Sales Figures & Gear Failures '99-'01 GSXF & GSXR750

[The CyberPoet]

I was searching through the NHTSA's recall database and found that in response to an investigation on a failed 2nd gear issue on an '01 GSX750R, Suzuki released their sales figures for both that platform and for the Kat for three years.

Sold by American Suzuki Motor Corp, not including Hawaii & PR:
1999 GSX750F (Katana): 1,406
1999 GSX-R750 (Gixxer): 4,080
2000 GSX750F (Katana): 1,775
2000 GSX-R750: 4,855
2001 GSX750F (Katana): 2,097
2001 GSX-R750: 6,696

Identified by dealer claims, warrantee claims and service records, the following number of 2nd gear or shifting-related client-complaints which occured in the warrantee period, as of 10 December, 2002 (note that none of these claims were verified to seek the actual reason -- whether there was user abuse, bad parts, or defective engineering at fault):
1999 GSX750F (Katana): 1
1999 GSX-R750: 7
2000 GSX750F (Katana): 0
2000 GSX-R750: 224
2001 GSX750F (Katana): 2
2001 GSX-R750: 24

Number of Suzuki's inside tech-line calls made by dealer mechanics/service personnel concerning any transmission related issues for the same three model-years:
1999 GSX750F (Katana): 2
1999 GSX-R750: 8
2000 GSX750F (Katana): 2
2000 GSX-R750: 414
2001 GSX750F (Katana): 2
2001 GSX-R750: 78

Accident data reported to American Suzuki Corp for these models relating to transmission-related issues:
1999 GSX750F (Katana): 0
1999 GSX-R750: 0
2000 GSX750F (Katana): 0
2000 GSX-R750: 4 by customers, plus 3 by technical staff.
2001 GSX750F (Katana): 0
2001 GSX-R750: 0

Total warrantee & goodwill claims covered relating to part numbers starting with digits 24 (transmission gears) or 25 (shifting-related parts):
1999 GSX750F (Katana): 2 warrantee / 0 goodwill
1999 GSX-R750: 5 warrantee / 0 goodwill
2000 GSX750F (Katana): 2 warrantee / 0 goodwill
2000 GSX-R750: 338 warrantee / 53 goodwill
2001 GSX750F (Katana): 2 warrantee / 0 goodwill
2001 GSX-R750: 45 warrantee / 3 goodwill

9 Sep 2000: Inspection of 6th gear stock ready for assembly found to be of expected values in terms of hardness, uniformity, shape, etc. by Suzuki Precision Industries, Co.
12 Sep 2000: Inspection of 2nd gear stock ready for assembly found to be of expected values in terms of hardness, uniformity, shape, etc., by I.S. Precision Machinery, Inc.
12 Sep 2000: Post-repair inspection of one of the failed 2nd & 6th gears from a customer-owned MC in the warrantee coverage group found both gears were worn on the top and rounded at the edges.
14 Sep 2000: post-repair inspection of two additional sets of failed gears from clients that had been replaced under warrantee found: rounding at the edges of the engagement dogs. All other measurements were found to be within normal limits.

11 - 24 January 2003: Suzuki set out to reproduce the field failures that were plaguing their GSXR's, using specially prepared parts representing worst-case wear. Suzuki was able to reproduce the 2nd gear disengagement condition, and (claims that they) "confirmed" that there is no safety risk even with worst-case components.

Results:
Oct/Nov 2000: Suzuki changed their 2nd gear design for the GSXR 750 so that the web-portion of 2nd gear was extended from 8mm to 8.7mm, increasing the engagement depth from 3.5mm to 4.2mm. This change was made to address complaints from the field cocnerning momentary disengagement of 2nd gear. The old part was not withdrawn from the field (i.e. from parts warehouses), but was phased in as the standard production part effective 8 Nov 2000. The part was made available as a service component in Oct 2000.

Suzuki's statement on 2nd gear failures for the '00 model GSXR750's:
(A) Suzuki believes that the following two conditions must exist for the problem of momentary disengagement of 2nd gear to occur:
1. Transmission parts with specifications that can impact the engagement depth of teh 2nd driven gear must have specifications near the end of the tolerance that results in a worst-case condition (i.e. - the amoun tof engagement depth must be near the minimum possible); AND
2. The motorcycle that has this condition must be subjected to repeated improper and/or abusive shifting (i.e. - incomplete shifting or shifting without using the clutch).

(B) As repeated improper and/or abusive shifting occurs, the engagement dogs of the 2nd driven gear that engages it (the 6th driven gear) become worn at the edges. As the edges of the engagement dogs become more an dmore worn, the amount of contact surface between the 2nd driven gear and the 6th driven gear become less and less.
Eventually, the amount of contact surface can be reduced to the extent that when the motorcycle is under very rapid acceleration, a very high load at the engement contact points can cause the 2nd driven gear to become momentarily disengaged. The 2nd driven gear, which is in a fixed position on the transmission shaft, becomes disengaged by forcing the engaging gear (the 6th driven gear) away, against the shift fork. Since the shift fork is also in a fixed position, a bending force is applied to the shift fork when the 6th driven gear is forced against it. Spring tension from the shift fork then immediately forces the 6th driven gear in the opposite direction on the stransmission shaft to reengage the 2nd driven gear.

Cheers
=-= The CyberPoet

[iwannadie]

i would like to see the age and experience stats of the gsxr riders who had gear problems. prolly all young riders with their first bike going out hammering it red light to red light ;p