FD seal gone?

[Jagman]

Hey guys..... could use some advise here. I've got a 2002 BMW 1150RT with 115k on it. Bought it last year with 109k. Bike has been very, very good. But of course with that many miles on it I worry about it quite a bit. This spring I noticed some oil on the outside of the swingarm and I'm guessing that a seal from the FD is going south. This is the first time I'm posting a pic, so if it doesn't show up this time I'll try again.

 

https://picasaweb.google.com/100217806829659406639/ProfilePhotosDraft#5952466251598681650

 

Noticed quite a bit more oil the other day so decided to check the FD oil.... and damn, I think it was down quite a bit. Didn't notice anything, no noise, etc. Bike runs great. Earlier in the summer before a 2k ride to Colorado I'd changed the FD oil, using Valvoline synthetic 75-90. Maybe that wasn't the thing to do? Any suggestions? Could just keep an eye on it and keep putting a little oil in it I guess. I'm not afraid to tackle the repair with a little guidance, or I can at least take it out and send to someone who knows what to do.

 

Suggestions.

 

 

[racer7]

The first thing you need to understand is that you don't want this to be an expensive mess if such is avoidable. Here's the basic deal on that

 

Seals can go all by themselves or a leaker can be a preliminary warning that your FD is about to fail. The latter is when it can go from a bit expensive (a rebuild) to a lot more expensive (new drive or used if you can get a good one).

 

So inspecting the drive completely and carefully must be done now.

You will want to disconnect the FD from the shaft, get the caliper/pads off as well as the tire and spin it by hand. It should be dead smooth, no ratchet or sticky spots.

 

Then drain the fluid into a clear container through a very fine screen. Check both the drain plug and the fluid for any shiney metal flakes- they can be off a bearing race and indicate a bearing about to fail or already failed even if it spins pretty smooth. If all you see is what looks like a bit of greasey metallic mush on the plug, that's a good sign and what you want.

 

If the drive seems sound then you can replace the seal- any seal replacement is about like any other.

 

If not, you need to fix the drive and the seal. There are rebuild specialists you can send it to if it needs one.

 

Do not let it run out so you ride very low. Will speed that rebuild.

[AndyS]

Sorry I can't access that picture.

Is the oil coming from the rubber gaiter between the swing arm and the FD? or is it coming from the output area between the FD and the wheel?

racer7 makes good suggestion about draining and inspecting the oil.

Have you checked your rear wheel for any sideways movement?

It is time to establish where the oil is actually coming from and whether it is a worn out seal, or a worn bearing.

Does the rear FD make any grumbling noises if the wheel is spun by hand with the bike on the centre stand and in neutral (with the oil warm - say after a ride).

[Jagman]

Thanks for the ideas.... sounds like a plan. May take me awhile to get this done of course. Got a feeling it is just the seal, but that may be my wishful thinking.

[dirtrider]

Morning Jagman

 

I couldn't get the picture to open either.

 

In any case, an oil leak in the final drive can be anything from an annoyance to a problem waiting to get real expensive in a hurry.

 

First thing that we need to know to help you is having you explain (in detail) EXACTLY where (what seal) the gear oil is leaking from or seeping from.

 

A crown bearing seal replacement is no big deal even for a limited shop with limited mechanical experience.

 

On the other hand, a pinion seal replacement is very difficulty at home without special tools & thorough understanding/know how & probably should not be tackled by a do-it-yourselfer unless very mechanical minded & able to make some moderately complex tooling.

 

So, first thing, see if you can re-post your picture on a web site we can open.

 

Or at least explain in detail EXACTLY where on the final drive that the leak is coming from.

 

You also need to put the bike on the center stand, then grab the rear wheel at 12 & 6 o'clock then 3 & 9 o'clock & give the rear wheel a push/pull shake (ie push with one hand while pulling with the other) to see IF you have any crown bearing movement. (try to isolate any wheel movement from final drive movement).

 

If you have a lot of crown bearing movement then a new seal will do nothing & the possibility of crown bearing failure out on the road is high.

 

So let us know IF you have any crown bearing play as well as where the gear oil is leaking from then we can advise from there.

 

[Jagman]

I'll try to post this pic again:

 

 

Will check the bearing play tomorrow morning. Just took a 120 mile ride after wiping it off and it has shown up again, not as bad but I can see it.

[dirtrider]

Evening Jagman

 

 

That does appear to be a pinion seal leaking (or at least seeping).

 

Might possibly be the rear trans seal with the oil running down the inside of the swing arm but IF your final drive oil level was low probably a pinion seal leaking.

 

That pinion seal is really not a do-it-at-home project unless you have high knowledge of the procedure & some special made tools.

 

I see in your earlier posting you used synthetic gear oil last change?

 

You might try switching back to conventional (non-synthetic) gear oil as most conventional gear oil has more seal conditioner in it. That tends to swell the seals up just a little more.

