Final Drive Issue/Query

[Gary C]

Greetings, a strange occurance and hopefully someone may be able to shed some light. I changed all of my oils prior to my vacation. From Ontario Canada to Idaho via US2, return through Canada.

 

On the return leg, east of Sault Ste Marie Ontario, I pulled over as I felt something strange with the bike. On the centre stand the rear wheel wobbled left to right and the final drive housing was hot.

 

Once the mechanics opened it up, they informed me there was no oil in the housing. During the trip I checked twice daily visually, no leaks, seepage etc. Has anyone heard of such an occurrance?

 

 

[NonComp]

I think that the unfortunate conclusion would be that you inadvertantly forgot to refill the final drive. There is enough oil in there to definitely make a significant mess of your rear wheel if it was leaking out. What type of gear oil did you use?

[T__]

Gary, was the final dive removed from the bike to open it up or are you just talking about removing the drain plug..

 

If it was just the drain plug that was opened up & no oil then look in the front boot that attaches to the swing arm tube.. Sometimes the front pinion seal will leak oil into the boot area & you won’t easily see it..

 

If it was COMPLETELY empty then probably no oil put in it at last service..

 

 

Twisty

 

[RandyBailey]

Just finished an Iron Butt 1000 last night. When I went to clean up the bike this a.m. I found the dreaded oil stain all over the right rear. Yep! It's the final drive seal and it will be fixed on my '03 RT for nada on Tuesday through my extended warranty. This is the only warranty I've ever purchased where I actually came out ahead!

 

Lucky it must have started leaking on the final leg as I checked over the bike at each stop.

[flat_twin]

Let's find out what model and year he's talking about first. Some RT's had no drain plug for the final drive.

[NonComp]

Let's find out what model and year he's talking about first. Some RT's had no drain plug for the final drive.

I think that's only on newer 1200's??

[effexer1]

Check your jug of gear oil and see if it is full....

[Gary C]

Thanks for the replies. I can assure you that I did change and fill the final drive. Now what I don't know if the mechanic looked at the boot or not, I need to find this out today. The shop I am dealing with is not the local BMW dealer and that is for another discussion.

To balance the viewpoint that I did not fill the final drive, I would ask if the system could travel 6933 km without any oil before failing?

[NonComp]

Thanks for the replies. I can assure you that I did change and fill the final drive. Now what I don't know if the mechanic looked at the boot or not, I need to find this out today. The shop I am dealing with is not the local BMW dealer and that is for another discussion. To balance the viewpoint that I did not fill the final drive, I would ask if the system could travel 6933 km without any oil before failing?

Maybe it could go that far. Did you monitor the temperature of the drive each day (put your hand on it) as part of your daily inspection?

 

An 1100 final drive (like mine) holds a 1/4 of litre of oil. Even if it somehow pumped all that oil into the driveshaft cavity, it would come pouring out once the final drive was separated from the driveshaft for rebuild. There is no way for that oil to evaporate or disappear (unless it was something like WD40).

 

As someone who troubleshoots computers and software for a living, the first question I ask when a problem occurs is "what changed" immediately prior to the problem occurring. In your case, it was a fluid change. I guess you can do the math on how much oil you used for the change. It should approximately 1 1/4 litres for the gearbox + the final drive. One litre is 1.06 US quarts.

 

It is not without precident for this kind of thing to happen, even at a dealer. Mechanic gets called away and forgets that he has not refilled the oil and subsequently buttons it up.

[Joe Frickin' Friday]

It is not without precident for this kind of thing to happen, even at a dealer. Mechanic gets called away and forgets that he has not refilled the oil and subsequently buttons it up.

 

Two good reasons to remove the fill plug before removing the drain plug:

 

1. If for some reason you have trouble removing the fill plug, the bike is still ridable, since you haven't yet removed the drain plug.

 

2. With the fill plug out, it's obvious whether or not you've added new oil.

 

The oil that should have been in the final drive is somewhere. The OP is certain it's not in the bottle, which leaves two other destinations:

 

1. forward of the pinion shaft seal, inside the swingarm. If it was here, the shop tech should have gotten a whole bunch of oil on the floor the instant he pulled back the rubber boot connecting the final drive to the swingarm.

