12 Bolt Rear End Question
12 Bolt Rear End Question I have a strange 12 bolt in my car, 4.10 gears and HD posi, 33 spline i believe it was. Had it in there for close to 2 years now atleast. And just recently, its began to make noise taking turns a slow speeds. It gives off the sound to the roll of the tires. In other words, its got a pattern to the noise, its not just random clunking. It sounds like the clutches engaging and such.. but its never done this before.
I dont beat on the car a whole lot, nor am I making enough power to kill the HD Posi that i know of. Only thing ive done lately is put DR's on it, but even then, i havent sat there doing burnouts or driven all that differently. I find it kinda hard to believe the posi is dying from pretty much nothing. I will be taking car in to have rearend drained and to take a look for metal shavings. Then put some new fluid and see what it does following.
Any ideas what else to look into? Any help or comments are appreciated. Thanks
I dont beat on the car a whole lot, nor am I making enough power to kill the HD Posi that i know of. Only thing ive done lately is put DR's on it, but even then, i havent sat there doing burnouts or driven all that differently. I find it kinda hard to believe the posi is dying from pretty much nothing. I will be taking car in to have rearend drained and to take a look for metal shavings. Then put some new fluid and see what it does following.
Any ideas what else to look into? Any help or comments are appreciated. Thanks
TECH Fanatic
Joined: Sep 2004
Posts: 1,124
Likes: 1
From: Las Vegas
DR's slip a-lot less than your normal street radials... so, its probably working the diff a little more than it was with the last set of shoe's you were running. You may have not had enough friction modifier in the lube to begin with... and you may have just never noticed the tire slip or clutch chatter before the change.
With a tight clutch pack and the tire slip associated with modern, harder durometer street radials... I wouldnt think you'd hear the clutch chatter to begin with. The new DR's just plain hook... and I'll bet the clutch chatter is related to the amount of friction modifier in the base oil. You may need to run just a little bit more to take the chatter out of it. With the lube change, you'll need about 4oz of fric mod.
With a tight clutch pack and the tire slip associated with modern, harder durometer street radials... I wouldnt think you'd hear the clutch chatter to begin with. The new DR's just plain hook... and I'll bet the clutch chatter is related to the amount of friction modifier in the base oil. You may need to run just a little bit more to take the chatter out of it. With the lube change, you'll need about 4oz of fric mod.
