V11 greenie in trouble

[laurent]

Today working on my newly acquired V11 greenie, hoping to finish off doing the fluid replacements, I found the dreaded gearbox crack

It is like all others I have read about around the upper mounting bracket on the Lh side, going from the bracket to the flat surface.

I have mixed feelings at this time. The bike has 87000Km and is in good condition. 

My options....

1. pump into the bike more time and money (new gearbox housing) or get the housing welded (outcome unsure)

2. find a second hand gearbox (difficult I think)

3. sell the bike for parts

4.close the garage and pretend it does not exist

5. ignore the problem and drive the bike until it leaks too much oil

 

P.s.. for those who have been on this website long enough, the bike I got is Kiwi_roy's old bike (didn't buy it off him though)

 

I really am looking forward to your inputs as I stand alone facing that dilemma at this time, what a bummer.

 

L.

 

 

 

[LowRyter]

I got my GB case fixed.  Of course the transmission had to be removed and taken apart- all beyond my skill level.  For the fix, it was sent to powder coat oven for several heat cycles to clean out all the residual fluids and then welded.  So far it's held up. 

The shop that did it for me sells a brace kit to prevent it from happening again.

[gstallons]

This should have been a winter project . Fix ( have the case fixed ) the case and have it done right . It will be done once and for all & install the case bracket . Then enjoy the bike !

[Scud]

Assuming you decide to keep the bike, absolutely get one of those transmission braces.

I agree on having the case repaired. It would be a good time to renew all the seals, and check the other internals for wear. Also a good time to inspect the clutch and replace anything that is close to its wear limit.

But given the 87,000 kms it might be cheaper in the long run to find a spare, low-mile transmission. Since the search might take a while, you could just ride it sparingly this summer and queue up the project for next winter. If you do find a suitable spare, your cracked one still has value as it can be repaired and rebuilt.

[Pressureangle]

If it's not broken through to the fluid compartment, I wouldn't even disassemble it. I haven't seen the crack-prone area, but if it's a dry crack in the bellhousing, I'd consider having it repaired in situ while it's bolted to the motor and cools to it's appropriate position. If you have more reason or desire to get the motor out of the frame, so much the easier. 

What's perfect, preferred, or a sufficient minimum are all different answers but don't serve the question, only your sensibilities. Mine run towards 'best utility with sufficient optics'. 

Anyone have a picture of a similar crack?

[Lucky Phil]

3 hours ago, laurent said:

Today working on my newly acquired V11 greenie, hoping to finish off doing the fluid replacements, I found the dreaded gearbox crack

It is like all others I have read about around the upper mounting bracket on the Lh side, going from the bracket to the flat surface.

I have mixed feelings at this time. The bike has 87000Km and is in good condition. 

My options....

1. pump into the bike more time and money (new gearbox housing) or get the housing welded (outcome unsure)

2. find a second hand gearbox (difficult I think)

3. sell the bike for parts

4.close the garage and pretend it does not exist

5. ignore the problem and drive the bike until it leaks too much oil

 

P.s.. for those who have been on this website long enough, the bike I got is Kiwi_roy's old bike (didn't buy it off him though)

 

I really am looking forward to your inputs as I stand alone facing that dilemma at this time, what a bummer.

 

L.

 

 

 

The gearbox repair information you need is here including the repair and gearbox re assembly. To me it was just an engineering thing but to others probably more scary. You need a good welder whos dedicated to getting it done without distorting the case sealing face which wasn't a problem with mine. I'd suggest an licenced aircraft welder. Mine now stronger than a std one and I also run the additional frame support. 

 

Ciao

[Scud]

Seems there are two issues: 1) leaking, and 2) structural integrity. I've not heard of a gearbox actually breaking in use. I've only heard of cracks and related leaks. So if the concern is just the leak for now (is it even leaking?), you could probably use JB Weld or QuickSteel to cover the crack and stop the leak. Then later, if you want it welded, the welder can remove that stuff. 

[laurent]

21 minutes ago, LowRyter said:

I got my GB case fixed.  Of course the transmission had to be removed and taken apart- all beyond my skill level.  For the fix, it was sent to powder coat oven for several heat cycles to clean out all the residual fluids and then welded.  So far it's held up. 

The shop that did it for me sells a brace kit to prevent it from happening again.

