76 GL1000 Rear Brake Master Cyl and Final Drive Maintance question


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johnfm3
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76 GL1000 Rear Brake Master Cyl and Final Drive Maintance question

Post by johnfm3 » Mon Sep 04, 2017 10:36 am



Been working hard on my 76 GL1000 getting it ready for its first time on the road in 23 yrs. With the wheels off getting new tires and wheel bearings, I have been working on the rebuilding the brakes and heard a noise in the drive system that I wanted to touch on.

The rear master cyl, do I have to drop the exhaust system to gain access to the fastener which attaches the master cyl to the foot pedal? If so, can I drop the rear half, or do I drop the entire system?

Regarding the Final Drive. I am thinking since it has sat for all these years, a tear down, clean, and re assemble with new oil is a good thought. I own the honda shop manual which the original owner purchased with the bike new, and looking it over seems a bit scary as it looks as if there are seals which get damaged and need to be replaced during tear down. I have the final drive off the bike now. Any good recommendations as too how to proceed? More importantly, anyone local with experience want to go thru it with me? If so, PM me and let me know how much you would want me to pay for your time.

Some of the things I have done on cars include just filling diff's and tranny's (or tcase's) with ATF 3 and using that to clean out the inner parts (NOT driving under a load but on jack stands), then draining and re filling with proper fluid one or two times till all the ATF is gone. Is this something to consider on the Final Drive? What about submerging the unit in Solvent (which wont hurt the seals) and flushing it out with a light oil before properly filling it?? Or do I just cycle fluid thru it a few times with a oil change every 25 miles for the first 100? Followed by every 100 miles for a few more?

Thanks,
John



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Re: 76 GL1000 Rear Brake Master Cyl and Final Drive Maintance question

Post by WingAdmin » Mon Sep 04, 2017 5:04 pm

johnfm3 wrote:
Mon Sep 04, 2017 10:36 am
Some of the things I have done on cars include just filling diff's and tranny's (or tcase's) with ATF 3 and using that to clean out the inner parts (NOT driving under a load but on jack stands), then draining and re filling with proper fluid one or two times till all the ATF is gone. Is this something to consider on the Final Drive? What about submerging the unit in Solvent (which wont hurt the seals) and flushing it out with a light oil before properly filling it?? Or do I just cycle fluid thru it a few times with a oil change every 25 miles for the first 100? Followed by every 100 miles for a few more?
I regularly do that when I do a rear drive oil change. After draining the old gear oil, I'll give it a quick flush with a volatile solvent to get rid of any sludge. After the solvent evaporates, I'll flush through some more gear oil, then fill it with fresh.

johnfm3
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Re: 76 GL1000 Rear Brake Master Cyl and Final Drive Maintance question

Post by johnfm3 » Tue Sep 05, 2017 9:12 am

So yesterday afternoon a friend showed up who has experience with early Honda's such as the CB360 to assist me with my bike. With his help, we were able to remove the rear brake master cyl without dropping the exhaust nor removing the rear swing arm. It looks as if I will be able to rebuild the rear master cyl, but due to lack of a clip tool long enough to reach, I will be taking the front master cyl in to the shop to be rebuilt for $120 labor. I may buy another front Master Cyl (which looks like I can get for about $60) till I can have mine rebuilt at a later time. And since I plan on keeping the bike, having a spare one would not be a bad idea.

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Re: 76 GL1000 Rear Brake Master Cyl and Final Drive Maintance question

Post by johnfm3 » Tue Sep 05, 2017 9:16 am

WingAdmin wrote:
Mon Sep 04, 2017 5:04 pm
I regularly do that when I do a rear drive oil change. After draining the old gear oil, I'll give it a quick flush with a volatile solvent to get rid of any sludge. After the solvent evaporates, I'll flush through some more gear oil, then fill it with fresh.
Thanks. So is there any specific solvent you use? And do you allow the entire part to be submerged in it for short or long periods of time? As I said in my above post, a friend stopped by to assist me. Though he has never worked on a Goldwing or owned a shaft driven bike, he suggested using diesel or kerosene with the thought that it most likely wouldn't ruin the seals. Do you have any thoughts on this?

johnfm3
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Re: 76 GL1000 Rear Brake Master Cyl and Final Drive Maintance question

Post by johnfm3 » Tue Sep 05, 2017 9:34 am

So there is a knocking noise when I had this bike in gear (on the center stand) which I am hoping is just oil issues in the final drive but dreading its a dry UJoint. I am contemplating just buying a second shaft in usable condition and dealing with replacing the ujoint in my drive shaft over the winter.

Does the drive shaft have to come out with the swing arm? Other than the hidden C Clip, is there anything else to consider? Are there any hard to find parts I should consider locating and saving in this area? What about the UJoint, is that something which is easily purchasable?

Thanks,
John

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Re: 76 GL1000 Rear Brake Master Cyl and Final Drive Maintance question

Post by WingAdmin » Tue Sep 05, 2017 7:04 pm

johnfm3 wrote:
Tue Sep 05, 2017 9:16 am
WingAdmin wrote:
Mon Sep 04, 2017 5:04 pm
I regularly do that when I do a rear drive oil change. After draining the old gear oil, I'll give it a quick flush with a volatile solvent to get rid of any sludge. After the solvent evaporates, I'll flush through some more gear oil, then fill it with fresh.
Thanks. So is there any specific solvent you use? And do you allow the entire part to be submerged in it for short or long periods of time? As I said in my above post, a friend stopped by to assist me. Though he has never worked on a Goldwing or owned a shaft driven bike, he suggested using diesel or kerosene with the thought that it most likely wouldn't ruin the seals. Do you have any thoughts on this?
Simple brake cleaner. Spray it up around on the various gears while rotating the wheel, allowing it to drain out as I do.

