Ok guys, I think I am having compensator problems on my 08 Ultra with 60K on the clock. I had the starter drive replaced under warranty a year ago and it got better, but still acted up on occasion. So I decided to order the SE compensator which is back-ordered.

Anyway I thought while I had it open, I would change out the clutch spring with the SE spring since I plan on doing the 103 by years end. I already have the 255 cams and the PC III with Supertrapp 2:1 exhaust.

I bought the SE 37951-98 spring from the local HD dealership before I read on the forums about the 37871-98A spring working fine. I then got on ebay and bought a slightly used 98A off ebay for $15 free shipping. It came in today and it doesn't have any paint or part numbers on it so I can't tell if it is the correct one or not. I mic-ed it and come up with a thickness of .071. The SE I bought is .078. Since I haven't pulled mine down yet I can't check my OEM spring for thickness to see where this one falls in size.

Does anyone have an OEM spring they can mic or the 98A they can mic to get the thickness numbers on? Or is there someplace I can find that info? I have checked and found some info, but it is lacking at best.

Here is what I found for what it is worth since I don't know the guy that posted this in another forum I can't vouch for any of this. Also my parts manual says that my oem spring part number is 37882-06 which is the same as his 06 number and according to him it is supposed to be .064 thick.


Year Models P/N
99 99 - * ALL 37871-98
01 01 - * ALL 37871-98A
03 ALL 37871-98A
04 ALL 37871-04
with the 06's having the 37882-06


37882-06 has a brown paint mark.

The problem you have with the springs is that they not all are identical

Supposed to be
SE 380 lbs
98 330 lbs
04 300 lbs
06 300 lbs, except as soon as you load it from spec installed height it goes down


37951-98 Clutch diaphragm spring, high performance, is in SE Street Legal Big-Bore (EFI) Stage 2 Kit
37951-98 Clutch diaphragm spring, high performance, is in SE Twin Cam 103B C.I. Stage Kit

37807-03 CVO Clutch spring Yellow dot / Pink dot .381" Free Height
37871-98A 2003 Spring Yellow dot .398" Free Height (FSG does not agree 10.5mm .413")
37871-04 2004 Spring Yellow dot / Yellow Stripe .395" Free Height (FSG does not agree 10.1mm .398") .071" Thick
37951-98 SE Spring Nothing .405" Free Height (FSG does not agree 10.4mm .410") .078" Thick
37882-06 06-07 Spring Redish Brown Square / Yellow dot .410" Free Height, 10.4mm .064" Thick

110" and 103" Engine Kits use S.E. Spring P/N 37951-98