Spring 2024 i picked up a TC4 in a trade. Looks like a bunch has been hopped up (blue stuff). The diffs have metal internals but the out drives and gears are still the stocker plastic units. Is there ANYTHING available out there in terms of aftermarket parts or is dead?

You're probably limited to what you'll be able to find for sale on eBay and Buy/Sell sections in forums like this one. Don't get sucked in by shiny aluminum bits, they generally just add weight and transfer the forces from an impact to harder to replace and more expensive parts. If you're committed to hopping the car up, try and track down the Factory Team option parts made specifically for the car.

Some basic parts can still be found here and there, but to be honest, the TC4 should be placed on the shelf, and if you just want a cheaper car to run on parking lots, street, and driveway, get a Traxxas 4-Tec, they are designed for that. For racing, unless your local track has a class that has all other racers in that class using a Traxxas 4-Tec or Tamiya TT-02, they will not be competitive against actual race platforms like XRAY, Awesomatix, Mugen, and Schumacher.

I only have tc3s, but I think they shared drive lines with the tc4. There are steel out drives that came with the nitro TC3, but they're pretty thick and heavy. The diff gears were still the yellow-ish composite on the nitro. NOS parts seem to still be available, or lots of used parts out there to keep it running.

I imagine new diff balls are easy enough to find since they should be interchangeable with new stuff.

The TC4 was a decent RTR car when sold and from my own personal racing experience, the TC4 was less capable than the TC3. I recall these were selling for under $100 USD when they came out and also came fully built. They only ever sold these as a chassis, never with tires, rims and a body.

The weak point with the TC4 is the steering belcranks, and they will break and often. You can replace these with after market alloy, but those will break as well. Poor design.

The drive train is not the same as the TC3 and parts don't exchange between them. Yes, they are both shaft drive with inline motors but the similarity ends there. The suspension is different as well.

I raced a TC4 in the Canadian VTA class where we were limited to a 25.5 brushless motor and the car ran great in this class. It helped to make a wider bumper to reduce the steering belcrank breakage somewhat.

Parts these days are scarce, so if you plan to race a TC4 you'd best stock up on all the parts you can find. Probably best to buy complete rollers / sliders if you can to save a few bucks.

Good Luck finding parts : Bert got all of them already to run mod carpet !!!

Uh... what? The drivetrains are interchangeable between the 3 and 4. Other than the front spool on the TC4 vs the diff in the TC3 they're basically identical. The entire gearbox is directly interchangeable. Suspension parts are somewhat compatible too. The arms aren't because they use a different size inner hinge pin, but the hubs and knuckles are.

I stand corrected, and below is a comparison chart for those interested in parts compatibility.

https://rcparts.app/compare/teamassociated/tc3-tc4

I’m going through a FT TC4 and put a post in the WTB thread. Spares are getting harder to find. If the chassis I’m looking for is too elusive I’ll be posting my FT and all my parts. Best of luck to ya.