Author Topic: Oil Leaks, maybe I'll fix one (Read 19037 times)

enialb2 · « **on:** February 09, 2016, 11:39:23 PM »

Hello everyone!

I’ve been looking at the various oil leak threads, and wanted to post some images of my various leaks to get a bit of feedback before preemptively ordering some gaskets, RTV, o-rings, etc. Given the weather in NY, now is a good time to do a bit of work in the garage.

The bike has always had a bit of slow oil seep on the engine, but no actual dripping while parked until recently. During the summer I stored the bike in my brother’s garage for a few weeks on the center stand and noticed a small clear puddle of oil by/under the center stand. Smells like clean oil, not used motor oil.

I immediately checked the transmission oil and final drive oil, but both were at their proper levels. A leak, but also a slow one it seems. Based on the oily nature of my center stand and transmission bell housing area, I’m guessing that the gear oil usually just collects in the bell housing when I use the side stand for daily use and then straight down out the weep hole while I’m riding.

Based on what I’ve learned here http://www.motobrick.com/index.php/topic,6933.msg47896.html#msg47896 I might go ahead and order the works (rear main seal, a new clutch O ring seal, a gear box input shaft seal, and clutch push rod rear seal) at least for that section of the bike. I figure I might as well buy them while they’re still around, and install them now while I’m in the mood. I think I should also take a look at the condition of the clutch boot next time I’m in the garage.

As for the leaks at the front of the engine, can anyone shed some light onto what I’m looking at. I haven’t found a diagram that is more informative than the parts fiche. Perhaps one or two leaks could be fixed with a cleanup and a fresh seal or gasket. I’ll post a selection of pics below. No drips, but a fair amount of seep.

I’m also planning to do my first look at the valve clearances, a spline lube, and whatever else I should do while the bike is apart. I bought the bike, a well cared for 1991 K75, at 32k miles and have put on a mostly trouble free 13k since. In the last two years I’ve done new spark plugs, air filter, fuel filter, fork oil, coolant, oil filter, and of course engine oil.

K1300S · « **Reply #1 on:** February 10, 2016, 06:07:42 AM »

Replace all rubber bits. the fuel and coolant hoses and the monkey nuts.

Scott_ · « **Reply #2 on:** February 10, 2016, 06:48:44 AM »

Looks like you have some seepage around the timing chain cover as well. That is just a RTV gasket seal there.
Otherwise it sounds like you are on the right track with the rear of the engine.
As mlytle suggests, change any/all the rubber hoses, vacuum lines, etc.... that you can find. Especially the ones behind the throttle body assy.

enialb2 · « **Reply #3 on:** February 10, 2016, 09:37:48 AM »

Thank you both! Hadn't thought of all the other rubber bits.

orforester · « **Reply #4 on:** February 11, 2016, 01:35:35 PM »

If you are doing a spline lube it is only a little further to replace the rear main seal, and a good idea given the age of our bikes. But before you do make sure you have the clutch alignment tool and MAKE SURE YOU KEEP THE PARTS IN ORDER and in the SAME POSITION!! Very important. Study the how to's listed here. I did the job my myself for the first time, but go slow, get all the parts ordered and in hand. the Clutch centering tool is not required, but it is sure helpful. I did chicken out and have someone replace all the tranny seals for me, about $250 bucks, local good guy, cheap.

TimTyler · « **Reply #5 on:** February 11, 2016, 01:42:21 PM »

I'd clean off all the oil on your engine. Then run it to see exactly where it's leaking from.

F14CRAZY · « **Reply #6 on:** February 11, 2016, 02:55:28 PM »

I like using Permatex's The Right Stuff for RTV-ed parts

enialb2 · « **Reply #7 on:** February 12, 2016, 11:18:46 PM »

Building my to-do list, and my to-buy list!

enialb2 · « **Reply #8 on:** March 25, 2016, 10:23:18 AM »

After pulling everything from the rear wheel to the drive shaft. Thus far all splines still show good moly type lube present and are in great shape. The front u-joint of the drive shaft isn't totally buttery, a little notchy, but after reading this http://www.motobrick.com/index.php?topic=6604.0 I'm going to continue using it since the whole assembly was well coated with lube of some sort and no corrosion was present. Chris Harris shows off a f&?!$ing notchy drive shaft in one of his YouTube videos, so I was a bit worried when I inspected the u-joint.

enialb2 · « **Reply #9 on:** March 25, 2016, 10:38:06 AM »

Pulled the gearbox last night with a vital set of extra hands, and I finally get an up close look at the suspected source of my gear oil leak.

No damning evidence that the gearbox input shaft seal is to blame, but the entire area has a thin film of gear oil mixed with clutch dust, and a slight puddle of gear oil in the bottom of the bell housing area. No motor oil whatsoever. It doesn't look like the yellowish green gasket for the front cover of the gearbox is leaking, but hard to be sure. I have the new input shaft seal, so I'll install that next chance I get.

enialb2 · « **Reply #10 on:** March 25, 2016, 11:37:44 AM »

No photos of the pulled clutch, but it really took lots of encouragement with a mallet and choice vocal persuasion. I could have easily knocked the bike over during this struggle without help from my friend.

Boy was the clutch nut almost impossible to get out! Now I see the benefit of an actual breaker bar over a ratchet with a breaker bar attached to it. I had to use one hand just to keep the socket seated properly, but my guess is that a breaker bar with socket attachment will have much less play in it and let me pull with both hands while my friend keeps the bike from falling over. Do not try to remove the clutch nut without a fully secured bike.

