1989 E30 with half shaft leak, plus introduction

[MikeyE30]

My son just got his 1989 E30 off Ebay. It's been his dream to restore and own one since 6th grade and he finally got one. We are in Florida and the car came from California. At first, the car seemed to run and drive OK as claimed in the Ebay ad, but within the first mile the selector rod on the M5 popped out leaving the shifter to flop around: not possible to put it in gear. We fixed that: turns out the selector rod had the wrong length pin on the transmission end and wouldn't go all the way through the collar so the clip could be placed on the end... so they wrapped TAPE around the pin to make it fit snug in the collar! Makes me wonder what other shoddy work was done on this car.

Anyway, after fixing that (properly), we took it for a short drive and everything seemed OK but when we got home, we noticed oil leaking from the right rear half shaft. I looked for info on replacing an E30 half shaft seal but the one YouTube video on the subject specific to the E30 doesn't show the guys work and I'm not sure he did it right. Other videos and instructions seem to refer to different models. Fortunately the E30 looks very open back there and it looks like you can just drop the half shaft without removing other parts. But I want to make sure we know how to do it properly. Does anyone have a link for replacing half shaft seals on a 1989 E30? We are n00bs at BMW's but I have a bit of experience on other vehicles, mostly American cars. I'm already impressed with how the E30 is put together! Lots of things seem to be made easy to work on. I just want to be sure I know the steps before I get into doing the half shaft seals.

Also, I ran into some threads here suggesting to check the pressure relief hole to be sure that's free. Not sure where that is or if there are other things we should check before getting into the seals.

Thanks!

Mike

[superj]

the best thing to do is to get a Bentley manual. that is the most helpful manual you can get for the e30.

I don't have experience in what you are doing so I cannot help

[MikeyE30]

Thank you! Just ordered the service manual.

Regards,
Mike

[superj]

no problem

[323i E30]

Welcome!

This site also has a lot of good info, easy to browse: http://www.e30zone.net/e30zonewiki/index.php/Main_Page

This one as well of course, regarding part#s and exploded diagrams: https://www.realoem.com

[JamieG296]

I've changed both my half shafts on my e30. You'll have to get get but off the hub before you can remove it. It took me getting a torch to hear it up and a small chisel to gently turn the nut until it came off. They are not too bad to remove. You'll have to put the car in gear after to loosen the bolts at the half shaft. I had to go and loosen the onesie could get to up and then crawl out, take it out of gear and then go under turn the shaft and then go back and put it in gear again. Its not too bad though. I have never worked on bmws until I bought my wife's e39 and then I turned around about a year later and bought an e30, which has been a basket case lol.i have already replaced the suspension front to back and I'm going through the motor now. I've replaced the timing belt,water pump and all sorts of stuff and still have a whole lot more to do.
I'm about to build an oak kitchen table that in trading out for the work to finish mine and get it back on the road. Its been a bit since its seen the road.
This site is very helpful though for sure. Parts,advice,whatever you need,its here somewhere.

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[MikeyE30]

I've changed both my half shafts on my e30. You'll have to get get but off the hub before you can remove it. It took me getting a torch to hear it up and a small chisel to gently turn the nut until it came off. They are not too bad to remove. You'll have to put the car in gear after to loosen the bolts at the half shaft. I had to go and loosen the onesie could get to up and then crawl out, take it out of gear and then go under turn the shaft and then go back and put it in gear again. Its not too bad though. I have never worked on bmws until I bought my wife's e39 and then I turned around about a year later and bought an e30, which has been a basket case lol.i have already replaced the suspension front to back and I'm going through the motor now. I've replaced the timing belt,water pump and all sorts of stuff and still have a whole lot more to do.
I'm about to build an oak kitchen table that in trading out for the work to finish mine and get it back on the road. Its been a bit since its seen the road.
This site is very helpful though for sure. Parts,advice,whatever you need,its here somewhere.

Sent from my SM-G950U using Tapatalk

Sounds like you are the person to ask... There's not much in the way in the back of the E30 and the half shafts look well exposed, so I was wondering, can't you just loosen the outer bolts on the end of the shaft closest to the diff and then be able to pull the diff side of the shaft down and out of the way? After the diff end of the shaft is hanging out of the way, it was my understanding that you can remove a retaining clip and/or some bolts and pull the hub (the piece that goes into the diff) out? And the seal is in there?

I'm sure it'll be clearer once the service manual arrives but it's always good to talk to someone who has done it.

Regards,
Mike

[JamieG296]

You can do that I'm sure. I had no real trouble getting them out once I got all the bolts loose. I pulled mine completely out though and put new ones in. There was nothing obstructing them when I pulled them from the diff.
I also replaced my trailing arm bushings and my subframe bushings while i was back there along with installing ss braided brake hoses as well. If those are worn out, fo ahead and get them while you got the car in the air. It's a PITA though for sure.

