Upgrading Slash for BL
 

I picked up the FLM tranny for my Slash specifically because I wanted a more solid mounting surface for the motor and the case acts like a heatsink (ok, the nice shiny aluminum had something to do with it too :smile:). Well, I have some problems:

Problem 1: Hinge pins. Is there a better hinge pin to use? I got some brand new stock pins and they bind like crazy! Once I do get them out, much of the plating is scratched off the pin. I imagine these tiny flakes are causing the issue. I used a pipe cleaner to clean out the hinge pin holes on the tranny, but it only helps as long as it takes me to insert the pin again. Again, these are brand new pins. I even checked them for any surface irregularities before I installed them and they were fine. I pull them out and they are noticeably scratched/scuffed. This is happening just during installation, I'd hate to see what happens after it's been running for a while - I'd probably have to cut them out!

If I can't find a decent pin replacement, I'm gonna hack off the hinge parts from the stock plastic tranny and put those on there instead.

Problem 2: RPM arms. I got some RPM arms and they do not fit. I had to dremel out about 1mm total from the inside of the arms where the hinge pins are. This really isn't an FLM issue as the stock arms fit fine. And the RPM arms fit the stock tranny. Go figure. The modded arms are ok, but am thinking about going back to stock. If I need to replace something in the field, I probably won't have my dremel with me. :wink:

Problem 3: Play in the input shaft. After installing the gears according to the Trx blow-up diagram (including the proper size shims), there is about 0.5mm of play on the input shaft (spur gear shaft). I had to disassemble it and add one more shim. Now it's good but I did not enjoy taking everything apart for just one shim. Grr.

Basically, I am stuck at the hinge pin issue. So if anyone has some answers for that, I'd be grateful.

On this Slash, I went from stock on 7 cells, to the MM/5700 on 10 cells, and now to a Medusa 50/2200 on 4s. I'm beginning to think I should just bring it back to stock. :no:

I assume any slash/rusty/pede specific hinge pin will have the same issue. If it were me I'd take a 3mm(or whatever the hingepin is) drill bit and run it through the holes.

yea i just ran a drill bit through the holes, didnt you get the rear bumper mount? it also works but you gotta come up with a couple of little spacers...

I have the FLM rear arms and they come with hinge pins I think - They are black so maybe a slightly different size than the traxxas ones. I would run through a 3mm drill and I also put a little lithium grease on pins.

RPM arms - No comment on the arms as seems very odd - however if it is a field issue why not prep up a spare set of arms for the pit box.

Ahh the joys of putting everything together and taking it all apart again - I had the same issue but wasn't sure if I hadn't missed a shim...

I did run a 1/8" bit (perfect fit) through the holes and they seemed fine. I even slightly rocked the bit back and forth for a hair larger hole. 1/8" = 3.175mm. I think I need a 3.2mm or 3.3mm bit for this to work perfect.

Even after playing with the holes a bit (ok, that sounded bad, lol), the pins slide easier, up to about 1/4" before the threads on the pin where they must be a teeny-tiny bit larger. Seems that those pins aren't perfect. IIRC, the width of the arms is 41mm. If I could find a hinge pin/c-clip setup from something else close to that (could use a couple washers if I had to), that would work too...

About the arms: I gotta get a new set anyway since I attempted to mod one to use a Jato axle carrier (wanted to use the Jato shafts as they are tougher). I might just get stock arms in the rear - or a set of FLM arms. Then, I might as well get the FLM CVDs. Argg. Upgrade one thing and it dominoes into a full project!.

Yeah, I thought I might have missed the shim too, but could have sworn I put it in right. Well, when I took it apart, I DID have everything in right, there just must be a little extra play. Adding one more made it perfect.

So if you're using stock pins then you have these, correct?
http://www3.towerhobbies.com/cgi-bin...&I=LXSGY7&P=ML

Here's an e-clip pin version:
http://www3.towerhobbies.com/cgi-bin...?&I=LXJG85&P=7
It's strange that Traxxas doesn't list this part as an optional replacement for the screw pins.

Thank you! That e-clip version is exactly what I was looking for! If you were a girl and I wasn't taken, I'd kiss you! :love: Instead, how about a virtual friendly handshake? :lol:

Yup, those (first link) are the ones I have. Actually, buytraxxas.com lists two pin sets, both seem identical. But I saw them at my LHS and one of them uses hex and the other is phillips - aside from that, they are identical. I got the hex set since that was what the Slash came with.

It is weird now that you mention it. The front uses an e-clip setup, but the rear uses that crappy screw pin.

I guess I'm off to Tower to place an order... :smile:

Quick question: do the stock springs fit the optional big-bore shocks?

Yes they do... But try front buggy shocks - SOOOO much nicer especially with that heavy transmission

I thought you knew about this one!!! http://www.misbehavin-rc.com/pit-lan...nsion-pins.asp

Actually, I'm using the stock rear on the front, and red maxx springs on the rear right now. But, I think I have some extra buggy springs laying around. Thanks for the tip.

Just finished the order. And of course you can't just buy one thing at Tower... so now my wallet is $150 lighter...

PS check the link above - Do you have any spare jot / revo shocks they work well on front to

Actually, I didn't know about that. Oh well, at least I got the rears squared away.

I used the lunsford kit with my rusty. I did big air with the truck though, so the Ti was preferred after several sets of bent flm pins.

