of an incline ramp, on one wheel. Plenty of tractive effort.