Last week, my friend Arthur bring one of his AE86's axle 3rd member to me. And asking if i could help him fix it or not. For he had read that i had a few experience with my car's LSD/axle. And his was in really bad conditions. At first glance, the pinion and ring gear still in work-able condition which leave me to check out the crush sleeve's pre-tension on the pinion bearings. And the result~~ I was correct. The pinion gear is sitting loose in it's housing. which means a faulty crush sleeve we were looking here.
After taking apart the 3rd member. i compare the crush sleeve with my 'reference' unit which i made with a new crush sleeve and lock the pinion bearing until 60lb/f.
And Arthur's crush sleeve was 2.6mm shorter, yaiks~
After discuss with Arthur, he agree that he will let me made a guinea pig out of him bt making him a Solid pinion spacer.
that 's what i had made by boreing out the sleeve from a single piece of mild steel.
the standard crush sleeve is 1.65mm thick with a weaken ring to let it actually 'crush' when it's under tremendous pressure.
And the one i made for Arthur is 3mm thick and no weak point. Now it's cleaned, installed and send back for Arthur to install and tell me the result in his next Taman Selat Drift day~
So~ you may asking y went through all the hustle doing this???
This is the explanation i copy from a famous axle specialist in US call-ed Weir Performance.
"What these parts do whencorrectlyinstalled is set the distance between theinnerandouterpinion bearings (bearing preload). At the same time, these parts also locate the pinion gear relative to the ring gear within the casing. So, why does the crush sleeve fail? It fails because it is too weak to resist deflection when high pinion loads are applied. This is why we often hear people say, “my ring and pinion finally blew up”. The failure is not instantaneous as it would be if the gears were over-powered. The failure happens over time, due to repeated hard driving. High pinion loads deflect the pinion gear over and over until the o.e.m. crush sleeve becomes “loose” and cannot properly maintain the bearing preload. This also allows the position of the pinion gear within the casing to move causing misalignment of the ring and pinion gears. Over time, this leads to “howling” gears followed by “ground up” gear teeth and eventually destroys the gears. Protect your ring and pinion with one of our high strength steel solid pinion spacer kits."