lifted99GMC

iTrader: (4)

Has anyone every done it themselves? I have installed many gears in the rear of trucks and f-body's, but never have attempted to install some gears in the front on a 4x4. I would guess that it would be the same principle as the rear, but it looks like you have to separate the trans axle to get tot he gears. Anyone know of any info or website i can look at to give me an idea what to expect? I plan on a gear swap when i lift my truck. thanks

Chad

Zac's05

I have geared several of the gm ifs front ends, 1/2 ton and 3/4 ton. they are different but once you do one it's way easier. they have spanners on the side bearings, but you need some special tools to put new races in the case.

Zac

mjgjr72

i did mine, all in all it wasn't too bad, u need a special jig to press out the pinion if you plan on reusing the outer bearing if you have to readjust the depth, the races you can punch out and use the aluminum disc race installers to reinstall, you need a specialty tool for the spanner nuts to adjust the side bearing preload and cage position for backlash, backlash is measured off the yoke after case reassembly, and you have to do the gear pattern threw the plastic vent on the side of the case, also have to check endplay on the drivers side axle flang. i have dealer manual 2000 c/k if you want me to fax or email ya a copy of the dif section
mjgjr72@juno.com

lifted99GMC

iTrader: (4)

thanks for the replies fellas, i appreciate it. mjgjr72, i sent you an e-mail. I have a few more questions, though. First is, are there any recommendations on where to buy the gears and what brand to get? What is the gear diameter for a 3/4 ton avalanche in the front? What is the backlash supposed to be set at on the front? What is the endplay supposed to be on the driver's side axle flange? Where can i get the special tool for the spanner nuts? To press off the pinion bearing, do you have to have a different tool than a regular bearing splitter? I use a bearing splitter to pull the pinion bearings off of a regular rear end pinion gear....just wondering if I can use that on the ffront, too. Also, have any of you guys installed the locker assembly for the IFS? I thought i remember seeing them in Summit mag. or something. If so, how do you like it? Sorry for all the questions, i just want to know what to expect when i take it apart. thanks again

Chad

mjgjr72

got the e-mail, try to get it to you sometime this weekend
as for gears it depends on what you want dealer has 4.11's
would recommend inless you want to go bigger, usually drop right in with oe shims and don't make noise if set up right
for 4.56 you will have to go aftermarket biggest you can go on a 7.25 ifs
if you have a 8.25 ifs you can go up to 5.13
i'm not positive but i think you have an 8.5
might want to call dealer with vin to make sure
as far as brand i don't have that much experiance i got mine here and had no problems
they where very helpfull
http://www.differentials.com/index.html
as for specialty tools i borrowed them from local dealer i bought truck from and get parts from
you can also purchase them from kent moore they make them for gm and others
http://www.spxkentmoore.com/
backlash and endplay will be shown in manual pages i'll try to send this weekend
both use dail indicator backlash is measured off pinion flange turn flange and measure play divide by 2 and should be (0.0003-0.010) with preferred of (0.005-0.007 in)
for flange backlash reassemble pass axle housing without sealer, use indicator to measure in and out play, spec is (0.001-0.020 in)
inner pinoin bearing can be pressed on and off same as rear, the hard pard is pressing the pinion out of case without ruining outer pinion bearing i used a big brass hammer and the old outer bearing intill i was happy with pinion depth on gear pattern and then reassembled with new bearing
and i don't know about locker, i have seen them for the 7.25, i don't go wheeling that often and my truck is a daily driver so i stuck with stock carriar

mike

lifted99GMC

iTrader: (4)

Thanks for all the info mjgjr.

-Chad