HPI Savage X 4.6 Not working at all

[mw24hr]

Hi all, 2nd run out today with my sons savage and we have problems again. We have had it running fine on its previous outing but needing tuning. So today we decided to tune it after watching youtube vids. All was going well until at almost full speed it revved really high but didnt move anywhere. The engine is running fine but on the stand when I revved it up it would stall. Then I put it back on the ground, set it off and again its revving high but not moving. I am a complete novice to this hobby but with actual cars this would suggest to me clutch problems ? Any ideas ? Oh and I ended up building a stand instead of buying one 🙂
See videos

 

[Jam Racing 1]

Check the slipper nut and see if it backed off, tighten it all the way down and try again, the setting HPI recommends is back it off 1/4 to 1/2 turn, at this setting it will loosen up and slip all the time...

 

[mw24hr]

http://s1318.photobucket.com/user/mw24hr/media/Mobile Uploads/798A837B-C250-47C4-832F-57584FD2D038_zpshuvdsmbu.mp4.html

 

[paulnewman]

Agree with Jam. Looking at the video the nut on your slipper clutch has backed of way too much (I can see gaps in the spring) so needs to be tightened right up. On the stand it will move the wheels without a problem but when you put it on the ground the clutch will slip and the truck will not move.

You will have probably glazed the slipper pad as well so you may end up changing that too.

If the nut keeps backing off, replace with a new one or put some thread lock on the shaft to stop it moving.

I like the stand you made, looks nice & sturdy!

 

[mw24hr]

Agree with Jam. Looking at the video the nut on your slipper clutch has backed of way too much (I can see gaps in the spring) so needs to be tightened right up. On the stand it will move the wheels without a problem but when you put it on the ground the clutch will slip and the truck will not move.

You will have probably glazed the slipper pad as well so you may end up changing that too.

If the nut keeps backing off, replace with a new one or put some thread lock on the shaft to stop it moving.

I like the stand you made, looks nice & sturdy!

Yer the stand turned out surprisingly well actually. Car fits really well in it. Is there any instructions on this site regarding the slipper nut ? Is it easy to get to or do I have to start stripping it down?

 

[Jam Racing 1]

the slipper nut is in the center of the spur, take an 8mm wrench and tighten the nut down tight....

 

[paulnewman]

Make sure the nut shown here is good and tight.

 

[mw24hr]

Arrr I see, spot on that cheers I will have a look

 

[mw24hr]

Right then, I tightened the nut up and I have tried it this morning. It did work for a few minutes but has now gone again. Its revving high when I apply throttle and not going anywhere. I tried tightening the nut again but its just turning now not having any effect. I am holding the large cog and tightening but it just slips. Any more ideas ? Could this be the slipper pads that paulnewman spoke of ?

 

[francis Labarbara]

The slipper pad is stuck to the back of the large cog which is called the spur gear. The spur gear can turn on the shaft and is not fixed to it. It is held by the nut you have been tightening. The nut presses the spur gear with the slipper pad on the back against a plate that is fixed on the shaft and these parts make up the slipper clutch. The tightness of the nut determins how much force the slipper clutch will take before it will slip.

At this point you should probably take it apart and look at it to see if the pad is still usable. If it is glazed you can scuff it and still use it.
The nut should not be coming loose though so either get another one or locktite it. It is a nylok nutt and they wear out.

 

[paulnewman]

Couldn't have said what Francis said any better!!

Sometimes when the slipper clutch slips it melts the glue on the back of the pad and it loses it's grip on the spur gear. It is probably worth you getting a few spare pads and changing it for peace of mind.

 

[Jam Racing 1]

Right then, I tightened the nut up and I have tried it this morning. It did work for a few minutes but has now gone again. Its revving high when I apply throttle and not going anywhere. I tried tightening the nut again but its just turning now not having any effect. I am holding the large cog and tightening but it just slips. Any more ideas ? Could this be the slipper pads that paulnewman spoke of ?

Do you have the manual, if so there are detailed instructions on how to replace the slipper pad....

 

[mw24hr]

Whic part is the slipper pad ? And is this why its not working ? What parts do i need ?

 

[Jam Racing 1]

See that material on back of the spur gear, that USED to be a slipper pad, best off getting a new spur and pad, I do believe the new spur will have a new pad included with it...... also should clean the metal backing plate also as there appears to be used up slipper pad materials on that also, when you reinstall the parts make sure to LOCK down the slipper to keep it from being eaten up again......

 

[mw24hr]

Great stuff, What is the best way to clean this car, degrease etc without damaging any parts ?

 

[Jam Racing 1]

Great stuff, What is the best way to clean this car, degrease etc without damaging any parts ?

I use a spray bottle with a 50/50 mix of denatured alcohol and water, then use my air compressor to blow it dry, be careful around the servos and receiver so they don't get wet....

 

[paulnewman]

You might want to get a couple of spur gears and a couple of packs of slipper pads to keep in your spares box just in case!!!! I would also get a new locknut to be 100% sure that it will not back off when tight and get some locktite on the thread for extra insurance.

I also keep a couple of cheap household paintbrushes handy as they are great for getting grass and mud out of all those hard to reach places.

Keep at it, sometimes it can be frustrating when things break or seem not to work properly but it will all be forgotten when you have the truck running well, it's getting muddy and you find that you keep saying to yourself "just 10 more minutes and I will pack up" over and over again 🙂🙂🙂

 

[olds97_lss]

Also, when you install the new slipper pad, clean the back of the spur first with DA (alcohol) to remove any oil residue, then make sure to peal the backing off the pad and then the adhesive will hold it on the spur. Press it down on the spur hard so it's well seated. It's a good idea to rough up the pad gently with some fine sand paper. Clean the slipper washer that the pad presses against as well and rough it up too.