Mystery Diagnosis

toadstool

Active Member
Mystery Diagnosis:
I am experiencing a bothersome noise from the primary on my 2008 Big Dog. The noise sounds as though a foreign object is being tossed around in the primary case and appears to be coming from the front. I did not notice a difference when the clutch was pulled. Has anyone experienced this and what should I expect to find once I open the primary?

Noise from Primary - YouTube
 

BBChopper

Supports 2 Disabled Vets
Troop Supporter
Easiest thing is just pull the cover off and check everything! Not worth taking any chances! :2thumbs:
 

toadstool

Active Member
I am not the most mechanically inclined individual to grace the earth. This is my plan; please inform me if this information is correct. I will place the bike on a lift so that it is upright, loosen the bolts and break the seal on the case. As long as the seal is good and I am careful I should be able to reuse it. Is any preparation of the seal required besides cleaning it such as adding a bead silicone or something? Also, do you remove the smaller case window first in order to drain the fluid? What is the best way to drain the fluid, or do you just let it run in a pan? When I replace the fluid, assuming I find and fix the issue, how much and what kind of fluid do I use? If I do not see any obvious issues once the case is open, will I be able to start the bike momentarily to try and replicate the sound?
 

stlmikie

I wish I had more money.
You will be able to start it but it will make a mess. It will sling oil pretty good. Even if you think you got it pretty drained.
 

BBChopper

Supports 2 Disabled Vets
Troop Supporter
Just check the crank and carrier nuts to see if they are tight. I would bet one is loose!!!! I have reused the seal many times before replacing them!:2thumbs:
 

kona dawg

Member
I dont know much about the 2008 but i am assuming there is a drain plug on the bottom toward the front. If u drain it here first be a lot less messy
 

woodbutcher

Mr. Old Fart member #145
Staff member
first, pull the window and see if the chain shoe is there. it could have come loose and fallen down in the bottom of the case. get you 1 quart of rev-tech fluid and you're good to go. pour it in the window after you have put the outer half of the primary case back on.

the torque sequence for the case is, starting at the 9:00 position,

9, 11, 6, 4, 2, 13, 12, 14, 10, 8, 1, 3, 5, 7

make sure you do it in order to have the best shot at it not leaking.
 

toadstool

Active Member
first, pull the window and see if the chain shoe is there. it could have come loose and fallen down in the bottom of the case. get you 1 quart of rev-tech fluid and you're good to go. pour it in the window after you have put the outer half of the primary case back on.

the torque sequence for the case is, starting at the 9:00 position,

9, 11, 6, 4, 2, 13, 12, 14, 10, 8, 1, 3, 5, 7

make sure you do it in order to have the best shot at it not leaking.
Thank you, I appreciate this information.
 

Fibersnake

Banjo Playing PsychoBilly
Also be careful with the torque, suggest a good inch pound torque wrench and bring them up in two steps. Cannot recall the exact torque right off hand, but it is not much.

I always clean the bolts thread and run a clean tap into the holes, and then put just a tad of Blue Loctite on mine.

The drain plug should be a little set screw with a socket head in the rear section on the bottom. It has a little o-ring on it, make sure to check it for any cuts, if re-using, cleaning all the surface with good brake cleaner including the bolt holes, then use good silicone and follow woodbutcher sequence.

Personnaly I always change the o-ring gasket on mine, but there is also a flat gasket that is available too. Never had an issue with leakage with the o-ring, never re-use it either nor the window one/s.

On the inspection window, some of them had a little notch on the top side cut out to allow it to breath better for venting. There was a little sponge filter in there. I always clean mine, and then install the o-ring (new) no silicon, and make sure that it seats right. Never had a problem with it leaking, also check the vent button on the inner side top to make sure it is clean.

Others just re-use and do not worry about the vent notch on the window and have had no issues, your call!

If the chain adjuster is loose (make sure you check the other bolts also and the clutch carrier for any loosness), read the procedure (should be on here somewhere) and adjust with it loaded at the tighest spot (rotate the wheel like in fifth gear, no fuel, ignition off, spark plug removed) to find the tight spot).

Clean everything good with brake cleaner before re-assembly. When you reinstall the bolts, start them by hand and make you do not get them cross threaded. Same for the drain plug, be careful not to over tighten any of the bolts or the plugs not using the proper socket head and thus round out the heads internally (bitch to get out later if you do).

Let us know how you make out or is there is something else found. As mentioned 1 Qt of good primary fluid. I also go with the simple RevTech.
 
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firedog19

Active Member
If it is the chain tensioner I would contact the guys at southern oregon hot bikes and replace it with a hydraulic tensioner. It eliminates adjusting the chain and removes all of the slack. I have run one in my Heritage Springer three years and piles of miles with no issues and currently have one in my 04 ridgeback.
 

woodbutcher

Mr. Old Fart member #145
Staff member
torque is at 100 in*lbs (8 ft*lbs) sorry i left that out.

also the drain plug is at 70-75 in*lbs (6 ft*lbs)
 

MyDogPete

Active Member
Not sure if this will help but there is a BDM baker drive line service manual along with other down loads here. BD Manuals - Home
I found this site doing some searches here. Cannot rember what member on here posted the site but I downloaded them all.
 

cajunbiker

Member
My 2011 K9 250 which has the HD style primary has developed the same type noise Toad described. Have not had time to pull the primary covers yet.
 

Brew

Troop Supporter
Be careful with this one, I had the same thing happen and it was my bearing carrier. Two bolts on the back had loosened up and was grinding on the inner primary housing. Made quite the grove in the housing. Stopped that right away and got me a 4" Karata...:D
 

toadstool

Active Member
Well, this turned out to be nothing serious other than a loose bolt rattling around the primary, potentially causing a catastrophic failure. I want to bring this piss poor design flaw to your attention so that you can be forewarned. The stock chain guide bolts in my primary were 1/8” too long, meaning that at maximum torque, they were not flush but instead sticking up slightly. This error makes them prone to backing out, which both did – one the entire way. Next time you are in the primary, check yours and replace with the proper length if necessary.
 

erldawg

Guru
Well, this turned out to be nothing serious other than a loose bolt rattling around the primary, potentially causing a catastrophic failure. I want to bring this piss poor design flaw to your attention so that you can be forewarned. The stock chain guide bolts in my primary were 1/8” too long, meaning that at maximum torque, they were not flush but instead sticking up slightly. This error makes them prone to backing out, which both did – one the entire way. Next time you are in the primary, check yours and replace with the proper length if necessary.
Looking at Chapter 9 Primary/Clutch exploded view in the service manual what #'s are you referring to? 22 and 65? I do not see chain guide bolts. I do see however the chain tensioning shoe bolts. Or do you have a picture of the bolts that came loose?
 
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