Alright heres the deal, I was driving home on the expressway the other night and I started to hear a real quiet like "dum...p, dum...p, dum...p, dum...p" from the back and would get faster as I accelerated. you wouldnt even barely notice it if you didnt drive the car everyday. Today it just got worse real fast untill it was an EXTREMELY loud banging whenever i accelerated OR came to a stop... (you could feel it in the whole car) the time i got it home (at about 2 miles an hour) it was so bad i could barely give it enough gas to get up my inclined driveway without sounding like i was going to snap something. this morning i woke up, put it in N and was going to push it out of the garage to take a look undernearth as it was to cold and dark last night, the car rolled back about an inch and woudlnt budge, i then put it in revese and imedeiatly stopped when it made the worse grinding sound i have ever heard before.... WHAT HAPPENED?... im thinkin i the rear end went out???? please help, and sorry about the longer post. =;\

you might have to get under the car and take a look and maybe pull the rear cover to look at it, but it sounds like you broke something in the rear

You're rearend needs to be rebuilt.

A third for the rearend.

Alright, well yeah we took it apart and iv got two teeth missing on the pinion gear. Turns out my car had a 4.10 in there all this time.... my question is though since i dont know a whole lot about the gearing and all, If i go back to what was supposed to be in there 2.73 i think??.. will I notice a real big difference if so good or bad?? thanks for the replys

If you go to 2.73 gears, it would make a great highway car. There would be a huge difference in acceleration, mainly being slower off the line. If you don't want 4.10's I'd go 3.42's.

Yeah. Hey man, it sucks that the rear end went out but to put a positive twist on it, at least now you've got the opportunity to try different gearing out.

I agree - if you go from 4.10 to 2.73 your car will, with out doubt, be a completly different animal. That change is about as drastic a change that can be made. If you want to really fly on the highway and get killer fuel mileage 2.73s will back that up hands down. I agree though that they might take some away from the fun factor 'round about town.

My IROC has 3.08s - I haven't confirmed that, but I think that's what's in there. It's pretty good round town - I do believe 3.42s would be more fun - but it does great on the highway. Of course, 3.42s would be better for cruising and mileage than the 4.10s, but not as good as 3.08s not to mention 2.73s. I can cruise at 70mph and she'll only be turning 1700 or 1800rpm, in that neighborhood. I bought it in Dayton OH and had to drive it from there to my parents house in Michigan for storage so I had the chance to drive it on a long trip right away - got 25 or 26 mpg on the way home doing 65-70 the whole way and really getting my foot in it oh, maybe 3 or 4 times too ;-) - that's over about 250 miles total trip.

Hope this provides some perspective for ya in choosing new gearing - good luck.

I got about 22 mpg with the 305 and 3.42 gears. Also had the same TH400 I'm running now, a torker II intake, 750 demon and a XE256 in it though.

alright, I think im going to try to go with the 3.42's then, because i think i would probably miss some of that off the line pick up... and i guess i would still be getting better mileage than the 4.10's also. Is there a real big diff between 3.42's and 3.73's? or should i just be fine with the 3.42's?.... again thnx for the replys