I make my own hinge pins - buy K&S 1/8" diameter music wire, and figure out a way to secure the pin (with a set screw). I still bend the music wire, but it's more flexible and much cheaper to replace than the Traxxas or Lunsford or FLM pins are.

FWIW, I use the RPM arms on my Rustler. They were a little tight when I first installed them, but they have worn in nicely. I use the stock TRX screw pins instead of hinge pins w/ e-clips. They work fine since the arms are plastic anyways.

Let me tell you, upgrading this Slash is a royal PITA!!! Everytime I get something, I have to modify it to work. Now, I don't mind modding, but when you get something that is SUPPOSED to fit, I think it should fit, no?

Latest issue: I got the big bore shocks (#2660 and #2662) just to find that the spring retainers are too small. Let me remind you; these are listed as a Slash option part. The springs "kinda" fit, but they overhang the retainers a bit. So, I have to go get the Slash retainers. Then, the diameter of the "big bore" shocks are smaller than the stock Slash shocks, so even when I get new retainers, I have to find some way to take up the slop on the top retainer. Aggg!

BTW: I decided to change the title of this thread and move it since it's turning out to be a general Slash upgrade thread...

Here is a pic showing the differences between the stock hinge and hinge from the FLM tranny. You can clearly see the FLM hinge is longer by about 1mm:

http://scriptasylum.com/forumpics/sl...m_vs_stock.jpg

This pic shows how much material needs to be removed from the RPM arms to allow them to work with the FLM hinges. Note: RPM arms work fine as-is when using the stock hinge/tranny:

http://scriptasylum.com/forumpics/slash_rpm_arm_mod.jpg

Well, the upgrades are complete.

To get around the "big bore" shock issue, I added a piece of heatshrink tubing to the shock and used Slash spring retainers. The heatshrink was the perfect thickness to take up the slack on the top retainer.

The only things left to do:

- Come up with a decent way to seal the diff so I can tune it. There was an article in an R/C mag I saw at the LHS that describes how to do it. Basically, you dremel down the outdrive raised part flush with the rest of the diff. Then, countersink the outdrive hole and put an 8th scale o-ring in there. The o-ring should stick out as far as the original raised section that was dremeled off. Then add a thin shim, then outdrive bearing. To seal the diff cover, some RTV silicone. I have an extra diff that I'll be trying this on. But I'll wait to actually replace it until the existing diff goes out.

- Change the top shock mounting scheme. I want to replace the shoulder bolts with long bolts/nuts and use some type of spacer/shim to use in the shock cap.

But she's running now and am quite happy. Even with punch control at 70%, timing = low, and start power = low, it still has too much power for those Slash tires. Perfect! :smile:

where?????? i wanna see it :yipi: ive just been filling mine with 3k and 7k and then after a month or so ill pull it out and wipe out the tranny and fill it again......makes it handle worlds better. but if there is a way to keep it in there longer im all eyes and ears.

Can't remember exactly. The guy at the LHS said he remembered seeing it in some "Xtreme RC" mag (or something like that). He flipped through several mags before he found it.

A friend/coworker is coming over to my "shop" today, and we are going to modify his Slash diff in this exact fashion. If there's time we might get around to modding the diff in my Rustler but that's not so important.

Do you have a drill press Brian? I think that will make drilling the countersunk hole a lot more precise.

Drill press? If you mean holding the diff in one hand and the drill in the other, then yes. If you mean a piece of machinery that drills precise and perpendicular holes, then no. :smile:

[QUOTE=MetalMan;243150]A friend/coworker is coming over to my "shop" today, and we are going to modify his Slash diff in this exact fashion. If there's time we might get around to modding the diff in my Rustler but that's not so important.[QUOTE]

Mind Taking a few snapshots? Mine Unloads badly after about 5-10 packs through it. you can even see the grease on the output yoke bearing. Horrible... Thank you Sir.

You know what I meant :whip:.

Unfortunately I didn't get any pics of it, as he pretty much had to rush off to his shift at work. This procedure is very simple, and took about 20mins to complete (not including breaking down the tranny). We put in 70k oil, will see how that works.
The hardest part of this who process is just making sure that you don't remove too much material with the countersink bit. This is very easy to do, and I think he might have taken too much off on one side (hopefully it will still hold up). Otherwise, it's very straightforward if you follow the article - which is in "Xtreme RC", quite possibly the January edition.

lol, I know what you meant. :smile:

If you take a tad too much material off the outdrives, couldn't you just add an extra shim to keep the o-ring pressed in?

I wish it were that simple. Remember that the output shaft goes through that hole, and if you remove too much plastic you can enlarge the opening the output shaft goes through. This isn't good because then the diff won't be supported well enough by the output shafts.

That's true. Someone outta make a nice 7075 Al version of that, but done right, and keep the price around $30-$40...

Yeah, it'd be cool if Mike could make an o-ring sealed version, but he's got much more important things going on.

Now, what could he possibly be doing that is more important than making an item for me? :lol:

here is that ectreme rc article about diff the seal
 

yup here it is
sorry thought it would be a pic, pdf is easy though
sooo you can't edit the title when you misspell everything and add needless words huh lol. Dont judge me it's hot buttered rum time:)

awesome thanks.


now i wonder if that is a typo with the 30,000 and 50,000 wt because the bottles in the picture are 3,000 and 5,000 i have used 3k and 7k . from my expercience any more than 7k would be little too much like a locked rear, 7k works good on hard packed and generally smooth tracks and 3k works great for those loose and really rough tracks.

hey i finally helped someone.:yipi: