ADVrider

Go Back   ADVrider > Bikes > Old's Cool > Airheads
User Name
Password
Register Inmates Photos Site Rules Search Today's Posts Mark Forums Read

Reply
 
Thread Tools Search this Thread Display Modes
Old 09-29-2013, 12:50 AM   #31
dilandau OP
Studly Adventurer
 
dilandau's Avatar
 
Joined: Aug 2009
Location: oakland, ca
Oddometer: 743
thanks for all of this guys. sorry I have not been quick with new information as its "mother in town extended weekend".

as noted, I am in the bay area and there are a couple of people around these parts who know their way around an airhead. I also have a lead on a 79 5 speed for $300, and if that seems legit and not in terrible shape I might pick it up just because.

but still going to bring this one in first to get a professional opinion. as soon as my mother leaves and i can make some phone calls.

thanks for the links above and I'll post more info when it comes in. Odometer is broken on the bike- clocks in at 43k but estimated from the PO to be about 50k. of course no way to verify.
__________________
morini 3.5 strada & sport, r75/6, duc 900sd (project)
dilandau is offline   Reply With Quote
Old 09-29-2013, 11:50 AM   #32
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 8,973
Turns out I have to change my tune.



The one on top matches the one in the transmission I am rebuilding. The one on the bottom is the later model, I believe. All of my spare transmission parts except for the one seem to be the early 5 speed variety. i.e. 1974.

Somebody else warned earlier that the 1975 trans should or may have early parts. I seem to have more early parts than later and I don't seem to have any late model forks. Don't seem to have any spare forks for that mater.

I'll continue looking through my junk and see what I can learn. (wonder where all the shifting forks went?)
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, piratejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is offline   Reply With Quote
Old 09-29-2013, 01:02 PM   #33
190e
Studly Adventurer
 
Joined: Feb 2013
Oddometer: 569
I suspect some of the info on gearbox life and 4 vs 5 speed came from this on Duane Ausherman's web site. These comments are attributed to
Rick weber. http://w6rec.com/duane/bmw/trans/index.htm




"The secret to long tranny life is using synthetic gear lube, Spectro is the one I've used and had the most experience with. Usually 50k to 75k seemed average life span for the bearings getting regular oil changes with petro based lubes. You can at least double that with synthetic. I had one customer who had used nothing but synthetic and wanted me to inspect his gearbox that had 135k miles on it, and never had been opened. I swear it looked like brand new inside, no gray sludge, no metal on the drain plug. The 4 speed gear boxes seem to go longer than the 5 speeds, so I'd think the 4 speed could have a longer interval"
190e is offline   Reply With Quote
Old 09-30-2013, 07:56 AM   #34
CaptainCrunch
Gnarly Adventurer
 
CaptainCrunch's Avatar
 
Joined: Jun 2013
Location: Chicago ILL
Oddometer: 112
That's exactly what I remember reading, though I couldn't find it.

Thank you.
__________________
Hobbies: Breaking things. Fixing things.
I build/repair/refin/restore old drums and guitars.

1976 BMW R75/6 with '78 R100S heart transplant. 1967 Honda CL90 Scrambler project. 2011 LaVita Vespa clone (for the missus)
CaptainCrunch is offline   Reply With Quote
Old 10-07-2013, 06:33 PM   #35
dilandau OP
Studly Adventurer
 
dilandau's Avatar
 
Joined: Aug 2009
Location: oakland, ca
Oddometer: 743
so did my due diligence on the clutch: looks like everything is in an acceptable range. so its all going back in:


diaphragm plate looks clean. friction plate needs to be roughed up a bit but im just gonna put it all back in as is. which is a good thing because its like $600 in parts to replace it all.
these numbers look alright?

spring: .690"
backing plate: .303"
friction plate: .236"






and i got a 79 transmission that seems smooth and fine. I might just stick it in because I want to get riding. meanwhile Ill see how much it is to fix the old one.
__________________
morini 3.5 strada & sport, r75/6, duc 900sd (project)
dilandau is offline   Reply With Quote
Old 10-07-2013, 06:59 PM   #36
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 8,973
Wash the clutch plate with Brake Cleaner. Lightly sand.

