Granite Just what is the "Slipper" - what does it do and how do you check it / know when to tighten it?

[Spook]

I see lots of reference to the slipper and people suggesting to tighten it up - but I am struggling to find details on just what it is and how you know when to tighten it, can anyone enlighten me please?

My new Granite as developed a bit of a grinding noise which most people have told me its normal, but it didn't initially do it. It has been suggested I should check and tighten the slipper.

I have also noticed that a couple of times, while traveling quickly and wheelie / turning I have heard a squeal / screech (only twice) - is this the slipper?

Is there a way to check the slipper? do I need the lock tight on the screw if I am just checking and tightening or is this just if I take it out and take it apart?

Many Thanks all.

 

[bicketybam]

I see lots of reference to the slipper and people suggesting to tighten it up - but I am struggling to find details on just what it is and how you know when to tighten it, can anyone enlighten me please?

My new Granite as developed a bit of a grinding noise which most people have told me its normal, but it didn't initially do it. It has been suggested I should check and tighten the slipper.

I have also noticed that a couple of times, while traveling quickly and wheelie / turning I have heard a squeal / screech (only twice) - is this the slipper?

Is there a way to check the slipper? do I need the lock tight on the screw if I am just checking and tightening or is this just if I take it out and take it apart?

Many Thanks all.

A slipper clutch is used in a 4wd RC that doesn't have a center differential. The clutch allows the a little bit of give between the motor and the driveline, especially at startup. Electric brushless motors produce instant torque and transferring all that torque directly to the driveline can cause problems (in the case of the 3S/4S trucks it's the wheel driveshafts that can break). The slipper clutch allows a gentler transfer of torque and it will also prevent damage in certain situations where one set of wheels are suddenly stopped while the other set can still move freely. A common situation is landing a jump on either the front or rear wheels. Even though the front and rear wheels are "locked" the slipper will allow them to act independently for a split second and prevent any damage. I hope this makes some kind of sense.

As far as tightness goes, there is a screw/spring setup that determines how much "slip" there is between the two halves of the clutch assembly. If the clutch assembly doesn't have enough pressure holding the two halves together (too loose) then instead of transferring the power from the motor to the driveline the motor will end up excessively spinning the half that is connected to it and little to no power gets transferred to the driveline. This is how the clutch pads get burned up. You can usually tell this is the case when you apply full power from a dead stop and instead of the truck taking off almost immediately or pulling a wheelie, you will hear the motor spin quicky but the truck doesn't move forward quickly at all.

If the slipper clutch is set too tightly, then the power from the motor is instantly transfered to the driveline and it can cause things to break. If you apply full power from a dead stop and your truck does a standing backflip, chances are it is set too tightly. You should hear the motor spin for a fraction of a second before the power is delivered.

In the manual it describes what the factory settings is (I don't have it in front of me at the moment). That's usually the best setting. What ends up happening is the screw that adjusts how tightly the two have are pushed together ends up loosening on its own. This will cause am excessively loose slipper. Some people have a problem.with it constantly loosening so they will use a bit of loctite of the screw once they have it set properly.

Anyway, I'm sure someone can break down the loctite procedure. I just wanted to explain (as best I could) what a slipper does.

 

[jondilly1974]

I see lots of reference to the slipper and people suggesting to tighten it up - but I am struggling to find details on just what it is and how you know when to tighten it, can anyone enlighten me please?

My new Granite as developed a bit of a grinding noise which most people have told me its normal, but it didn't initially do it. It has been suggested I should check and tighten the slipper.

I have also noticed that a couple of times, while traveling quickly and wheelie / turning I have heard a squeal / screech (only twice) - is this the slipper?

Is there a way to check the slipper? do I need the lock tight on the screw if I am just checking and tightening or is this just if I take it out and take it apart?

Many Thanks all.

Which Granite do you have specifically? The methods are different depending on model.

 

[Yonic]

Great explanation @bicketybam. The deeper i dive into the slipper the more i learn.

the squeal / screech sound you've heard is definitely the slipper slipping.

