Thread: 9 inch troubles

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Hopefully a simple on to solve.. Could some one please explain to me the difference between a 2 pinion and a 4 pinion 9 inch and how i can work out visually what i have?

Any links to websites with explanations are welcome too as i had no luck!

I know zero about these, other than you bolt them in and they make the wheels turn. However, here is part of an excellent tutorial on the internet:

Internally the number of clutch disc and plates differs between the equa loc and trac loc spools, the equa loc having only 3 fiber plates and 4 steel with one large belveder spring applying force.The trac loc unit utilizes 4 fiber plates and 5 steel plates, with 4 smaller springs applying force.Both equa lock and trac loc units were available in 2 pin and 4 pin varieties, in either 28 spline or 31 spline versions.The four pin 31 spline unit would be more commonly found as a trac loc piece. The four pin being the heavier duty unit utilizing 4 spider gears vs just two in the two pin variety (as noted in figure above a four pin variety will have actually just 3 pins and a two pin will in reality just have 1 pin- the number of spider gears is actually what is being referred to).Shown below are the internals of a four pin equa loc, note the five “fingers” on the steel clutch plates-the tiny circular tabs on outer edge- (trac loc units will have only 4).


Here is the website, and it seems to show pictures of 2 pin and 4 pin units for comparison. This is one of the best, most informative sites I have found on this subject, and if you read through it, especially toward the end, it might have the answer you are looking for.

http://www.kevinstang.com/Ninecase.htm

Don

I'd be interested in this answer too. Never heard of a 2 or 4 pinion 9". I've heard of 5 or 10 bolt ''pinion supports'' for the 9''.

Sorry, I should have read further. I thought you were talking about the pinion.