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Old 01-04-2013, 05:07 AM   #16
Beemerboff
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8jest - try a search on this forum, or Google for final drive rebuilding - there have been a few threads

From memory most have not addressed replacement of the bronze spacer between the bevel and the either needle or taper roller bearing on the drive side.

The spacer sets the mesh of the pinion and bevel gears, so it is nice to have it is close as possible.

These bronze spacers are available in 0.1 mm (4 thou) increments from 2.5 to 3.5mm?, so if the dimension of the existing isnt an even 0.1mm a new spacer at least the next size up is required- mine was 0.127" thick so I replaced it with a 0.130" (3.3mm) one, which I think will be close.

This of course means a couple of orders, first after strip down for a bearing, spacer, gasket and seal, then for the correct shims after you have measured clearance with the new spacer fitted - the big shims are $12- each so ordering a selection isnt really an option.

I was quoted $280- for replacing the large bearing , spacer and seal , included resetting the pinion to the correct mesh and reshimming the bearing.

If there is a next time I will let them do it - list on parts is more than half of that, and measuring the mesh and bearing preload for the taper bearing or clearance for the needle roller is hit or miss without the correct equipment.

The drive I just pulled had 8 thou preload on the needle roller even with a spacer worn 3 thou so it was probably assembled with around 12 thou preload instead of zero, FWIW around the error you would expect if you measure the clearance by crushing a few strips of solder, as suggested some places.

And also just about as bad as the factory built the Oilhead drives, but that is another , long, long, story.
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Old 01-04-2013, 04:49 PM   #17
8jest OP
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Quote:
Originally Posted by Beemerboff View Post
8jest - try a search on this forum, or Google for final drive rebuilding - there have been a few threads

From memory most have not addressed replacement of the bronze spacer between the bevel and the either needle or taper roller bearing on the drive side.

The spacer sets the mesh of the pinion and bevel gears, so it is nice to have it is close as possible.

These bronze spacers are available in 0.1 mm (4 thou) increments from 2.5 to 3.5mm?, so if the dimension of the existing isnt an even 0.1mm a new spacer at least the next size up is required- mine was 0.127" thick so I replaced it with a 0.130" (3.3mm) one, which I think will be close.

This of course means a couple of orders, first after strip down for a bearing, spacer, gasket and seal, then for the correct shims after you have measured clearance with the new spacer fitted - the big shims are $12- each so ordering a selection isnt really an option.

I was quoted $280- for replacing the large bearing , spacer and seal , included resetting the pinion to the correct mesh and reshimming the bearing.

If there is a next time I will let them do it - list on parts is more than half of that, and measuring the mesh and bearing preload for the taper bearing or clearance for the needle roller is hit or miss without the correct equipment.

The drive I just pulled had 8 thou preload on the needle roller even with a spacer worn 3 thou so it was probably assembled with around 12 thou preload instead of zero, FWIW around the error you would expect if you measure the clearance by crushing a few strips of solder, as suggested some places.

And also just about as bad as the factory built the Oilhead drives, but that is another , long, long, story.
Do mind me asking where that quote was from? That seems pretty reasonable. I was quoted more than twice that.
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Old 01-05-2013, 04:52 AM   #18
Stan_R80/7
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Here is a link to Jorg's R80GS page, about final drives: http://jhau.maliwi.de/mot/r80gs.html#finaldrive

I agree with his assessment. Unless you want to change the gear ratio or do something custom, getting a replacement final drive is better and easier than rebuilding your current drive.

Opinions vary, and someone may come up with the 'best final drive rebuild company'. But it is not a home repair job for someone unfamiliar with the process and the instruments and tooling may cost as much as a good rebuild or another good used final drive. YMMV. Good luck!

Edit: here is a link from Snowbum's site on rear drive information: http://bmwmotorcycletech.info/rearwhlsplines.htm

p.s. Australian dollars are more than US dollars and shipping is expensive to Australia.

Stan_R80/7 screwed with this post 01-05-2013 at 05:14 AM Reason: added link
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Old 01-05-2013, 06:14 AM   #19
Beemerboff
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The quote for $280- was from Motohansa in Sydney, Australia.

I obtained it around 3 years ago when I bought my G/S , and noticed a fair bit of play at the wheel rim.

The drive will fit into a USPS $50- flat rate box to Oz but it would probably cost more than twice that for return postage

I decided to let my drive run, and 100,000 km on it isnt much worse, so I assume it was just set up wrong, not worn out.

Three stud G/S final drives are hard to find and usually expensive, but I finally found a ''good used " spare on US Ebay for $200.00.

I checked it out for play in the bearing, it felt good and it was put on the shelf to be used when the play in my existing drive started to increase.

However, I read a post somewhere by someone asking how hard it should be to turn a good final drive, and when I checked this one to see if I could help found out mine was stiff too.

Slackening off the 8? bolts on the bearing carrier slackened off the drive bearing too, and as this was a needle roller drive which should have zero preload I surmised the bearing had been shimmed wrong, and pulled it apart.

It has the later 19 ball deep groove bearing so I assume it has been rebuilt at some time. The bearing feels slightly rough and will be replaced together with the bronze spacer on the other side which shows more wear than would be expected on a unloaded spacer.

For a couple of years some oilhead final drives came new from the factory with between 8 and 12 thou to much preload, and most failed between 10,000 and 30,000 km, so it is possible that my drive has seen a few years light use since it was rebuilt.

If the guy who parted out the bike checked the play with the wheel still on he probably wouldn't notice the stiffness, same as the factory and the dealers didnt notice the stiff oilhead drives, so I have accepted that he sold it in good faith and will replace the bearing and spacer at my cost.

The bearings are half list from Motorworks in England, $50- or so and with another $20- for the shim and spacer it will still be a cheap drive as the only other one I saw, on German Ebay, went for over EU500- , which is more than $600-.

The oilhead guys ended up measuring the bearing clearance by temporary refitting the carrier with tank repair epoxy strip in the shim space, and I will use this method as it seems to have worked for them, when checked against setting with the proper tool.

Then I bumped into this guy who has replaced the large deep groove ball bearing with a taper roller and convinced me I should do the same !
http://www.youtube.com/watch?v=28mPGhqDW8I
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Beemerboff screwed with this post 01-05-2013 at 06:23 AM
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Old 01-14-2013, 04:49 PM   #20
8jest OP
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So I got the new battery and upgraded to the enduralast 400 watt charging system. I am so so happy with this upgrade!! My bike is more responsive, accelerates better, holds at higher rpms. It's like a new bike. I did not expect the charging system to have such a grand effect. New wiring harness showed up today and the alpha ignition is a week out. But I cannot wait to see how that improves the bike.

One thing I notice today though is a little bit of an exhaust leak at the connection of the exhaust collector to the exhaust silencer. I tightened it as it was fairly loose but still getting seepage. Any advice in how to make that connection better. I was going to pull my exhaust apart any way to clean it up and paint it with VHT flame proof paint. So any suggestions while I am in there would be great.

Thanks!
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Old 01-14-2013, 05:14 PM   #21
Beemerboff
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The parts fiche shows a gasket there , but a smear of high temp silicone would probably do.
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Old 01-14-2013, 05:33 PM   #22
One Less Harley
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Here's a pict of the spacers refereed to earlier. These are angled aluminum blocks and not washers though.

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