rebuilding TRF501x diffs

[delanobe]

I'm rebuilding my diffs but and was wondering what grease to use??

Some say the green slime stuff is best or Tamiya ceramic grease?

What to use?

Thanks

[jimmy]

Don't use either of those greases! The ceramic grease is meant for gears I think, and the slime is for shocks - not sure if it will work but I wouldn't use it. I wouldn't put either of those anywhere near the diffs.

I use Tamiya silicone grease, the clear stuff - it's some of the best I've used. If you don't have any or can't find it (finding Tamiya stuff can be hard) then pretty much any silicone grease will be 'ok'

For the thrust bearing I use anti-wear grease (again, some came in the kit)

[GRIFF55]

when i ran the tamiya, i used associated clear on the diff balls and black on the thrust bearing.

[DaveG28]

I use tamiya ball diff grease all the time.


I also get to about round 2 of the first day before my diff goes all gritty though, so maybe I'm an idiot....

[BORMAC]

From what Ive learnt,the dark grey-'MOLY' type grease is good for metal to metal thrust race type applications.As for diff balls which fit through nylon diff gears-only use the clear-'BALL DIFF' type grease.Ive tried the reverse and the diff gear gets chewed up real fasr with the MOLY.

[bender]

Jason,

Never use "moly" grease in ball diffs. This grease is not designed for high shear pressure use - great for metal bevel gears, but not for ball diffs.

You should always use a silicon grease for the main diff rings and balls. For the thrust race, the Tamiya Anti Wear grease (as Jimmy said) will work well, as will Associated "black" grease or old Losi "red" grease.

[rcracer]

when you rebuild the diffs are you useing the same nut and bolt

[jimmy]

I always have done.. I had the diff come loose at southport once - but it might have been a dry thrust that caused it. Either way I threadlocked the screw / nut and its been fine since. Never a bad idea to change the nut for a fresh one though - I would have done if I had any!

[rcracer]

ye i had the same problem with my diff unwinding even after fitting a new nut and bolt and using thread lock and greasing the thrust bearing

[V-Rossi]

My last 2 races were spoiled because of the loose diff, it stays good for about 2 minutes, after that I had no braking at all (I'm using the one-way) and the next moment I thought I had an RC-plane when I took a jump
I'm going to replace it with the Hot Bodies screw (with titanium coating), it's expensive ($6,50 for 1 screw and nut) but probably it will be worth it. I also ordered the screws from HPI.

[rcracer]

Originally Posted by V-Rossi

My last 2 races were spoiled because of the loose diff, it stays good for about 2 minutes, after that I had no braking at all (I'm using the one-way) and the next moment I thought I had an RC-plane when I took a jump
I'm going to replace it with the Hot Bodies screw (with titanium coating), it's expensive ($6,50 for 1 screw and nut) but probably it will be worth it. I also ordered the screws from HPI.

you got a part number for these or link

[V-Rossi]

http://shopping.rcmodel.hk/advanced_search_result.php?keywords=diff+screw &osCsid=qi8pgu7sbdt6l4h0a9oq09gis0
I ordered the Hot Bodies and HPI screw. Today I tried the one of Hot Bodies, and it is a nice, very tight fit, the small hex is really stuck in the small black part with the 2 pins on the outsides, which makes it possible more reliable. I wasn't able to drive the car just yet, but it seems to be a lot better now. But of course: don't forget the locktite to be sure.

[rcracer]

Thanx for that m8

[Fabs]

I have never ever had a Tamiya diff come loose, and been racing tamiyas for 7 years now... You guys must be doing something wrong, possibly you're not tightening them enough and what happens is that you wear your diff plates, which makes the diff feel like it's coming loose.

[rcracer]

Fabs what tamiya's have you been racing ?

[Fabs]

Originally Posted by rcracer

Fabs what tamiya's have you been racing ?

TA 04, TRF 414, TRF 414M, TRF 415, TRF 415MSX, TRF 501X... They all use the same diff construction...

[jimmy]

rcracer I will gladly take a look at the diff next time were racing - where will you be racing?

I didn't have a problem with loose diff at the Euros exactly - but I simply couldn't stop it slipping. it was impossible. since then Its been ok when I rebuilt it with new parts on the big pulley

Something that Hupo does is to reduce the width of the diff pulley inside - where the balls fit there is a lip. Hupo sands this so the entire inside surface of the pulley is flat - he said this helps him to have a non-slip diff.. No idea how it works but it's a pain to do on the old pulleys - on the new big pulleys you can do it in a few mins with a scalpel though as they are just 'dots' that you can cut off.