TRX 3.3 rust
 

My trx3.3 has rust on the crank and crankcase, it’s mild but I still want to get rid of it, should I use CLR or something else?

The crankcase is aluminum. It cannot rust. If there is brown crud stuck to the crankcase, it’s probably castor residue. Soak in acetone to remove/dissolve the castor sludge. If the crank is actually rusty, the bearings probably are too. Replace the bearings and soak the crank in Evaporust. Rinse and oil well or the crank will rust again just sitting in ambient air.

This is what I did when I rebuild my 3.3 and another 30+year old Webra engine. Get some fine grit sandpaper, 1200-2000 grit, you can get it at Walmart, fully take apart the engine, soak all the rusty stuff in acetone (like SlowLST2 said) or use LA totally awesome cleaner, you can find it at the dollar store, it will take off the rust, sand the crankshaft lightly to get the residue of rust off, just remember, once you take material off, you can't get it back. Get new bearings, Avid and Boca bearings are great replacements (and of course Traxxas bearings), I would also disassemble your carb and make sure there is no gummed up fuel in there. When your re-assembling your engine, put some 3in1 oil on the moving parts, not a bunch just a drop to lube it up (especially on the starter shaft), that will help since once you clean it there will be not lubrication.

Evaporust will remove the need to sand ANY rust off of Ferrous parts. Soak it for a couple hours and Ferrous parts come out looking darn near like new. Rinse with clear water, dry thoroughly, and liberally oil it. I like Dexron ATF due to its high corrosion inhibitor content.

Replace the bearings. You can get a crankcase with OEM bearings installed for dirt cheap from DollarHobbyz.com. I built a complete 3.3 engine for $30 having just a NIP piston/liner/rod, carb, and backplate. Otherwise get bearings from Avid or RCBearings. Boca Bearings sucks for two reasons. They sell Chinese bearings for 10-20 times what Avid and RCBearings sell them for (same quality) and Boca’s search turns up the right bearing sizes about 50% of the time. Remove the old bearings and measure them before ordering new ones.

I’d like to see pictures of the “rust”.

ATF is a good after run and storage oil, correct?

Yes sir. One of the best.

Don't sand any part of your engine. A scotchbrite pad, maybe.
Also, get Avid bearings. The 3.3 is widely known for the OEM bearings, specifically the rear, disentegrating. Every 3.3 I owned had the same exact thing happen. I'm not sure who makes Avid's stuff, but it works.

I am going to say that the fuel used will/can have a pretty dramatic effect on engine longevity and performance. Crappy oils and crappy nitromethane do crappy things to engine parts. I have a pair of 3.3s in use currently - one is over the 8 gallon mark and the other is at 5 gallons; both engines got new bearings a year ago. The engines came to me used - with 5 gallons and 5 tanks of fuel respectively. The bearings weren’t rusty, they just got a little loose. They’ve been run on my home brew fuel since I got them.

https://cimg0.ibsrv.net/gimg/www.rct...5c7d81350.jpeg
Thanks guys for the input, I’m going to get some ATF and evaporust tomorrow, the rust is extremely mild, I gave it a bath in WD40 and most of the rust came off however there are small specs of rust coloured stuff on the crank, but the bearings look fine however it’s only a matter of time before they leak so I’m gonna replace em soom also i’ll try and get some photos today

EDIT: here's a photo

That isn’t rust. That’s castor oil residue. Rust doesn’t rinse away with just solvent (WD40 is mostly solvent.)

I was worried for a little while there, also I’m going to get new bearings, I should go with avid correct?

If they have the right sizes. I don’t think they have the rear bearing - it’s a weird size IIRC. If I have the bearing sizes jotted down, I’ll post them. Otherwise you’ll need to remove the old ones and measure them. Typical bearing listings will go ID x OD x Width.

It seems like both Avid and TKO have bearings for that engine, both should work fine.

Avid does carry both bearings now. They didn’t a year ago when I replaced the bearings in two of my 3.3s. I stand corrected.

Hello SlowLST2 and OV99,

If I'm not wrong the Rear Bearing of TRX 3.3 is 12x21x5mm..

Cheers.. :)