Clutch questions and recommendations? 05 Pitbull

gaddog

gaddog

Member
Okay... I'm back and it's been a bad month for the big dog. I'm still sorting out the damn electrical issues but I've been able to ride the Pitbull a bit this summer. At the end of the last month I encountered the dreaded "clutch hub nut" issue (was on a short ride around town and the clutch lever went slack). Searching the various threads found the solution (split primary and tighten aforesaid clutch hub nut to 120lbs) and I was able to deal with it. HOWEVER... the clutch had been starting to slip when I got on it in 4th, 5th and so on. So I figured while I had the primary split I'd replace the clutch pack. I ordered a new 9 disk from Energy clutches and put it in. Started to pull out of the garage and notice it was slipping from the get go in 1st gear. I have now had the primary apart 3 times trying to diagnose the issue. I called a Big Dog dealer and after 3 or 4 calls was able to get someone that explained the dome height issue. I again split the primary and used a straight edge across the top of the clutch retainer and measured at the outside of the retaining ring and again on the outside edge of the clutch pack and it measures .043 diff. The overall clutch measured 1.963 when I installed it and the old clutch was 1.943 (a little bit of wear). Apparently shimming is not the issue here (which is not covered in the service manual). Suggestions? I did find a thread that indicates a stiffer diaphram spring might be needed for the 05's (bdm part# 120-000007-00). Is this the issue or is there some guru type clutch adjusting tecnique I'm missing here. By the way... anyone know the torque specs for the four bolts that hold the clutch pack and the retainer ring to the basket?
 
gaddog

gaddog

Member
Okay ... After a week of diagnosing... researching and ultimate bitching... I think I have worked this out.

The uprated diaphram spring has been installed and works great. If you have an 05, the part number is mentioned in my previous post. I can't argue as to the validity of the reaon why the spring works (whether the 05's had a weaker spring and the 06's and later were stronger) but it works and that's all I'm going to say about that.

Some things to be aware of when working on the stock big dog clutch:

1. Apparently spring dome height is critical. There are shims available to either shrink or expand the dome height and are available from the BD dealer. Unfortunately none of the installation manuals either from BD in the service manual or the clutch manufacture say anything about shimming. I believe the dome height is expected to be within .020-.048 as I recall but that number IS in the service manual.
2. I measured my dome height by running a straight edge across the retainer ring and using a plunge micrometer along the edge of the retaining ring from the straight edge to the spring and then again from the straight edge to the spring along the outer edge.
3. Torque spec for the clutch diaphram spring bolts were not noted anywhere that I can find but the previously mentioned 20ftlbs seems to work very well.
4. Do not expect to get ANY tech support from BD regarding installing the clutch unless you have an extraordinary relationship with your dealer.
5. ALWAYS install the primary drain plug BEFORE pouring in the new virgin fresh primary fluid (7.00 bucks a quart) unless you enjoy toweling off your shop floor when the bike marks it's territory and screaming in frustration.
6. If you have ANY other problems with your Big Dog... use the search function on here and more likely than not.. one of the other guys has had the problem already and there's a thread to cover it.

Thanks guys for the resource... this board has been worth it's weight in gold (okay... maybe not gold but at least good beer).

If you have any questions or suggestions... drop me an email at donutairservices@yahoo.com
 
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