Please help Limited slip Diff

[bajatrailrider]

Hi Guys new member.Building 93 Bronco. On rear diff,The ID tag on door  jamb painted over. On changing Rear diff oil.I think this is Limited slip diff.Both rear wheel turn same way.Is the Bronco clutch type,or gear type LS.       Front diff tag reads 3.55  Will try later to post picture of Diff with cover off.

 

[Bully Bob]

Your local auto parts will tell you what's in there (factory)

Could be aftermarket as well.

I've not heard of geared "posi" (limit. slip)  Pretty sure they're all clutched.

Req. gear oil & additive  to work right.

 

[Rons beast]

The LS could be done with clutches or cones. The cone type is rare but either needs the LS/Posi additive...OR Valvoline makes a gear oil that is synthetic and has the additive in.  It is inert and compatible with any remaining dyno gear oil that may be left behind. 

80-W90 part #VV831.

 

[bajatrailrider]

If I can post picture of inside diff,then could you tell me if cone type LS.?

 

[bajatrailrider]

Ok the mystery gets deeper.This truck is registered as 93.Paper ID tag covered with paint on door jam says. Date 06/89 trans T / Axel H5.This bronco has mustang 302 Gt motor,with overdrive trans.Tomorrow I will get numbers from Axel tags.This thing is mis match truck. I cant fine info how to down size photos? Wont let me post.  

 

[Rons beast]

Hey baha,

Yes if you post a pic we most likely can determine if your diff is clutch or cone...however either or even non-posi can use the same gear oil.

Often these older vehicles are put together with pieces from various others by any number of previous owners.   What is the vin #  that will tell you the info at least on the cab. Again what is the need for knowing the exact year? Are you having a hard time finding parts, or just want to know? 

The down sizing of photos is out of my knowledge box as is most anything computer related. Someone here knows how. They can chime in. 

 

[Bully Bob]

This is why we press hard for filling in your info pages.

Folks with answers won't come forward until all known info. on ea. vehicle is posted.

W/O the profile/info..., it takes 5-15 posts to burrow down to the actual problem.

It's "fluid" meaning you can update at any time.

 

[miesk5]

EDITED at 1127 hours on 3 March 2016

Yo,

Identification Based on VIN, Door Jamb Label, Build Sheet (Ford 999 Report), Paint Color Code, VECI Label, Transmission/Differential Pan & Gasket Sizes/Shapes, etc.; "... made a mistake 15 years ago by telling someone to use the Driver's side label to ID their Rear Differential (axle, pumpkin type, etc.); turned out that a previous owner had swapped a Dana 60 in place of the stock 8.8..." by me here @

http://broncozone.com/topic/22440-drivetrain-identification/

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Axle (aka Differential) Codes by Ford & Helm via Keith L (TTB Blows, Bling-Bling) at http://web.archive.org/web/20020220012159/http://90bronco.homestead.com/axlecode.html

H5 is 4.10 limited slip

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btw,

Differential/GEAR FAQs, Determine Ratio, Open or Closed Diff (Posi or Locker), etc. - GREAT INFO! Recommended Gear Ratio, General; "...Differential Gear Ratio determines the number of times the drive shaft (or pinion) will rotate for each turn of the wheels (or ring gear). So if you have a 3.73:1 gear ratio the drive shaft turns 3.73 times for every turn of the wheel. Gear ratio is calculated by dividing the number of teeth on the ring gear by the number of teeth on the pinion gear. The higher the number, the lower the ratio: a 5.29 gear has a lower ratio than a 4.10 gear. With a lower gear ratio the drive shaft (and thus the engine) turns more for each revolution of the wheel, delivering more power and torque to the wheel for any given speed. Lower ratios are generally desirable when going off-road. Higher ratios are better for freeway driving since they run at lower RPM's and offer better fuel economy. Changing tire size affects the final drive ratio. Switching from a 30" tire to a 35" tire changes the final drive ratio by about 17%. This may drop the engine out of its' "power band" and result in poor performance and fuel economy. To restore performance you must change the gear ratio to compensate for the change in tire size. If you originally had 3.07 gears you need a ratio that is approximately 17% lower, such as 3.55. If you want to increase off road performance you might want a 4.10 or lower ratio. Recommended Engine RPM @ Highway Speed; 4 cylinder 2200 - 3200; V6 cylinder 2000 - 3200; Small block 1800 - 2800; Big block 1800 - 2600; Diesel: 1600-2800. A limited slip or positraction differential typically uses some form of clutches that bind up the differential, providing traction to the both tires. The clutches will slip to some extent to allow tires to turn at different speeds on corners. Some limited slip differentials are more aggressive than others, and some can be set up or "pre-loaded" more or less aggressively. Limited slip units require a special gear oil additive and may chatter when turning. Clutch packs may also wear with time and require replacement. Jack up one tire if you have an open diff, or both tires if you have a working posi or locking differential. Rotate the tire one full revolution for posis and lockers and 2 full revolutions for open diffs. Carefully count the number of full revolutions the driveshaft makes. This is your gear ratio. In other words, if the drive shaft turns 3 ¾ turns, you probably have a 3.73 gear ratio. Turning the tire for twice the number of full revolutions and dividing the drive shaft revolutions by two will give you a more accurate reading. Put the transmission in neutral and jack up both tires. Turn one tire. If the other tire spins the opposite direction you have an open differential, and if it spins the same direction you have a posi or a locker..." See diagram to show ring gear and pinion gear depiction.

