BMW E21 Rear Differential Restoration
ฝัง
- เผยแพร่เมื่อ 3 ก.พ. 2022
- Hello TH-cam-
We are working on another project with our E21 restoration. We decided to do a restoration on the rear 3.91 LSD differential. As you can see, it was in rusty shape and needed some help. First order of business was to try to scrap as much of the debris we could before hitting it with the pressure washer. The we could begin disassembly and really be able to clean each individual part up. After all of the grease and oil was removed, we took it over to our modified Harbor Freight blast cabinet ( • SAND BLASTING CABINET ... ) and removed the remaining rust and old paint. Next up was metal etch primer and the a few coats of black urethane paint.
Now we get to reassembly the entire unit using fresh o-rings, seals and gaskets. Doing our best to try to now scratch any of the nice new paintjob. As you can see the end result is an amazing transformation. Old rusty diff turned into a brand new looking unit.
Here are the parts used in this video:
Diff Gasket - www.fcpeuro.com/products/bmw-...
Rear Diff Plug - www.fcpeuro.com/products/bmw-...
(2) Side Shaft Seal - www.fcpeuro.com/products/bmw-...
Pinion Seal - www.fcpeuro.com/products/bmw-...
Crush Sleeve - www.fcpeuro.com/products/bmw-...
Securing Plate - www.fcpeuro.com/products/bmw-...
Hope you enjoyed the Video!!!
Cheers!
Follow Bradleys' Garage:
Website bradleysgarage.com -coming soon
Instagram / bradleygarage
If you liked the video, remember to give it a "thumbs up" and consider subscribing.
Thanks again for hanging out!
#bmw #E21 #restoration
Disclaimer:
Due to factors beyond the control of BradleysGarage, we cannot guarantee against improper use or unauthorized modifications of this information. BradleysGarage assumes no liability for property damage or injury incurred as a result of any of the information contained in this video. Use this information at your own risk. BradleysGarage recommends safe practices when working on vehicles and or with tools seen or implied in this video. Due to factors beyond the control of BradleysGarage, no information contained in this video shall create any expressed or implied warranty or guarantee of any particular result. Any injury, damage, or loss that may result from improper use of these tools, equipment, or from the information contained in this video is the sole responsibility of the user and not BradleysGarage. - ยานยนต์และพาหนะ
From a fellow E21 owner, thank you!
Thanks for the comments Dr. Long, appreciate the feedback. We hope it inspired you to work on your E21. Glad you enjoyed the video, stay tuned for more E21 content in the near future, Cheers!
Awesome vid!!
Love the E21 videos!
Glad you enjoyed the videos Adam. Additional videos are in the works, Stay tuned, Cheers!
Looks great! Nice job.
Thanks for watching, appreciate the feedback, Cheers!
I love watching restorations! Nice video
Glad you enjoyed the video, thanks for watching, Cheers!
That was top tier satisfying. Great job on the restoration!
Thanks Jordan, glad you enjoyed the video, Cheers!
amazing work!
Thanks for the kind words, glad you enjoyed the video. Cheers!
Excellent restoration!!
Thanks for the kind words Luis, glad you enjoyed the video. Cheers!
Congratulations and well done; amazing level of detail and the quality is outstanding! Thank you for sharing! Keep em coming!
Appreciate the feedback Joel, we will keep working on the E21 and keep putting out our progress. Glad you enjoyed the video, Cheers!
High quality work and attention to detail
Thanks for the comments Sensei, appreciate the feedback. Glad you enjoyed the video, Cheers!
That was satisfying
Glad you enjoyed the video, thanks for hanging out, Cheers!
Amazing, do the same video in timelaps -> 1M view
Thanks for the comments Jazon, glad you enjoyed the video. We did create a short with this footage but we are a little shy of the 1M mark... 😜
th-cam.com/users/shorts9gyObrzoIiY?feature=share
Thanks for hanging out, Cheers!
Amazing work. Close attention to detail and precision. Love your videos! I can not wait for more!!!
Thanks for the comments, appreciate the feedback. Stay tuned for more to come, Cheers!
@@BradleysGarage😮😮😮😮😮😮😅e😮😮😮😮😮😅😅
😮😮😮e😮😮😮😮😮😮e😮😅e😮😮😅r😮😮😮😮😮😮😮😮😅w😅😅
@@BradleysGarage😮😮😮😮😅😮😮
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I like the rotisserie.
Thanks for the comments Eric, it's actually pretty handy for more than just filming stuff. Great addition to the garage toolbox.
We picked it up from JEGS for less than $50.
www.jegs.com/i/JEGS/555/81495/10002/-1
Cheers!
