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Diff differential install removal writeup

30K views 10 replies 8 participants last post by  Wookers Garage 
#1 · (Edited)
This is my old thread, but the pics were missing cuz I moved my photobucket around (my bad) I had lots of pm's for pics, and sorry I didn't have time til now to put them in order so they made sense.

I did a few tweaks to updates it here and there as well. Sorry it's not a fancy .pdf :lol:

Maybe Tony can replace this link with the old one.

Ok I want to start out saying I'm posting this because I hope it helps someone else thru the install/take out process that I just went through. I'm sure the day will come when you are out of warranty, and you need to replace your broken diff. I did this not knowing much of anything about it except for what ewill3rd helped me out on as I went thru it. So a HUGE thanks to ewill3rd for answering my PM's and questions along the way.

If you don't understand something, PM me and I'll be happy to explain.

You are going to need the following tools:

21MM Socket (almost all bolts/nuts on knuckle are this size)
21MM Gear Wrench (essential that it's a GEAR WRENCH...you'll see)
34mm Deep Socket (Spindle Nut on Hub)
18mm socket
10mm alllen wrench
8mm allen wrench
Long 1/2" Breaker Bar
Masking Tape/Marker (for marking all the bolts you are going to be removing)
Beer of Choice
Long Pry Bar

Parts for new/used diff:

Two Axle Seals
Vent
Spindle Nut
Seal Protector (optional but recommended)

1st thing's first. You have to remove the RIGHT REAR knuckle assy from the car in order to get the diff out, which is the majority of the entire job.

After you take the caps off the lug nuts, Loosen up the RIGHT REAR tire Lug Nuts. Jack up your V as high as your jack will allow in Jack Stands. I did this in my driveway on my back without a lift, so you'll need to get a good amount of room to work.


Once up in the air, remove exhaust including resonator (or xpipe). If you need directions on how to do this, you shouldn't be attempting this. Once exhaust is off, remove the bolts marked (#2) in the picture. They are Allen Head bolts and are 8mm. (#1) is where the half shaft/drive shaft hit the floor board when my first diff broke. It's slightly out of round, but hasn't produced any sort of vibes (yet...crossing fingers) Put a jack stand underneath the "drive shaft" to keep the weight of the front bolts holding it to trans. Drain the diff now if it hasn't drained itself already like mine did.



Next remove the RIGHT REAR wheel exposing the hub/caliper. You need to take the spindle nut off the axle first. This spindle nut is 34mm. There is also a torx screw that you'll need to take off



Look at (#4) in the picture below. You need to place a drift punch or equivelant (I used the allen wrench) in between the slots in the rotor and the caliper. This will keep the rotor/axle from turning while you are cranking down on the spindle nut.
(#4) shows where the punch/allen wrench goes when you are TIGHTENING the spindle nut. When LOOSENING the spindle nut, the punch/allen wrench goes on the other side of the caliper in the slots in the rotor.
(#3) is the Top Caliper Bolt which is 18mm. The top bolt is longer than the Bottom Caliper Bolt so label them with the tape and marker (just to be safe)



Here's another pic, hopefully explaining it better....



Once the caliper is off, tie it up and out of the way. I used a bungee cord and wrapped it around the shock. Now is a good time to place a jack under the lower control arm since the bolts you will be taking out will make the knuckle assy/hub sag.
(#5) shows the caliper mount where the top bolt was. (#6) is nut holding in the Ball Joint. If you want to rent a Ball Joint Puller, be my guest. What I did (and ewill3rd does) was use a 1/2" extension for a socket wrench BACKWARDS (so the opening was facing the threads/nut. I loosened (not removed yet) the nut and then put the extension on the nut and hit the ext. with a hammer. One good crack and the Ball Joint popped loose.




(#9) Is the bolt holding the Trailing Arm to the Knuckle. Remove this one first cuz the lower control arm will sag once the other bolts are out, and it's just more of a PITA to take out. Using the 21mm socket on bolt head, use the 21mm Gear Wrench on the nut. (#8) tie rod bolt is also 21mm and needs to come out. Label the Bolts/Nuts (tape and marker) and set aside the other bolts. (#7) is just the bottom of the Caliper Mount where the Bottom bolt came out.




(#12) is the ABS Wheel Sensor. BE CAREFUL WITH THIS. Unclip it and keep it up and tucked away from everything. (#11) is the Emergency Brake Cable. You don't need to remove this, and actually ewill3rd said it was ok to let the enitre knuckle assy/hub hang by it once it was removed. <- Less work!
(#10) is the Lower Control Arm Bolt, which was 21mm. Remove it and label and set with other bolts. When you take this out the knuckle should only be held in by the shock mount bolt which is...surprise...21mm.




