When you click on links to various merchants on this site and make a purchase, this can result in this site earning a commission. Affiliate programs and affiliations include, but are not limited to, the eBay Partner Network.
Yeah, I will just plan on pulling the primary. The AIM VPC looks tempting, but I have to stop somewhere. After all the talk about the 386 lb SE spring, I'm wondering if that's not a bit overkill for my build? Wondering if I should maybe go with either the 364 lb. 37807-03 or even the 320 lb. 37871-98A to strike a happy medium on the clutch pull feel. Any suggestions there?
I went with the 37807, my understanding is that this is the spring used on the police bikes. The pull is heavier, wont know if it's too heavy until I log some stop and go miles. So far I don't find it to be a problem.
Yeah, I will just plan on pulling the primary. The AIM VPC looks tempting, but I have to stop somewhere. After all the talk about the 386 lb SE spring, I'm wondering if that's not a bit overkill for my build? Wondering if I should maybe go with either the 364 lb. 37807-03 or even the 320 lb. 37871-98A to strike a happy medium on the clutch pull feel. Any suggestions there?
when i had the 107 fm kit done on my bike, i didn't want to spring (pun not intended ) for the aim vpc. went the cheap(er) route and got the upgraded spring. after riding for a couple of months, i decided that i should have just gone with the vpc in the first place. that heavier spring really sucked for slow speed/parking lot maneuvers.
and yes, i had to take the primary off to do it. the spring does not fit through the derby cover hole. not a hard job to do at all.
I thought I read somewhere in this forum that you can replace the clutch spring for the heavier SE spring by just pulling the derby cover instead of the whole primary. Is that true? I've searched and searched, but can't find the thread. I have a 2012 Limited and wanted to do this mod after my cam install.
Don, the problem is not so much whether the spring will fit through the derby cover hole as it is the location of the spring in relation to the location of the hole. As you can see from the pic, it sets down quite a bit from the hole so you're not going to be able to properly TQ bolts down and you run the risk of stripping heads in trying to do it with the derby cover off.
So to answer your question, yes the primary needs to come off. Otherwise you won't be able to TQ bolts down properly. Last thing you want coming apart in the primary is your clutch pack at 70MPH.
The primary is actually really easy to get off. Don't forget to drain the primary fluid first otherwise you'll have one hell of a mess to clean up. The only 2 things that need to come off IMO (mainly to get them out of your way) is the 2 floorboards. I know some will chime in and say "oh you don't need to take those off" and so be it. I prefer to do things correctly and not have things hindering my work space, that leads to accidents, miscalculations, scratches on chrome, etc.
If this is, and apparently sound like it is, the first time the primary has been off, re-use the primary gasket as it will be in great shape. Just make sure to clean the surfaces of both the inner and outer primary before reinstalling and make sure to TQ down to spec and sequence. DO NOT use RTV silicone on that gasket. It's not a gasket that RTV is to be used on.
Don, the problem is not so much whether the spring will fit through the derby cover hole as it is the location of the spring in relation to the location of the hole. As you can see from the pic, it sets down quite a bit from the hole so you're not going to be able to properly TQ bolts down and you run the risk of stripping heads in trying to do it with the derby cover off.
So to answer your question, yes the primary needs to come off. Otherwise you won't be able to TQ bolts down properly. Last thing you want coming apart in the primary is your clutch pack at 70MPH.
The primary is actually really easy to get off. Don't forget to drain the primary fluid first otherwise you'll have one hell of a mess to clean up. The only 2 things that need to come off IMO (mainly to get them out of your way) is the 2 floorboards. I know some will chime in and say "oh you don't need to take those off" and so be it. I prefer to do things correctly and not have things hindering my work space, that leads to accidents, miscalculations, scratches on chrome, etc.
If this is, and apparently sound like it is, the first time the primary has been off, re-use the primary gasket as it will be in great shape. Just make sure to clean the surfaces of both the inner and outer primary before reinstalling and make sure to TQ down to spec and sequence. DO NOT use RTV silicone on that gasket. It's not a gasket that RTV is to be used on.
Thanks UN - I'm cool with that part.... was really looking for your opinion on spring selection for my build (I think it was post 11). I think the SE spring might be overkill for my build and was wondering if the police or another spring might strike a happy medium. Again, no slipping currently, just looking for some problem avoidance in the future.
Thanks UN - I'm cool with that part.... was really looking for your opinion on spring selection for my build (I think it was post 11). I think the SE spring might be overkill for my build and was wondering if the police or another spring might strike a happy medium. Again, no slipping currently, just looking for some problem avoidance in the future.
*EDIT*
Sorry I missed that post above.
Many a people go down that path of no return in changing a perfectly good clutch pack setup for no apparent reason other than to have something new or what their buddy has. If your clutch is not slipping, I wouldn't fool with it. When it does start to slip in the future, break loose the clutch cable ferrule, pop open the derby cover, adjust your clutch per the manual, and you're good to go. Even when I build out a higher HP/TQ bike, I don't fool with the clutch unless the guy I send the bike to for tuning tells me it's slipping on the Dyno. And then unless it's a worn clutch, all it simply needs is an adjustment. Those stock clutch packs are pretty bullet-proof IMO.
Last edited by UltraNutZ; Dec 3, 2014 at 08:48 AM.
Many a people go down that path of no return in changing a perfectly good clutch pack setup for no apparent reason other than to have something new or what their buddy has. If your clutch is not slipping, I wouldn't fool with it. When it does start to slip in the future, break loose the clutch cable ferrule, pop open the derby cover, adjust your clutch per the manual, and you're good to go. Even when I build out a higher HP/TQ bike, I don't fool with the clutch unless the guy I send the bike to for tuning tells me it's slipping on the Dyno. And then unless it's a worn clutch, all it simply needs is an adjustment. Those stock clutch packs are pretty bullet-proof IMO.
Perfect, I'll point my energies in a different direction.... Thanks again ULtra!
I thought I read somewhere in this forum that you can replace the clutch spring for the heavier SE spring by just pulling the derby cover instead of the whole primary. Is that true? I've searched and searched, but can't find the thread. I have a 2012 Limited and wanted to do this mod after my cam install.
I had to pull the whole cover on my Heritage and I reused the gasket.
7 Surprising Harley-Davidson Products that Are Not Motorcycles
Slideshow: The bar-and-shield logo shows up on far more than motorcycles, some of the company's most unexpected products have nothing to do with riding.
Slideshow: From the troubled AMF years to modern misfires, these bikes earned reputations for reliability issues, questionable engineering, or disappointing performance.
Crazy Bunderbike Build Looks Amazing, But Is It Impossible to Ride?
Slideshow: The Swiss custom shop has taken a Harley Softail and stretched it into something so long and low that it looks closer to a rolling sculpture than a conventional motorcycle.
Engraved Rebellion: Inside Bundnerbike's Glam Rock II
Slideshow: A standard cruiser becomes an intricate metal canvas in the hands of a Swiss custom house known for pushing Harley-Davidson platforms far beyond their factory brief.
Slideshow: Harley-Davidson's challenges aren't abstract; they show up in dropping shipments, shrinking dealer traffic, and strategic decisions that aren't yet translating into growth.
) for the aim vpc. went the cheap(er) route and got the upgraded spring. after riding for a couple of months, i decided that i should have just gone with the vpc in the first place. that heavier spring really sucked for slow speed/parking lot maneuvers.