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Re: 76 GL1000 Rear Brake Master Cyl and Final Drive Maintance question

Post by Shadowjack » Wed Sep 06, 2017 8:19 am

About the driveshaft: pull the boot back and see if the u-joint is loose before tearing it apart. Put it in gear and rock the wheel, it will show up if it's loose. There are pictures out there of exploded yokes, so if it's got any slop, you should fix it.
Once you get the swingarm off, there's a snapring in the final drive coupler at the rear that has to come out before you can pull the shaft out the front. I think you'd be lucky to find a brand-new driveshaft, and it would be expensive. A used shaft is by far the cheapest way to go, although you won't know the condition of the u-joint. They're not made to be repairable, but it can be done if you want to spend the money. I just had this done because I'm changing a GL1000 swingarm out for one from a GL1100. Long story.
I bought a replacement 19mm x 44mm u-joint from theujointstore.com. It's usually used for steering gear in semi-trucks. The joint is staked in, meaning there are no snaprings holding the caps in. You have to have new grooves cut in the yokes, and there's not much meat there; see the picture. This cost me $150 for the machining and $20 for the new u-joint, but there was no option in this case. I couldn't justify the expense for a stock part; there are plenty of used ones still out there.
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johnfm3
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Re: 76 GL1000 Rear Brake Master Cyl and Final Drive Maintance question

Post by johnfm3 » Wed Sep 06, 2017 9:45 am

WingAdmin wrote:
Tue Sep 05, 2017 7:04 pm
Simple brake cleaner. Spray it up around on the various gears while rotating the wheel, allowing it to drain out as I do.
Thanks for the advise. Since I have it apart now, do you know if its possible to split the final drive open to gain direct access to the gears without getting into it so deep that I am replacing parts?

Shadowjack wrote:
Wed Sep 06, 2017 8:19 am
About the driveshaft: pull the boot back and see if the u-joint is loose before tearing it apart. Put it in gear and rock the wheel, it will show up if it's loose. There are pictures out there of exploded yokes, so if it's got any slop, you should fix it.
Once you get the swingarm off, there's a snapring in the final drive coupler at the rear that has to come out before you can pull the shaft out the front. I think you'd be lucky to find a brand-new driveshaft, and it would be expensive. A used shaft is by far the cheapest way to go, although you won't know the condition of the u-joint. They're not made to be repairable, but it can be done if you want to spend the money. I just had this done because I'm changing a GL1000 swingarm out for one from a GL1100. Long story.
I bought a replacement 19mm x 44mm u-joint from theujointstore.com. It's usually used for steering gear in semi-trucks. The joint is staked in, meaning there are no snaprings holding the caps in. You have to have new grooves cut in the yokes, and there's not much meat there; see the picture. This cost me $150 for the machining and $20 for the new u-joint, but there was no option in this case. I couldn't justify the expense for a stock part; there are plenty of used ones still out there.
So based on your comment, I can summarize that the drive shaft comes out the front of the swing arm which confirms my fear that I have to pull the swing arm to replace the drive shaft.

Hopefully the cleaning and lubrication of the final drive clears up the noise I am hearing.
John

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Re: 76 GL1000 Rear Brake Master Cyl and Final Drive Maintance question

Post by johnfm3 » Mon Sep 18, 2017 9:55 am

Ok, so I have allowed the final drive to soak in in Diesel for 24 hrs, during that time I moved the gears and dumped out debris. Bunch of oil chunks came out.

The seal at the input shaft popped off, an as such I cleaned the area behind it. Before re installing, should I pack that with grease? I am guessing its probably a good idea to grease the splines of the input shaft. Also, is it necessary to apply grease to the splined surface between the final drive and the wheel?

I have looked over the rest of the drive system, even started the bike and put it in gear lifting and lowering the rear swing arm listening of any sign of noise coming from the rear shaft. So far I have heard nothing and am hoping that the cleaning of the final drive and new drive fluid will quite things down. Real question will be how it sounds on the road. I may just have heard the noise as the rear wheel was in the air with no resistance.

The other question is, should I wait to install the rear wheel till after I install the rear brake master cyl? Parts for rebuilding the master cyl should be in this week.

Thanks,
John

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Re: 76 GL1000 Rear Brake Master Cyl and Final Drive Maintance question

Post by johnfm3 » Wed Sep 20, 2017 11:14 am

Any Thoughts on my above questions?

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Re: 76 GL1000 Rear Brake Master Cyl and Final Drive Maintance question

Post by WingAdmin » Sat Sep 30, 2017 10:26 am

You MUST apply grease to the splined shaft between the final drive and the wheel, or the splined surfaces will wear.

The grease must be high-moly grease - regular grease will be quickly squeezed out, leaving behind zero lubrication.

The proper grease recommended by Honda is M-77 paste.

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Re: 76 GL1000 Rear Brake Master Cyl and Final Drive Maintance question

Post by johnfm3 » Mon Oct 02, 2017 1:27 pm

WingAdmin wrote:
Sat Sep 30, 2017 10:26 am
You MUST apply grease to the splined shaft between the final drive and the wheel, or the splined surfaces will wear.

The grease must be high-moly grease - regular grease will be quickly squeezed out, leaving behind zero lubrication.

The proper grease recommended by Honda is M-77 paste.
Thanks. Yeah I found that out and ended up buying from the local Honda dealer.

So far, the bike is back on the ground with most the work has been completed with exception of the timing belts. As well as the Front brake master cyl needs to be rebuilt. I have the parts, but not the tooling to get the clip out. Will be taking this to the dealer with the parts to rebuild the master cyl.

John



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