(#18) is the Lower Shock Mount. Remove the 21mm Bolt/Nut and the Knuckle should be free (if I haven't missed anything)
(#19) is just another view of the Trailing Arm Bolt/Nut. Sorry the numbers are out of order, I forgot this pic. At this point, the axle half will be connected to the Hub/knuckle assy still. Holding the axle splines straight with your knee and pulling the knuckle towards you, it should slip out no problem. Now that the knuckle is free, place it off to the side and let it hang by the Emergency Brake Cable.




TAKE A BREAK A DRINK A BEER (OR TWO)

Ok now for the Diff itself.......
Once you get the jack (with piece of wood) underneath the Diff, remove the 21mm diff bushing screw and bolt FIRST(#14), 21mm socket on bolt head side, and 21mm Gear Wrench on nut side. (the pic was taken after the bolt and nut were removed.




The side of the diff facing the rear of the car is tight. The GearWrench is essential for getting to the back bolts. I remember having to insert the wrench on the inside of the Ebrake cable, and then once the bolt was out far enough, you have to take the wrench off the bolt head and start again on the outside of the cable. (#15) is the right rear side bolt.




(#16) is the Left Rear side 21mm bolt. Same story as the right side, and you'll want to use the 21mm Gear Wrench again. Jacking up the diff a little until the bolt is straight across helps with removal. Make sure you keep an eye on the diff when you remove the bolt, as it is the last bolt holding it in. It could wobble off the jack. When lowering the diff, it's tight getting it of the middle of the cradle. You'll have to tip the diff to one side (I did left side) so you can clear the cradle. Hold the one side of the diff with your hand (while it's tipped) and lower the jack SLOWLY watching for clearance issues. Once it's down, hold it on the jack while you pull it out from your V. ELVIS HAS LEFT THE BUILDING!!!!




DRINK SOME MORE BEER(S)

After you admire the destruction of the old diff (if you borke yours) it's time to change the axle seals on the new diff. I took a pic of my prybar inserted into underneah the axle seal itself. (#17) BE CAREFUL!! Only insert it so the prybar just touches the inside of the seal NOT THE CASE! This "awesome" diff case is ALuminum and you could score the inside lip and cause more probs for yourself. They pop out easily. Grab your new axle seals, put a little gear lube around the seal, and insert it into your new diff. Mine came with shipping plugs (thank you CTSV_Rob) so I turned them upside down and lightly tapped on the plastic plugs until the seals were seated. You can use a piece of wood, just make sure you hit in the center and make sure they are properly seated.




My new diff needed a vent, and you have to replace them anyways, so now it's time for that portion. (#20) shows the part I'm talking about. Use a 9/16" socket to go over the top of the vent and rest on the base of it and hit the socket NOT the vent. In a pinch, you could use a open end wrench, just make sure you hit the wrench and not the vent.




Alright, so once the diff is ready to go, get it on the jack (holding it so it doesnt tip off) get it underneath the cradle and jack it up. Once you tip it to the side and get it up there, the left side axle shaft will be in your way.
This is where the seal protector would be used while inserting the axle shaft. I did not use one, but I was EXTREMELY careful not to have the splines grind into the seal itself!!!! You are going to have to play weeble wobble with the diff on the jack in order to get the axle shaft into the diff. BE PATIENT!!! If the splines don't automatically lineup, turn the front pinion "bell" on the diff and it will turn the gears inside (thus moving the splines). Once you get the splines to match up, it's not over. You have to get the snap rings on the end of the axle shaft to "snap" back into the diff. This was a PITA. I pretty much had to manhandle the diff and axle shaft in order to "pop" it back in. ewill3rd said they use a prybar to get em back in. I was on my back and didn't have enough room between the car and the driveway to have any leverage, so I resorted to just pushing the two together. You might have to pull the jack and diff over a little closer to the axle shaft so you don't yank the diff off the jack.

Once you get the axle shaft "snapped" back into the diff, give it a good tug to be sure the snap rings have made their final resting place. You'll know when they "snap" back in.

Once that BS is over with, it's time to put the other halfshaft back in. Same process as before, but it's much easier on the right rear side since the axle shaft is just sitting there from when you removed it before.

