A $2 PART DASHES ALL HOPE?
Today sucked major. However, today's update will identify the source of the problem and try to put a positive light on the outcome.
Let’s start with the “Positive Light”. Last year Robby flipped his car early on and lost over 6 hours, almost ran out of gas. Then ripped his car apart for Jutta, fixed hers, and had to follow her as a mule buddy/mechanic and still finished 12th overall over 20 hours down. So with 75% of the Dakar remaining a top 5 is not totally unreasonable. Expect the DeZert Fox to turn into the Rabbit for the rest of the Rally. It will be no holds barred from here on out. A win would have to be just flat out taken from these guys now with some wishing bad luck on everyone else. Lets not lie to ourselves, We need some good luck and they all need some bad luck to win this thing!
Let's read a blurb of the official Robby Gordon release;
Once this morning’s race had begun, on the timed “Special” middle stage of the Er Rachidia-Quarzaate trail, Gordon’s Hummer quickly began to demolish Schlesser’s time advantage for the race. “He had a solid 12 minutes on us at the start and we were seven cars back with two minutes spacing between us, so he had disappeared by the time we took to the course. Our Hummer was doing really well and we’d gained almost everything we’d lost when we began to realize that we had a serious transmission problem. A drive flange finally failed, which killed any chance of us taking the overall win.” Fortunately Gordon was able to signal another competitor, who relayed the information of the problem to Gordon’s crew, which was awaiting his arrival in Quarzazate. Gordon and Skilton managed to keep the transmission working sufficiently to limp along at a frustratingly slow pace, but their tenacity paid off in that the two were able to cross the finish line, even though it took them 7 hours and 44 minutes to get there. The official finish for the stage will keep Gordon in the race, provided he and his crew can get the Hummer back to Quarzazate and cross the finish line of the Liasion stage in time to make the cut-off time to be an official finisher, and be qualified to start tomorrow’s Fifth Stage from Quarzazate to Tan Tan on the Atlantic Coast of Morocco. “There’s little chance now for an overall win,” said Gordon when questioned about his chances, “but if we can repair the transmission in time to start tomorrow, we can, and certainly will continue. This race has just begun and there will be several more chances to win one of the remaining Special Stages." (RG.COM)
Alright, let’s talk Brass Tacks here.
The source of the issue; The transmission, a 5-Speed sequential Albins/Weddel manual shift transaxle. The specific part of the transaxle that failed is a bolt that holds the stub axle into the side of the differential case. This bolt is located just behind the inner(Trans Side) constant velocity (CV) joint attached to the axle shaft that connects directly to the wheel hub. When the bolt fails the stub axle slips out of the transmission. Two things happen with this result; first, fluid can dump out of the case. Secondly, and more severe is one side of the differential dislocates causing the opposite wheel not to engage and drive the car forward. Some might wonder why if the transaxle has a solid spool how does this can happen. Well... transaxles don't have a spool. They have to run a loose limited slip differential. This is because a transaxle has independent rear suspension. As the suspension cycles up and down from side to side the actual rear track width changes. If you had a spooled (solid locked) rear diff every time the cars rear suspension cycled it would pull the car from side to side making for a very squirrelly ride.
What's the fix? Remove the sheered bolt, replace the stub axle and insert and tighten a new High Grade bolt, Replace the axle shaft it is pretty easy. That is, unless you are in the middle of the desert without the bolt or proper tools.
Now for the big question; How did this F#%&’n, piss-ant bolt head snap the hell off?
Simple, my educated guess is the axle shafts are too short and when the travel extends to full droop the axle shaft unplunges to its fullest length and tries to yank the stub axle out of the transmission. This is like a bad ass slide hammer yanking on the head of the bolt over and over. This must have been even more pronounced on this really rough stage. The other cause could be right length axle wrong geometry on the rear trailing arm thus articulating too much and yanking the axle.
What is the fix for this Rally? A few things could be done as a band aid till next year. 1. Limit the amount of droop by relocating the limit strap mounting point. This will just pull a few inches of travel out and not effect how the car feels too much. 2. Tighten the Rebound setting on the By-Pass Shock to limit the amount of "snap" when the rear wheels come of the ground. If I was crew chief I would do the strap first.
