GMT-400 K2500 front end repairs

[Stumpuller6.5]

this will be an on going thread, over the period of a few days, as i progress when i can working on the truck. when completed this will be usufull for anyone working on 96-00 OBS GMT 400 series GM K2500 4x4 trucks. I will be replacing Upper and Lower ball joints, front rotors, and brake pads, plus flushing the brake fluid in the entire brake system. At this time i will not be covering idler arm, pitman arm, or tie rod end replacement. i may include a process to replace these items, but will not have pictures as this is not what i am currently replacing.

First off i must ask that to undertake this project please wear appropriate saftey gear. (steel toed boots, saftey glasses, coveralls and gloves, and from time to time hearing protection)

This project is not for the beginner, but for a moderate vehicle knowledged person and if so, someone who is willing to take on a big task, requireing heavy lifting, prying and hammer accuracy.

first off i will list off some tools required, (this may be updated from time to time...)
-3/8" and 1/2" rachet, 7/8" socket, 18mm socket, 13mm socket, 3/8" allen key or socket, 15mm socket and 12" extension, 36mm socket, ball pein hammer and
2-3lb steel hammer, prybars, a 6" and 10" works well. I highly recommend air tools, mostly to save time, and aggravation. in which case you would need a compressor, 1/2" and 3/8" impact and/or air rachet, air hammer and pin bit, also a ball joint press kit. (borrow one or rent one, or buy one for $100 bucks or so.) and upohlstry removal tool, dead blow hammer,

Alright lets get down and dirty, first off we need to jack up the vehicle and support it with a jack stand, i have a 3 ton jack and set of stands (2). they are the perfect size for the task at hand. I prefure to jack on the front frame of the truck and then install the stand under the cross beam in the lower control arm, this allows for a very sturdy point.

vehcicle raised and supported

 

[Stumpuller6.5]

remove inner fender liner with upohlstry removale tool or something of the like...

pry open the metal holding clips for the abs wire, unplug it and remove from frame and let it hang down out of the way for now...

remove bolt holding brake hose clamp...

undo tie rod end with a 18m socket, leaving the nut on about three turns or so strike the steering knuckle with a hammer near the tie rod to loosen it from the knuckle, ( leave the nut on incase you miss the knuckle... cause shit happens i know...lol.) when loose remove nut and let tie rods hang down out of the way, or replace as neccesary.

with the tie rod off you can swing the knuckle around to easily access the bolts holding the caliper on, using 3/8" allen key or drive socket, remove the two caliper bolts, you may have to get a small screw driver in to pry the caliper off, depending on how much of a groove is on the rotor, you may also have to pry the piston back to gain clearance for the pads to come off. with the caliper off use something to hold it up and out of the way, i used a bungee cord, but anything will work, thi prevents the heavy caliper from stretching and damadginf the brake hose.

 

[Stumpuller6.5]

at this time remove the lower bolt from the shock, this will help the axle come out easier.

undo the six 15mm bolts from axle to differential, also remove the 36mm nut on the end of the axle (not pictured)

lift the inner end of the axle forward and down to remove from vehicle, at this time feel free to start grunting swearing or what ever calms you best... some times its not so bad and sometimes it takes some grunt... turn the axle and flange as necceary to get them past each other

if the axle will not come out of the hub, use a dead blow hamer to get the axle to move its ass out of the knuckle. then remove the axle from the truck from the bottom.

 

[Stumpuller6.5]

its optional but makes it easier if you can remove the old cotter pins, other wise hammer your socket on and bust away, they are soft and will not damage the threads if you are not replacing that particular ball joint. factory uppers are 18mm nuts and the lowers are 1 /16th, uppers that have been replaced are usually bigger than 18mm.

just as we removed the outer tie rod end, undo your nut most of the way and strike the knuckle, when the ball joint is loose remove the knuckle from the vehicle.

and its off...

 

[Alljackedup408]

sweet.. another tool you can use.. if the hammer will not break the ball joint loose.. is a pickle fork.