Wash the pressure plates with simple green or brake cleaner. Sand the faces of both with 80 grit.
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, piratejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is offline   Reply With Quote
Old 10-25-2013, 08:07 PM   #37
dilandau OP
Studly Adventurer
 
dilandau's Avatar
 
Joined: Aug 2009
Location: oakland, ca
Oddometer: 743
maiden voyage today- still some kinks to work out but shes back on the road- pulls nicely and feels fine. transmission is way smoother than my old r100- so i'm thinking i lucked out with that $300 used but "in good shape" purchase.

a few little things to sort out- clutch lever perch is cracked- need a bungee for my side panels, i rather not have chincy chromed starter cover and airbox. but all and all- im pretty damn stoked!

__________________
morini 3.5 strada & sport, r75/6, duc 900sd (project)
dilandau is offline   Reply With Quote
Old 10-26-2013, 04:37 PM   #38
685
Scarred Adventurer
 
685's Avatar
 
Joined: May 2009
Location: Tucson (east side) AZ
Oddometer: 999
Now that the OP has reached a satisfactory conclusion, I'll continue the thread and introduce my trannie problem.

Mine is a 76 R90/6, according to the engine number it was manufactured November 1975. I'm assuming, hoping in fact, that it's all the later 5 speed trannie components.

Here's the picture. Won't stay in first gear under load, tho on the centerstand it works just fine. Jumps out of 1st under load at anything more than idle speed. All the other gears are smooth and stay in the selected gear.

From what I've read, it's the 1st gear shift dogs. I haven't been inside the box yet, but found a 1976 complete lay shaft assembly (is that right?) the complete output shaft assembly. For about $100. Shaft, gears, bushings, etc. all still on the shaft as it was taken out of the trans and clean and unmolested.

Side note, the p-o built out the engine from a 900 to about 1050 cc, it has Mikuni VM38's, and electronic ignition & 2 spark plug heads. He did a lot of work, before he abandoned the project. I basically got it for nothing--a bike for my brother to ride when he comes to Tucson and he's paying for the parts while I provide the labor. The transmission is the main thing wrong with the bike--as long as I don't try to start out on a hill, starting in second seems to be okay.

I was hoping it was a matter of cracking the case open, pulling the old layshaft out (I have sources of heat, btw,) and putting the new one in, and buttoning it all up. From what I read on this forum, it sounds like rocket science--I've never done an airhead trans. but have done 4 & 5 speed automotive trannies. I can read a bunch and there seems to be a lot of specific info on the internet. I'm a newbie to airheads. Not a newbie to mechanicals, tho. I have a stable, well lit work space, a drill press and welder to fab. tools if needed, and stuff for taking accurate measurement. Air, airtools, and many, many mechanicking tools as well.


Is it really that unforgiving and complicated?
__________________
To post images. Go to http://postimage.org/ and do what they require. Copy it to clipboard (there's a box.) Paste the link (right click on the mouse, then left click 'Paste'.) Voila you got an image!
685 is offline   Reply With Quote
Old 10-26-2013, 06:08 PM   #39
Plaka
Brevis illi vita est
 
Joined: Jun 2010
Oddometer: 4,582
Quote:
Originally Posted by 685 View Post
Now that the OP has reached a satisfactory conclusion, I'll continue the thread and introduce my trannie problem.

Mine is a 76 R90/6, according to the engine number it was manufactured November 1975. I'm assuming, hoping in fact, that it's all the later 5 speed trannie components.

Here's the picture. Won't stay in first gear under load, tho on the centerstand it works just fine. Jumps out of 1st under load at anything more than idle speed. All the other gears are smooth and stay in the selected gear.

From what I've read, it's the 1st gear shift dogs. I haven't been inside the box yet, but found a 1976 complete lay shaft assembly (is that right?) the complete output shaft assembly. For about $100. Shaft, gears, bushings, etc. all still on the shaft as it was taken out of the trans and clean and unmolested.

Side note, the p-o built out the engine from a 900 to about 1050 cc, it has Mikuni VM38's, and electronic ignition & 2 spark plug heads. He did a lot of work, before he abandoned the project. I basically got it for nothing--a bike for my brother to ride when he comes to Tucson and he's paying for the parts while I provide the labor. The transmission is the main thing wrong with the bike--as long as I don't try to start out on a hill, starting in second seems to be okay.

I was hoping it was a matter of cracking the case open, pulling the old layshaft out (I have sources of heat, btw,) and putting the new one in, and buttoning it all up. From what I read on this forum, it sounds like rocket science--I've never done an airhead trans. but have done 4 & 5 speed automotive trannies. I can read a bunch and there seems to be a lot of specific info on the internet. I'm a newbie to airheads. Not a newbie to mechanicals, tho. I have a stable, well lit work space, a drill press and welder to fab. tools if needed, and stuff for taking accurate measurement. Air, airtools, and many, many mechanicking tools as well.


