By David Porter, Customer and Technical Support at The Bonneville Shop
Triumph SERVICE BULLETIN
A change was made in the lubrication of the rocker arms and push rods during the later part of 1968. Beginning with 650cc engine number DU79965 and 500cc engine number H63307, the drilled hole in the rocker arm to supply oil to the ball end was deleted in favor of a notch at each end of the rocker arm bearing. The picture in the parts books shows the wrong order of assembly.
Any Triumph engine which uses this new method of lubrication to the rocker ball ends must have the plain flat (thrust) washers assembled next to the rocker arm. When correctly assembled, the Thackery washers will be separated from the rocker arms by the flat steel washers. The rocker ball ends could have insufficient lubrication if the spring washer is assembled next to the rocker arm. What this means is that if the rocker ball pins have a drilled hole in the center of the ball, they are the earlier style, used up until the change was made in late 1968. The new rocker ball pins and “notched” rocker arms went into production officially for the 1969 model year.
There was in fact, three phases to the rocker spindle oiling update. First, the change in the position of the washers, second, the cuts machined into the rockers, and lastly, the adoption of oilways in the rocker spindles. In fact, the last update was not put into practice until the 750cc TR7/T140 range debuted in 1973.
3 Phases to the Rocker Spindle Oiling Update:
- Change in the position of the washers
- The cuts machined into the rockers
- Adoption of Oilways in the rocker spindles
The previous rocker spindles (70-1512) had no oilways, which made the repositioning of the washers and the undrilled rocker arms and machined grooves on the 1969-1972 650cc rockers largely inconsequential in improving the oiling of the pushrods and rocker spindles.
The BSA A75 and Triumph T150 models did benefit from the practice of having oil galleys machined into the rocker spindles, but the twins did not receive this update until 1973, perhaps due to the commercial concerns of the additional costs of manufacturing during a period of financial difficulties within the BSA Group. The 1971 models were late to the market due to the problems fitting the Triumph 650 engines to the P39 oil-bearing frames. By the time they arrived in the dealer’s showrooms, it was late enough in the selling season that they had to sold at a lower retail price, resulting in lower profit margins.
The first generation 5-speed gearboxes plagued the 1972 Triumph 650 models.
The first generation 5-speed gearboxes plagued the 1972 Triumph 650 models, and warranty claims quickly beset dealerships and Meriden, resulting in further financial difficulties. Once the new rocker spindles (71-3549) were fitted to the 750cc twins, the final phase of rocker box oiling was complete. A survey of the 1970 parts book shows the revised order of the rocker spindle washers however the complete adoption of the T150-style rocker and spindle upgrade wasn’t realized until the 1973 model year.
Triumph Service Notes
Bulletin No. 14-69 (Page 2) May 2, 1969
Lubrication – Rocker Arm, Ball End
A change was made in the lubrication of the rocker arms and push rods during the later part of 1968. Beginning with 650cc engine number DU79965 and 500cc engine number H63307, the drilled hole in the rocker arm to supply oil to the ball end was deleted in favor of a notch at each end of the rocker arm bearing.
Assembly Order of Spring Washer
The picture in the Parts Books show wrong order of assembly. ANY Triumph engine which uses this new method of lubrication to rocker ball ends MUST have plain flat washers assembled next to the rocker arm. When correctly assembled, spring washers will be separated from rocker arms by the flat steel washers. The rocker ball ends could have insufficient lubrication if spring washer is assembled next to the rocker arm.
