r80 driveshaft oil level

[KARSTEN]

Today I changed the final drive- and driveshaft oil in the new to me bike(1984R80)I have not received my shop manual for this bike(it is on order).Anyway,I opened the drain for the final drive and let it drain a while, I removed the 12mm bolt at the rear of the drive and shortly after I started to refill, gear oil starte out of the same.was told that when oil starts out of the hole that the final drive oil is at propper level.It took a lot less to put in comared to what drained out.Now I need to know how much fluid it takes for the driveshaft.Tranny is full and I have read about oiul transfer issues,hope this is not one of them and the previous owner simply overfilled the rearend.If anyone knows how much gear oil it takes in the shaft please share.thanks in advance

 

[88bmwjeff]

The swing arm is usually 150 cc.

 

[dduelin]

90-150 cc. The amount is not critical as long as when you insert a thin screwdriver or suitable dipstick in the filler hole there is 1-2 mm of oil on the tip of it.

 

[20774]

90-150 cc. The amount is not critical as long as when you insert a thin screwdriver or suitable dipstick in the filler hole there is 1-2 mm of oil on the tip of it.

I've never found this method for measurement to be all that helpful. I just drain and refill with the proper amount...usually around 100cc.

 

[dennisdarrow]

+1 on the measuring. I use a broom straw to reach down in there as for me, there is a lip or something in the way if I use something very stiff. The distance to the shaft is maybe an inch down to the top of the driveshaft and I try to come out with maybe 1/8 inch showing as a big drop on the end of the broom straw..........Good luck.......Dennis

 

[PGlaves]

I think we have a terminology problem. I think he was draining/filling the final drive on a model where you pour oil into the (removed) top vent until the oil runs out the little bolt hole in the back of the housing.

My spec book isn't handy, but I think he wants the final drive fill spec for a late model airhead with that type of final drive.

Nowhere near 100cc - more like 250 to 350 in my foggy memory.

 

[20774]

I think he was draining/filling the final drive on a model where you pour oil into the (removed) top vent until the oil runs out the little bolt hole in the back of the housing.

Paul -

He was and seemed to get through that. Then Karsten asked "Now I need to know how much fluid it takes for the driveshaft." We've been responding to that question.

According to Haynes, the driveshaft takes 150cc and the final drive on an '81 does take 350cc.

 

[dennisdarrow]

Yes, Kurt, I read it that way also; but Paul does have a good point..........give us all a pat on the back for tryin...........

 

[lkchris]

It took a lot less to put in comared to what drained out.

Possibly a sign the seal is bad and your driveshaft oil is draining into the final drive.

BTW, although the rear drive "level check screw" works and was designed for the purpose, it is neverthess a set of stripped threads waiting to happen. Especially if you ignore the instructions to replace washers with new ones (every drain plug everywhere every time).

When you get yourself an owners manual plus something with which to measure in cc and pour from that to your components, you'll be better off just pouring the correct amount into your rear drive rather than using the overflow method.

 

[MARTYH]

Oil level

I had a 1976 R90. Final drive was filled by removing the fill plug (NOT the vent) and fill to the bottom of the threads. Drive shaft method is more difficult. Only fool proof method is to drain and refill. I can't remember the amount.

 

[PGlaves]

I had a 1976 R90. Final drive was filled by removing the fill plug (NOT the vent) and fill to the bottom of the threads. Drive shaft method is more difficult. Only fool proof method is to drain and refill. I can't remember the amount.

One of BMW's improvements - there is no "fill plug" to fill to on the later model drives. You fill at the top till it runs out the hole in the back. 350cc