It would have been hard for Elfyn Evans to imagine how his Saturday could have gotten any worse.
Ejected from the fight at the front of Secto Rally Finland when his front-right driveshaft broke, the Welshman lost over six minutes guiding his ailing GR Yaris Rally1 through one and a half stages.
Poised to gain ground on Thierry Neuville in the championship, suddenly Evans was barely in the points at all. But with two Rally2 cars and Toyota team-mate Sami Pajari ahead, there was at least talk in the media zone that Pajari might be asked to slow to let Evans ahead, and score more points from Saturday, once he’d cleared the WRC2 leaders.
Such talk evaporated as quickly as Evans’ victory hopes when Toyota mechanics were faced with a trickier job than anticipated to repair the #33 Yaris.
Leaving service 16 minutes late, Evans was hit with 2m40s of time penalties and thrown well outside the top-10. Perhaps if the afternoon loop was one stage longer Evans would have made it back in, but as it was he ended Saturday 12th and 29.9 seconds adrift of a crucial world championship point.
But why did he leave service so late?
“So actually the reason for being late was not associated to the transmission,” Toyota technical director Tom Fowler revealed to DirtFish.
“Another part of the bad luck of it being the front right driveshaft is that in a Rally1 car, because of the hybrid system installed in the back, as you will be aware, the exhaust system runs down the right hand side of the car.
“And the interaction between the engine, the exhaust system and the front right transmission assembly is quite complicated. So it turned out that we needed to replace some parts of the exhaust, which run through the space frame chassis which, unfortunately, anyone who’s worked on exhaust systems, they are the b****** of the car.
“So they cycle between ambient temperature and 1000 degrees a few times every day, so they don’t stay quite the same shape and things can unfortunately be difficult to work on in those areas, and that’s what we were facing was that we had to replace part of this system and we didn’t have any choice on that because obviously the exhaust is a safety related item, so we made sure the car was safe before it left.”
As for the driveshaft that failed, Fowler described it as a “big surprise” and said it was a problem Toyota has never seen before.
“To be honest it’s a very disappointing situation because obviously a driveshaft is an assembly of many different pieces and the piece which we believe has caused the issue is something which would be a long, long, long way down our list of suspects of things that might bite us,” he explained.
“I think I’ve discussed before about our reliability, that it falls into different categories, that some things are really inherently reliable in the car and they just run forever and other things we have to monitor and we have to check and we have to change more often and that’s how we control it.
“This falls into a part which we know is designed to be capable of all the scenarios that we expect it to see. It didn’t see anything unusual and at the moment, it’s kind of a big surprise that this is exactly what happened.
“So we have to investigate why that is. And of course, there can be numerous reasons from the manufacturing, from something that happened in the stage that we don’t know about yet or whatever.
“But we are very surprised that this particular part has done what it’s done.”