I think the cleanest part of my bike is the bare aluminum engine block half above the rear main seal! No signs of motor oil seep, but the gear oil and clutch dust is similarly sitting at the bottom of the bell housing. Now that everything is apart, time to replace the clutch o ring, rear main seal, and gearbox input shaft seal.

Thanks everyone, and Chris Harris for getting me this far! I have so much anti seize ready to use. No broken bolts yet, but one of the 6 bolts that connect the gearbox to the motor was entirely missing. That was a surprise.

enialb2 · « **Reply #11 on:** March 25, 2016, 02:03:48 PM »

One more thing, what do people use when reinstalling/torquing the 27mm locknut on the left side swingarm pivot bolt.
#10 here:

Do you use an open sided 27mm socket to get the torque right while holding the pivot pin in place with an allen key, or just estimate the torque?

One of these for example?
http://www.ebay.com/itm/Strut-removal-tool-27mm-socket-1-2-drive-impact-quality-bmw-vw-audi-etc-/311570748123?hash=item488b1052db

TimTyler · « **Reply #12 on:** March 25, 2016, 02:54:25 PM »

I estimate, but that may not be god advice.

The Mighty Gryphon · « **Reply #13 on:** March 25, 2016, 03:23:59 PM »

+1 on the estimate. I just get it tight enough that I'm confident it won't fall off.

enialb2 · « **Reply #14 on:** March 25, 2016, 04:22:21 PM »

Thanks, will give that a try before and see how it feels.

The Mighty Gryphon · « **Reply #15 on:** March 25, 2016, 06:15:16 PM »

Yeah, the critical torque is on the pin. This torque on the pin preloads the swing arm bearings. The nut is just there to hold the pin in position so the preload doesn't change.

Scott_ · « **Reply #16 on:** March 25, 2016, 11:20:38 PM »

Before you spend the time installing the new trans input shaft seal, I'd suggest you check the bearing on that end of the input shaft as well. Something has "given" to allow shaft to set so "off center" in that seal, thus causing the leak.

billday · « **Reply #17 on:** March 26, 2016, 12:57:08 PM »

Your bike's not stable just propped up on the oil pan. Remove the "brain," put a sawhorse on either side of the bike, and slide a 2x4 through the frame with the ends on the sawhorses.

I'd show you a pic but I can't get my jpeg's past Motobrick security.

Martin · « **Reply #18 on:** March 26, 2016, 01:58:25 PM »

Bill as per Laitch you need to downsize the size of your picture. The site does not like large pictures, I now use a program called Picresize at a 75% reduction. There are probably better ones available.
Regards Martin

enialb2 · « **Reply #19 on:** March 26, 2016, 03:25:08 PM »

Yes, I currently have a strap going through the frame to a hookup in the ceiling, but it's not ideal for a number of reasons. I'll change approach next time, but I'm more focused on this seal vs bearing issue at the moment.

Can I check for play in the shaft, or service the bearings without cracking open the gearbox?

Scott_ · « **Reply #20 on:** March 26, 2016, 08:49:15 PM »

Quote from: enialb2 on March 26, 2016, 03:25:08 PM

Can I check for play in the shaft, or service the bearings without cracking open the gearbox?

Well, honestly I wish I had an answer for you on that. I don't know if the bearing is seated in the front cover and comes off with the cover, or if the shaft has to come out to get the bearing off.
I've not opened one up. Maybe a U-tube video would help????

The Mighty Gryphon · « **Reply #21 on:** March 27, 2016, 01:43:29 AM »

When I went into mine to tighten the grub screw on the shifter shaft all the gear and shift fork shafts were removable and the bearing were pressed into the cases, as were the seals. Take your time and carefully follow the instructions in your Clymer manual and you should be in good shape.

It also wouldn't hurt to have a nice well lit workbench, a helper, and a whole lot of patience when it comes time to get all that stuff back in there. As I recall, it took me and my son about 2 hours to get the cases back together. Seems we spent a lot of time fishing parts out of the bottom half. The worst was, I think, one of the rollers that follows the groove in the shift drum that got under a gear and refused to come out. Took about a half hour to get it without pulling everything out of the case and starting over.

enialb2 · « **Reply #22 on:** March 27, 2016, 08:24:51 PM »

Alright, got back over to the garage to clean and degrease all the bits I've been removing and to take a closer look at the gearbox input shaft. The shaft spins smoothly and has zero play in it, so my plan is to replace the seal and avoid a bearing replacement or reshimming. The splines are in excellent condition, which I hope is also a sign of healthy bearings.

enialb2 · « **Reply #23 on:** March 30, 2016, 09:14:31 AM »

New gearbox input shaft seal and Rear Main Seal (RMS) installed! I'm glad I did the smaller one first since these are my first two seal installs, and not as easy or forgiving as I thought. It took me a while to find a drift that worked well on the RMS, especially something that let me focus my efforts on the proudest part of the seal once it started going in a little unevenly.

In standard fashion, my phone died after getting this shot but before I could photograph my humble .5mm depth gauge. I found that the thin cardboard box for my small propane torch was just thick enough to do the job. I could just slide a small piece of it up next to the edge of the seal and feel where the seal still needed to be driven in and where it matched the .5mm depth of the cardboard.

Martin · « **Reply #24 on:** March 30, 2016, 12:06:00 PM »

Good job that's what I call thinking outside the box.
Regards Martin.

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Author Topic: Oil Leaks, maybe I'll fix one (Read 19037 times)