Fourth code cracker identified

Fourth code cracker identified ImageImage Fifteen years ago Jeff Lehmann and Bill Spratt started a torque converter rebuilding company called Precision Converters of Ohio. Jeff was a third-generation transmission technician and had worked in his father’s shop for many years. Bill’s background was in sales, and together they made a great team.

Being a start-up company and having to go head to head with the major players in the area proved to be quite a challenge. To meet this challenge, Jeff and Bill had to be creative in their marketing. Some large converter rebuilding facilities were warehousing converters in their area, and they knew they couldn’t compete with the daily delivery offered by the local distributors. To overcome that edge, Jeff and Bill decided to place a consignment inventory in each of the shops they dealt with. They would call every shop two times each week and replace the converters that the shop had taken out of stock the following day.

The system worked well as long as the transmission shop properly identified the converter being replaced. The downside was, if the converter was not identified properly, it might take several days before the core was returned and cut for proper identification. This was particularly important in determining the correct friction material on GM converters with the FLHB code. (Where have we heard this before?)

It was a good guess that FLHB converters that had the early part numbers (the seven-digit part number that started with 86) would have paper linings. But any identification beyond the early paper was just a guess. In 1998 Jeff and Bill started noticing that all of the FLHB converters with the large four-digit number 4741 on the I.D. tag had woven graphite friction material on the clutch.

This heightened awareness of the large four-digit number allowed them to identify a second number that was also found exclusively on converters with woven graphite linings. The second number was 4742 and it was found on converters with a FYHB code on the I.D. tag. Soon they had expanded their I.D. system to cover as many converters as possible. They educated their customers on the system and kept them informed of any new information. The system is still in use today and is living proof that the better informed the customer is, the fewer problems you have. When the Torque Converter Rebuilders Association Board of Directors received this information for verification, their first reaction was generally, “Wow!" along with the realization of having looked past the forest without seeing the trees. The large four-digit numbers have been ignored for years. Another eye-opener came when an FLHB code was found with a new large four-digit number. This new number was 9827.

This converter was very similar to the FLHB converter with the 4741 number except that it had a 21-vane stator. The converters with the FLHB code historically have had a 14-vane stator. It’s very uncharacteristic for GM to use a different stator in a converter with the same code. The good news is that this FLHB converter with the 21-vane stator has a different large four-digit number. Is it possible that the stator can also be identified by this number? This information also raises questions about the identification of other components of the converter by the large four-digit number.

After much research and many long hours the TCRA Board has compiled as complete a list as possible of the information learned about the four-digit number. The list will undoubtedly continue to grow for some time.

Jeff Lehmann and Bill Spratt have opened the eyes of our industry, and their findings will undoubtedly be an inspiration to the rest of us to look at things a little more closely. They wholeheartedly deserve to be the fourth winners of the Sonnax “Help Break the Code" contest. Special thanks to the TCRA board of directors for judging this contest.

– ©2006 Sonnax Industries Inc.

– Found in September 2006 Newsletter