 

I have seen a number of BMW final drives quit seeping gear oil at the pinion seal when switched back to conventional gear oil. (worth a try anyhow).

 

[Jagman]

Very much worth a try doing the conventional oil. tomorrow is supposed to be much warmer so I think I'll change the oil, take it for a ride.

[Jim Moore]

have you [ulled back the rubber boot to see how much oil is actually leaking? A little bit of oil can make a pretty big mess. I could live with a tiny leak for a long time.

[dirtrider]

Morning Jagman

 

Once you change to conventional oil that usually takes a while to take effect & swell the seal so give it some time after the change to slow or stop the leak.

 

More than likely that gaiter boot is also full of gear oil in the folds so you might have to remove the rear cable tie to drain it, or possibly (carefully) slide a very thin tool in between the boot & the final drive housing to allow the existing oil to drain out.

 

If you don't drain the gear oil out of the boot area you will never know if you have effected the leak as it will probably keep seeping out as you ride.

 

[RobinW]

I'd be looking under the rubber boot to see how much is in there.

 

And you might wanna throw out the zip ties and get some real jubilee clips.

http://www.motorworks.co.uk/vlive/Shop/Parts.php?T=5&NU=15&M=30&Ct=EA&SbCt=BA_15_30_EA_80

[tallman]

I'd be looking under the rubber boot to see how much is in there.

 

And you might wanna throw out the zip ties and get some real jubilee clips.

http://www.motorworks.co.uk/vlive/Shop/Parts.php?T=5&NU=15&M=30&Ct=EA&SbCt=BA_15_30_EA_80

 

So are those diamond coated or just Queen approved?

[Jagman]

Good idea. Supposed to be nice this afternoon so I'm planning to ride some to heat the oil up and then I'll take the gaiter off, then fill with conventional oil. That will be plan "A",and I wonder to what letter we will get to by the time this is all done!

[PAS]

It's a bit more complicated then that.

[jfremder]

 

You might try switching back to conventional (non-synthetic) gear oil as most conventional gear oil has more seal conditioner in it. That tends to swell the seals up just a little more.

 

I have seen a number of BMW final drives quit seeping gear oil at the pinion seal when switched back to conventional gear oil. (worth a try anyhow).

 

My experience also parallel's DR's No more Synthetic in the F/D. It does make for a smoother shifting tranny though.

[RobinW]

I'd be looking under the rubber boot to see how much is in there.

 

And you might wanna throw out the zip ties and get some real jubilee clips.

http://www.motorworks.co.uk/vlive/Shop/Parts.php?T=5&NU=15&M=30&Ct=EA&SbCt=BA_15_30_EA_80

 

So are those diamond coated or just Queen approved?

Sorry I forgot you lived in dreamland USA. Once the chinese take over you'll have to pay exactly the same as the rest of the planet. Won't be long now.. Please wait a bit.

[philbytx]

Ah!

 

You are only jealous mate. We pay US$15.99 for a 12 pack of 375ml Foster's lager, which is less than half of what you pay for a six pack over in Oz !

[Jagman]

Well..... I checked the rear tire for play at the 6 and 3, and 12 and 6 positions and found a very slight amount of play. At first I didn't think any was there, but I finally did detect it. Very slight though, but I'm sure there isn't supposed to be ANY... So I put some non synthetic 80-90 into it, of course forgetting to look for fines. But the drain plug did seem to be a magnet and I didn't really see anything stuck to it, just some slimmy grease.

 

So... do you think it is toast and just go ahead and redo the FD, or should I wait a bit to see if the non synthetic helps in some way?

[AndyS]

Jagman, That movement could be 2 things. It May be the FD output bearing, but more likely the FD pivot bearing which can be easily replaced or even adjusted.

Lets go back a step.

How much oil did you find in the area of the FD when the gaiter was removed?

Use a mirror in the FD area to see if the oil is running down from the gearbox end (less likely). Or coming from the FD Input bearing seal (more likely). You need to do this to confirm if the steps you are (have) taken are of any value.

As has already been said, a tiny bit of oil goes a long way and can look a lot worse when it has been blown around and wicked its way along dust and grime.

Make sure you clean everything up, so that you can accurately monitor any improvement (or not), you have achieved.

[dirtrider]

Morning Jagman

 

As Andy mentioned, before getting too upset about the rear wheel play you really need to determine where it is coming from.

 

If the rear wheel is moving in relation to the final drive housing (that is crown bearing movement), OR if the ENTIRE final drive (wheel & all) is moving in relation to the swing arm.

 

You can usually do that by wedging one of your fingers between the brake rotor & the caliper mount while moving the rear wheel at 12/6 & 3/9.

