What is the gear ratio?

[KirkLipscomb]

I'm trying to determine the gear ratio on the front differential - 1990

Cherokee. The tag shows this:

53005576
55 610 17-7

And stamped on the cover is:

DANA 4 - 0869
193 9
Rev E
11 22 88

Not sure what the numbers mean.

[AlohaBra]

Don't know what all those numbers mean but FYI:

A "Disconnect" Dana 30 was used in the 90MY. This axle uses a vacuum actuator on the passenger side to slide a locking collar between an intermediate shaft and an outer shaft. This feature keeps the driveshaft from spinning on the highway, thereby yielding a vibe free ride. This axle came with 260 sized u-joints, and 27 spline shafts, just like all other Dana 30s.

The gear ratio for the front is the same as for the back, usually 3.07 for manual transmission or 3.55 for auto trans..

Other Gearing Information:

3.07 - used with 4.0L engine / manual transmission
3.31 - only available on older (pre87?) 2 door XJs with "Fuel Economy" package
3.55 - used with 4.0L engine with automatic transmission; also used with 2WD 4-cyl engines (possibly 4WD as well) equipped with the 4-speed manual transmission
3.73 - found in some XJs with the towing package
4.10 - used with 2.5L engine usually, and older XJs with the "Off-Highway Vehicle" package.

[fredjacksonsan]

Right on with the gear ratios (as usual) AlohaBra.

Backyard mechanic's way to measure the axle ratio is to tape some string to the driveshaft, move the vehicle until the wheels rotate once, and count how many times the string is would around the driveshaft.