Chevy TrailBlazer, TrailBlazer SS and GMC Envoy Forum banner

Removing front differential!!

126K views 34 replies 14 participants last post by  rodneymccray83 
#1 ·
Hi guys, got a problem,i have to remove the oil pan so now Im trying to remove the front Differental on my 02 TB 4x4. I got the passenger side assembly of and pulled out of the oil pan now i cant get the driver side off. How many bolts is it, I took out 4 or 5 of them the ones that i could see. Is there any hidden up there anywhere. WHY can I not pry the damn thing off. PLEASE HELP.
 
#2 ·
There are 2 bolts going horizontally from trans to oil pan. Their is also 2 little bolts hiding in the holes circled going Straight up into the block. Their will be some sort of plug in the holes. Mine has rubber wingnut looking things.



Also, on the driver side the 2 lower bolts on the A/C compressor go into the oil pan. Not to mention the 3 little guys up front

 
#4 ·
removal

passenger side is called the splinned disconnect. that is in two pieces. and slides on to the oil pan and bolted on. be careful taking that off and dont break it off in oil pan. you will need to remove both cv axles. the driver side of oil pan is called a carrier. there are a few bolts holding that on to pan. did you get the bolt off were the front drive axle hooks up?



to remove the oil pan, you will need to remove the side bolts and front bolts, oil filter, and the bolts that mount to the trans, remove that rubber spacer thing there are two long bolts there that will also need to be removed, and when you have the oil pan separated from bottom of engine look inside you will see another bolt that is attached to the oil pan and to the bottom of motor, its inside the driver side edge of oil pan, also remove that bolt. on passenger side of pan there are some trans lines that run along the side of the pan they tend to get in the way.

you will need to remove your rack and pinion. put on some gloves son, because you will bust them hands up. tie seatbelt through steering wheel and when under truck locate steer column separate rubber cover and take bolt out, thats were the steering connects to rack. you will also see were your power steering lines connect to the rack there is a plastic cover and under that is a screwing holding lines to rack. take that out to disconnect your lines, get a bucket you will loose some steering fluid.

If you cant get that shaft out of the carrier, you can still drop the oil pan with carrier and shaft going through oil pan. i did it, it can be done, you will probably need a buddy to help you out.

you need any parts?


oh yeah drain the oil !!!
 
#7 ·
I got the 4 bolts out, I took off the passenger side section, are there any clips or anything on the passenger side after you get the dif off? Do i have to pull the shaft out of the passenger side? Or do I have to take off the drive shaft companion flange to pull the drivers side off? I am really stuck. I took all the bolts out, and pulled and pryed on it and it has not budged. The socket that holds the drive shaft cv shaft thingy is still attached to the dif, does that have to be removed before the dif will come off? HELP!! Thanks
 
#8 ·
If you can take some pics and post them or email them we might be able to see something.

Here's my checklist of what I remember that came out.

First was the 4 bolts for the diff. 2 are in the front of the diff on top of each other. 1 is toward the middle real low. 1 is at the very back of the diff by the u joint.


3 small bolts at front of pan
21 small oil pan bolt from the sides

4 long bolts at rear of pan (horizontal)

2 bolts at rear of pan between pan and trans bell housing (vertival)

2 long bolts thru the A/C pump into the pan

4 long bolts from passanger side axle disconnect and disconnect harness
jackshaft thru oil pan

U joint at front diff from transfer case --- diff bungied out of the way against the frame

right before the pan went back up
 
#10 ·
removal

the passenger side is called splinned disconnect. its in two parts that bolt together and is bolted to oil pan. that part should just slide out, mine didnt, it broke off when i was prying it. but get you a pry bar or something and walk it out of oil pan. there are two bolts above the splinned disconnect that you will need to remove in order to remove the oil pan. same concept on drivers side, walk it out of oil pan with screw driver.

I dropped my oil pan with the the middle shaft still going through to the carrier. because my shaft was seized up in there. remember you have to remove rack. put a seatbelt through steering wheel to hold in place. take bolt off steering nuckle under rubber protective sleeve. and remove the bolts holding rack to frame and lower it.

ps. i know that middle shaft is messing with your mind. I took mine out with carrier unbolted and setting loose.
 
#13 · (Edited)
You don't need to remove oil pan to replace inner seal. I was at the dealers today in fact talking with a couple tech friends of mine, one of which incidently happened to have a TB front diff leak. The leak was at the case halves which is very common due to lack of sealant. He also said the oil pans never leak either. I watched him completely remove and disassemble front diff in no time!:eek:
Now I can hardly wait to do mine!
 
