Request TSB for 2003-2006 Limited Slip Differential

[j-rho]

Hello,
Hoping this catches the eyes or ears of individuals within Dodge.

I would like to request a Technical Service Bulletin applicable to 2003-2006 Dodge Viper SRT-10s. This TSB would authorize replacment of the OEM Dana "Hydra-Lok" differential with the newer GKN "Visco-Lok" unit as standard on 2008+ Vipers, for situations where the Hydra-Lok unit is malfunctioning or failed. It's my understanding the Visco-Lok unit fits right in the 2003-2006 pumpkin with no other modifications.

As a bit of background, I am campaigning my 2004 SRT-10 with the SCCA in a "Stock" class that mandates use of the stock differential, but has also exluded the 2008+ Viper. We are not allowed to swap parts around between years except as specifically authorized by the manufacturer via parts supercedence or TSBs.

I believe the Visco-Lok would be a big improvement over the Hydra-Lok when used in an autocross situation, making this a great favor to a Viper racer. For more information on my car and campaign efforts, please see:
http://forums.viperclub.org/viper-racing/611364-j-rho-autocrosses-srt-10-scca-ss-class.html

Many thanks,

 

[Camfab]

Is the SCCA actually going to check your Diff., and if they did would they actually be able to tell the difference? It seems unlikely to me that they are sharp enough to note the difference.

 

[j-rho]

Autocross is a competitor-policed sport. Part of the reason I'm basically the only guy trying to campaign a stock Viper in the SCCA is that everyone else is afraid of the diff. With a bit of experimentation I've been able to get it to work okay but its behavior is still rather inconsistent, and the spider gears are a weak point.

If I suddenly went a bunch faster, the diff is probably the first place my competitors would look. They'd check to see if I'd changed the final drive ratio or the limited slip, both of which would help tremendously in autocross.

Since there is a better factory limited slip out right now, thinking maybe I can improve part of the situation. My understanding is the GKN Visco-Lok as 4 spider gears which would distribute the load better, and that its anti-slip takeup is quicker and more consistent.

There is precedent for this sort of thing and it being of benefit to SCCA racers. When I had an S2000 Honda did a couple TSBs for us, so we could fix our A-arm mounts properly, and another so we could upgrade our diff bearing caps once they came out with revised stuff.

Would be great to get that kind of support here.

 

[FrankBarba]

So you want Dodge/Chrysler to offer a TSB so you can feel more comfortable about AutoCrossing your Viper? I can see it now. Everyone will be going to their local dealer for the replacement TSB just like they did with the 96 Cross Member, this was just suppose to be if you tracked your Viper. All of a sudden everyone tracked & raced their 96 GTS.

 

[j-rho]

I don't think "comfortable" is the right word for it. The newer diff will make the car faster and more reliable, plain and simple. I don't care if the diff breaks while I'm autocrossing, it's safe there.

Seems like some people have had diff failures out on the public streets where there could be consequences, so maybe there are other benefits to be had.

The TSB would only apply to failed or nearly-failed diffs to be replaced at the dealer's discretion. They could put in all the clauses they want about "you'll only have this problem if you race", or "only if yours already broke" etc. I have two dead ones in the garage...