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[Texaslonghorn1]

Mike - I have replaced the half shafts in my E30 and an E46. Yes, you can remove the inner (diff end) flange but it may not go quite that easy. You will have to compress the shaft a bit in order to get the flange out of the final drive. The diff output flange is like a cup and the center of the half shaft flange is "raised" to fit into the "cup". It isn't a tight fit but you can't just slide the half shaft straight out. Are you only looking to replace the boot? If you aren't already familiar with how to inspect CV joints, do some research and inspect things. You will probably want to clean out old grease and pump in new stuff before you put new boots on. It is pretty easy to disassemble/reassemble the bearing on the inner (diff end) joint to clean and repack - which you will have to do in order to get the boots on in the first place. If you think you need to do more servicing to them, you need to just buy a whole new one. Trust me on that - I spent a fair amount of time this summer trying to figure out if the outer bearing/joint could be serviced any more than light cleaning/repacking/new boot. It can't. But if you are going to try to extract the spindle from the hub - be prepared for a long, frustrating and painful battle. Hopefully yours won't be as bad as mine. In a perfect world, like JamieG296 mentioned, you would drop out the whole rear end and replace all the bushings, brake lines/components, etc. Honestly, it isn't that difficult at all once you get the rear end to drop out. But that in itself can be a big frustrating and painful battle.

One final thought - you said you saw "oil" leaking from the half shaft. Do you really mean liquid? The half shaft joints are supposed to be greased with pretty thick goo that shouldn't be much of a liquid. It might soften up at temp but I don't think it is supposed to liquify. If you saw it on the inner flange, you may want to check out the diff seals - diff fluid is a liquid. Best of luck - I am sure your son will have a blast working on the car.

[MikeyE30]

Thanks for the great info. It's a liquid that looks like diff fluid and it's leaking from where the axle shaft flange meets the diff. Hopefully you'll be able to see this pic:

https://www.flickr.com/photos/160990.../shares/348u5t

There's also some sort of bent piece close to the diff that shows in the photo: don't know what that is. Due to finding that the shift selector rod was held in place by wrapping tape around the rod pin, the car had some seriously shoddy work done, probably just to get it to start and roll so the seller could claim "runs and drives". So now everything I look at is suspect in my mind. I wouldn't be surprised if they put the half shaft in with NO seal... if that's even possible. Don't know what I'm going to find under there.

Mike

[superj]

the bent plate looking piece looks like the dust shield. that fluid on the diff that looks wet looks like gear oil from inside the diff.

[Texaslonghorn1]

I would agree with superj that you need to look at the diff - the output flange of the diff and the bottom of the diff housing look "wet" from a leak there. If the CV joint was leaking, there would most likely be an unholy ugly black goo mess all over the place. Plus the boot looks in good shape and is dry along with the shaft itself, other than a slight thin discoloration on the sheet metal above it from what is probably a little bit of grease being flung off due to centrifugal force. I might even suggest that the half shafts are relatively new based on how clean everything looks. Read up on diff servicing before you do it - it can be more complicated that it seems.

[MikeyE30]

Thanks for all the great info. One thing keeps confusing me. You guys seem to be under the impression that if it's the half shaft hub/flange seal, it wouldn't be leaking gear oil. If the seal where the half shaft (flange) goes into the diff is leaking, wouldn't that allow gear oil out where that flange enters the diff, causing gear oil to leak out the side there and get the side/bottom of the diff wet as a result? I thought that's why there's a seal where the half shaft flange goes into the diff: to keep the diff oil in the diff?

Mike

[superj]

the reason that is being said is because of the wet spot on the side of the diff, and bottom, under that shaft. it gives the appearance on a leak at the output shaft of the diff

[MikeyE30]

the reason that is being said is because of the wet spot on the side of the diff, and bottom, under that shaft. it gives the appearance on a leak at the output shaft of the diff

Yeah, the confusion comes from me not knowing what to call these parts so I've likely mislabelled parts in my posts. My Bentley manual is due here at the end of the week and I'll know what to call all these things but if you look at the picture, I was talking about dropping the half shaft and removing the "flange" to the right of that bent dust plate: remove that from the diff and replace the seal between that and the diff. This is the only video I can find on doing this on an E30 and the guy doesn't show his work:

https://youtu.be/3frd1aqN2pc

But if you look at 6:30 in the video, I'm talking about removing that piece from the diff and replacing the seal inside.

Mike

[superj]

ohhh, that is what everyone is talking about. you got the right plan to fix it than but yes, everyone was using different terminology

[Texaslonghorn1]

Got it. Yes indeed I agree with superj - that is the part I was trying to explain was the likely culprit. The thing that is the goo source (and therefore NOT the likely source of the oil) is the part of the half shaft on the video for the few seconds BEFORE 6:30. If I have confused you, ignore everything I said.

[msservices]

He said half shaft seal, which is in fact part of the differential, I would be checking for play in the carrier bearing(s) before pulling the drive flange out. Also harbor freight sells a seal driver kit which worked well when I rebuilt my diff.