501x shock shafts?

d16dcoe45 · #1 03-03-2008

I just came back from a day of racing my 501x Worlds. First time out with it--absolutely awesome car!! One issue I am having is with the shock shafts. After just one day of racing it appears some of the gold-nitride coating is coming off the rear shafts!! There is definately some silver showing though. Now, I usually replace rear o-rings (on any car) after one day of racing and front o-rings after 2 maybe 3 race days--and that keeps the shafts scratch free. But to have the gold come off on brand new o-rings seems a little strange to me. Any one else have this problem? Are the stock (non-worlds) shafts better? For some reason they are a bit shorter than the worlds shafts. What about the Yokomo gold shafts--which ones do people use? I love the car but I don't like the durability on these shafts--otherwise the shocks are great, super smooth with the Worlds low friction rod guides.

Also, when building my 501 I had to ream the holes larger in the bottom shock cartridges (where the o-rings and rod guides are held) otherwise the shafts would actually contact and bind on the hole ID!! I have never had to do this on Losi shocks which have a very similar screw on bottom cartridge. Have you guys had to do this on your 501x shocks? I am wondering if the shafts wore because I didn't ream the holes large enough--doesn't seem likely but I suppose its possible.

WailinOnYa · #2 03-03-2008

Never had that problem, but I don't have the Nitride shafts, I have the original 501X and not the Worlds. I think the binding is inrelation to the machined pistons which have such a close tolerance that they don't allow even the slightest sided to side play, so if the shaft is riding to one side of the bottom cap it rubs because there is very little clearance with the piston and shock body. I have used RC10B4 shock shafts on the front of mine after snapping the originals, they are the same length, but the B4 ones are a larger diameter and I had to ream out the holes in the bottom caps to use them. The other problem could be coming from the large plastic washer that is at the top of the bottom cap that covers the seals! I wouldn't think the original shaft would give you too much problem due to their smaller diameter, but with the B4 shafts it seems to be fine untill you go to tighten the bottom cap all the way down then it binds, I think most of my rubbing is coming from that inner washer. The regular molded pistons aren't as precise but they have a noticeable amount of blowby around the piston which allows them to move slightly from side to side with no binding. Thats why you have to run different oils with the different pistons meening the molded or machined because the machined have such a tighter tolerance so they require lighter oil to get the same feel. I would think that being that they are machined that the hole would be dead center for the shaft, but after tightening the bottom cap they tend to bind on either the bottom cap or that inner washer, at least that is where mine binds then of course the piston will rub on one side of the body also if it has pressure applied to the shaft which just increases the problem.

bender · #3 03-03-2008

Quote:

Originally Posted by d16dcoe45

Now, I usually replace rear o-rings (on any car) after one day of racing and front o-rings after 2 maybe 3 race days--and that keeps the shafts scratch free.

Bloody heck, I'd be lucky to replace o-rings twice per season!

d16dcoe45 · #4 03-03-2008

I am sure the binding was coming from the shaft going through the bottom cartridge. I took a shaft and pushed it through the opening in the bottom cartridge and it was rubbing--and wouldn't move up and down on its own. I then reamed out the bottom cartridge to match the clearance that the stock Losi cartridges have with their shafts installed. It didn't rub anymore.

with the Worlds pistons and low friction rod guides there is practically zero side to side movement of the shaft in the body--so I don't think it was rubbing on the cartrridge. And there is still 95% of the coating left, it just looks "thinner" or lighter in certain areas--so it might have had to wear in and should be fine from now on. Like I said, shocks are still very smooth, I just want to be sure they last a little while.

d16dcoe45 · #5 04-03-2008

I just want to clear up something I posted earlier about the 501x WE shocks. I had some of the gold nitride coating come off of the rear shafts after one day of racing and was a bit concerned. Afer doing some research and going over the instruction again I realized that I had assembled the shocks incorrectly!! It seems that a directional plastic spacer that should have fit in the bottom part of the shocks on top of the o-rings, I had installed in the shock body as a droop limiter! So basically since this plastic piece functions as a stabilizer and limits side to side movement of the shaft, my shock shafts were able to move side to side quite a bit--this movement caused the shafts to rub on the bottom cartridge opening which eventually wore off some of teh coating. Not only that, but since there was too much space above the o-rings in the bottom cartridge the o-rings eventually shifted upwards and allowed alot of oil to leak out.

I reassembled the shocks properly, used some Green Slime and now the shocks are even smoother than before. By FAR the best shocks I have ever used. Combined with WE machined Delrin pistons (which have virtually zero play in teh shock body) the action is incredibly smooth--there is virtually zero play.

Also, the WE shock insides are totally different than the standard 501x guts. I don't know how the stock shocks are but the WE shocks are insanely good. Assembling the WE insides can get a little confusing as the chart they show isn't that self explanatory, IMO. I think its a worthwhile upgrade from teh stock shocks, all you need:

low friction rod guide (enough for all 4)--53979
machined Delring pistons--53978, 1.4mm=to Associated #1
53977, 1.3mm=to Associated #2
53976, 1.2mm=to Associated #3
And its not necessay, but I think worthwhile:
ti-nitride shock shafts--I don't have the part numbers, and for some reason they are each about 4-5mm longer than the stock parts.

I just didn't want anyone to be swayed from a great car when the issue with the shocks was user installed error.

B44&501xRacerEX · #6 24-04-2008

Quote:

Originally Posted by d16dcoe45

I just came back from a day of racing my 501x Worlds. First time out with it--absolutely awesome car!! One issue I am having is with the shock shafts. After just one day of racing it appears some of the gold-nitride coating is coming off the rear shafts!! There is definately some silver showing though. Now, I usually replace rear o-rings (on any car) after one day of racing and front o-rings after 2 maybe 3 race days--and that keeps the shafts scratch free. But to have the gold come off on brand new o-rings seems a little strange to me. Any one else have this problem? Are the stock (non-worlds) shafts better? For some reason they are a bit shorter than the worlds shafts. What about the Yokomo gold shafts--which ones do people use? I love the car but I don't like the durability on these shafts--otherwise the shocks are great, super smooth with the Worlds low friction rod guides.

