Ok that's good to know.

Could this be a beneficial change by itself?

I mean would I need to make other mods for this to really take effect? Like if I were to replace my exhaust, it would also be good to put on headers to help that out.

Is there other stuff that I would need to do to enhance the benefit of a better gear ratio?

 

All those little thing's together will make a very very noticeable difference. The gears alone will stand out tho. You'll get more torque out of your car with them.

 

with 4.10 I hope you have decent tires...and watch driving in rain lol

 

Bad news; a nasty click/popping sound started coming from my rear end - it sounded like it was coming from the fender well. All was good with the rotor and bearings, so I had the rear plate removed, sure enough, the pin is beat to dust on both ends and the housing is wore flat (well, not really, but almost) on one side.

I didn't take the time to count, but I assume I'm running 3:23 - it definitely is lim slip.

I have to have a new (or like new) rear end put in. Do 3:73's have posi, or are they lim slip also? Would it be beneficial to have posi or lim slip with 3:73?

Also, what sort of price should I look at? the guy at the shop said it would be cheaper for me to buy another rear end than to repair the one I have (just the gears, bearings and maybe carrier - but the axles fine).

In other words, what should I NOT pay? What is overpaying and what is a fair price?

Thanks guys - this'll help immensely.

 

yep it would be cheaper to find a complete used rearend. what you are looking for is a limited slip also known as a posi. you had what is known as a open (one wheel wonder) rearend. 323 unit should be easy to find, 342 harder, 373 lucky to find one. you can pick up a good used one and have a shop switch the ring and pinion to a 373, cost should be 300 bucks for the labor and about 300 for the rebuild kit and ring and pinion.

 

Ok, he said he was going to shop around for a used one and I should call him tomorrow around 11. I specifically asked for a 373, but I didn't know it would be very difficult to find one.

Hopefully he'll keep any in mind that he finds.

I looked around for new ones online, and they were all like $900-$1200.

But when I call him tomorrow, I'll just tell him that a 323 is fine, as long as it's posi? Then I'll just go and buy a 373 ring and pinion and have it installed later on.

edit: also, the guy who was looking at it, I asked if I had a posi trac, and he said no, a limited slip; what's the difference between posi trac and limited slip? If an "open" is the one wheel wonder...?

 

no difference, they are the same thing. posi trac is the gm name for it, limited slip is the generic name. if there was no slip you would be squeeling the tires (well, one tire) every time you went around a corner. on a corner the outside tire travels farther than the inside tire so they need to turn at different speeds for short times and small amounts. the carrier on a posi has clutches in it that allow for slippage for one side or the other at the same time holding both to the same torque to turn.

 

ok cool; I'll just tell him that I still want to keep my old rear end also, that way I can have a spare.

thanks for the help!

 

I'm not sure what happened, but I was blown away at what I was told; a remanufactured diff from Jasper (3:23) from the shop I usually go to would cost me $2000 after parts and labor (WTF??)!! A 373 would be even more.

The shop owner told me it would cost more to repair my diff than to replace it (the price above is what it would cost for a full replacement), but the mechanic who took the plate off and inspected it showed me what was going on with it, and said I needed a new pin and carrier, but the gears looked and felt fine. He said he didn't feel any gouging in the gears from shaved metal or anything.

So I ordered some parts from Summit; a new ring and pinion (3:73), an installation kit (bearings and gasket), and a new pin and carrier.

Do you guys think I should buy anything else? I'm really not sure what I need other than the above parts; I'm not sure whether to trust the shops or not now. Meineke said they'd install it, but they said it would take 10.5 hours at $90 an hour (hell no), and the original shop they went to said they'd do it for $300 - but I think they were referring to a whole new rear-end and not breaking one down and replacing parts...

I just wish I had the resources to do it myself.

edit: also, what part of the differential dictates it being limited slip or open? What would I need to replace to convert it? and the carrier I ordered says it's a Eaton Posi LSD; the guy at Summit said this would be fine, and that my car used a 28 spline??

 

Setting up rears is not complicated but it is very unforgiving. One mistake and instead of 100K miles it last 2K.

You should not have bought parts until you had a plan. Most of your best guys will not install customer supplied parts. The reason being, what if they are defective? You come back 2 months from now with a junk rear. What caused it? Was it the parts or was it the way it was installed? You supply the parts and they are going to say, hey your parts broke. The reason even skilled mechanic will not install other people’s parts is because no matter what the cause for the failure they will get the blame and loose a customer. If they sell the parts and they make a profit on them they have a lot better chance of convincing the manufacture that it was a defect and they will get the replacement parts for free.

Anyone that quotes 9 hours to setup a rear is worried about it. You should find someone that sets them up all the time. Expect to pay $400-$600 for it labor. Go to a car show talk to some hot rodders and find out who the best in your area is. Since you already ordered the parts you better get a few names then call around and see if they will install your parts. Guys that are used to setting up racing rears will generally do better then an average mechanic because they do so many.

Posi Vs Limited Slip.
Anything from the factory would be limited slip (I am a GM guy). When I here Posi or the term true posi I think of a racing or locking rears. You do not want a true posi on a street car unless you don’t mind bucking, jerking and tires chirping when ever you do a U-turn.
http://www.reiderracing.com/rtech-diffs.php


If budget is an issue and you need to get this car up and running return your summit parts and get the complete rear. Fparts on ebay sells low miles limited slip rears for around $350. They even get 3:73 once in awhile, 2-3 times a year, and they sell for about the same price. Most likely they would have one before spring.