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LOCKING YOUR AXLES
Part 1:
I'm going to try and provide a guide on how to lock a differential
on a Clod truck. I decide to do this project after searching and not
being able to find a good description of how to do this anywhere on
the web. I am by no means an expert on this, but my method works.
There may also be other ways of doing this. The advantages of a
locked diff are greatly increased traction while pulling or climbing.
The disadvantages are increased turning radius, somewhat
increased wear on tires and some driveline parts. I have found 2
different glues that work well for locking the gears; both are 2 part
epoxies, which require mixing. J B Weld, and a new product I found
at a local automotive supply store called "Plastic Welding System"
it is designed special for plastics. (See pic 1-2)
Next. It’s time to tear things apart. This pic shows it before I begin,
and with the wheels removed. During this project, it is also a good
time for a good cleaning of any off-road grime which has
accumulated, check for any loose hardware, and damage which
needs repair, and a time for a good oil/grease where needed
Next step is to prepare to remove the steering linkages and all
suspension links. Depending on your truck these may vary
somewhat, but should be similar.
More linkages to be removed, along with the pivot bolts. Hint: If
you sometimes have trouble remembering how things fit back
together, take some pics with a camera, make sketches, or even
use a camcorder. It will give you an instant reference on how
everything fits. (Not that I have ever had this problem!)
Now you can see the steering links and pivot bolts removed. Next
the wheel hubs have been removed. I find it helpful, after removing
any nuts or washers from a bolt, place them back on the bolt in the
same arrangement they were removed. It keeps everything together
and less likely to lose any small parts.
More linkages removed. Finally after removing everything
necessary, the axle is free from the truck (Note! I missed getting
any pics of removing the motor and servo mount. They share the
same mounting screws, so it is pretty straightforward.)
Now we are ready to open up the axle housing. The screws marked
"a" are the ones we need to remove. The sleeves marked "b" are
what the motor/servo mount screws pass thru. Use caution when
opening the case up as these sleeves are a tight fit thru the case,
just go-slow and you won't have a problem.
Now the case is open, we can see what we will be dealing with.
Part 2
These are the gears we are concerned with. First thing to do is
thoroughly degrease them with a non-caustic cleaner, so as not to
harm the plastic gears. Now that they are clean, let them dry for a
while and before proceeding, make sure they are completely dry.
OK, now that the gears have finished drying, we can start the
locking/gluing process. The areas to apply the epoxy are indicated
in the first pic. The second shows the gears assembled. Depending
on the type of epoxy, the drying time will vary. If you will be using
J B Weld, it would be best to allow them to dry overnight for full
strength. The PWS epoxy I used for this project dries solid in about
15 minutes. I do not recommend using this PWS epoxy indoors as
the fumes are very strong! Even with using the faster dry PWS, I
will still allow it to set overnight before running the truck.
Before the glue dries totally, take the time to make certain that
you don't have any excess squirting out, check the areas I have
indicated. If it has already dried some, you can very carefully use a
knife to trim the excess. Now is also the time to check the 4
screws in each axle half, make certain they are tight now, because
the only way to do this is with it taken apart. The last thing you
want is for a screw to come out, and bounce around inside with all
the gears.
After waiting the recommended time for the epoxy to dry, it is time to begin reassembly. The pics show the gears back in their proper
location, along with a couple of areas to apply a small amount of
grease. You can use hobby type diff grease, white lithium grease or
a good silicone base grease. Be careful not to use too much, as it
will just work its way out and attract a lot of extra dirt.
Now we can start putting the 2 axle halves back together making
certain that all the gears mesh together properly, and all shafts are
aligned. Be careful with the 2 motor screw sleeves as they fit
rather snug. It may also be necessary to rotate one or both of the
stub axle shafts to allow the unit to slip into their proper positions.
Go ahead and start all the screws in, but don't tighten completely,
until you are certain everything is in proper alignment. I have found
it helpful to mark the motor screw hole with a little paint; it allows my feeble old eyes to align it quicker when reattaching it to the
gear case.
Now begin to re-mount the axle to the frame/links, starting with the
sway bar mount if your Clod is so equipped. After the axle
assemble is partly in position, go ahead and attach the motor and
servo mount using the shared screws.