 

2. all over the wheel. If the big axle seal leaked - or if the drain plug leaked (no crush washer, or a distorted one, or some other reason for a poor seal), the wheel and tire should be absolutely hosed with gear oil. This would have been obvious during your daily inspections, and would have been overwhelming when you first inspected the bike by the side of the road (assuming you are able to stop without lowsiding due to a scary-slick rear tire).

 

Talk to the tech who diagnosed the bike; get more info.

[NonComp]

My point with the oil quantity is that if the OP bought one litre or one quart of gear oil for the oil change for both gearbox and final drive, he would be short approximately the amount that the final drive holds.

[Anton Largiader]

Was the drain plug present? If there was truly no oil in the FD, and the drain plug was in place, it probably wasn't filled. I just can't see it pumping everything into the swingarm, and if it all came out of the big seal you would see something on the wheel.

 

... I would ask if the system could travel 6933 km without any oil before failing?

 

I'd think that was very unlikely, but they can go a few hundred.

 

How little oil is 'no oil'? Although I guess it might be hard to tell how much had been in there if the unit eventually overheated (which it will, without oil). I have a FD here that died for lack of oil.

[270]

I can tell you for a fact that a final will indeed NOT travel that distance without oil. A very close friend of mine had this situation occur in is '94 RS about 10 years ago. Tech simply neglected to refill the FD. Bike made it about 60 miles before nearly welding itself together.

 

I'm no BMW tech (I'll leave that to Anton!) but I don't think placing your hand on the final drive to determine whether or not it's operating properly. I can assure you that you won't be able to leave your hand on the FD after it's parked in the Texas sun for an hour.

 

As to where the oil went; There's no way the entire amount can drain into the swing arm. The pinion seal is about half way up the FD body where it connects to the swing arm. Quite a bit may get into it, but certainly not the full amount. If NO OIL was in the FD, it simply wasn't filled. The only way ALL OF THE OIL can escape is through the drain plug.

[NonComp]

Maybe it wasn't fully drained either. If the OP bought one litre of gear oil and then split the amount between the gearbox and the final drive, it could mean that the FD came up short. We could speculate forever, but without further input from the OP, there's really no way to know. It definitely doesn't add up.

[270]

Agreed.

[Gary C]

Greetings, thankyou for your thoughts and opinions. I purchased 3 containers of 1L each of oil for the clutch and the final drive - I like to have extra. So, no worries with the lack of oil. In fact with the final drive I over filled it until it flowed out, levelled the bike and allowed the oil to find the level, wiped off excess and put in the fill plug.

 

What the mechanic meant to say was no oil came out. When I went to look at the damage there was a fair amount of sludge, which to my minimum mechanical knowledge would mean that there was oil. There was no oil in the arm or boot.

 

With my limited mechanical prowess all I can assume is that it leaked slowly during the course of the trip but not enough to cause any staining on the bike, any that would be warranted as an oil leak. All I know is that I did fill the final drive as being an owner of a BMW I was terrified of the final drive issue. Didn't escape that one though did I.

 

Regardless of how or why, I am receiving a new fd, based on other forums there will still be those out there that believe I didn't fill the fd, so be it. Thankyou again for your thoughts and opinions please consider this thread finished.

[270]

Regardless of how or why, I am receiving a new fd, based on other forums there will still be those out there that believe I didn't fill the fd, so be it. Thankyou again for your thoughts and opinions please consider this thread finished.

 

Good news is that you've got a new FD! Happy miles!

[NonComp]

Gary, how much oil did you actually use and what kind of oil was it (I presume that when you said "clutch" you meant "gearbox").

 

Oil doesn't evaporate. There is no way that 1/4 litre (or more - overfilled) of oil "leaked slowly" over 6900 km (which would be a pretty fast leak) and showed nothing on the rim and tire. Period.

 

Sorry for the bluntness. Your story doesn't add up, so I am afraid that I can't validate it for you.

[Jerry Duke]

GlenT, sorry for the bluntness here too, but I don't remember anyone appointing you the "Validator".

The guy says what he did. Either believe it or not, but no one appointed you the official "Validator".

Yet...

Do I have a motion?

[NonComp]

GlenT, sorry for the bluntness here too, but I don't remember anyone appointing you the "Validator".

The guy says what he did. Either believe it or not, but no one appointed you the official "Validator".

Yet...

Do I have a motion?