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"...Ford typically builds 4WD trucks with a slightly faster/numerically lower front gear ratio than the rear so that off-road steering is enhanced. So a truck built with 3.55 rear gears will have 3.54 front; 3.08 rear - 3.07 front; 4.11 rear - 4.10 front, etc..." Following was in my MS WORD Notes and the source, Randy's Ring & Pinion has removed it from their current web site; The gear ratio in the front of a four wheel drive has to be different from the front so the front wheels will pull more. There have been many different ratio combinations used in four-wheel drive vehicles, but not so that the front will pull more. Gear manufactures use different ratios for many different reasons. Some of those reasons are: strength, gear life, noise (or lack of it), geometric constraints, or simply because of the tooling they have available. I have seen Ford use a 3.50 ratio in the rear with a 3.54 in the front, or a 4.11 in the rear with a 4.09 in the front. As long as the front and rear ratios are within 1%, the vehicle works just fine on the road, and can even be as different as 2% for off-road use with no side effects. point difference in ratio is equal to 1%. To find the percentage difference in ratios it is necessary to divide, not subtract. In order to find the difference, divide one ratio by the other and look at the numbers to the right of the decimal point to see how far they vary from 1.00. For example: 3.54 ÷ 3.50 = 1.01, or 1%, not 4% different. And likewise 4.11 ÷ 4.09 = 1.005, or only a 1/2% difference. These differences are about the same as a 1/3" variation in front to rear tire height, which probably happens more often than we realize. A difference in the ratio will damage the transfer case. Any extreme difference in front and rear ratios or front and rear tire height will put undue force on the drive train. However, any difference will put strain on all parts of the drivetrain. The forces generated from the difference have to travel through the axle assemblies and the driveshafts to get to the transfer case. These excessive forces can just as easily break a front u-joint or rear spider gear as well as parts in the transfer case. By me here

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VIN Decoder Chart for 81-86 & 87-96 Bronco & Ford Trucks BEST!

Source: by lmctruck.com @

http://www.lmctruck.com/icatalog/fd/full.aspx?Page=11

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96 Bronco-F-Series Workshop Manual (PARTIAL) by FORD via

http://www.diesel-dave.com/vehic/manual/stj/stjleft.htm

Same as most earlier years especially 92-96, excepts for OBD II in 96, 4WABS (93-96); ABS (87-92); Air Bag (94-96); 3 ***** Automatic Locking Hubs (Built from May 95 through 96); Spark Plug Wire Routing & Firing Order (The firing order for 1987-1993 5.0Ls is 1-5-4-2-6-3-7-8. The firing order for 1994- 96 5.0Ls & all 5.8Ls is 1-3-7-2-6-5-4-8.);

2-piece Spindle Rolling Diaphragm Seal (RDS) used on 5/95 to 96 Broncos & F Series 1/2-ton 4WD

and a few other items that I still need to research...

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Section 05-02H:

Differential, Traction-Lok Limited Slip, 8.8-Inch Ring Gear was optional...Description

The limited slip axle assembly is identical to the conventional rear axle (4001) except for the differential (4026).

The limited slip differential employs two sets of differential clutch packs (4947) to control differential action. The mounting distance of the differential side gear (4236) is controlled by seven plates on each side: four steel, three friction, and one steel rear axle differential clutch shim (4A324). This steel rear axle differential clutch shim is of the selective type to control the position of the differential side gear.

The plates are stacked on the side gear hub and are housed in the differential case (4204). Also located in the differential case, between the differential side gears, is a differential clutch spring (4214), which applies an initial force to the differential clutch pack. Additional clutch capacity is delivered from the ****** loads of the differential side gear. Splined plates are splined to the side gear hubs which, in turn, are splined to the axle shaft (4234). The friction plate ears are keyed to the case so the differential clutch packs are always engaged. see this and internal depiction at http://www.diesel-dave.com/vehic/manual/stj/stj52h01.htm

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Model: AOD

Type: Four speed non-electronic

Years:

'85-'93 F-150

'85-'89 Bronco

Engines: 302

Display: PRN(D)D1

Pan square with small ****

Fluid: Mercon

Ratios:

1st 2.40:1

2nd 1.47:1

3rd 1.00:1

4th 0.67:1

Trans code: T

By Seabronc at

http://broncozone.com/topic/10386-transmission-id-chart/

*****

For the heckUva it...

Here is a 92 Bronco window sticker showing the 3.55 LS as an option

http://www.supermotors.net/registry/media/600611_1 by amtarsha

 

[bajatrailrider]

Thank you guys for Info,I will try to post Vin number.I think Dash vin/door jam vin are different.As last owner,changed many parts.Then Rolled it.I replaced cab roof,with posts/doors/front sheet metal.I keep truck in Baja,Mexico.All the parts I got for it,where dirt cheap.From wreckers here.Where is frame vin number? Still I cant find,How to down size pictures.

 

[Rons beast]

If so many parts were replaced a VIN is of little use since you can't be sure what it codes is what you actually have.

AND you original post indicated you wanted to know what gear oil to use in the diff. That info was provided.

So pics are a moot point.

I guess I'm confused as to what info you now seek.

 

[bajatrailrider]

Took me long time to post this.Is this Clutch type,or cone type Diff. Thanks Guys.

 

[Bully Bob]

Clutch

Looks the same as the pic above that M5 sent you.

 

[bajatrailrider]

Thank you,I missed that picture.