 

On the amount of movement allowed (IF) the movement is ALL in the crown bearing? That is a real good question. BMW doesn't give a max wear number so there is no real go/no-go number.

 

The original (new bearing installed) play is actually preloaded to .002"-.004" so there should be NO bearing play in a "new" or low mile bearing.

 

But as we all know things wear as they get more miles on them so a bearing that started out with .002" preload could easily have a little (normal) movement at higher miles.

 

I would presume that your 115K bike has already had at least one new crown bearing installed in it's life & possibly a few.

 

If by some slim chance your bike still has the original crown bearing then a measurable amount of crown bearing movement would be expected at 115K.

 

A little movement won't kill the bearing if the ball race stays intact. The usual bearing failure is a little ball wear, then some ball & race pitting or brinneling, then the ball retaining/spacing ring self destructs, then all the balls go to one spot bunched together on the race & the thing gets real loose & wobbly.

 

If your magnet was free of SHARP little shiny pieces that is a good sign, that grayish/blackish goo is perfectly normal as that is mostly gear tooth rubbings with a little moly mixed in.

 

Do that gear oil change to conventional & also get a base line on crown bearing movement. Then ride it a while as well as monitoring the crown bearing movement. If the crown bearing movement doesn't keep getting worse & your oil seepage becomes less or none then just check the rear wheel movement every thousand miles or so.

 

Then, next gear oil change, filter the drained gear oil through a paper towel or coffee filter, then take the paper towel (or coffee filter) out in the sunlight & look for shiny things or sharp little pieces.

 

[Jagman]

Jagman, That movement could be 2 things. It May be the FD output bearing, but more likely the FD pivot bearing which can be easily replaced or even adjusted.

Lets go back a step.

How much oil did you find in the area of the FD when the gaiter was removed?

Use a mirror in the FD area to see if the oil is running down from the gearbox end (less likely). Or coming from the FD Input bearing seal (more likely). You need to do this to confirm if the steps you are (have) taken are of any value.

As has already been said, a tiny bit of oil goes a long way and can look a lot worse when it has been blown around and wicked its way along dust and grime.

Make sure you clean everything up, so that you can accurately monitor any improvement (or not), you have achieved.

 

After I took the gaiter strap off I didn't find any oil in the area at all,,, and that's a good thing I think.

[Jagman]

Morning Jagman

 

As Andy mentioned, before getting too upset about the rear wheel play you really need to determine where it is coming from.

 

If the rear wheel is moving in relation to the final drive housing (that is crown bearing movement), OR if the ENTIRE final drive (wheel & all) is moving in relation to the swing arm.

 

You can usually do that by wedging one of your fingers between the brake rotor & the caliper mount while moving the rear wheel at 12/6 & 3/9.

 

On the amount of movement allowed (IF) the movement is ALL in the crown bearing? That is a real good question. BMW doesn't give a max wear number so there is no real go/no-go number.

 

The original (new bearing installed) play is actually preloaded to .002"-.004" so there should be NO bearing play in a "new" or low mile bearing.

 

But as we all know things wear as they get more miles on them so a bearing that started out with .002" preload could easily have a little (normal) movement at higher miles.

 

I would presume that your 115K bike has already had at least one new crown bearing installed in it's life & possibly a few.

 

If by some slim chance your bike still has the original crown bearing then a measurable amount of crown bearing movement would be expected at 115K.

 

A little movement won't kill the bearing if the ball race stays intact. The usual bearing failure is a little ball wear, then some ball & race pitting or brinneling, then the ball retaining/spacing ring self destructs, then all the balls go to one spot bunched together on the race & the thing gets real loose & wobbly.

 

If your magnet was free of SHARP little shiny pieces that is a good sign, that grayish/blackish goo is perfectly normal as that is mostly gear tooth rubbings with a little moly mixed in.

 

Do that gear oil change to conventional & also get a base line on crown bearing movement. Then ride it a while as well as monitoring the crown bearing movement. If the crown bearing movement doesn't keep getting worse & your oil seepage becomes less or none then just check the rear wheel movement every thousand miles or so.

 

Then, next gear oil change, filter the drained gear oil through a paper towel or coffee filter, then take the paper towel (or coffee filter) out in the sunlight & look for shiny things or sharp little pieces.

 

All good ideas,,,, thank you. I'm pretty sure the previous owner said that he'd changed the FD at about 70k, but it certainly could be time for a new one also. If after riding the bike for awhile and I don't see any significant increase in wheel movement is there a way to tighten the bearings up a bit, or do I just leave them alone?

[AndyS]

Hi Jagman

You have had some great advice here. When you spin the back wheel (engine off and in neutral), does the FD bearing sound grumbly?

The movement you can check as DR suggests the method.

However, from your picture, the oil seems to be coming from that gaiter.

You say you have just checked it by sliding the gaiter off the flanges and there is none in the gaiter or the entrance to the FD???