You are right. And I apologize. But the OP came here looking for an explanation. But I don't think that we have all the facts. And I get the feeling that the OP knows more than he is willing to say. And I guess I can't blame him.

 

So, on my drive in to work, I got to thinking that maybe I'm wrong. Maybe oil CAN evaporate. Suppose the OP used automotive engine oil instead of gear oil. A light viscosity oil. Is it possible that the oil was heated to the point that it boiled and left the FD as vapor and eventually, smoke, via the vent. Is the sludge that is left in the hub, burned oil???

 

If so, then Gary's gearbox may also be in peril, if he used the same oil in it.

[AndyS]

....

On the return leg, east of Sault Ste Marie Ontario, I pulled over as I felt something strange with the bike. On the centre stand the rear wheel wobbled left to right and the final drive housing was hot....

Was there any oil residue coming from the hub at the time you discovered your wobbly wheel?

Andy

[Joe Frickin' Friday]

What the mechanic meant to say was no oil came out. When I went to look at the damage there was a fair amount of sludge, which to my minimum mechanical knowledge would mean that there was oil. There was no oil in the arm or boot.

 

Refilling the final drive during a lube change requires nearly eight ounces of gear oil. If no oil came out when the mechanic pulled the drain plug, then the final drive was missing those eight ounces.

 

With my limited mechanical prowess all I can assume is that it leaked slowly during the course of the trip but not enough to cause any staining on the bike, any that would be warranted as an oil leak.

 

Many RT owners can attest to the fact that a mere teaspoon of oil, leaked over time and spread on the underside of the final drive during several thousand miles of riding, will collect enough road grit/grime to thoroughly blacken the exterior of hte final drive. If eight ounces had somehow leaked out through the pinion shaft seal or the axle seal or the drain plug, the exterior of the final drive wouldn't just be dirty, it would be absolutely slippery, dripping with oil. Oil would be on the brake rotor, and would be transferred to your brake pads. Oil would be all over your rim and tire.

 

Eight ounces of oil is presently unaccounted for. If you're certain you filled it (and if you went 4000+ miles without incident, then it seems clear that you did), and there's no evidence of cataclysmic leakage, then I suspect the mechanic is misrepresenting his observations.

[effexer1]

Mitch, I like your motion best. Seconded!

[millbert]

The oil that was put in the final drive was either the wrong oil or inferior gear oil.That would explain the distance covered by the time the oil vapourized or burned off to when there was none left.I've seen this before with industrial gear oil at Work,once ,when everyone was on this synthetic oil kick -a waste of money- in the mill a new synthetic oil was used in the paper machine drives and the oil literally creeped out of the gearbox through the breather and dipstick at operating speed!

 

[millbert]

From Hexheads-rear drive oil by

It sounds like they filled it twice.

 

Kinda what i was thinking.

 

If you took half and put in Gary C.'s Final Drive we would be even!

[Gary C]

Gentlemen

 

All I can tell you is what I know, I am not hiding anything, I am not a mechanic nor profess to be. I have spoken with Millbert offline and he may have a portion of the equation. Perhaps the oil (synthetic) was not as quality as it could have been, this would be an experience/knowledge issue - lesson learned the hard way (perhaps).

I stand corrected I meant gear not clutch. I ensured that both housings had adequate/correct amount of oil. No issue of not enough.

The other point is, at the bottom of the final drive housing was as stated previously (I believe) a large amount of sludge. So again the mechanic shouldn't have indicated that it was "dry" but should have said no oil came out. With the amount of sludge at the bottom and the amount of metal mixed in it, again my limited knowledge would say it was destroying itself over a (short) period of time and the oil mixed with the metal.

So, the oil really didn't disappear. I should have gone to the shop before posting, but I trusted the mechanic with some question. So I would assume that the 8 oz or "x" mls was mixed with the metal filings/shards/pieces.

I thank everyone for their insight and suggestions. I believe that the mystery really wasn't, but poor communication and explanation. I should have asked how often does the bearing housing etc destroy itself.

[NonComp]

Gary, for the benefit of those who will read this post and hope to avoid a similar problem, could you please tell us what brand of oil, the product name and what viscosity you used? Clearly, no one wants to find themselves in a similar position.

 

I would also strongly recommend that you immediately change the oil in the geabox, but capture a sample and have it analyzed to determine if the same oil has caused damage to your (very expensive) gearbox.