Loose Clutch Hub Nut fallout - Mastiff

[Rintintin]

Hello and Happy New Year. I have fallen victim to the loose clutch hub nut problem! My bike is a 2006 Mastiff with about 5,000 miles. It ran and shifted great with no leaks until the clutch lever just went limp. After adjusting the clutch, which restored the clutch lever pressure, I could not put the bike in gear with the bike running and with the clutch lever fully depressed without killing the motor. I could also not push the bike while in gear with the clutch lever depressed with the bike not running. It pushed fine in neutral.

After reviewing multiple threads here and the service manuals on Dropbox, I started to further diagnose the extent of the damage and put together a remediation plan. I apologize in advance for this long post, but really need some help. I’ve done what I can own my own, but at this point I am getting over my head. I want to be careful and deliberate to fix the problem without creating collateral damage. Here is the state of the assessment along with some pictures:

• Drained the primary and found approximately 34 oz of dark fluid containing fine sparkly flakes. (About 400 miles ago I took the bike to a local Harley dealer to replace the stripped primary drain plug and change the fluid. I provided a bottle of Spectro dino primary fluid with written instructions to use less than 24 oz.) I was surprised to drain that much fluid, in that condition.
• I drained the transmission and found about 10oz of fluid resembling what came out of the primary with a very fine shimmer to it. (At the time of the primary fluid change, I also changed the transmission fluid myself using 20 oz of Spectro synth 75/140 oil.)
• Removed the outer primary cover and found some small shiny filings in the corners but nothing major. I also found scrapes on the inside of the primary cover corresponding to the clutch spring rubbing against it due to the in and out shifting of the clutch components caused by the loose nut. I am assuming this is the source of the sparkly flakes in the fluid. The clutch components did not rock side-to-side or wobble. The shaft that extends back into the transmission has no free play in any direction.
• Removed the clutch spring, pressure plate and clutch plates - 12 pack. All of these looked ok. Removed hub nut by hand. No damage to the nut or washer. The throw out bearing appears to be solid and spins freely.
• I found a couple of globs of a foreign substance stuck behind the spring with a couple of other pieces sitting about. It is black and feels rubbery. At first, I thought some previous owner or the Harley dealer had used a silicone gasket sealant that overflowed inside the primary, but on further thought I suspect it is a seal of some sort that could have contributed to what seems to be a fluid exchange between the transmission and the primary.
• Removed the bolts from the inner hub and removed it. It shows no visible damage.
• Now I’m stuck. I need to get the rest of the clutch assembly (flanged hub, outer hub and sprocket, and carrier bearing) out to check for damage. I also believe there is an O ring on the back side of the bearing carrier that needs to be assessed (I expect it to be gone or severely damaged).

How do you get the clutch outer hub and sprocket out? Do you have to remove the motor sprocket? If you have to remove the motor sprocket (which I would rather not do), how do you get it to break loose and how do you keep the motor sprocket from turning while trying to loosen it?

I really appreciate any guidance and tips on how to move forward. I’m happy to answer any questions or share other pictures as well. Thank you

Dave

 

[Mr. Wright]

Your not showing anything out of the ordinary, for when a hub nut comes loose. The black blob is excess silicone. You can see on the primary cover oring, someone used silicone instead or replacing the oring. Let see the back side if the pressure plate. And you need to measure the thickness of the clutch pack. Needs to be a minimum of 1.970. Get with HDM for a inner and outer primary seal kit, trans input seal, and new hub nut.
https://www.bigdogpartskingpin.com/
Make sure the vent on the back side of the inner primary is clean.
24 oz oil in primary
21 oz oil in trans.
I'll also send you a pm with my number in case you need to chat about it.

 

[Rintintin]

Your not showing anything out of the ordinary, for when a hub nut comes loose. The black blob is excess silicone. You can see on the primary cover oring, someone used silicone instead or replacing the oring. Let see the back side if the pressure plate. And you need to measure the thickness of the clutch pack. Needs to be a minimum of 1.970. Get with HDM for a inner and outer primary seal kit, trans input seal, and new hub nut.
https://www.bigdogpartskingpin.com/
Make sure the vent on the back side of the inner primary is clean.
24 oz oil in primary
21 oz oil in trans.
I'll also send you a pm with my number in case you need to chat about it.

Thanks Mr. Wright for the response. Here's a picture of the back side of the pressure plate. I'll measure the clutch pack later and post the update. Thanks for the PM. I will reach out tomorrow. There is a big gap in my head from where it is to applying primary and trans input seals...

Dave

 

[Mr. Wright]

Pressure plate looks ok

 

[Rintintin]

Thanks Mr. Wright for the response. Here's a picture of the back side of the pressure plate. I'll measure the clutch pack later and post the update. Thanks for the PM. I will reach out tomorrow. There is a big gap in my head from where it is to applying primary and trans input seals...