May I suggest at this point you REALLY clean the inside and outside of the gaiter. Where possible wipe out the inside area by the FD input and as far as possible up the inside of the swing arm. Ensure the outside areas are nice and clean too.

Now, you have changed to Mineral oil and it is correctly topped up.

Now relax for a while and keep a weather eye on all the components externally. You may have what many of us have and that is the lightest weep that is REALLY nothing to worry about.

 

[mike23217]

I would change it to non-synthetic gear oil. But, while doing this, I would also add "Seal-Swell" to the quart/liter of gear oil (the prescribed amount listed on the Seal-Swell container). This will most likely fix the leak. My FD has leaked since I bought it. I am just now thinking about adding Seal-Swell.

 

I wouldn't get too excited about the slight movement you have. If the FD crown bearing is grumbly, or the crown bearing seal is leaking, then definitely replace the crown bearing and seal. It is also possible that the crown bearing shim is one size too large. Better too large then too small.

 

The crown bearing fairly easy to replace. About 1-2 hours. The original crown bearing have been superceded by a new crown bearing. But, most likely, you already have the upgraded bearing one at 115k.

 

When you get to 120k, you will need to grease the transmission input shaft (large job), so I would go back and evaluate the situation again at that point.

 

My advice is pretty much the same as some of the other posters. The only difference is I think Seal-Swell might be warranted at this point.

[dirtrider]

Morning Jagman

 

I'm afraid going to have to disagree with adding extra seal swell.

 

Standard (non synthetic) gear oil has a fair amount of seal conditioner in it already & adding extra can soften & swell the seals to the point of premature wear on that thin lipped pinion seal.

 

In most cases (that I have seen in the past) just the switch to conventional gear oil usually clears up any pinion seal seepage.

 

Save the extra seal swell usage until you see (IF) just the switch to conventional stops your seepage.

 

By your above post it sounds like you don't have a real leak anyhow, just a slight seep.

 

[Jagman]

All good suggestions. I'll certainly keep a close eye on this. Probably won't put many miles on the RT until better weather but if it is a mild winter I'll get in a couple of thousand miles so that should give me an idea of what is going on.

 

Thanks everyone....

[AnotherLee]

I was running synthetic in my FD and noticed some seepage so I changed to non-syn (mineral, dino) and now after 8K mi it's as dry as a bone. Thanks, D.R.

[mike23217]

When I worked as a chemist for a major oil company, we used seal swell in synthetic oils to counteract the effects of synthetic oil on polymers (seals). Almost all synthetic oils contain seal swell.

 

Non-synthetic oils usually have demulsifiers and seal conditioners instead of seal swell. These two additives are different from seal swell.

 

Non-synthetic oils often contain demulsifiers to remove the water from the oil and keep it from breaking off the sulfide bonds in the polymers. The sulfide bonds keep the seals from falling apart.

 

Seal conditioner (different from Seal Swell) softens the polymers (seals), and keeps them from shrinking. If the seal has already reduced in size from shrinkage, then seal conditioner will do little to help it. Seal conditioner would probably keep oil from escaping from the cracks.

 

Seal swell will cause the seal to expand, where seal condition will keep it from shrinking.

 

I suspect that Jagman's pinion seal has shrinkage. That is why I believe that seal swell will help him.

[LBump]

When I worked as a chemist for a major oil company, we used seal swell in synthetic oils to counteract the effects of synthetic oil on polymers (seals). Almost all synthetic oils contain seal swell.

 

Non-synthetic oils usually have demulsifiers and seal conditioners instead of seal swell. These two additives are different from seal swell.

 

Non-synthetic oils often contain demulsifiers to remove the water from the oil and keep it from breaking off the sulfide bonds in the polymers. The sulfide bonds keep the seals from falling apart.

 

 

 

Seal conditioner (different from Seal Swell) softens the polymers (seals), and keeps them from shrinking. If the seal has already reduced in size from shrinkage, then seal conditioner will do little to help it. Seal conditioner would probably keep oil from escaping from the cracks.

 

Seal swell will cause the seal to expand, where seal condition will keep it from shrinking.

 

I suspect that Jagman's pinion seal has shrinkage. That is why I believe that seal swell will help him.

 

 

The information available on this site is the best, bar none.

[RobinW]

Ah!

 

You are only jealous mate. We pay US$15.99 for a 12 pack of 375ml Foster's lager, which is less than half of what you pay for a six pack over in Oz !

It's about AU$13 for a 6 pack for average beer, but they don't sell fosters here. And the normal beer here is 5%. I though US beer was like making love in a canoe. (f***ing close to water) I haven't been there since the 80's but we are doing the east coast next August.

 

Cost me $8 to see a doctor twice, get an xray and an ultra sound last week. None of that was against my private health insurance. Was government health insurance. So it must all balance out in the end.