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1971 R75/5 Rear Seal and Oil pump seal replacement

NCmotomark

NCmotomark

Motomark
I am looking into replacing a leaky rear main seal and possibly clutch on my /5.The shelf at the rear of the engine always has oil pooling on it and draining aft towards rear.No sulphur odor,so not transmission oil. I did a similar project last year on my K75 and later a friends K100rt,replacing the rear main seal,clutch seal and re-lubing all the splines.Also inspecting all of the parts that were removed during the process.All went well on both with no leaks resulting from my limited wrenching skills.Now, I have decided to do the same services on my 71 R75/5 (80,000 mi) and later on my friends 72 R60/5.I am needing to know what special tools that I will need to complete this project?What parts will be needed that can't be reused?I could spent hours/days on the internet looking up all of this information.I am hoping someone reading this posting has probably just completed this same service.Your input would be of great help.Please advise me on this future project.

Thanks
 
Get new bolts for reattaching the drive shaft to the trans. Main oil seal and O-ring for the oil pump cover. As long as you have the trans out, check/replace the throw-out bearing. Get a needle adapter for your grease gun for doing the swingarm bearings after reinstalling the swingarm. Get some longer bolta and nuts for removing the clutch. Paint marker for removing the clutch. When you have the flywheel off, clean thoroughly and then use white paint to highlight the timing marks. Remember to block the front of the crank before removing the flywheel. Have you got the special 27mm socket for the swingarm nuts? Do you have an impact driver with #2 and #3 Phillips bits? Helpful when removing the oil pump cover.
 
* Clutch compressor bolts/nuts - just long bolts with nuts you tighten down on to compress the clutch and remove it
* Something to block the front of the crank before you remove the flywheel and left in place until the flywheel is replaced
* a piece of steel to bolt onto the flywheel to keep it from rotating when you remove the flywheel bolts
* a rear main seal installer, essentially something to press in the seal at the correct depth
* Clutch alignment tool - I used one, but a lot of people don't

if you don't want to make your own stuff, a one stop shop for everything can be found at: http://www.northwoodsairheads.com/Tools.html

The process is pretty easy, you shouldn't have any problem. My transmission input seal wasn't leaking, but I replaced it anyone "since I was in there," IIRC BMW redesigned that as they did their RMS
 
replace all the fasteners

Drive shaft bolts were mentioned, also the 6 allens holding the clutch pack, they are like $1.80 each, then the five bolts on the flywheel MUST be replaced. They are a bit more pricey, $4.50. They are different than /6 or /7.
All in all a couple of bucks, but most likely the very last time you will ever do this project.
26 11 1 242 297 driveshaft bolt M8x1x13mm 09.1980 on $ 1.80 (bettern than older ones with lock washer)
21 21 1 231 463 clutch bolt 1970 - 1980 $ 1.80
11 22 0 016 759 flywheel bolt 24mm / 5 $ 4.50
11 11 1 261 739 rear main seal 80 x 100 x 10 1970 on $ 26.15
11 41 1 335 896 oil pump cover O-ring 62 x 2 1970 on $ 3.80
It's fun and a great time to clean up the tranny and rear of engine case. I also use this time to remove the starter and clean the area underneath it of collected geasey goo and grit.
Have fun, don't rush it.
Regards,
Kurt
 
motomark said:
I am looking into replacing a leaky rear main seal and possibly clutch on my /5.The shelf at the rear of the engine always has oil pooling on it and draining aft towards rear.No sulphur odor,so not transmission oil. I did a similar project last year on my K75 and later a friends K100rt,replacing the rear main seal,clutch seal and re-lubing all the splines.Also inspecting all of the parts that were removed during the process.All went well on both with no leaks resulting from my limited wrenching skills.Now, I have decided to do the same services on my 71 R75/5 (80,000 mi) and later on my friends 72 R60/5.I am needing to know what special tools that I will need to complete this project?What parts will be needed that can't be reused?I could spent hours/days on the internet looking up all of this information.I am hoping someone reading this posting has probably just completed this same service.Your input would be of great help.Please advise me on this future project.

Thanks
Click to expand...

If you're near central IL I've got all the tools having done this last winter and you're welcome to borrow them. Not very hard if you take your time. Good time to check clutch and pressure plates while you're in there. Whatever you do DO NOT forget to block the front of the crankshaft before pulling the flywheel!
 
motomark said:
I am looking into replacing a leaky rear main seal and possibly clutch on my /5.The shelf at the rear of the engine always has oil pooling on it and draining aft towards rear.No sulphur odor,so not transmission oil. I did a similar project last year on my K75 and later a friends K100rt,replacing the rear main seal,clutch seal and re-lubing all the splines.Also inspecting all of the parts that were removed during the process.All went well on both with no leaks resulting from my limited wrenching skills.Now, I have decided to do the same services on my 71 R75/5 (80,000 mi) and later on my friends 72 R60/5.I am needing to know what special tools that I will need to complete this project?What parts will be needed that can't be reused?I could spent hours/days on the internet looking up all of this information.I am hoping someone reading this posting has probably just completed this same service.Your input would be of great help.Please advise me on this future project.

Thanks
Click to expand...

Hi Motomark,

Here's how I did the project on my 1973 R75/5. It includes parts and tools for reference. Enjoy.
 
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