Let’s start with the “Positive Light”. Last year Robby flipped his car early on and lost over 6 hours, almost ran out of gas. Then ripped his car apart for Jutta, fixed hers, and had to follow her as a mule buddy/mechanic and still finished 12th overall over 20 hours down. So with 75% of the Dakar remaining a top 5 is not totally unreasonable. Expect the DeZert Fox to turn into the Rabbit for the rest of the Rally. It will be no holds barred from here on out. A win would have to be just flat out taken from these guys now with some wishing bad luck on everyone else. Lets not lie to ourselves, We need some good luck and they all need some bad luck to win this thing!
Let's read a blurb of the official Robby Gordon release;
Once this morning’s race had begun, on the timed “Special” middle stage of the Er Rachidia-Quarzaate trail, Gordon’s Hummer quickly began to demolish Schlesser’s time advantage for the race. “He had a solid 12 minutes on us at the start and we were seven cars back with two minutes spacing between us, so he had disappeared by the time we took to the course. Our Hummer was doing really well and we’d gained almost everything we’d lost when we began to realize that we had a serious transmission problem. A drive flange finally failed, which killed any chance of us taking the overall win.” Fortunately Gordon was able to signal another competitor, who relayed the information of the problem to Gordon’s crew, which was awaiting his arrival in Quarzazate. Gordon and Skilton managed to keep the transmission working sufficiently to limp along at a frustratingly slow pace, but their tenacity paid off in that the two were able to cross the finish line, even though it took them 7 hours and 44 minutes to get there. The official finish for the stage will keep Gordon in the race, provided he and his crew can get the Hummer back to Quarzazate and cross the finish line of the Liasion stage in time to make the cut-off time to be an official finisher, and be qualified to start tomorrow’s Fifth Stage from Quarzazate to Tan Tan on the Atlantic Coast of Morocco. “There’s little chance now for an overall win,” said Gordon when questioned about his chances, “but if we can repair the transmission in time to start tomorrow, we can, and certainly will continue. This race has just begun and there will be several more chances to win one of the remaining Special Stages." (RG.COM)
Alright, let’s talk Brass Tacks here.
The source of the issue; The transmission, a 5-Speed sequential Albins/Weddel manual shift transaxle. The specific part of the transaxle that failed is a bolt that holds the stub axle into the side of the differential case. This bolt is located just behind the inner(Trans Side) constant velocity (CV) joint attached to the axle shaft that connects directly to the wheel hub. When the bolt fails the stub axle slips out of the transmission. Two things happen with this result; first, fluid can dump out of the case. Secondly, and more severe is one side of the differential dislocates causing the opposite wheel not to engage and drive the car forward. Some might wonder why if the transaxle has a solid spool how does this can happen. Well... transaxles don't have a spool. They have to run a loose limited slip differential. This is because a transaxle has independent rear suspension. As the suspension cycles up and down from side to side the actual rear track width changes. If you had a spooled (solid locked) rear diff every time the cars rear suspension cycled it would pull the car from side to side making for a very squirrelly ride.
What's the fix? Remove the sheered bolt, replace the stub axle and insert and tighten a new High Grade bolt, Replace the axle shaft it is pretty easy. That is, unless you are in the middle of the desert without the bolt or proper tools.
Now for the big question; How did this F#%&’n, piss-ant bolt head snap the hell off?
Simple, my educated guess is the axle shafts are too short and when the travel extends to full droop the axle shaft unplunges to its fullest length and tries to yank the stub axle out of the transmission. This is like a bad ass slide hammer yanking on the head of the bolt over and over. This must have been even more pronounced on this really rough stage. The other cause could be right length axle wrong geometry on the rear trailing arm thus articulating too much and yanking the axle.
What is the fix for this Rally? A few things could be done as a band aid till next year. 1. Limit the amount of droop by relocating the limit strap mounting point. This will just pull a few inches of travel out and not effect how the car feels too much. 2. Tighten the Rebound setting on the By-Pass Shock to limit the amount of "snap" when the rear wheels come of the ground. If I was crew chief I would do the strap first.
Good Luck Robby, we are Robby fans and this doesn't phase us! We have thick skin! 48 more days till Daytona
By the way, Robby and Darren will win tomorrow’s stage putting them in 24th overall with 10 stages to go.
Stage 5 Preview; Ouarzazate-Tan Tan: The wadi road Communication between driver and co-driver will have to be fine-tuned to a maximum on account alternate fast stretches and navigational traps. In comparison to the 2005 edition, competitors will have almost tripled their mileage in specials before leaving Morocco. The timing of the 1,250 kms already covered should produce a coherent classification.
posted by FLYHIFLYLO @ 9:37 AM
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