Discussion in 'The Garage' started by CHEVY 4WD, Feb 20, 2003.
How do detroit no-spin and powertrax lock right and no-spin work?
Picture the turrets of a castle. They've got those slots in them for the archers to shoot thru, right ? Ok, now picture a similar part in metal, with a couple of small changes. The depth of those slots isn't very much and the sides of those slots are angled so that they are narrow to the 'top'.
Lock-Rites are comprised of 4 main pieces of metal, all shaped like this. There are two pairs mated so that the slots fit together. The outer most two of the pieces have splines for the axles to engage in. The inner two have a 'V' shaped groove with a round bottom across their backside. The pin for the spider gears fits in the hole created by this pair of grooves, but it is an intentionally sloppy fit.
In use the R&P drives the diff case just like normal. The pin drives the inner pair of parts by being trapped in the V groove. The castlations of the inner pair drive the outer pair. The outers drive the axles.
When one tire has no traction it allows the axle to be easily twisted. That allows the pin to ride up the side of the V groove a little. Since the groove is a V, it acts like a ramp. In this case the pin slides up the ramp of both inner parts which compress' the castlations so that they can't skip past each other very easily.
When the twist in the axles is very great, one or both pairs of castlations will overcome the pin-V groove ramp loading and skip past each other. That is the 'bang' or 'snap' you hear on occasion.
That help ?
Your explination of a lock right is excellent. I installed a front and rear some time back and even though it was a simple job I wish you would have written the manual. Thanks Nike
Have you ever experimented with differing preload spring presures?
I think the Detroit in a Dana 70 app is very stiff as it is destined for a heavier truck.
Stock Car Products sells a range of springs for 9" Detroits
I haven't played with diferent spring pressures. I only have one and it beahves well enough as it is. I'm kinda at a loss as to why you'd want to. I'm sure that there is a valid need to do this in some application, I just don't know what that might be. Since a roundy car supplier has the springs, I wonder if they're trying to soften or stiffen up the engage/disengagment point to tune the diff to a given track.
Maybe going to a lighter spring would allow for easier steering with one in the front, so long as you're not on the throttle ? huuuummmmm........
The previous owner of my front axle (bought it with lockright already installed) firgured out how to get it from popping, or at least you hearing the pops. I haven't heard a pop from it yet with it in 4x4. The answer to the pop is Redline Heavy Shockproof Gear oil. It is SUPER heavy, and acts like a shock absorber in the diff. I think the thickness combined with the shockproof characteristics is what stops the pops. The gear oil is expensive ($8-9 a quart), but it works.
You can thank DesertDueler for this cure.
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