I want to put a set of posi 10 bolt 3.73s that i have into my 1986 LG4 Iroc-Z 5spd. Can i do it myself or do i need to have a shop do it. Everytime i see differentials put it they use all these fancy meters to measure distances and stuff. How hard is it to install gears. And what should be replaced along with the gears/carrier and fluid? My car only has 45,000 miles on it. Thanks.

 

They need to be setup properly. Have a shop do it.

 

ok. Do i need to replace anything else.

 

Usually you'll want an "install kit" that includes new bearings, seals, and shims.

 

ok. Do you know if any thing changed for 10 bolts over the years that would keep mine from installing?

 

Nope. Should be straight forward. Just have a shop do it. Lots of little things that require special tools (like a pinion depth gauge for instance) and, if its not set up properly it will whine like crazy or might even grenade. Leave it to the pros.

 

It's not THAT bad... here are some good article on line that show you what's involved. See if it's something you can handle... It's a tedious job so a shop will charge you an arm and a leg to do it, so if you can make the investment in time and tools to do it yourself, then you'll be ahead of the game.

http://www.pirate4x4.com/articles/te...sta/Gear_Setup

http://www.drivetrain.com/ringpinioninstal.html

 

I dropped my car off tuesday and wont get it back till most likely wensday so you will be with out a car for a day or two. I am having other stuff done to though. But if you dont replace the speed gear and sencor then your speedometer will be off like 30 mph. (correct me if im wrong)
kevin

 

i saw them do it on spikes powerblock and it looked tedious. I'm gonna have a shop do it. How much do you think they will charge, and do they need to take the whole rear down?

 

GoodlookinRS is 100% correct about the speedo gears. You can search this board for "speedo gears" and probably come up with the right combination for you. The gears are dirt cheap, the problem is installing them.

And no ... they don't have to pull the whole rear. Just pull the cover off of the diff, pull the axles and voila!

 

did your trans is a mechanical speedo or electronic???1990 camaro i had a 2.73 to a 3.42 and now my speedo is way off there is no gear in the transmison is ther somting i can do to bring me speedo back to normal speed

 

Here's a few things to consider when upgrading a 10 bolt. This is what I did with mine. A Eaton 28 spline posi, new 28 spline axles ,3.42 ring and pinion and LPW Ultimate cover. Here's a link to the Eaton posi unit. = http://www.eaton.com/EatonCom/Produc...iteId=EatonCom and here's a link for the LPW cover.= http://www.jegs.com/i/L.P.W./619/301-7.5G/10002/-1

This is what it cost me. $700.00 for master bearing kit , axle bearing and seals, 28 spline axles, including 3.42 ring and pinion, and labor .$535.00 for Eaton 28 spline Posi.,$169.00 for LPW Ultimate support cover.. 3 year warranty on parts and labor. Total = $1,404.00.
I will tell you that the new upgraded unit has made a "huge" improvement over the 2.73s and open rear.Drives like a totally different car.

 

ok ya i just baught a
PART # 542046 - AUBURN PRO SERIES DIFFERENTIAL 10 BOLT 7.5 (3.23-UP)-- 28 SPLINE
and all run a all stars 3.42 gear but now my speedo is all **** up since i hade a 2.73 orig. in the cars
what i can do to fix my milage on the cars do i need to change or reprograme a new ACM??

 

how did you fix your speedometer or you just dint bather with it?

 

I did not need to change my speedo gears because I went over to 27in. tall 255/60r15 rear tires. The fix was really not intentional. Just happen to be right on the money, at least that's what those digital roadside speed limit boxes say.No problem with the cops radar guns either.( they like to shine one on my car every once and awhile.)
Most of the guys here replace the speedometer gears in the transmission. Some one else will have explained the process or do a search.

 

Need to buy the correct speedo gear. A small plastic gear that installs in the side of the transmission. U need one for 342.