Question about 1984 Jeep CJ7

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Major bind in 4 wheel drive

Rear driveline rotates a little over 4.5 times for each rotation of wheel. Front driveline rotates a little over 2 times with each rotation of the wheel. It was like this when I bought it and the only thing the previous owner told me about the rear end was that he had it welded to work like it had lockers. It had a bad hub so I didn,t find out there was a problem until I fixed the hub quite awhile later. How do I identify the differentials that are in it? My book says it should have a Dana 30 in the front and a Dana 20 in the rear.

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Yuo deifinitely have to get rid of one differential to match the other. I would change the rear diff as the gearing in that one will give you really poor mileage... additionally welded spider gears (poor mans positraction) make cornering a nightmare (the outside wheel must turn faster than the inner one on turns, which is why no one uses "spool" type differentials on anything but drag race vehicles (because they only go in straight lines).
As far as which Dana unit you are supposed to have, YOU MUST MATCH THE EXACT GEAR RATIO TO THE FRONT UNIT or, it will destroy the transfer case!!! You could even modify a chevy or ford diff to fit under there, but the ratio match has to be exact!!! To find ratio, count the ring gear teeth and the pinion gear teeth. I don't remember the formula but you need to establish a ratio from these two #s.(divide the ring gear# by the pinion#??? answer is expressed as (answer:1 such as 3.23:1))

Posted on Feb 01, 2009


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