1988 bronco

[Stewmeat2]

My LS is worn out. This one is going to be a hiway rig. Which kit do I need to rebuild 8.8 inch Dana 44 IFS? Front diff tag has:

354 E8TA LD 610335-3. I'm thinking about a Dana 44 TrueTrac kit made by Eaton for 3.73 and Down,30 Spline..? The rear has no diff tag and the axle(s) end play is excessive. I'm thinking about a 3.55 Gear, Complete True-Trac Differential, Master Rebuild Kit..?

Strangly enough, I have another Bronco, same year: Front diff tag 354 E8TA SC 610310-2, Rear diff tag 55 88 702-S807D; REAR ring gear code: 2 373 547 AF 11 41 2H8. I'M SURE THE TAGS ARE WRONG and the last owner had LS carriers, ring and pinions installed with 3:73 ratio.

...2700 RPM @ 55mph but this one isn't good on gas!!

 

[Justshootme84]

(Post moved to appropriate forum)

Welcome to Bronco Zone!!! I'm assuming you are refering to the rear 8.8" axle L/S being worn out, and not the front, since very few fullsize Broncos came from the factory with a front L/S. For reference, the 3.54 front ratio in the Dana44 TTB is used with a 3.55 rear axle ratio. If you know for certain that the axles are stock and untouched, you can bouble-check the gear ratios with the axle code on the safety sticker located on the driver's-side door jamb. The code should be "H9" for a 3.55 factory L/S Ford 8.8" rear, found on 1983-1996 Broncos.

You have the option of rebuilding the factory L/S with new clutches, or replacing entirely with a new unit. The Detroit TrueTrac is a gear-driven L/S, as opposed to the clutch-type found in the factory Trac-Lok L/S. For a highway rig with 33" tires or less, the factory or replacement Trac-Lok should be sufficient whenever you need the added traction.

If you are looking to add a L/S unit to the front for 4WD use, the TrueTrac is a good choice. There is also an aftermarket Dana trac-Lok available for the front Dana44 TTB for about half the price of the TrueTrac.

IN the case of the second rig, the tag numbers "55 88 702..." indicate a stock 3.55 gear ratio without L/S (the 3 is hidden under the tag bolt). Since someone has installed 3.73 gears with L/S and not replaced the tag, the only 100% surefire way to tell what you have in your rig is to pull the rear cover and look for the numbers. Or you can use the method of rotating the rear tires two revolutions and counting the number of revs of the rear driveshaft, then dividing by two to account for the spider gears.

If you need more info, post up or take a look at Miesk5's Homepage of Bronco links. There is a ton of info on axle ratios, gear swaps, limited slips, etc. JSM84