 

2 hours ago, Lucky Phil said:

The gearbox repair information you need is here. 

 

Ciao

This is great, thank you. In the meantime here a few pictures of my 'crack'. I am wondering if someone didn't over tighten the bolt between the box and the frame...

[docc]

So, no leak?

[laurent]

4 hours ago, Pressureangle said:

If it's not broken through to the fluid compartment, I wouldn't even disassemble it. I haven't seen the crack-prone area, but if it's a dry crack in the bellhousing, I'd consider having it repaired in situ while it's bolted to the motor and cools to it's appropriate position. If you have more reason or desire to get the motor out of the frame, so much the easier. 

What's perfect, preferred, or a sufficient minimum are all different answers but don't serve the question, only your sensibilities. Mine run towards 'best utility with sufficient optics'. 

Anyone have a picture of a similar crack?

It is leaking gearbox oil/cracked through

[Lucky Phil]

3 hours ago, laurent said:

 

This is great, thank you. In the meantime here a few pictures of my 'crack'. I am wondering if someone didn't over tighten the bolt between the box and the frame...

This theory's been mentioned before and I'm not convinced this is the issue. I believe it's a micro crack initiated when the casting cools and is due to the sharp edge at this point and the large cross sectional change which causes a differential cooling rate. The crack then propagates over the miles and heating/cooling cycles. Yours is way worse than mine and well beyond any JBweld temporary solution. You may as well get it properly repaired because the chances of buying a second hand one that already has a latent crack is high. Part of owning an old classic like a V11. You need to do some "engineering" eventually and more often than not on a few different areas.

To effectively repair this you need to chase out the crack with a die grinder and get it welded by someone that knows what they are doing. The idea is to heat the case to around 150 C before the welding starts and in your case half way through the weld repair stop and peen the weld to stress relieve the area and then finish it off and peen the finishing weld. It's not a complex scenario to someone that knows what they are doing.

My gearbox mount showed no signs of any cracking, I just checked it because I'm a physco and knew of the issue. Seems it was a good decision. My original gearbox needs the same done to it as well.

Ciao   

[deadpen69]

6 hours ago, Scud said:

Assuming you decide to keep the bike, absolutely get one of those transmission braces.

I agree on having the case repaired. It would be a good time to renew all the seals, and check the other internals for wear. Also a good time to inspect the clutch and replace anything that is close to its wear limit.

But given the 87,000 kms it might be cheaper in the long run to find a spare, low-mile transmission. Since the search might take a while, you could just ride it sparingly this summer and queue up the project for next winter. If you do find a suitable spare, your cracked one still has value as it can be repaired and rebuilt.

Are those transmission braces available for purchase anywhere Scud? I looked around here a little and couldn't find any info. 

[laurent]

8 minutes ago, deadpen69 said:

Are those transmission braces available for purchase anywhere Scud? I looked around here a little and couldn't find any info. 

I ordered them at don@motivcycleworks.com

[deadpen69]

Many thanks. My bike is at 12,000 miles. I haven't inspected the case yet but if there's something I can do preemptively I'll give it a shot. Best Wishes

[laurent]

1 hour ago, Lucky Phil said:

This theory's been mentioned before and I'm not convinced this is the issue. I believe it's a micro crack initiated when the casting cools and is due to the sharp edge at this point and the large cross sectional change which causes a differential cooling rate. The crack then propagates over the miles and heating/cooling cycles. Yours is way worse than mine and well beyond any temporary JBweld temporary solution. You may as well get it properly repaired because the chances of buying a second hand one that already has a latent crack is high. Part of owning an old classic like a V11. You need to do some "engineering" eventually and more often than not on a few different areas.

To effectively repair this you need to chase out the crack with a die grinder and get it welded by someone that knows what they are doing. The idea is to heat the case to around 150 C before the welding starts and in your case half way through the weld repair stop and peen the weld to stress relieve the area and then finish it off and peen the finishing weld. It's not a complex scenario to someone that knows what they are doing.

My gearbox mount showed no signs of any cracking, I just checked it because I'm a physco and knew of the issue. Seems it was a good decision. My original gearbox needs the same done to it as well.

Ciao   

You're lucky to be in Australia......I would already be on your doorstep harassing to buy your other gearbox HaHaha