The average shelf life of the original transmission is 350,000 miles. Some get more, some get less, but 350,000 is the average.
Mine went at 372,000. I have 148,000 miles on the Silverstar replacement.
What causes it to fail is a design flaw that is fixed in Silverstar and Jasper remans, and possibly in Mercedes remans, as well.
My Silverstar was installed by my local mechanic, not a Sprinter tech, who ordered the transmission at wholesale for $1995 (instead of the $2195 retail) plus the $300 core charge, and it was $210 shipping. They only charged me $245 labor (it's 6 hours labor to do the swap, but they didn't charge me for all of it, and they're only $64 an hour to begin with). Including tax and misc shop charge, my total bill was $2632.20. They ordered mine on a Tuesday morning, it arrived Thursday morning, and 5:00 Thursday afternoon I drove it away.
It's certainly good if you have a Sprinter tech do the swap, but you do not NEED one. Any competent shop, especially one that normally replaces transmissions with Jasper transmissions, will be able to do it. It's unlikely they will have the correct dipstick tool unless they do a lot of work on Sprinters, and it'll be needed in order to properly fill the transmission after the install, so if they don't have it (or you don't already) you can order that from Silverstar when you order the transmission.
Unless the shop works on a lot of Sprinters, it is unlikely they will have the Chrysler or Mercedes DRBIII tool with the Sprinter module that is required to reset the adatives. You don't want to drive with the new transmission very far (certainly no more than 100 miles) without resetting it. So you WILL need a Sprinter tech for that (or someone with a DAD).
When you get the new one installed, you will want to change the fluid every 30,000 miles. You can use the regular approved
transmission fluid (or any fluid on
this list for that matter), or the specially made fluid from BG that's designed for the Silverstar modifications, but the BG fluid will cost you a really lot ($90 a gallon). If you use the regular fluid, you will also want to add one can of
BG ATC Plus Automatic Transmission Conditioner in order to add the special friction modifiers of the BG fluid to the Mercedes fluid, making them the same fluid. It's also a good idea to dump a can of
BG ATC Quick Clean into the transmission and drive it for 5-20 miles (or follow the directions on the can) before each fluid change.
