Rear differential removal and installation
 

Hello All,

My rear differential will arrive in 2 weeks...all the way from Germany.

How do I remove and install the differential? I more or less know this: the axles must be unbolted and supported, the driveshaft too, remove the rear anti roll bar and remove the three diff bolts n lower to ground.

do i have to mark the positions of anything? do I have to align the new diff back into the spot the old one was?

Oh- and i will be changing the three differential support bushings/mounts while I'm under there....i figure some odd sizes of pipe and plumbing fittings should allow me to press them out/in on the car. Any thoughts on this? or should i invest in a ball joint press tool with adapters?

thanks..

There is a special tool for removing & installing those bushings that costs just under $100; might not hurt to check around to see if anyone has one for rent or for sale. I've had some success using plumbing fittings for other bushings, but considering the time it takes to gather parts & cobble things together, I've become a fan of spending the money on the right tools for the job.

If the diff is like others, it pretty much just bolts up, and there isn't much adjustment room, so alignment isn't an issue. Getting it lined up though can be a bear. You'll definitely want to have some kind of jack to lift it into place; these things are heavy. The e32 medium-size diff I sold & shipped last year weighed 90 lbs with the crate. I installed a similar diff on my 735i last year & just used a standard floor jack but had my son under the car with me to keep it steady and get it lined up. If you're doing the job solo, a transmission jack would almost be a necessity.

Hi. Thank you for the tips... The diff comes in around 90 odd lbs and I intend on using a floor jack with a helper. do you have a link for that tool? I've been searching and can't find a definitive place. I'm not located in the USA/Canada/any-first-world-country so I HAVE to get my tooling purchases correct from the get go... otherwise i lose out big time....if there is a non-oem bushing tool that will work (say from otc, harbor freight alltrade etc) I'll go that way too.

like you said....i had luck with pipes and plumbing fittings in the past...but it's time to step up for such an expensive DIY ....

thanks a million

Here's one: BMW E38 E39 E52 E53 E60 E61 Rear Axles Bush Removal Installer Bushing Tool | eBay

I think if you poke around on eBay and elsewhere you could do better on price though too. From what I've read, the E38, E39, E52, E53, E60, E61, E63, E64, E65, E66, E67 & E70 all can use the same tool for those bushings. I don't think the bushings are interchangeable though.

so this changes the sub frame bushing AND the three differential mounts/bushings?

i think no....HCB Auto Tools - BMW (E38/E39/E52/E53/E60/E61/E63/E65/E66/E67/E70) REAR AXLES

That was wrong tool altogether in my earlier comment; it's for removing/installing the rear wheel ball joint. Sorry.

I did a little more digging and it looks like there are two different tools for the three bushings; one for the forward two and another for the rear.
BMW Rear Differential Mount Bushing Tool Set E46 E85
BMW Rear Subframe Differential Bushing Tool Set E46 E85

It's too bad the manufacturer doesn't have both sets of plates and cups in a single kit with one threaded rod. I wonder if getting a universal bearing adapter/puller kit would work as well as the BMW-recommended tool. It would definitely be easier to find. FWD Front Wheel Bearing Adapters

hmm....that wheel bearing thing looks awesome....

i was thinking

Alltrade 648617 Kit #46 Master Ball Joint / U-Joint Service Tool Set - 23 Piece - Amazon.com

so i can do ball joints on other vehicles.... my bearings don't wear as much as my suspension parts.

i'm surprised no one else can help.. thanks so much this far. i patiently await my diff. after work, i'm going to begin the removal process. measure up the bushings on the car and see which tool option will be the best.
if all goes well, i'll post tonight

Yeah, I'm also surprised nobody else is chiming in. Plenty of people are looking...

If you don't mind me asking, why are you replacing the differential?

started hearing a rubbing/grinding noise in the back....
i've a thread in here somewhere with a pic of the filings found in the oil

http://www.xoutpost.com/bmw-sav-foru...rear-diff.html

the root cause of failure is yet to be determined

You're likely not going to get much input on this as there may only be a handful of guys who have actually changed these bushings....and who knows if the're even active members anymore.

That being said though, if you're after any special tool(s) needed for this particular job, I'd try and contact any of the guys here who have access to BMW's technical repair literature. At the end of the day they're just bushings though.

Keep us posted on the how it goes!

Removed the anti roll bar, the two output shafts (damaged a bolt in the process) and removed the nuts for the exhaust shield.
Tomorrow i remove the prop shaft and hopefully pull out the diff.

apart from the damaged torx bolt everything is going fairly straightforward.

Do a search on the forum for "bushing rent". There are some members who have the tools and also you will find a few links to places online that will rent them also. Plus, if you decide to buy, some good info on the various tool sets out there.

Aren't those for the subframe bushes?...

Got the diff out today. The most tedious part was actually getting the prop shaft out.
The internals of the diff look like it went through war. Chipped teeth, metal shards and cracked gear carrier thing.
Pics to come tomorrow.

You got those pics??