Dave

The clutch pack looks to be 1.97 if I'm reading it correctly.

 

[SKOGDOG]

A loose clutch hub nut can result in transmission oil seeping into the primary—if you only got 10 oz out of the transmission and an extra 10 Oz in the primary, that tells you something…… If it were me, I’d put it all back together and ride, keeping a careful watch on the transmission oil level. If it drops, you need to replace the transmission input seal, which is more likely to be the culprit than the O-ring, which would leak and drip from the backside of your primary case to drain plug. Mr. Wright is a great deal more experienced than me, and maybe since you already have it torn down that far, you might as well take off the primary drive nut and remove the rest of the drive train and replace that transmission input shaft seal. If you’ve been riding a lot of miles with that loose hub, the seal may well be compromised. Call Mr. Wright. You need a decent impact wrench and of course a torque wrench. Some of us tighten the clutch and crankshaft nut a bit more than your manual says.

 

[Rintintin]

Thanks Skogdog for the heads up. After conferring with Mr. Wright and learning it was possible to pull the clutch sprocket without removing the engine sprocket (whew), here's some additional pictures. I am looking to identify the transmission input seal in one of the pictures. Is it the seal identified by the arrow in the drawing (that was already loose when I pulled the clutch sprocket) or is it the black ring that is still in place inside the assembly?

 

[Mr. Wright]

I forgot about that little o-ring in there. No the seal is the other part not the o-ring

 

[SKOGDOG]

The transmission input seal is item #8 on the schematic below. HDM should be able to send you one. I think probably Mr. Wright can give the best advice on removal and replacement of that seal. There are specialty tools that make it easier-I don’t have any and have been known to make installation tools out of PCV pipe. Primitive, but worked out OK. I’ve also been known to order two seals bcs sure as the dickens I’ll bend the first one trying to get it started. Buy two seals and guaranteed the first one will go in perfectly—so then you’ll have a spare. The important thing is to use something the size of the seal so it starts and seats evenly all the way around. A large socket will do. I’m sure Mr. Wright can put one in with a drift pin and a small hammer, but I seem to bend them. It’s OK to visit some damage on the one you’re removing tho, but don’t score the seat. Again—phone Mr. Wright for the best advice.
The transmission input shaft should have zero play in it—play means trouble and at a minimum you’ll need to replace bearings—maybe more. Check it after you remove the seal — a dial indicator is precise if you have one. I used to know what the end play specs were but can’t recall—it’s like <.006 or something tiny like that. Any end play you feel with your fingers is way too much.
I’m recalling you found some silvery in your transmission oil—I’d ride it a couple hundred miles and drain it again (put it right back in if it’s good). Hopefully the issue will be resolved.
Please keep us posted—we like it when guys learn fix their own!!

 

[Rintintin]

The transmission input seal is item #8 on the schematic below. HDM should be able to send you one. I think probably Mr. Wright can give the best advice on removal and replacement of that seal. There are specialty tools that make it easier-I don’t have any and have been known to make installation tools out of PCV pipe. Primitive, but worked out OK. I’ve also been known to order two seals bcs sure as the dickens I’ll bend the first one trying to get it started. Buy two seals and guaranteed the first one will go in perfectly—so then you’ll have a spare. The important thing is to use something the size of the seal so it starts and seats evenly all the way around. A large socket will do. I’m sure Mr. Wright can put one in with a drift pin and a small hammer, but I seem to bend them. It’s OK to visit some damage on the one you’re removing tho, but don’t score the seat. Again—phone Mr. Wright for the best advice.
The transmission input shaft should have zero play in it—play means trouble and at a minimum you’ll need to replace bearings—maybe more. Check it after you remove the seal — a dial indicator is precise if you have one. I used to know what the end play specs were but can’t recall—it’s like <.006 or something tiny like that. Any end play you feel with your fingers is way too much.
I’m recalling you found some silvery in your transmission oil—I’d ride it a couple hundred miles and drain it again (put it right back in if it’s good). Hopefully the issue will be resolved.
Please keep us posted—we like it when guys learn fix their own!!
View attachment 109227View attachment 109228

Thank you. I had not looked at the transmission drawing. I’ve ordered a couple of spares and plan to ditch transmission and primary fluid after a few -that’s a great idea. Should have a follow up sometime next week!

 

[Rintintin]

Notes from Rebuild Day (1/21) - The short version is, everything is back together, and my dog is shifting better than new! Thanks to all that chipped in to help! The play-by-play version follows:

This post is another long-winded outline of the steps taken to put my dog back together after receiving parts from HDM and WSW.

Removed Shaft O Ring and Transmission Input Seal – This was done without removing the inner primary case. As can be seen in the previous picture, the O Ring was loose and came out easily. To remove the Transmission Input Seal, I used a small drill bit to start a hole in the middle groove of the seal. Once a hole was started, I screwed a wood screw in just far enough to grip. I then used pliers and a lot of force to pull the seal loose. It took several tries working on it, but it finally came out.

