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my E30 story


johnprusinski

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http://www.davelength.net/car/diff_swap.html

This little writeup does a fine job of explaining what needs to be done. The particular hangup you are having can be resolved with what he says here towards the bottom of the page:

"The bolts screw down through the bracket into the top of the differential. You can get to the lower two with either the ratchet or the combo wrench. The top two (towards the rear of the car) can only be accessed with the combo wrench, since there is not much room between the bracket and the bottom of the car. Make sure that the floor jack is positioned to hold the differential once you start to take the bolts out. Once the bolts are out, slowly let the jack down, balancing the differential with your hand. The back of the diff will need to drop down just far enough to get the mount below the mount bracket, then the diff will need to move towards the rear of the car, to separate it from the driveshaft. Once the driveshaft bolts are clear, slowly lower the differential all the way down. At this point you can pull the jack and diff out from under the car, and set the differential on the ground."

 

 

If that isnt working out too well then you will need to loosen the collar nut on the driveshaft. You can see it in the picture below, it is just behind the center support bearing. When you loosen the collar nut on the driveshaft you can collapse the driveshaft about 3" which is plenty enough to separate it from the diff input flange.  Getting to the driveshaft means possibly dropping the exhaust, and dropping the heat shields which can be a little tedious, but the fact that the PO of your car pad-locked the trunk means he may have done some other nutty things like removed the heat shields under the car which would make it easy to access that collar nut. It may be worth a quick look. Hopefully you dont have to deal with the driveshaft at all but loosening the collar nut is another option you have if the normal diff removal method just isnt working. 

flex_disc_center_mount_bracket.jpg

Just a note in general. The two-piece driveshaft is balanced as a unit. The last time I pulled my diff, the collar nut wasnt quite tight enough and the rear half of the driveshaft came out with the diff. Luckily my driveshaft is only a year old and the balancing alignment stickers are still on there and easily visible, but if you find yourself ever needing to remove the driveshaft, make sure to make a mark on each piece with paint so that you can re-align the shafts properly. Otherwise you will get some nasty vibrations at freeway speeds. 

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I didn't mark mine when I dropped my diff, pulled the 2nd drive shaft out with the diff, threw it back on. It's still fine. Just some insight.

 

You got lucky. Snap is right. It can cause some serious vibration if not assembled right. They balance driveshaft assemblies for a reason=)

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PS belt could be slipping, pump could be failing, PS. reservoir could be low on fluid and have air in the system. 

You can diagnose this easily by removing the PS belt and taking a short drive. I cant remember which belt drives the water pump, whether its the PS belt or alternator belt, but if its the PS belt, make sure the drive is REALLY short, like just up and down the driveway when the engine is cold.

I have no experience with a welded diff but i would have to imagine it would be a lot like riding an ATV on the street where low speed  turning is difficult. 

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disconnect all bolts from diff, put something soft to catch the diff, shake it angrily until it falls. :)

 

this reminds me of a funny story:  some guy on r3v setup a webcam so he could chat and have people watch as he worked on his e30, it was pretty fun. so we could hear and watch him, and just type stuff into the chat window. he would ask questions and we would help him since he was new to e30s. anyways, one day he is working on dropping the diff and having trouble getting it to drop.  so he comes and chats in the room and we all tell him how to wiggle it out. well, he goes back under the car and starts working. he gets a jack into position to lower it, and is shifting it around.  of course, it was obvious he was going to drop it and everyone was typing 'oh shit get ready, this is going to be funny' and sure enough it fell off the jack and smashed his arm, and everyone is rolling.

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disconnect all bolts from diff, put something soft to catch the diff, shake it angrily until it falls. :)

 

this reminds me of a funny story:  some guy on r3v setup a webcam so he could chat and have people watch as he worked on his e30, it was pretty fun. so we could hear and watch him, and just type stuff into the chat window. he would ask questions and we would help him since he was new to e30s. anyways, one day he is working on dropping the diff and having trouble getting it to drop.  so he comes and chats in the room and we all tell him how to wiggle it out. well, he goes back under the car and starts working. he gets a jack into position to lower it, and is shifting it around.  of course, it was obvious he was going to drop it and everyone was typing 'oh shit get ready, this is going to be funny' and sure enough it fell off the jack and smashed his arm, and everyone is rolling.

 

hahahahahahahahahahahahahaha i got it out and im glad i had a friend help me get it back in. 

 

as you can see, it got a little out of hand when i got done. 

 

IMG_04821_zps32fba746.jpg

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update:

 

i got jakes old exhaust last night and i decided to see if i can hang it today. i got the exhaust welded back up and was ready to weld the new exhaust to the existing pipe. when i went to go clean the existing pipe with a wire brush, the O2 wire came un tucked and it wraped around the wire wheel. the O2 got ripped out and it was destroyed. i will now have to order a new O2 and put that back in. i did however, learn to weld half way decent today.

 

IMG_04901_zps185dce32.jpg

 

IMG_04881_zps04272c42.jpg

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