Who has done a 3.08 to 3.42 swap themselves?

[quick99]

Hey guys I am considering doing the 3.08 to 3.42+LSD swap. I need to know if anybody has done this themselves and has any advice. And what was your experience like. I searched on this a lot and got mixed responses. So Please dont say "search". What I got as the hardest part of the process is setting the pinion depth using shims. Any advice on this? I have a fairly good ammount of mechanical ability and my brother is a mechanic for a mini dealership. It is hard to justify $150+ for the install when there are so many more mods I want to do.
Thanks guys

[WishIHad$$$]

Hmm, I heard that the ring and pinion have to be set within a 1/1000 of an inch or something of the sort. If you're not comfortable doing this, maybe you should consider shelling out the $$$. I've heard the LSD is easy to do, but the gears no. A lot of general maintenance shops will not do a gear change, you have to take it to a specialty place.

Good luck on the install

[ellik]

the gm book tells you that the acceptable window to set the ing and pinion backlash in falls between .007 and .012 inches. Thats a pretty small damn window considering you will ruin the gears if they are not set properly. I gave mine to a guy who rebuilds theses things for a living.

[DrFix2Fly]

$150 for a proper install of the gear and carrier is a bargain. You can try to do it yourself, but you will probably regret it if you don't have the tools or skills. You will need a few torque wrenches, a dial indicator and liquid nitrogen is really cool to make that .003 interference fit of the pinion bearing to the pinion gear work. Also, if you don't have the tool to calculate your pinion bearing shim, you will simply be guessing and hoping. Do yourself a favor and have a qualified shop do the work.

[FunkZ]

I've seen guys who work on cars for a living mess up a rear end because they didn't get the pinion depth set correctly. Incidently, the pinion gear uses a crush sleeve (not shims), so if you overtighten it you will have to pull it back out and start over with a new sleeve.

I swapped in a Zexel LSD on my own but I would not attempt a gear change myself. My advice is to take it to a professional, and not just any garage either but someone who specializes in building GM rears.

Alternately, rather than paying hundreds of dollars for a gear install you could just buy a whole new rear end that has the gears you want (plus LSD) already installed. Hell of a lot easier to swap rears than gears. I plan on doing this to get not only the gears I want but also rear discs.

[SkAchilles]

I did it, and it takes a micrometer to set the backlash correctly. Honetly, if its only $150 to have done, JUMP ON THAT. $150 is a deal, I was getting quoted over $350 so I decided to try it myself and it did work, but its nothing I would ever do again.

[quick99]

Well this sucks. Sounds like something i dont want to try myself. I don't know what it costs I just put the $150+ as a guess. I was also thinking about swapping the rear from a Z28 but i heard something about 3 and 4 channel. And if you dont get the right one you will lose your ABS. Any info on this? I need to make some calls and find out what it costs, but I probably wont like what I will here.
Thanks

[ November 11, 2003: Message edited by: quick99 ]

[ November 11, 2003: Message edited by: quick99 ]</p>

[FunkZ]

I believe the 93-97 Fbody rears only use 1 ABS sensor in the pumpkin, that's what the reluctor gear is for.

I have also heard that at some point they switched to 2 sensors, one for each wheel. I don't know what year however.