Few points about the slipper.
- Arrma removed the (little as it was) slipper adjustments instructions when the cars were updated to the Spektrum radios, so to find it you need to look at the first versions of the manual at Arrma's site.
- The 3s/4s slipper is a bit unique (as far as i can tell, i don't have much knowledge in other cars) in the way that it can slip the rear/front parts independently, with the rear having twice the torque transfer as the front before it gives. So you can (should) set it so the front gives when you break hard. (you can see the front wheels still spinning while the rears lock)
- There's a tiny "thrust bearing" on the screw (that looks like 3 shims), it needs to run freely for the slipper wont get loose, as it allows for the slipper to spin without effecting the screw . in my case cleaning it didnt always help, so loctite is needed.
- The most reliable way to setup the slipper is the amount of turns you unscrew it from a locked position. Arrma suggested 1.5 turns, i set it with 2.5 turns and it works great for me (still allows to wheelie)
- Definitely don't keep the slipper tighten all the way, also when you tighten it all the way (to count the turn back to loosen it), never tight it too strong. you should stop immediately as you feel it stop turning.
- To set the slipper, you can leave the power module installed in the car and access the screw with the center driveshaft removed. Remove the screw all the way, put some loctite on it and screw it back all the way until it stops and then 1.5 to 2.5 turns back. Leave overnight for the loctite to grab.

Your grinding noise i would be is from the motor bearing... but that's another unrelated issue

 

[Spook]

Thank you for all the excellent information, that is really helpful. I am amazed at the detailed explanation and help offered in this forum.

I have the Granite 3S BLX, just a couple of weeks old.

The Grinding noise has worried me a little, as I said, new to this and its only been out for a few runs and had a couple of knocks but I noticed the additional sort of grinding noise when slowing down predominantly and slower speeds all of a sudden, so was concerned that something needed attention.... it can be heard rocking the car gently forwards and backwards too.

Most people have said that the noise is normal, should I be investigating the motor bearings or is it "safe" to leave along?

 

[Yonic]

it might also be one of your wheel bearing seized. you should find where it's coming from, so something wont get damaged more than it needs to.

Start by removing the power module and reving it a bit to see if the sound is from the motor area, with it still removed, roll the car to see if it's from the drivetrain.

 

[jondilly1974]

Thank you for all the excellent information, that is really helpful. I am amazed at the detailed explanation and help offered in this forum.

I have the Granite 3S BLX, just a couple of weeks old.

The Grinding noise has worried me a little, as I said, new to this and its only been out for a few runs and had a couple of knocks but I noticed the additional sort of grinding noise when slowing down predominantly and slower speeds all of a sudden, so was concerned that something needed attention.... it can be heard rocking the car gently forwards and backwards too.

Most people have said that the noise is normal, should I be investigating the motor bearings or is it "safe" to leave along?

I would be pulling it apart and investigating. Do not run a truck that has bad sounds emanating from it. Trust your instincts and figure out where the sound is coming from. Bearings can be checked by hand for grit. You can visually inspect some other items for wear. Take your time and go thru everything and look for signs of wear.

 

[Camaroboy383]

A slipper clutch is used in a 4wd RC that doesn't have a center differential. The clutch allows the a little bit of give between the motor and the driveline, especially at startup. Electric brushless motors produce instant torque and transferring all that torque directly to the driveline can cause problems (in the case of the 3S/4S trucks it's the wheel driveshafts that can break). The slipper clutch allows a gentler transfer of torque and it will also prevent damage in certain situations where one set of wheels are suddenly stopped while the other set can still move freely. A common situation is landing a jump on either the front or rear wheels. Even though the front and rear wheels are "locked" the slipper will allow them to act independently for a split second and prevent any damage. I hope this makes some kind of sense.

As far as tightness goes, there is a screw/spring setup that determines how much "slip" there is between the two halves of the clutch assembly. If the clutch assembly doesn't have enough pressure holding the two halves together (too loose) then instead of transferring the power from the motor to the driveline the motor will end up excessively spinning the half that is connected to it and little to no power gets transferred to the driveline. This is how the clutch pads get burned up. You can usually tell this is the case when you apply full power from a dead stop and instead of the truck taking off almost immediately or pulling a wheelie, you will hear the motor spin quicky but the truck doesn't move forward quickly at all.

If the slipper clutch is set too tightly, then the power from the motor is instantly transfered to the driveline and it can cause things to break. If you apply full power from a dead stop and your truck does a standing backflip, chances are it is set too tightly. You should hear the motor spin for a fraction of a second before the power is delivered.

In the manual it describes what the factory settings is (I don't have it in front of me at the moment). That's usually the best setting. What ends up happening is the screw that adjusts how tightly the two have are pushed together ends up loosening on its own. This will cause am excessively loose slipper. Some people have a problem.with it constantly loosening so they will use a bit of loctite of the screw once they have it set properly.

Anyway, I'm sure someone can break down the loctite procedure. I just wanted to explain (as best I could) what a slipper does.

well typed out, i will only add a slipper clutch can be found on many rigs both 2wd and 4wd, nitro and electric.. before brushless motors they mainly saved the gear sets when landing jumps, or traction was unloaded and tires free spinning then coming back in contact with the ground while tire rpm was up...

as for your sqeal or screech, i would suspect a bearing starting to fail... has the rig been in wet conditions?

@jondilly1974 has a great point as well on the tightening procedure's, there are 2 different setups.. ?

Thank you for all the excellent information, that is really helpful. I am amazed at the detailed explanation and help offered in this forum.

I have the Granite 3S BLX, just a couple of weeks old.

The Grinding noise has worried me a little, as I said, new to this and its only been out for a few runs and had a couple of knocks but I noticed the additional sort of grinding noise when slowing down predominantly and slower speeds all of a sudden, so was concerned that something needed attention.... it can be heard rocking the car gently forwards and backwards too.

Most people have said that the noise is normal, should I be investigating the motor bearings or is it "safe" to leave along?

to help further we would need to hear the grinding noise you speak of.. cause they make alot of noise normally..?

 

[Spook]

well typed out, i will only add a slipper clutch can be found on many rigs both 2wd and 4wd, nitro and electric.. before brushless motors they mainly saved the gear sets when landing jumps, or traction was unloaded and tires free spinning then coming back in contact with the ground while tire rpm was up...

as for your sqeal or screech, i would suspect a bearing starting to fail... has the rig been in wet conditions?

@jondilly1974 has a great point as well on the tightening procedure's, there are 2 different setups.. ?



to help further we would need to hear the grinding noise you speak of.. cause they make alot of noise normally..?

The sound is quite hard to describe, I have (I hope) linked e few videos but I'm not sure if you can really hear anything from it. The (slight) grinding noise seems new, I am pretty sure it wasnt doing it initially and developed it., I heard a difference in how it sounds. I hope this is evident from the videos but I'm not sure it will be. I didn't try rocking the car before the noise so cant be sure, but it sounds a bit "grindy" to me...

Thanks again

 

[bicketybam]

The sound is quite hard to describe, I have (I hope) linked e few videos but I'm not sure if you can really hear anything from it. The (slight) grinding noise seems new, I am pretty sure it wasnt doing it initially and developed it., I heard a difference in how it sounds. I hope this is evident from the videos but I'm not sure it will be. I didn't try rocking the car before the noise so cant be sure, but it sounds a bit "grindy" to me...

Thanks again

You have the videos set to private. You need to change it to either unlisted or public through YouTube.

 

[ph47mf]

that to me is normal, all the brushless cars do that.

 

[Spook]

I haven't uploaded to youtube before either, hopefully they are visable now. Thanks for pointing it out...

 

[jondilly1974]

All sound fine to me. That’s how all of my 3S rigs sound.

 

[Surchaufeur]

The sound you hear is the pinion and spur rotating off throttle maybe check the bearings where the slipper clutch assembly sits on the stock ones wear down fast

 

[bicketybam]

All sounds normal to me ???

 

[Camaroboy383]

i agree as well.. totally normal..✌

 

[Spook]

Thanks all that's a relief - funny how it just started though, the extra sort of rattle. Anyway - I will stop worrying about it... phew.

Thank you everyone..

 

[parcou]

Thanks all that's a relief - funny how it just started though, the extra sort of rattle. Anyway - I will stop worrying about it... phew.

Thank you everyone..

I'm a newbie here as well...

As far as the bearing not saying that is the issue when I got the nerves to change all my bearings to shielded the metal ones were not too bad but I could hear the grit and grind since they were not shielded. I was blown away at the one bearing when I removed the motor and the rear diff it was all rusty and just all gritty.

I do not run in water but there was a time I hit a puddle by accident and I was under 8 full battery packs of runs at the time of bearing change. I clean the rig after each run with air compressor and simple green and blow it out again to remove all moisture paying attention to all bearing I can see with wheels removed.

I said all that after watching Razor RC change all his he pointed that one out to check it often. I had no other bearing that looked as bad as that on between the motor and rear diff bearing when I removed that outer motor house bearing. Could be your sound per what Surchaufeur posted...just a thought.

Video Razor RC @ 9:41s what I am referring to:

 

[Pablos]

yeah I totally understand your concerns. I am a newbie RC guy as well and my granite makes loads of different noises. The way I look at it is it comes with 2 year warranty so if something breaks down I will just use it! I am not able to make a call what is normal and not normal noise and if something is not normal anyway let it break that's what warranty is for!

Paul

 

[Pablos]

would anyone be able to post relevant bearing sizes for all granite car? What's the consensus on best bearing for granite in terms of value and quality? I only bashed 3 battery packs on the car at this stage so all is stock!

Thanks
Paul