#16 · (Edited)
u dont have to remove the oil pan to get the diff out
1.remove belt
2. remove cooling fan and surround
3. remove alternator
4.remove a/c compressor (u dont have to disconnect lines it will reach if flopped onto top of engine)
5.remove axles,pass. side diff actuator,and the shaft that goes through the oil pan
6.remove drive shaft(front)
7.unbolt the diff
i also removed the thermostat with the lower hose
(the fun part)
muscle the diff out the top
i did my bosses in about 3.5 hours in and out (he blew the pinion out the sideso we had a rebuilt unit on hand when i changed it:thumbsup:
 
#20 ·
any one out there who can help me

..did u receive help on this question. How did you end up getting it off. I have an 02 gmc envoy xl slt.

I know I have to remove differentials to get the oil pan off and I removed the 4 main bolts
on differential but the differential will not budge is there a keeper of some sort in there. Please help it will budge
 
#23 ·
So you're saying poke it from the passenger side out through the driver's side?
To be honest, I have changed most everything on vehicles before. Unfortunately, never owned a 4x4 so all these parts are new to me.

I picked up a diff from a local junkyard from an 05 envoy. Their computer says it may not fit. I have no idea why but there could be some small change they made that is not noticeable to the eye. Looking at them, they look identical...although the casing is split in half off the old one. But everything does look the same. I made sure the code in the glove box read "GU6" - like mine. I don't know what else could possibly be different.
 
#26 ·
I have the answer to the original poster's question. Looks like some others had the same problem, and I did also. The problem is corrosion causing the aluminum housings to stick together. In my case it took enormous force to wedge them apart. But wedging is what did it for me. Get yourself an industrial chisel and punch set, 12 pieces from Harbor Freight for about 12 bucks. Start driving the chisels like wedges between the two parts. Pry bars are too flexible to be effective here, so you won't make any progress with them until the thing is almost off anyway.
 
#27 ·
Awe Crap! Now an Oil Pan!

Folks, Here is my story:

Finished a $1300 rear end rebuild and upper left ball joint on my wifes TB 3 weeks ago. I just finished replacing Right Upper Ball Joint, both front CV Axles and the Axle Disconnect thanks to the mechanic who punctured a hole in the left inner CV boot. The right CV was already in need of replacement and the seal on the disconnect was AWOL with needle bearings sticking out. So I replaced them. However when I was installing the new Axle Disconnect I mixed up the bolts as far as which hole they went into and one was little long, and as I tightened the bolt up I must have cracked the oil pan.:bonk::duh: I didn't even know I had done this until I was test driving it and noticed it was leaking, and leaking bad.​

So I am going to replace the oil pan this weekend. Autozone wants $700 and O Riley Auto want about $600. I'g going to the salvage yard to resurrect an oil pan unless someone gives me a good enough reason not to.

I am going to take many pictures of the R&R procedure and post them here over the weekend. If anyone would like some extra good karma and would like to donate to the cause, I could use the funds (PM me).

Before I get started, I would like some advice about taking the photos as far as resolution, how to get a good focus with little lighting etc. Also, if you have a particular photo in which would be a benefit to all forum readers that you would like, please let me know.

My Plan:

I am following the Chilton manual which basically states:
  1. remove axles
  2. remove disconnect and int. shaft
  3. disconnect drive shaft from transfer case
  4. remove steering crossmembers
  5. unbolt differential from oil pan and secure

Any advice is greatly appreciated. Thank you all in advance. Please pray for me!
 
#28 ·
Oil pans are not that expensive

Check the GM dealer. List price on an oil pan is about $300. GM Parts Direct sells them for less than $200. I agree that salvage yard would probably be cheaper, but then you might get one that has been damaged getting it off. They are cast aluminum, pretty rigid, but it could still be damaged and it might be hard to detect until you try to get it up in place.

I just did this job, and one of the hardest parts for me was getting the steering gear removed plus the crossmembers. Actually, getting it off was easy, but putting it back up was hard because everything was so rusty.
 
#29 ·
Here's another thought

Maybe your damaged oil pan is repairable. Take it to a machine shop or a place that repairs cracked aluminum wheels. These places are easy to find and the repairs are pretty cheap. I think they weld the cracks somehow, which is a no-no on cast iron, but on aluminum the outcome is much better.
 
#30 ·
Ebay ????

So I found an oil pan on Ebay ($60), and even better, it was in the Denver Metro area, so I picked it up today. It has a casting number of 12584321, and mine has a casting number of 12579218. I called 2 chevy dealers in the area and both said these will work. I do not have my oil pan removed yet to compare to. Does anyone else have confirmation of this or another location to check interchangeability?
 
#32 ·
2 Vertical Bolts

From LMMLJ's post with pictures, just to note that the 2 bolts between the engine and bell housing that are "vertical", mine were behind a rubber gasket and I could not see them. You will need to remove the rubber gasket with a screwdriver and pliers to access the bolts that are up inside the bell housing.
 
This is an older thread, you may not receive a response, and could be reviving an old thread. Please consider creating a new thread.
Top