Is it really that unforgiving and complicated?
You need some special pulling tools to get it open. See the home made tools thread. Also various support and alignment plates.

You need a depth mic. to set up the bearing preloads---that's the critical part.

Sometimes the shift dogs can be salvaged. They were on my 4 speed with the same symptoms.

If you want a tranny you can count on for a long, long time, have a seasoned pro work on it rather than taking it to a beginner just learning, and making their first mistakes, on your transmission. Let 'em learn on somebody elses. There are judgement calls to be made after looking inside. The pro can make them well. The newbie, unless very well supervised, cannot---indeed, won't even know what to look at or what they're seeing when they do.
Plaka is offline   Reply With Quote
Old 10-26-2013, 06:52 PM   #40
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 8,973
There is a special tool to remove and replace the output flange. Make your own or buy from the several after market tool suppliers. I use tools from Cycle Works a bunch. I have the flange puller from them.



http://www.cycleworks.net/index.php?...id=3&chapter=1

However this tool doesn't seem to be in the catalog anymore. maybe Dan has some or will make more? You could always ask. Maybe I don't know how the read the catalog?

It does sound like the problem is the dogs on the Lay shaft. But you have to look. $100 for those two parts is a good enough deal that I think I'd get them now before they disappear anyway.

Aside from being able to spot the several special problems that may be present and information is very scant about, the big deal is proper shimming of the trans. Some kind of holding fixture should be used to keep the shafts straight while measurements are made. There is a tool made for this also from Cycle Works.

The clutch should be checked, couple more tools, some of these are found at the corner hardware store

If there is wet oil on the shelf under the trans the the rear main engine oil seal and the cover O-ring from the oil pump should be replaced. Make sure you understand the issue about blocking the crank before removing the flywheel.

That's enough to get you started I think. Do you have a Clymer's or Hayne's Manual?
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, piratejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is offline   Reply With Quote
Old 10-26-2013, 07:05 PM   #41
Stan_R80/7
Beastly Gnarly
 
Stan_R80/7's Avatar
 
Joined: May 2012
Location: VA
Oddometer: 1,277
Cycle works redesigned the flange lossening/pulling tool (replaces the older version) : http://www.cycleworks.net/index.php?...roducts_id=321

If I hadn't made my flange removal tool, I would have bought the Cycle Works tool.
Stan_R80/7 is offline   Reply With Quote
Old 10-29-2013, 04:42 PM   #42
685
Scarred Adventurer
 
685's Avatar
 
Joined: May 2009
Location: Tucson (east side) AZ
Oddometer: 999
The $75 price tag for the puller kinda has me in shock. I'm probably gonna run the whole trannie over to the BMW (Ironhorse in Tucson) and have them pull the output flange. Or I'll fabricate something. One of the articles I read gives dimensions for cutting the flange plate and there is an Industrial Metal Supply shop here in town that could cut the plate out.

Same with the holder. I can cut steel and have a mig and a drill press.

It's all a little hard to picture until I can get into the trans, I'll read & study as I go along. I do have a Haynes and a BMW factory service manual as well.

Something to do on the kitchen table this winter, I think.
__________________
To post images. Go to http://postimage.org/ and do what they require. Copy it to clipboard (there's a box.) Paste the link (right click on the mouse, then left click 'Paste'.) Voila you got an image!
685 is offline   Reply With Quote
Old 10-29-2013, 05:14 PM   #43
disston
ShadeTreeExpert
 
disston's Avatar
 
Joined: Mar 2011
Location: Silver Spring, Md
Oddometer: 8,973
Do check out the thread about building one's own tools. There are several home made versions of this tool.
http://www.advrider.com/forums/showthread.php?t=927981

One nice feature of the Cycle Works tool is that the holder and the puller are the same tool. The large center plug comes out for holding the flange while the nut is removed and the center plug is replaced with the forcing screw to pull the flange. (hope this helps you see how it works)
__________________
.
Never memorize something you can look up.
---Albert Einstein

Pay your debt, piratejohn.http://www.advrider.com/forums/showthread.php?t=949341
disston is offline   Reply With Quote
Reply

Share

Thread Tools Search this Thread
Search this Thread:

.
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is On

Forum Jump


Times are GMT -7.   It's 11:24 PM.


Powered by vBulletin® Version 3.8.5
Copyright ©2000 - 2014, Jelsoft Enterprises Ltd.
Copyright ADVrider 2011-2014