Ariens Snow Blower 920 User Manual download pdf (Page 2)

Phone: 864.660.8036

Fax: 864.834.6670

E-mail: dougglass@lctllc.com

100 Roe Road

Travelers Rest, SC 29690

Liquid Combustion

Technology

Oil Drain Tube Oil Seepage 9/28/2011

PROBLEM DEFINITION:

Oil Seepage from 35mm Drain Tube Reported by customer. After internal inventory audit, seepage was con-

firmed. Further Investigative Analysis determined:

35mm Oil Tube Face (crush washer engagement area) does not meet surface finish drawing specification of

6.3um

Short Term Corrective Action:

LCT recommends increasing drain bolt torque to 23lb-ft to allow crush washer to fill excessive ridges/valleys

caused by the out of specification surface finish:

 Capability study was conducted on 30pc of Oil Drain Tubes removed from inventory product

 Engines were filled with oil and monitored over a 24hr period

 5pcs of the 30 were observed to have an oil witness mark below oil drain bolt (35mm drain tube

side)

 Oil Drain Tubes were removed from engines and service Oil Drain Tubes (with correct surface fin-

ish) installed and torqued and engines were placed back into inventory

 Removed Oil Drain Plugs were then torqued to 23lb-ft and pressurized in a submerged state to

look for joint seal failure. No failures were observed after torque was increased to 23lb-ft

Long Term Corrective Action:

 Currently working with supplier to determine root cause of oil drain tube missing the facing operation

 Will update with full 8D report once final root cause has been determined

Containment Activities:

 Inventory audits were conducted with product in South Carolina warehouse

 Product with May 25th date code (>15000 engine serial number) was discovered to have the “non faced”

machining condition

 Product from August 6th (<8000 engine serial number in August) was discovered to have correct machined

face surface area

 Total engine exposure based on the 5/30 statistical sample—5689

30pc Oil Drain Tube Samples

- Samples were torqued to 23lb-ft

- Samples were pressurized and sub-

merged

- No leaks were detected

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Ariens Snow Blower 920 User Manual Page 2