(Sorry in advance for all the words).'90 K75s, 103K miles (about 60K on the engine). I changed the transmission oil about 6 mos ago but hadn't ridden it since - about a month ago I found a little puddle of what sure seemed to be trans oil (under the drain hole that's at the bottom of the trans). For the first time I had filled it with Amsoil severe gear 75W-90 so I thought maybe that had something to do with it. So I pulled the transmission and it appears that there is some leakage from the front cover of the transmission (not the input/output shaft seals or the clutch actuator boot). So i plan to re-gasket that cover. However, there was evidence of oil on the inside of the housing that surrounds the clutch so I figured since I was in it this far I would pull out the clutch which I did (friction disk/pressure plate clean, about 5.0 mm friction disk thickness). When I removed the big nut that holds the clutch housing I had trouble pulling the housing out and (likely unwisely) used a slide hammer with a hook to try to get it out when I realized that rubber/viton/whatever O-ring was holding it in. So - removed the O ring and the clutch housing and now there is a steady drip of motor oil coming from where the driveshaft exits - about 4oz since I pulled the clutch housing/O-ring. Sooo...is that dripping to be expected when the O-ring comes out or is something else going on?
-
Welcome, Guest! We hope you enjoy the excellent technical knowledge, event information and discussions that the BMW MOA forum provides. Some forum content will be hidden from you if you remain logged out. If you want to view all content, please click the 'Log in' button above and enter your BMW MOA username and password. If you are not an MOA member, why not take the time to join the club, so you can enjoy posting on the forum, the BMW Owners News magazine, and all of the discounts and benefits the BMW MOA offers?
'90 K75s - bad engine output shaft seal?
- Thread starter jrx222
- Start date
The oil level in the crankcase is usually at or slightly higher than the bottom of the seal, so some leakage is normal with the clutch housing removed. Inspect the surface on the clutch housing where the seal rides to make sure that there is no wear where the seal rides. Check Euromotoelectrics.com for the seals.
Ok, back for a progress report. Replaced rear main engine seal and transmission input seal. Also re-gasketed the front transmission cover (ended up using thin layer of permatex ultra black for that).
- used a standard hooked oil seal puller for the rear main, using an 8 inch long piece of wood bridging the housing I levered the seal puller against the wood and the seal popped off. Needed a fair bit of force…
- to install the main seal I started using the end of a short length of 2x4 wood with a notch cut in it to clear the output shaft. The idea was to drive the seal in evenly across the width of the seal. Well the wood piece broke in half while hitting it and I ended up using a leftover stub of wood to tap around the perimeter. Started going in cockeyed but finally got it in. I saw a tech article saying that the replacement seal isn’t supposed to be installed totally flush like the original, but raised something like .020 inches … I did my best
- transmission input shaft seal was tapped out from the inside of the cover using a wrench socket. No drama there and the new seal went in fine.
- I reused the clutch but put the clutch pack together using new screws. Torqued to spec.
- lubed splines with 50/50 mix of Honda moly 60 / wurth sig-3000
I just installed the driveshaft and swing arm and just now put in a new clutch cable. I adjusted per the procedure in Clymers. BUT I’m worried… the clutch effort is way stiffer/heavier than it used to be (unacceptably so). FYI I measured the old and new cables and they’re identical lengths. Im pretty sure I installed the clutch correctly. It was a PITA to get the transmission on (I used guide pins and didn’t need to use a mallet to fully seat transmission until the case was about a half inch away from the engine). Any ideas? Maybe the clutch effort will loosen up once I start riding it?
- used a standard hooked oil seal puller for the rear main, using an 8 inch long piece of wood bridging the housing I levered the seal puller against the wood and the seal popped off. Needed a fair bit of force…
- to install the main seal I started using the end of a short length of 2x4 wood with a notch cut in it to clear the output shaft. The idea was to drive the seal in evenly across the width of the seal. Well the wood piece broke in half while hitting it and I ended up using a leftover stub of wood to tap around the perimeter. Started going in cockeyed but finally got it in. I saw a tech article saying that the replacement seal isn’t supposed to be installed totally flush like the original, but raised something like .020 inches … I did my best
- transmission input shaft seal was tapped out from the inside of the cover using a wrench socket. No drama there and the new seal went in fine.
- I reused the clutch but put the clutch pack together using new screws. Torqued to spec.
