To start, let me just say that I know very little about rearends. I can talk about cam design and engine stuff all day long, but put me at the other end of the car and I'm a dufus. Anyhow. About 7-8 years ago, I had a custom 12-bolt rearend built for me by Art Houser (RIP). I had him build it for me because he was able to build a true 2.56 12-bolt posi rearend for me. He had the 2.56 gears on his shelf, and was somehow able to adapt an aftermarket posi unit (I think he custom-machined a spacer plate or something). The only other things I remember is that he used sprigs that would give me 600# of pressure (by alternating springs for 400 and 800), and that the axles did not need the c-clip eliminators (something to do with the way the axles were made I think). After I installed the rearend, it would sometimes make a loud "clang" noise when going around corners. It sounded like someone was hitting my driveshaft with a steel hammer, and then resonating. People told me "you need to put in some more GM posi additive", and it worked. About 6-9 months ago, it started "clanging" again. So I've drained & refilled the fluid, and put in some posi additive. The clanging seemed worse now, so I added some more posi additive. Well that must have been the wrong thing to do, because now when it goes around corners it sounds like there is a machine gun going off back there! So, what do I do? (and don't tell me to get rid of the 2.56 gears, because I LOVE that ratio) Thanks! -Bob Cunningham
rearend noises Hi Bob, Give me a call and take some pictures of the rear cover of the rear we are talking about. Jim J D Race I would like to talk to you just to make sure i have all the info correct before trying to desiffer what is going on. 1 216 464 2313 x240 10 -5 weekdays est or email mitschke454@earthlink.net
spelling Do you think I would have my head in a freak'in smelly diff if I could spell...I would have a desk job and be making the big bucks...lol
Maybe you meant to type "desniffer" it??? Smelling the nasty sulfur in the rear goo will make you do funny things????? :laugh: :laugh: :laugh: Don't know what is worse....roadkill baking in the hot Florida sun w/maggots.....a loaded baby diaper or an old rear diff with fluid that is original?????? ou: uzzled: uzzled: uzzled:
Jim (and all)- Wound up bringing the car to a reputable (trustworthy and knowledgable) mechanic. Apparently the clutches & gears are just plain worn out. A new posi unit (carrier/clutches, springs, bearings, side gears) should fix it. A fair amount of money, but I guess that's life in the fast lane... Thanks for the help! -Bob C.
Usually when one hears a Banging noise from a differential, the pinion is loose. Smart to unbolt the driveshaft & ck the pinion out, esp if gear ratio is one of those that is not reproduced. Got Posi? :3gears: Roger
Roger- The car had to go to a mechanic, and turns out that the carrier & posi unit are shot. Thanks for the help though! -Bob C.