 

[Stumpuller6.5]

this next step you can use the ball joint press, but i love using a hammer, and you might end up using one anyways, lower balls are usually stuck in there pretty good, especially from factory (my case) i like to hit the ball joint hard to get it moving then use two hammers, put a ball pein on the ball joint that is small enough to pass through the control arm and hit it with another hammer, this is were eye coardination is key, maybe at this timemake sure you have some small ziplock bags, ice and a socond method of transportation to get you to the hospital with your severed finger...

if you survived this then great, lets carry on, i picked up a ball joint service kit, as i intend to hore out my knwoledge and skill to friends and family in the future... and dangit, i had to modify it right out of the box, no returning it now.... the inner size of the press sleev was too small, had to bore it out to fit over the boot on the ball joint.

here is the getup-setup for installing the new balljoint, ensure at this time it is correct (the ball joint), and also make DAM SURE you line the grease nippli up with the groove in the control arm (or just put in the same way the old one was in, usually points almost straight towards the back of the vehicle.)

alright so new lower is in, visually make sure it has been pressed in flush all the way around, the upper balljoint is easily unbolted and rebolted is as it was (use new hardware, usually provided with new joint) if the upper ball joint has steel rivets in it, it is original and has never been replaced, so you will need to air chisel the studs out (cut the heads and push out studs)


OKAY FOLKS ITS LATE I`M CALLING IT A DAY, I WILL UPDATE THIS AS I PROGRESS TOMMOROW....THANKS

 

[daddy]

Nice write-up, Clancy!!!

 

[Stumpuller6.5]

okay so i`m done one side, ended up having the wrong upper ball joint for the right, so had to pick one up this morning, and then found out i purchased 2 LH rotors...., wow what a great start for the day.

anyways the rest of the pics are loading up so i will have the finished write up soon, going to look up some torque specs and post them aswell.

 

[Stumpuller6.5]

okay so we have new balljoint installed, we now need to re-install the knuckle onto the truck, it easiest to lift the knuckle up and start the lower ball joint nut first, then install the upper one, depending if your truck has the torsion bars cranked or not you may need to use the jack under the knuckle to get it upp enough to attach the upper bal joint nut. torque the upper nut to 74 ft/lbs, and lower to 94 ft/lbs, then tighten them more if required to install the new cotter pins. NOW is a good time to grease those new ball joints... nice and easy to get to.

when they are torqued up remove the four 15mm bolts holding the hub/rotor assy onto the knuckle, then pry that assy off, if you bend the backing plate make sure to fix that up or it could be noisy....

at this time you know its probly a good time to have another beer, a break, or in my case feed and change the diaper on my little helper....

okay once you`ve got your little helper to have a nap (age of helper doesn`t really matter....)
the removed assy should look like this

 

[Stumpuller6.5]

so you`ll need to remove the abs sensor, use a 5mm allen key, be carfull when removing it, it is fragile and can break easy, and last time i checked aren`t cheap...

with it removed use something to keep the dirt from getting in the hole (use a plug, tisue, whatever.) i used a pail to hold the rotor for stud removal, i`m sure a 5 gallon pail would work too.

I used a air hammer with pin end to remove studs, but a hamer and punch works just as well, this is the hub and rotor assy seperated...

clean the suface of the hub and new rotor (in my case i found out i fricken bought two LH drilled and sloted rotors, so unfortunatley i re-intalled the old rotors for now...)

install new rotor onto hub and drive the studs back in, make sure they are all flush, a good way to know is to sit the assy on the floor, studs down and see if any studs are not contacting the floor. then re-install your abs sensor, good idea to put a it of grease or anti-sieze on the oring of the sensor to ease installation, and dissasembly in the future. Then install the completed assy onto the vehicle, ensure your backing plate in installed and in correctly, torque the four bolts to 133 ft/lbs. At this time rotate your rotor and double check your backing plate isn`t contacting it.