@@BradleysGarage thx for the link. You do nice work. 👍
Thanks man, appreciate the feedback. Cheers!
Can you please do more e21 restoration or upgrandes? It has been really helpful with the last caliper upgrade. Thank you sir
Thanks Reyner, we have lots of upcoming E21 stuff in the works, stay tuned. Appreciate you hanging out, Cheers!
Rewatching because this is ASMR for classic BMW owners...
Did you replace the clutch discs for the LSD?
Thanks for the feedback we are glad you enjoyed the video. On this particular diff it only had 121K and the breakaway torque was around 25-27 ft. lbs. We decided to keep it as is for now but we may record another video that covers the bearings and clutches along with setting the lash.
Thanks again for hanging out, Cheers!
Congratulations for the video. I am about to renew mine as well. What torque resistance are you looking for when turning clockwise and anti clockwise the end that links to the trans shaft ?
Best regards
Thanks for the comments, glad you enjoyed the video.
We are looking for around 18-20 inch pounds of drag for the pinion gear. The book says 15-29 in lbs when using a new seal so I just went in the lower middle of that range. Good luck with your project, Cheers!
Nice resto!
How is that sand blasting cabinet working out? Are there any mods or issues after the fact of the upgrade video for the cabinet?
Hey Ashlin, thanks for the comments, glad you enjoyed the video.
We have been very happy with the upgrades to the blast cabinet. Everything is working out well and functioning good.
I think the next upgrades for us will be a foot pedal for those longer projects and a larger compressor so we can take fewer air recharge breaks.
The rear subframe and trailing arms will be next on the to do list, so stay tuned for those, Cheers!
I've got so many questions. What did you do with the clock? Did you reuse the crush spacer? Did you reuse the outer rings of the bearings (because you didnt show removing and fitting them)? What about checking the backlash? I think if you added some of that info into the video you'd make a 10/10 video a 12/10 video :D
I'm currently on the edge if I should attempt this myself or have someone do it (incl converting to LSD). This video certainly gave some extra confidence.
Hey Kevin, thanks for the questions. I am not sure what "clock" you are referring to?
The crush sleeve was replaced (link in the description) and set to the proper drag. We did not change the bearings out on this video. If you mark the sides and put all parts back in their original positions you can reassemble without any issue.
If you don't want to hassle with the full disassembly, you can leave the flange intact and still perform a very good external restoration.
We plan on posting another video of the full bearing replacement along with the shim settings. Then we can demonstrate the backlash markings and adjustments.
Good luck on your project, Cheers!
ASMR.
Ahhhh, the sweet sweet sounds of Tink, Bang, Blast and Spray. Music for the ears, glad you enjoyed the video, Cheers!
Wow...just, wow. I'm bringing my '83 320i with the sport package back to life and I need to go through the rear diff. I don't know where you're located, but if you were close to SLC, I'd pay you to do mine.
Thanks Dan, it's definitely a process to bring these back to life. We are located in Southern California, so a bit far from SLC. Not sure if you saw our other E21 video where we did the paint correction?
th-cam.com/video/hpP4fP4HGFo/w-d-xo.htmlsi=Du750HiG3y2l10AJ
Ours has been in the garage for the past 20 years. So we are in the process of refreshing everything. Stay tuned for more E21 content in the future.
Thanks again for hanging out and good luck on your E21 restoration. Cheers!
@@BradleysGarage Thanks for the reply!
I see that you used what looks like a torque wrench with a needle on the input shaft. Is that for checking the correct preload on the bearing?
I haven't watched the paint correction vid, but I will. I'll look forward to more E21 content.
Sub'd. 👊
Hey Dan, yes that is an small old school torque wrench so we can test the drag on the bearing. That will need to be done if you remove the nut.
On another diff we left that in place and just pulled the shafts out and replaced the seals. As long as you put them back on the same side with the same shims, you shouldn't have any issues.
Thanks again for the sub, appreciate you hanging out. Cheers!
Fantastic video, thanks so much. I just got myself this exact diff. Not sure if I want to do a full rebuild on it. Could you just take off the cover and clean out the internals and re-oil?
Oh, also, what oil did you fill it with afterwards?
Hey Sam, thanks for the questions. I would recommend cleaning the exterior of the diff first if that's important to you then you can definitely remove the rear cover and drain it completely. You can use brake cleaner to remove the majority of the left over residue as gear oil is pretty nasty stuff (stinky too). Just make sure you are ready to reassemble after cleaning as you don't want any bare metal surfaces to be left to start corroding.
In regards to the oil, you can use any quality 75W-90 gear oil. Redline, Royal Purple, Torco and Motul are all great choices. You will need about 1.2 quarts for the diff so you will need 2 quarts.
