What type of Limited slip (Traction Loc) rear?

[k98dave]

Doing a rebuild on the rear in my car (gears, all bearings & seals including axles). Also got a set of clutch plates however the carrier is not like anything I had seen before in any Ford 7.5 or 8.8, as it has no clutch pack. Reminds me of the old GM 12 bolt carriers of the late 60's early 70's. What type carrier assy. is this? Is it unique to the SVO?

[MikeFleming]

ALL SVOs came originally with a 7.5 and Trac-Loc clutch-type differential. There's not much to replace that with for the 7.5 - just a Trac-Loc or open diff, afaik.

The 8.8 could have any variety of diff installed as many different things are availale for it: Ford Trac-Loc, Locker, Torsen, etc..

[k98dave]

Thanks,

It looks like a Alburn type, with the two piece case and 5 springs (2 on one side, 3 on the other) separating the spiders which are on what looked like cone shaped washers. Image below
There is no "clutch" disc stack like you would see in standard traction lock carriers on the 7.5 or 8.8. Like I said the only place I recall seeing this inner spring type setup was on the old GM style 12 bolts.
We did not split the case as the trac lock is working fine, just installed new gears/bearings etc. Looks like this was on a lot 7.5 Fords (see moser link)

http://www.moserengineering.com/differentials/auburn-hi-performance-series/7-5-ford-28-spline.html

http://www.auburngear.com/aftermarket/images/gallery/diff-exploded.jpg

[SVO4PWR2]

ALL SVOs came originally with a 7.5 and Trac-Loc clutch-type differential.

Not so Splicer made some 7.5 for Ford and it was Cone style.
I have that type in my 84.

-RICH-

[MikeFleming]

1984 Car Shop Manual - Powertrain, Lubrication, Maintenance
Section 15-42: Axle, Tractiojn-Lok Limited Slip Differential - 7.5 Inch Ring Gear

Vehicle Application
Mark Vii/Continental, Thunderbird/Cougar - LTD, Marquis, Mustang/Capri

Description
The frictional surface of the brake cones consists of a course spiral thread that provides lubrication passages.

The cones are pre-loaded with five springs mounted between spring thrust plates that press against the side gear and brake cone assembly.

Section 15-23: Axle, Traction-Lok Limited Slip Differential (Ford) - 7.5 Inch Ring Gear

Vehicle Application
Mark Vii/Continental, Thunderbird/Cougar - LTD, Marquis, Mustang/Capri

Description
The traction-lok axle assembly except for the differential case and its internal components. is identical to the conventional axle.

The traction-lok differential employs two sets of multiple disc clutches to control differential action.

This diff uses the S-shaped pre-load spring.

My 84 originally came with the clutch-type Trac-Loc. I suppose either could have been used according to the service manual application lists.

The stated break-away torque (testing diff friction function) states 30 Ft-Lbs for the cone type and "at least 200 Ft-Lbs" for the clutch type. I know for a fact my 84 SVO, when new, needed more than 150 Ft-Lbs to rotate a raised rear wheel with the other side on the ground.

[k98dave]

Great info.....that's what I like about sites like this researching the little changes.

My car was an early build (Sept 83) = 110th SVO made

"I have that type in my 84." Rich, was your car an early build also?

Perhaps only early cars used this type or maybe switch to clutch type for production unit costs. Auburn type to this day cost more to manufacture

[SVO4PWR2]

I dont recall the month but it is a Slapper car.

-RICH-

[Kendal Coker]

So far all the 84's I have taken apart have been the Auburn type. Also all the 85-86's I have taken apart were the clutch type. Just my .02 cents worth. I may find some different in the future.

[brsvo]

This looks like as good a place as any for my question. I have an 8.8 TC axel with the S spring and want to know what to torque the 4 trac loc carrier bolts to? I found it sooo much easyer to install the trac loc and S spring with it out!

[k98dave]

Torque/set-up specifications:



Torque


SAE


SI


Tool size




Pinion bearing pre-load, used


8-14 lb-in


.9-1.6 N-m


n/a




Pinion bearing pre-load, new


16-29 lb-in


1.8-3.2 N-m


n/a




Pinion nut, minimum


140 lb-ft


190 N-m


1-1/16"




Ring gear fasteners


70-85 lb-ft (in stages)


95-115 N-m


3/4"




Main bearing fasteners


70-85 lb-ft


95-115 N-m


3/4"




Pinion shaft lock bolt


15-30 lb-ft


20-41 N-m


5/16"




(Metal) Cover fasteners


25-35 lb-ft


34-47 N-m


1/2"




Driveshaft


70-95 lb-ft


95-130 N-m


12mm 12-point




Lugnuts


85-105 lb-ft


115-142 N-m





Set-up







Backlash


.008"-.015"


.203-.400 mm





Ring gear runout


.004" maximum


.0762 mm




References:
1991 Shop Manual. Helm Publishing
Part #:FPS-12193-91 (last two digits = year)

[brsvo]

Thanks