- lubed splines with 50/50 mix of Honda moly 60 / wurth sig-3000
I just installed the driveshaft and swing arm and just now put in a new clutch cable. I adjusted per the procedure in Clymers. BUT I’m worried… the clutch effort is way stiffer/heavier than it used to be (unacceptably so). FYI I measured the old and new cables and they’re identical lengths. Im pretty sure I installed the clutch correctly. It was a PITA to get the transmission on (I used guide pins and didn’t need to use a mallet to fully seat transmission until the case was about a half inch away from the engine). Any ideas? Maybe the clutch effort will loosen up once I start riding it?
Is your sidestand up while you are testing the clutch pull force?
Did you use a clutch alignment tool when assembling the clutch pack?
Are you SURE you didn’t bend the clutch actuating rod while installing the trans?
A mallet should not be needed to seat the trans if everything is properly aligned.
Did you use a clutch alignment tool when assembling the clutch pack?
Are you SURE you didn’t bend the clutch actuating rod while installing the trans?
A mallet should not be needed to seat the trans if everything is properly aligned.
Thanks much for the ideas Lee. Side stand was retracted (no interference from retraction mechanism). I did use a pilot tool…had to use it twice as I accidentally moved the clutch disk off center during my work to install the transmission (loosened the 6 clutch bolts and re-torqued while using the pilot tool). Bent clutch pushrod? Seems possible but I know it was straight when I started the transmission install process. I don’t think I bent it but not totally sure. Yeah I wasn’t happy about tapping the transmission to get through the last half inch to contact the engine housing but that’s what Chris Harris did in his spline lube video so I figured it was ok as long as I didn’t have to wail on it, and I was sure that the splines were engaged. It just occurred to me though…the arrangement of parts behind the clutch actuator boot (rear of transmission)…e.g. the spring and cup-like piston or whatever, doesn’t quite match clymers or the online parts fiche. That was one area that I did a crappy job of noting how it looked when it came out. I’m wondering if I installed that cup-like part backwards and that spring is sticking too far out? I recall that spring pushing back on the boot a little as I was installing the boot.
My theory didn’t pan out - I took out the clutch actuator boot, spring, and piston (it’s not really a cup). It’s pretty clear to me how that piston goes in (the end with the bearing goes in first so the clutch pushrod end fits in the bearing hole). FWIW when I pulled on the end of the pushrod it could be easily pulled rearward about 3/8” before it stopped. Not knowing any better my plan is to pull the transmission this weekend and take a look.
Update: removed transmission and clutch, inspected things best I could (didn’t see anything obvious…pushrod is not bent) and reinstalled them. Before reassembling the bike any further I hooked up the clutch cable to the lever and transmission- clutch action is still stiff- I’d guess about twice the force I’d expect, maybe a little better than my first attempt. I’m at a loss…thinking maybe it’ll loosen up once I start riding it(?)
Is it possible that you deformed the pilot bushing in the end of the output shaft during your attempts to install the transmission?
If it worked properly before you worked on it, and you used essentially the same parts, logic says it must be something you did during the time you worked on it.
What pilot tool did you use??? Did the pilot tool slide in and out freely after you tightened down all the clutch bolts? Did you lube all the points on the pressure plate indicated in the Clymer’s manual?
Did you grease the clutch cable barrels?
Try disconnecting the sidestand retract mechanism. Just remove the half moon shaped nut to deactivate it, then try the clutch again.
thanks much for the replies. I did not take any pictures of the clutch housing although I didn’t see anything obvious there. The pilot tool was one I believe I got from beemer boneyard years ago when I did my R1100RT clutch. Am pretty certain that the K75 uses the same one. It did seem to move freely (with a little resistance) as I tightened the clutch bolts. I didn’t grease the pressure plate but I did lightly spread some grease on the spring diaphragm where it touches the pressure plate. I had not yet attached the center stand/side stand assy; yep greased the barrel ends. The pilot bushing in the output shaft…the bushing that comes to mind is the one on the middle of the spring diaphragm - there is one in the engine output shaft? Agree- logic indicates that I did something wrong along the way. I should probably pull the transmission again for an even closer look. So far no one has indicated that it could loosen up after a couple of miles!
How much freeplay is at the clutch lever (the gap at the front of the lever)?
Is the new clutch cable a factory BMW one or aftermarket?
When you removed the transmission the second time, did the pilot tool still slide in and out freely?
Did you closely inspect the trans input splines for wear (a narrowing of each spline going back about 3/4 - 1” along each tooth)?
Is the new clutch cable a factory BMW one or aftermarket?
When you removed the transmission the second time, did the pilot tool still slide in and out freely?
Did you closely inspect the trans input splines for wear (a narrowing of each spline going back about 3/4 - 1” along each tooth)?
