able to sew it up .”
Luckily for Richardson , he was struck in the thigh by a single , 3-inch-long , half-inch-wide , quarter-inch-thick shard of metal . He also noted that as the surgical staff undressed him to prepare him for surgery , they found several pieces of transmission material floating around in his underwear as well .
“ I got lucky . If it would have hit the inside of my leg where the arteries are , I could have been gone . I did have the trans blanket and it helped keep a lot of the pieces from hitting me .”
All things considered , Richardson ’ s injury was manageable and he recovered in about a month ’ s time , but the medical staff did not want the overthe-road truck driver to be sitting for hours at a time for fear of blood clots , and the tissue around his wounds that were precariously closed with 30 or so stitches was thin and prone to opening up , so he had to take a month off of work as well .
During his recovery , Richardson and his wife , Wendi , set out to find what they could do to prevent this sort of thing from happening again . After watching drag-and-drive racer Alex Taylor and her father , Dennis , build a Turbo 400 with Sonnax ’ s Smart-Tech drum , Richardson called Sonnax and spoke with the company ’ s High Performance Product Line Manager , Gregg Nader , about the product .
“ There is plenty of evidence online of the destructive force of these explosions ,” explains Nader . “ This is the first time I ’ ve been personally involved with anyone who has experienced this . I was interested in getting the transmission to perform a forensic diagnosis on it and made a deal with Jeff . I was taken by their emphasis and priority in helping others to prevent this from occurring again . With all of the photos and documentation , there was an opportunity to help them get the message out to people running a stock case 400 .”
An aftermarket and lighter weight aluminum direct drum , along with regular inspections and rebuilds , can reduce the chances of a failure , but the possibility still exists due to the inherent design of Turbo 400 transmissions set up for drag racing .
“ There are two main failure modes ,” Nader says . “ If the low roller one-way clutch has failed , when you launch the vehicle , the geartrain will overdrive the direct drum to over 10-15,000 rpm and the drum can explode . The other way is if the vehicle is decelerating and the direct drum is disengaged but the forward clutch is still engaged , the wheels driving the geartrain can overspeed the drum and cause it to explode .”
The newer technology of the Smart-Tech drum module has no separate direct drum connected to the geartrain to overspeed or explode , thus eliminating that possibility .
Driveline trauma is certainly known to cause damage upstream in the transmission , and Richardson ’ s chain-driven transfer case was skipping
They don ’ t happen often , but transmission explosions do occur and the catastrophic failure can have dire consequences for the driver .
While the exploded transmission case is very eye-opening , the torn-up metal floor is perhaps even more alarming . In this photo , you can see how the blanket was not properly positioned , and it had also been torn by the ejected material as well . In addition to the Smart-Tech module and Reid case-equipped transmission , Richardson also added a halfinch aluminum plate to the floor for a further layer of protection .
at one point . He replaced it with a 205 gear-driven transfer case and had the transmission rebuilt .
“ The original aluminum drum was messed up , so we put the cast-iron one in ,” Richardson says . “ On the second pass , it blew up .”
Once Nader was able to look at the failed transmission , he found that the springs on the low roller clutch had collapsed , and that ultimately led to the overspeed .
Since the incident , Richardson purchased a Reid SFI-rated aluminum transmission case and had Automatic Transmission Design out of Wisconsin build the new Turbo 400 transmission with the Sonnax Smart-Tech drum module .
“ A bunch of my friends put scatter shields and trans blankets on after my incident ,” Richardson says . “ Some guys narrow the truck up and sit right over the transmission with nothing to protect them . Some races require scatter shields or
Going into the transmission for a detailed inspection , Nader found many of the springs on the low roller clutch ( the vertical , accordionshaped metal pieces in the ring pictured ) to have collapsed , which you can see here where those pieces are not closing the gap as they do on the other side .
blankets and some don ’ t , but after my incident , a lot of the races are going to where you have to have one with the high-horsepower vehicles .
“ At retail price , the transmission is about $ 8,000 , but that would have been nothing compared to the hospital bills and losing a month off of work ,” Richardson says . “ I didn ’ t want it to happen to someone else . A lot of people say it ’ s a fluke accident , but if they Google it , they ’ ll find out that it happens a lot .”
“ There ’ s a well-documented pattern of dangerous TH400 case explosions , and racers should be informed about the true causes and why sometimes routine safety precautions aren ’ t enough ,” adds Nader . “ It ’ s a real possibility that this can happen to anyone running a stock case Turbo 400 .”
While Richardson ’ s incident and subsequent injuries are somewhat rare , they do happen , and the end result could have been far worse . If you ’ re using a stock case Turbo 400 , you might want to consider adding the Smart-Tech drum module from Sonnax to your next transmission build . DI
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