Noob to off road and slipper clutch break in, help...

[MustangMan]

I've had a blast over the past few months breaking in my RS4 Evo (and a second for my son) but my RS4 will only go about a foot into the grass and doesn't like jumps :jk:

So...

I got a swinging deal on a MT2 and have just finished the two static break in tanks from the HPI manual...

I went to start on the next tank of break in, where you would drive it around part throttle, and due to the slipper clutch the truck won't move. I can get it to go at more throttle (and it does pick up and start to haul ass) but I don't want to break it in at WOT!

I checked the slipper setting and it is just like the manual states, a half turn backed off from tight. So, what should I do? I was thinking of locking the slipper down just for break in so I can drive it at part throttle. :shrug:

Does this sound like a wise thing to do? I want to have the same success and fun with the MT2 I have had with the RS4. Any other suggestions or tips, I'm all ears! Thanks!

 

[olds97_lss]

You sure it's the slipper and that you didn't get oil on your clutch shoes?

When I check a slipper to see if it is what is actually slipping, I hold the vehicle down on the ground hard and slowly apply the throttle until something slips while you can watch it slip.

Maybe you got oil on the slipper itself?

 

[Rolex]

It almost sounds like it's in the clutch bell. There are spring loaded centrifugal shoes in there, and if, at full throttle it will move and haul ass, they might be hooking up at too high of an RPM.
Possibly your idle is too high, causing the shoes to drag on the bell, making them heat up to a point where they slip too much.
Let everything cool down completely, then restart it and start to drive it immediately. If it seems to move out correctly, that's where the problem is.
Keep us posted, we'll narrow it down.

 

[MustangMan]

There's no oil on the slipper or the clutch. Everything is free of oil. The idle is not too high and there's no engagement of the clutch at idle (like I've had with the RS4 when the idle was too high).

Basically, I have to pull about half throttle on the transmitter to get the truck moving at all, but once it moves it gets some speed to it.

Temps are fine, but higher than I would like during break in, around 200-230...

Unfortunately you can't "see" the slipper on an MT2, it's in the center housing where it is covered, not like a Traxxas or an HPI Rush where you can see it right out in the open near the rear tire. I did take the slipper assembly completely out of the truck (before running it) and checked and set the slipper according to the manual. When trying to get it to slip by hand it took some real pressure to turn.

It does almost sound like a slipping clutch now that I reread my post. I'll pop the bell off and check the shoes. It's just HPI's standard two shoe plastic clutch in there, same thing in my RS4s.

I'll check the clutch and report back in the AM. If you guys think of anything else feel free to post. Thanks!

 

[vbgagnon]

First chekc if there is any oil on the shoes or inside the clutch bell, then take some fine grit sand paper and scuff the shoes and the clutch bell that will definatly eliminate any problems with the clutch.

 

[MustangMan]

Ok...

I pulled the bell this morning (and the tank, the electronics, and slipper/spur to get to it!) and everything was clean and dry. I went ahead and scuffed the clutch shoes and sanded the inside of the bell to scuff up the surface. I put everything back together and fired the MT2 up.

The situation is the same still...

You've got to pull about half throttle to get the truck moving, but then it really "shits and gits"

This may be normal, like I said, I've never owned an off road or anything with a slipper clutch before. I'm used to the RS4 just about burning rubber when you pull throttle on it!

I've already traction rolled it once and I'm having a blast, it's just hard to control the desire to pull full throttle when you're technically still breaking it in...

Any other thoughts, I'm all ears. I'll have to check with HPI tech and see what they say too...

Thanks...

 

[olds97_lss]

Can you tell which is slipping? The cb clutch or the slipper on the spur?

If you have to go half throttle, that doesn't sound quite right. But then again, since you are breaking it in, maybe half throttle just isn't enough yet?

 

[rocknbil]

Yeah I'd begin tightening the slipper a little bit (didn't see where you did that already.) Maybe not lock it down but begin tightening it. If you don't, you'll burn it up.

Depending on the surface, you should adjust your slipper so it has full lockdown within 6-8 feet of a standing stop, but still get no wheel spin.

There is another possible problem. Not familiar with your truck, does it have a ball diff? If it does, and the ball diff is slipping, this is NOT GOOD as the balls and diff rings will heat up and eventually burn themselves out or melt the diff gear. Make sure the diff is good and tight.

 

[olds97_lss]

I think it's a spider diff like my HPI RS4 Nitro MT.

 

[Candyman]

One other thing that it may be. He said in his initial post that he's currently breaking in the engine. Which means as a general rule it's set a bit rich. Because of that he may have to lay into the throttle a bit more to get the revs high enough to engage the clutch. It's possible that once the engine is ready to tune, a little leaning of the HSN may just clear it out a bit more and the clutch will engage much sooner.... Just a thought....

 

[Buncrana]

I don't think it's the slipper either. If you want to test it for sure, tighten it in all the way and see how it is then. Sounds more like the clutch to me even though you have already checked it. Maybe the springs are on wrong or are too tight?

 

[MustangMan]

I know this post is a few weeks old, but wanted to update for anyone reading in the future...

I tightened the slipper one "flat" of the adjustment nut and it helped a bit, then once I leaned it out from break in the throttle response was even better.

I've got about 10 tanks through it now and I took it to an R/C track at a city park today and tried some jumps and got it nice and dirty!

She ran fine until I missed the landing on the triple jump and broke the right front control arm and bent the pivot pin. Just a few bucks at Hobby Town and a tear down over the weekend and I'll be back in business.

Just updating...

Happy New Year everyone!

 

[olds97_lss]

Glad to hear you got it figured out!

 

[Rolex]

Yup, glad you're running it right, by breaking stuff.
Enjoy it in the new year.

 

[MustangMan]

I thought that was the moto of the RC off-road hobbiest "you're not having fun unless your breaking stuff!"