tremec 3550 rear seal leaking

There is a seal on the input shaft and another on the tailshaft housing for the drive shaft yoke. Which one are you talking about?

See http://www.ttcautomotive.com/English/onlineorder/product.asp to download a FREE service manual for T5 or Tremec 3550
You will need the Adobe Acrobat viewer which is also a free download – http://www.adobe.com/products/acrobat/readstep2.html

See http://www.ddperformance.com/index2.htm for parts
OR
http://www.hanlonmotorsports.com/

The Tremec rebuild kit I bought was $384, it included syncros and all the bearings. There were no shims in the kit, and you will need them to assemble the trans with proper preload on the roller bearings for the main shaft and countershaft.

There is a video on how to rebuild your T5 or Tremec 3550. If http://www.hanlonmotorsports.com/ are out of stock see http://cartapes.com. It costs less than $20, and is worth every penny of it.

The seal on the talshaft will leak if the yoke is worn. Remove the driveshaft and carefully inspect the yoke. There may be a groove worn in the yoke or other damage.

Can leaving a leaking/seeping seal in there (auto or manual) for a while cause any damage to the driveshaft?