Inserted new Transmission Input Seal – I lubed the seal and the opening with primary fluid. It is important to put the seal in so it is flush to the surrounding housing, but to not damage it. I experimented with piece of PVC pipe that mirrored the outer circle of the seal. I was able to get it to sit in there, but did not have confidence I could drive it all the way in. I then worked with the handle of an old hammer that had a flat bottom on the end. By carefully working my way around the seal rotating opposite sides, I worked the seal into place without damaging it. This took several trips around the seal; and patience is the key.

Inserted a new Shaft O Ring – lubed the O Ring with primary fluid and slid it all the way up the shaft.

Reinstalled the rear clutch assembly – I had purchased a new improved bearing carrier and bearing assembly and a new flanged hub planning to replace the original parts, but I honestly could not get the bolts loose that hold the bearing carrier to the outer hub sprocket. The originals looked OK so I doused the old bearing with primary fluid to clean it out and reinstalled the assembly. This required a little work as I did not remove the engine sprocket so the chain and clutch sprocket assembly had to be put on at the same time. This required some patience and finesse, but after a few skinned knuckles, I got it in place. (Thanks again Mr. Wright on the tip for removing the clutch and chain without removing the engine sprocket).

Once I had the O Ring, Input Shaft Seal and rear clutch assembly in place, I put everything back together loosely at first (without Loctite and high torque) to make sure I had the steps correctly and all the parts/tools handy.

Chain tensioner shoe – reinstalled the chain tensioner shoe and adjusted to spec

Reinstalled the inner hub – I reinstalled the inner hub adding 263 Loctite and torqued to 20 ft-lbs.

Hub Nut – I cleaned the end of the transmission input shaft using brake fluid to remove as much oil as possible and installed the new hub nut using 263 Loctite at 150 ft-lbs.

Clutch pack – Thanks to Mr. Wright’s insight, the original clutch was barely at spec. It had also been exposed to synthetic gear lube from the transmission so I decided to replace the clutch pack with a 9 plate pack. After soaking in primary fluid for 30 minutes, I installed the new clutch pack taking care to put the rounded side of the metal plates to the outside.

Pressure plate and throw out bearing. – I also purchased the new hardened pressure plate and a new throw out bearing. Using snap-ring pliers, I installed the new throw out bearing in the new pressure plate and added a spot of grease in the cup on the throw out bearing. I installed it along with the original diaphragm spring and pivot plate adding 263 Loctite at 20 ft-lbs.

Transmission fluid – I added 20 oz of 75/140 synthetic transmission gear oil.

Outer primary – I removed the old outer primary gasket that had pieces of gasket sealer stuck to it and installed a new outer primary gasket. I lubed it with primary fluid and installed the outer primary cover using the tightening steps around the case from bolt 1 – 14.

Primary fluid – I added 20 ounces of non-synthetic primary fluid to the primary. This was actually the new fluid that the clutch pack had been soaking in.

I let the bike sit overnight for the Loctite to harden.

Clutch adjustment – I followed the clutch adjustment process of collapsing the clutch cable all the way, inserting the clutch push rod until it made contact with the throw out bearing and reversed ¼ turn and then tighted the clutch jamb nut and then expanded the cable adjustment until the clutch lever was open all the way except for a 1/8 free-play.

I cleaned all the grease and oil off the chrome, especially the exhaust pipes.

Leaving the bike in gear, without starting it, I pulled in the clutch lever and the bike rolled freely. This was not possible before the repair! I was guardedly pumped. I let it sit another night until today when the weather was clear and took it for a test ride. From that brief ride, I can honestly say it shifts better than it ever has since I’ve owned it! Neutral was a real option at will, and there was no clunk putting it in 1st gear.

I’ll keep my fingers crossed and look forward to a nicer day for more time in the seat, but as of now, I am grinning ear to ear.

Thank you Mr. Wright and Skogdog for the great guidance and the support/thumbsup from others on this forum. As always, thanks to HDM and WSW for better-than-new parts. This was a challenging (to me), but successful repair. I’m going to put a hundred miles or so on it, and if all is well, drain and replace the primary and transmission fluids and look forward to springtime!

Note: If some reason I ever must do this or something similar again, I would rent or purchase an impact wrench to help remove some of the stubborn bolts along the way. I did rent a 3-foot ½ drive torque wrench to reinstall the hub nut to 150 ft-lbs. I would also purchase or rent a gear lock tool to keep the transmission sprocket from trying to turn while loosening or tightening bolts. A final note to self, maybe invest in a lift to get everything off the garage floor.

 

[SKOGDOG]

Congratulations, David—we need to send you an official “Wrench” designation. It’s always rewarding to see a member tie into a job and successfully repair their Dog to better than it was. Mazel Tov!! I wouldn’t even begin such a job w/o a table lift…….Mr.Wright is a genius……