Now reinstall the entire right rear suspension parts you removed to get the diff out. Pretty much reverse order of uninstalling it. The pic of (#4) is where you can put the allen wrench/or drift punch into the caliper to keep the hub from moving.

Once you get it all back together, get the wheel on, tighten your lug nuts. If you are installing a used diff (like me) take the drain plug out and make sure to wipe off the metal "goo" off the magnetic drain plug. Once you've wiped it off, reinstall with your 10mm allen wrench. Now it's time to fill the new diff with your choice of Gear Lube. Back then I used good old GM 75-90w "grape scented" (whatta joke) differential fluid, and the small bottle of Limited Slip Additive. Our diffs hold a quart and 1/4 of diff fluid. If you didn't remove the fill plug before hand, it's the same 10mm allen head wrench you used on the drain plug. Put the Limited Slip Additive in FIRST. That way you gaurantee you have room for it in the diff. You'll know it's full obviously when the fluid starts coming out the fill hole. I used a screw on to the bottle filler tube and squeezed the $hit out of the bottle. You can also use a suction gun which is probably better. I've since switched to Redline 75w90 (modifier already included) and love it.

Once diff is full, reinstall the half shaft/drive shaft while tightening down the allen head bolts (#2) ewill3rd told me blue loctite on these bolts. Now reinstall your exhaust, and let the V down off the jack stands with your jack.

Moment of truth.....start up the V, engage first gear and slowly let out the clutch. Get out on the street and go slow and listen for any sounds/creaks/bangs <-HOPE NOT.....test drive and you should be able to hear/feel if something is off. Get to operating temp and pull over and look for leaks. After a couple drives, just keep an eye on everything. Stand back and admire your work, you just saved yourself alot of $$!!!!!

If I missed anything, feel free to add. I will try and get part numbers for parts, and torque specs as well. I'll say it again, THANK YOU SO MUCH EWILL3RD!!!! You put up with my questions, and you are good people!!!! Also THANK YOU CTSV_ROB for the new/used diff. You helped a fellow V'r get back on the streets!!
 
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#4 ·
I realize I'm resurrecting a nearly 5 year old thread, but I found this the best place to put this. Today, I pulled the differential out of my 2003 junker cts and placed 2006 LSD internals inside it. I wanted to let everyone know, that the CTS-V internals do fit in the regular CTS housing.

Also, for the 2003, the axel nut is actually 35mm not 34...just so you don't have to run to the store twice. Here are some more pics to add.
















Oh, and accurate beer count :) Thanks. Overall, not too hard of a job. You can get buy without the gear wrench 21mm wrench if you have a swivel and extensions...just make sure you have some sort of 21mm wrench.
 
#5 · (Edited)
I realize I'm resurrecting a nearly 5 year old thread, but I found this the best place to put this. Today, I pulled the differential out of my 2003 junker cts and placed 2006 LSD internals inside it. I wanted to let everyone know, that the CTS-V internals do fit in the regular CTS housing.

Also, for the 2003, the axel nut is actually 35mm not 34...just so you don't have to run to the store twice. Here are some more pics to add.
















Oh, and accurate beer count :) Thanks. Overall, not too hard of a job. You can get by without the gear wrench 21mm wrench if you have a swivel and extensions...just make sure you have some sort of 21mm wrench.
 
#11 · (Edited by Moderator)
This is my old thread, but the pics were missing cuz I moved my photobucket around (my bad) I had lots of pm's for pics, and sorry I didn't have time til now to put them in order so they made sense.

I did a few tweaks to updates it here and there as well. Sorry it's not a fancy .pdf :lol:

Maybe Tony can replace this link with the old one.

Ok I want to start out saying I'm posting this because I hope it helps someone else thru the install/take out process that I just went through. I'm sure the day will come when you are out of warranty, and you need to replace your broken diff. I did this not knowing much of anything about it except for what ewill3rd helped me out on as I went thru it. So a HUGE thanks to ewill3rd for answering my PM's and questions along the way.

If you don't understand something, PM me and I'll be happy to explain.

You are going to need the following tools:

21MM Socket (almost all bolts/nuts on knuckle are this size)
21MM Gear Wrench (essential that it's a GEAR WRENCH...you'll see)
34mm Deep Socket (Spindle Nut on Hub)
18mm socket
10mm alllen wrench
8mm allen wrench
Long 1/2" Breaker Bar
Masking Tape/Marker (for marking all the bolts you are going to be removing)
Beer of Choice
Long Pry Bar



























Very Excellent write up, dude ....
 
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