The next step will be to reattach all of the upper and lower
suspension links. After the suspension linkages are attached we
will re-install the wheel/axle hubs. Apply a small amount of
powdered graphite to the shoulder of the pivot bolt before running it
all the way in. Do not over tighten the pivot bolt, as it will not
allow the hubs to pivot freely.
We continue attaching the wheel hubs and begin to attach the
steering linkages in their proper locations, being certain to place
the conical washers where they were originally. At this time we
also mount the bumper back to the axle housing.
Finally we finish attaching all the steering linkages, checking for
any possible interference, which would not allow it to work
smoothly. After this is complete, go back over everything and make
sure you have it all hooked up proper, and all the screws and bolts
are tightened properly.
All that is left is to reattach the wheels and we are done! Ready to
put the body back on, drop in a fresh battery pack, and take it out
crawling!
SHAVING THE AXLES
In the 1:1 world ground clearance is a big issue, every inch counts. So why would it be any different in the rc world of crawling. I noticed I got hung up on the stupid little screw boss on the bottom of the axle alot, so I clearanced my axles. I did this without taking the axles apart but if you add some JB Weld or epoxy to the area be sure to take it apart so you dont seal the two halves together.
Now the gains you see depend on how much you have the axle tilted to raise the motor, less tilt than I have means less gains. However, shaving the boss off does make the axle smoother so that should still help
Here is what the stock Clod axle clearance looks like with Savage tires. Clearance was measured at 1 7/8" looking directly from behind. That standard 35mm film cannister is roughly 2 1/8" tall.
Here is the shaved axle with the same tires. Clearance increased to 2". About an 1/8". Plus notice the smoother profile of the axle housing. I screwed some 3mm screws into the boss where the bumper usually mounts, they dont actually pull the two halves together but they do help to keep the halves from separating under flex, a little I guess.
Here you can see the boss on the stock axle. I used a dremel with a cutting disc to remove it. I cut a big piece off being careful to stay away from the haxle housing and then carefully ground away material. The plastic on the housing gets real thin in this area so be careful, it may be better to leave a little more material and fill the area with JB Weld or epoxy.
Just for giggles, here is the clearance with Losi LST tires. 2 1/2" here!
So that's it. I know guys in the 1:1 world that spend many hours grinding axle housings to gain an inch of clearance. You can gain the same thing in scale in less time in scale. Happy krawling.
Part 1:
I'm going to try and provide a guide on how to lock a differential
on a Clod truck. I decide to do this project after searching and not
being able to find a good description of how to do this anywhere on
the web. I am by no means an expert on this, but my method works.
There may also be other ways of doing this. The advantages of a
locked diff are greatly increased traction while pulling or climbing.
The disadvantages are increased turning radius, somewhat
increased wear on tires and some driveline parts. I have found 2
different glues that work well for locking the gears; both are 2 part
epoxies, which require mixing. J B Weld, and a new product I found
at a local automotive supply store called "Plastic Welding System"
it is designed special for plastics. (See pic 1-2)
Next. It’s time to tear things apart. This pic shows it before I begin,
and with the wheels removed. During this project, it is also a good
time for a good cleaning of any off-road grime which has
accumulated, check for any loose hardware, and damage which
needs repair, and a time for a good oil/grease where needed
Next step is to prepare to remove the steering linkages and all
suspension links. Depending on your truck these may vary
somewhat, but should be similar.
More linkages to be removed, along with the pivot bolts. Hint: If
you sometimes have trouble remembering how things fit back
together, take some pics with a camera, make sketches, or even
use a camcorder. It will give you an instant reference on how
everything fits. (Not that I have ever had this problem!)
Now you can see the steering links and pivot bolts removed. Next
the wheel hubs have been removed. I find it helpful, after removing
any nuts or washers from a bolt, place them back on the bolt in the
same arrangement they were removed. It keeps everything together
and less likely to lose any small parts.
More linkages removed. Finally after removing everything
necessary, the axle is free from the truck (Note! I missed getting
any pics of removing the motor and servo mount. They share the
same mounting screws, so it is pretty straightforward.)
Now we are ready to open up the axle housing. The screws marked
"a" are the ones we need to remove. The sleeves marked "b" are
what the motor/servo mount screws pass thru. Use caution when
opening the case up as these sleeves are a tight fit thru the case,
just go-slow and you won't have a problem.
