0437259 EVINRUDE ENGINE COVER ASSY., 112

85E (6JS),
CHALLENGER 95E (6KS) CHALLENGER AGRICULTURAL TRACTORSTIB 06/29/99 Which Is Titled "Engine Oil Filler Cap Loosens". Please Disregard The Old TIB And Replace With This One.Problem:
There have been reports of engine oil filler cap loss on Challenger E series Agricultural Tractors.Solution:
As a result of several changes, this problem should now be resolved. This TIB documents what was done and how to address which parts in stock and on machines are appropriate to use as a solution to cap loss.At first production of E series, 128-5988 Cap was available from two suppliers. The cap used in production was manufactured by Van Products, and may be identified by "Van Prods." stamped into the cap. This cap uses a flat washer with a weld nut in order to deform the rubber as you tighten the cap. Although this design works well in many other applications, it has not performed well in the Challenger oil filler tube, due to vibration caused by the filler tube length and the large diameter of the tube itself.As a result of a drawing change, the 128-5988 Cap will be available in the future from a single supplier ("Moeller Mfg"). This version also has improved retention characteristics. Since the "Van Products" cap works fine in other applications, the stock inventory was not recalled or replaced. As a result, if a 128-5988 Cap is replaced on a Challenger engine, you may not get the cap with the improved retention characteristics. If a dealer chooses to use a 128 -5988 Cap on a Challenger engine, use only the version identified by "Moeller Mfg" stamped in the cap.Because of the parts situation above, and to avoid cap loss, Caterpillar Ag Products introduced earlier this year a tethered 133-5946 Cap Assembly. This cap is also manufactured by Moeller Mfg. (identical to the NEW version of the 128-5988 Cap), but also includes a tether. The design of the cap uses a dished plate to deform the rubber during tightening of the cap. This dramatically improves cap retention by increasing contact around the perimeter of the oil filler tube. This design can be identified by two means: a stainless steel lanyard, and a "Moeller Mfg" stamp on the cap. The 133-5946 Cap Assembly is currently in production and is considered a good fix for the cap loss problem.One final incremental change is forthcoming. A new part number will be released that is identical to the 133-5946 Cap Assembly, with the exception of a weld nut which will be added to the dished plate. Because of previous cap loss problems, there is concern that customers will overtighten the cap. The additional weld nut will improve thread engagement and will accommodate overtorque conditions better. This change will be effective later this year, and will be announced in an upcoming Service Magazine article. The new part number will replace the 133-5946 Cap Assembly.In the interim, replacement of the older style 128-5988 Cap with either the newer style 128-5988 Cap (if available), or the tethered 133-5946 Cap Assembly, should remain an effective solution to cap loss.COPYRIGHT 2000 CATERPILLAR ALL RIGHTS RESERVED