Gear Oil -
www.fcpeuro.com/products/75w90-gear-oil-quart-oil-57904
Diff gasket -
www.fcpeuro.com/products/bmw-differential-cover-gasket-33113604117
After the refill, if it's removed from the car, i would spin it around to properly coat all the internal components. Or if it's still in the car, take it for a spin around the block to coat everything.
You can also service the manual transmission while you are under there as well. You will need around 1.5 quarts for the trans so you will also need to purchase 2 quarts.
Trans Oil -
www.fcpeuro.com/products/manual-transmission-gear-oil-redline-83522-50204
Good luck on your E21 project, Cheers!
@@BradleysGarage why are you so helpful! Haha thankyou 🙏 have ordered the redline oils, managed to find them in Australia. It's currently auto, but I've got a manual box ready to get installed so I'll do the oil before I install it. Thanks again
No worries Sam, glad you were able to source the Redline oil locally. Enjoy working on your E21, Cheers!
About to do the same for my e21, so glad to find out my non 320is car has an LSD. Any reason for the "S" stamp at the end?
All the E21 factory LSD's had an "S" ink stamp on them, as most of the 80's BMW's diffs did. Some of them had a thin square around the S as well. They also have a hard stamped "S" in the case itself. I added a few images so you can see what the OEM ink stamp looked like:
ibb.co/album/TD8Xwq
Since these are 40+ years old now, most of them have worn off or like this diff, are covered in rust and grim and are no longer legible.
My goal was to try to replicate the OEM ink stamp the best I could. Good luck with restoring your LSD unit. Cheers!
Hi,
great video. I am doing the same right now.
Can you tell me how far you compress the tension sleeve?
Thanks for the comments, glad you enjoyed the video. The pinion nut needs to be at least 108 ft. lbs. against the crush sleeve and have zero play. The crush sleeve needs to be changed anytime the pinion nut is removed.
The you can check the "drag" with an inch pound torque wrench. You are looking for 21 in. lbs. rotating the pinion nut in either direction. This is with a dry diff, no fluids inside.
If you are not quite at the 21 inch pounds, then you will keep tightening the pinion nut very small amounts and keep checking the drag. It may take several steps in order for the crush sleeve to be at the right tightness to give you the proper drag.
Here is a link to the Factory Service Manual - docs.google.com/file/d/0BxG0Q9vknRqsUEc2QU9NMmpua0k/edit?usp=docslist_api
Start at page 418 and review the steps.
Good luck on your BMW project, Cheers!
@@BradleysGarage Thx for your fast reply. Im working on a E10 differantial wich is pretty similar. Your manual is much better than the one I have. 👍
I have the correct vaulues for the torque. But How far did you compress the sleeve on the hydraulic press? (Or have you only used the press to put the bearing on the shaft?)
Greetings from Germany.
@HerrHorst Hey Thorsten, you will only use the press for the bearings. The crush sleeve is all done by tightening the pinion nut.
Just remember to take it slow, if you overtighten it, you will have to start over with a new crush sleeve.
Let us know how it goes with your BMW project.
Cheers!
Hello, could you share torque specs for the 6-bolt side bearing caps? 13:55
Thanks for the question, the side bolts should be torqued to 25 ft. lbs.
Good luck on your diff project, Cheers!
Were can I get that S-stamp?
Hey Fred, we purchased the rubber ink stamp from TheStampMaker.com. Here is the item number direct link - www.thestampmaker.com/Products/Wood-Rubber-Stamp-L1-x-H2__I-WH1X2.aspx
We also have 1-2 extra stamps that we made up for some other guys so they might still be here on a shelf if you just want to purchase one from us directly ready to go. I know we had to create the custom font "S" image to replicate the design from BMW.
Shoot us a message over on our Instagram page and we can work out the details. Cheers!
14:00 you put in the gasket dry or with oil?=
Thanks for the question. We didn't show it on the video but it was a quick wipe with a wet finger on the metal flange. Just enough to help the new seal slide right in and not "hang up" on anything. Cheers!
@@BradleysGarage Thank you!
What was the torque spec for the fill and drain plug?
Hey Typhoon, thanks for the question. The manual states around 35 ft/lbs for the crush washer style (I used this on my my full plug). The newer style with an o-ring (I used this on my rear fill plug) is the silver plug only needs about 25 ft/lbs.
Just remember that you can always tighten them a little more if you have seepage. If you crank them down too much initially, you run the risk of cracking the rear cover, since it's only aluminum.
Good luck on your project, Cheers!
@@BradleysGarage Thanks for the help. Mine is the washer style. almost ready to reinstall in the car.