I have a 7.0 Challenger 2. Two upgrades I'd like to do right away are metal drive sprockets with anti-slip rings and drive shaft support bearings. I've already found eBay listings for the drive sprockets, but after doing a search and reading several threads, I still have some questions about the bearings.
- I've seen listings for bearing holders that show compatibility for either 5.0 or 6.0 models (not both).
However, I've heard there were some chassis changes between 6.0 and 7.0.
Is the size of the opening different between the two generations?
The opening is ~12mm, and I've attached a photo for reference. - If the opening is the same, is there a reason to use a separate bearing holder vs. directly placing a bearing?
If the opening size is different, would the bearing itself be the same size? Somewhere I saw a suggestion of 12mm O.D., 8mm I.D. 3.5mm thick. - I've seem some threads for other tank models that mention putting a bearing inside the chassis instead.
Is that something I need to do as well, or is that specific to a different gearbox/chassis design?