Hello,

I have a 1990 L03 700R4 RS and I was searching for the past 30 minutes or so, and couldn't find the answer to my question...

I have absolutely ZERO experience with rear ends and gearing and all that good stuff. I have the stock 2.73s right now and want to switch to ANYTHING better (preferably like a 3.23 or something).

Now my question is, what is EVERYTHING I need? I kept searching but could not find out all the parts I need. I dont understand what carrier I have/need or anything like that. Could somebody please tell me EVERYTHING I need, where if I gave all the parts to a mechanic friend of mine he could say "wow, this is everything I need to do this, you are awesome man".

 

nothing?

everybody still asleep or was my question just too n00bish for anyone to bother with?

 

IF he's got the tools, all you need is a ring/pinion and gasket. Unless your going bigger than i think 3.23, which i would go to atleast a 3.73, you'll need a new carrier that accepts the higher(numerically)gear.If your lucky wherever you order your ring-pinion and carrier(a new limited slip would be cool) will include the bearings and gasket.Good luck.

 

Also make sure the axle bearing housing is in good shape it would suck royal to regear and find out a year or 2 down the road that the housing has to be replaced because the bearing seat is out of round from wear.

Or see if they offer a complete rebuild set with bearings and all the hard parts such as shims and such that may be inside.

And yes your going to want a new speedo cable gear.

I'm guessing this mod would be less than 500 bucks to do...

Now I have a question... who has done this swap and what kinds of gains did you experience? I'm thinking this is a great mod to pick up a second or two. Also, I'm thinking of going to 3.08 or even 3.23 instead of 3.73. I want to maintain a semblance of fuel economy.

Let us know what you saw with this change!

 

The easy way to do it is a donor V6 rear end in either 3.23 or 3.42 flavor. All you would need then is a good jack, a couple jack stands, a common variety of hand tools and a lazy after noon.

 

While that would be easy to do, I just wanted to get a new set so that way I have that peace of mind that everything wont break on me whenever. It's kind of like I want to rebuild it, but not really.

I hope you get what i'm trying to say here.

So, since i'm going 3.23, I don't need a new carrier? Can anybody suggest a website that possibly has the new gears as well as everything needed to put in there? Sorry for all the questions, but once I put the new cam in, I want to take full advantage of the added power without sacrificing TOO much gas mileage, it still is my daily driver.

 

3.08 and less = series 2 carrier
>3.08= series 3

Fuel economy isn't affected unless you're on the highway alot. Even then, the difference of gas mileage between 3.23 and 3.42 isn't noticeable. Swapping rear ends is much quicker and easier, and might as well do suspension while its out.

 

If you're willing to swap to 3.42 gears, Strange makes a 3.42 gearset for 2 series carriers so you don't need to get a 3 series carrier anymore.

Unless your stock diff is toast, then you might as well get a 3 series carrier and forget about what I just said above.

3.42s are the best between gas mileage and performance, IMHO. I don't think there's much difference between 3.23s and 3.42s either.

Also get an install kit which has new bearings, shims, etc. It's about another 100 bucks or so.

 

Thanks everybody. I think I know everything now.

I would call myself mechanically inclined except for rear ends. Could I do this myself?

And also, my differential is fine. No noises, grinding or anything. I haven't changed the fluid since I got the car though, so that may need to be done.

 

I think you can do this yourself. I am right now. (rebuilding a 10 bolt, not swapping gear ratios though).

You'll need a dial indicator and magnetic base (~$50) to set up the gears.
Does the car have a posi in it now? Otherwise you'll probably be buying a posi, then you can just find a posi to match the gears (series wise I mean).

Master install kit is recommended. I'd get one from Ratech, so you can get the solid pinion spacer that only they make.

There are a few other weird tools you need to rebuild your 10 bolt, that I can rattle off (that you probably don't have).

 

Do the rearends have a casting number, identifying them as to what gear ratio they are ? I'm thinking about trying to find one at the junkyard, might as well go disc and different ratio at the same time.

 

usually the tag on the diff cover shows what 'was' in it from the factory, or maybe that just shows posi/non. I think there is also a stamp on the back of the passenger side tube, that would show the gear ratio. Might want to remove the cover at the JY and count the teeth and double check the ratio. Then you can also check the condition of the gears, etc.

 

How would it show posi or not ? Be stamped "posi" ??

 

the tag would say limited slip or something... I think it'll give a code, like PWZ, some 3 letter gibberish.... this 3 letter stamp is either on the tag, or on the axle tube, I forget...
I think there's a decoder on the main page of TGO that lists those codes....TZF or something may decode to 3.23, posi. Then you know. Print the sheet and bring it with you to the wreckers. but like I say, open the cover to be sure, who knows, there may be no teeth left on the gears, maybe that's what caused the car to be in the wreckers in the first place....

 

ok thanks