Also, when building my 501 I had to ream the holes larger in the bottom shock cartridges (where the o-rings and rod guides are held) otherwise the shafts would actually contact and bind on the hole ID!! I have never had to do this on Losi shocks which have a very similar screw on bottom cartridge. Have you guys had to do this on your 501x shocks? I am wondering if the shafts wore because I didn't ream the holes large enough--doesn't seem likely but I suppose its possible.

I've hit practice with my 501x but wont start racing it til oct.
I might run it the appreciation day though...cause when golfland www.rcrcr.com is over with. Time to hit IILnios aka www.action-hobby.com.

I've ran my 501x up at reo's practice days www.reoraceway.com and it's a very stiff car.
I doubt I will ever break it.

stefke · #7 29-04-2008

I raced a TRF501X for the entire 2007 season. I soon realized that the kit shock shafts were letting the otherwise excellent TRF shocks down so I replaced them with Yokomo shafts. After that, the shocks were brilliant ! I only needed to replace the O-rings once !

For 2008, I got myself a nice new TRF501X WCE with the new Tamiya gold nitraded shafts. During the first race with the WCE, I also noticed the "gold" fading on the shafts. On top of that, I bend a front shockshaft coming down from a large jump !

After that : i dumped the Tamiya shafts and installed the excellent Yokomo shafts again. Never had a problem since.

My advice : Dump the crappy Tamiya shock shafts (steel or nitraded) and put in some Yokomo shockshafts.

CAClark · #8 29-04-2008

A good reminder that I need to strip down my shocks and correct my assembly error mentioned on her previously!

d16dcoe45 · #9 02-05-2008

Some updates on the 501x WCE gold shafts:

Originally, I thought the gold nitride was flaking off because I assembled the shafts incorrectly--I reassembled them correctly and STILL the gold is coming off the rear shocks mostly, fronts seem to be ok.

The rears look faded--fading from gold to silver. It only takes 1 or 2 track days to get noticable fading on the shafts. You can verify this is happening because the oil will look "gray/black"--not gray from dirt getting in the oil but gray from the nitride rubbing off and showing up black in oil.

I do service my o-rings very frequently on all the cars I own, but the 501 wouldn't need servicing as much if the nitride coating was up to the spec of Associated or Losi.

I suppose its time to switch to Yokomo shafts--I know the WCE shafts are a different length than the standard 501x shafts--I would like to keep that length (or close to it and make up the difference with spacers)--how long are the preferred Yokomo shafts and are they just the standard ones from the BXF 2007?

stefke · #10 02-05-2008

I got mine from http://www.brockmodels.com/. Same length as the Tamiya's

B44&501xRacerEX · #11 02-05-2008

I have the tungsten diff balls on order.
And a TA-05 36 tooth pulley because the 501x WE pulley my local hobby shop cannot
get in for some odd reason. I just hope the 3mm diff balls will fit a TA-05 pulley :/

I have also got the big tube of tamiya diff grease as well as an extra belt

.

People have been conplaining about the nitride coating comming off after a few shock rebuilds.
Mine is still coated after 3 re-builds. Suppose you have to just be careful...:/

d16dcoe45 · #12 06-05-2008

If you run the 36t pullies with the 18 tooth center pulley the belts will be too long. Even if they fit, it would leave you with a 2.00:1 drive ratio and you would have to run a smaller pinion to compensate. Also, if you only run one 36t pulley--the end you run it on will be overdriven--can be good and bad depending on how you drive. Also, I believe the 36t pulley only takes 8 diff balls.

Look hard on your shafts, I bet the gold looks very light and silvery. I would be surprised if you had zero loss of the nitride coating.

B44&501xRacerEX · #13 08-05-2008

Quote:

Originally Posted by d16dcoe45

If you run the 36t pullies with the 18 tooth center pulley the belts will be too long. Even if they fit, it would leave you with a 2.00:1 drive ratio and you would have to run a smaller pinion to compensate. Also, if you only run one 36t pulley--the end you run it on will be overdriven--can be good and bad depending on how you drive. Also, I believe the 36t pulley only takes 8 diff balls.

Look hard on your shafts, I bet the gold looks very light and silvery. I would be surprised if you had zero loss of the nitride coating.

What about a 40 tooth TC5 pulley?

Yes I dremeled some plastic to get it to fit properly.
And those 3mm tugsten diff balls(or the stock diff balls) will fit also.
Wont be til next week before I have them though...backordered..

A.J. Gee · #14 08-05-2008

Quote:

Originally Posted by B44&501xRacerEX

I've hit practice with my 501x but wont start racing it til oct.
I might run it the appreciation day though...cause when golfland www.rcrcr.com is over with. Time to hit IILnios aka www.action-hobby.com.

I've ran my 501x up at reo's practice days www.reoraceway.com and it's a very stiff car.
I doubt I will ever break it.

The Reoraceway track and facility looks awesome. Did they just open up recently? That place looks nice, professional, and clean. Your very lucky to be able to race there. How often do you go there?

B44&501xRacerEX · #15 09-05-2008

Quote:

Originally Posted by A.J. Gee

The Reoraceway track and facility looks awesome. Did they just open up recently? That place looks nice, professional, and clean. Your very lucky to be able to race there. How often do you go there?

Once every 2 weeks I guess.
Alot of famous drivers have shown up there on occassion.
Wes is doing a great job keeping the place cleaned up.