Now the case is open, we can see what we will be dealing with.
Part 2
These are the gears we are concerned with. First thing to do is
thoroughly degrease them with a non-caustic cleaner, so as not to
harm the plastic gears. Now that they are clean, let them dry for a
while and before proceeding, make sure they are completely dry.
OK, now that the gears have finished drying, we can start the
locking/gluing process. The areas to apply the epoxy are indicated
in the first pic. The second shows the gears assembled. Depending
on the type of epoxy, the drying time will vary. If you will be using
J B Weld, it would be best to allow them to dry overnight for full
strength. The PWS epoxy I used for this project dries solid in about
15 minutes. I do not recommend using this PWS epoxy indoors as
the fumes are very strong! Even with using the faster dry PWS, I
will still allow it to set overnight before running the truck.
Before the glue dries totally, take the time to make certain that
you don't have any excess squirting out, check the areas I have
indicated. If it has already dried some, you can very carefully use a
knife to trim the excess. Now is also the time to check the 4
screws in each axle half, make certain they are tight now, because
the only way to do this is with it taken apart. The last thing you
want is for a screw to come out, and bounce around inside with all
the gears.
After waiting the recommended time for the epoxy to dry, it is time to begin reassembly. The pics show the gears back in their proper
location, along with a couple of areas to apply a small amount of
grease. You can use hobby type diff grease, white lithium grease or
a good silicone base grease. Be careful not to use too much, as it
will just work its way out and attract a lot of extra dirt.
Now we can start putting the 2 axle halves back together making
certain that all the gears mesh together properly, and all shafts are
aligned. Be careful with the 2 motor screw sleeves as they fit
rather snug. It may also be necessary to rotate one or both of the
stub axle shafts to allow the unit to slip into their proper positions.
Go ahead and start all the screws in, but don't tighten completely,
until you are certain everything is in proper alignment. I have found
it helpful to mark the motor screw hole with a little paint; it allows my feeble old eyes to align it quicker when reattaching it to the
gear case.
Now begin to re-mount the axle to the frame/links, starting with the
sway bar mount if your Clod is so equipped. After the axle
assemble is partly in position, go ahead and attach the motor and
servo mount using the shared screws.
The next step will be to reattach all of the upper and lower
suspension links. After the suspension linkages are attached we
will re-install the wheel/axle hubs. Apply a small amount of
powdered graphite to the shoulder of the pivot bolt before running it
all the way in. Do not over tighten the pivot bolt, as it will not
allow the hubs to pivot freely.
We continue attaching the wheel hubs and begin to attach the
steering linkages in their proper locations, being certain to place
the conical washers where they were originally. At this time we
also mount the bumper back to the axle housing.
Finally we finish attaching all the steering linkages, checking for
any possible interference, which would not allow it to work
smoothly. After this is complete, go back over everything and make
sure you have it all hooked up proper, and all the screws and bolts
are tightened properly.
All that is left is to reattach the wheels and we are done! Ready to
put the body back on, drop in a fresh battery pack, and take it out
crawling!
SHAVING THE AXLES
In the 1:1 world ground clearance is a big issue, every inch counts. So why would it be any different in the rc world of crawling. I noticed I got hung up on the stupid little screw boss on the bottom of the axle alot, so I clearanced my axles. I did this without taking the axles apart but if you add some JB Weld or epoxy to the area be sure to take it apart so you dont seal the two halves together.
Now the gains you see depend on how much you have the axle tilted to raise the motor, less tilt than I have means less gains. However, shaving the boss off does make the axle smoother so that should still help
Here is what the stock Clod axle clearance looks like with Savage tires. Clearance was measured at 1 7/8" looking directly from behind. That standard 35mm film cannister is roughly 2 1/8" tall.
Here is the shaved axle with the same tires. Clearance increased to 2". About an 1/8". Plus notice the smoother profile of the axle housing. I screwed some 3mm screws into the boss where the bumper usually mounts, they dont actually pull the two halves together but they do help to keep the halves from separating under flex, a little I guess.
Here you can see the boss on the stock axle. I used a dremel with a cutting disc to remove it. I cut a big piece off being careful to stay away from the haxle housing and then carefully ground away material. The plastic on the housing gets real thin in this area so be careful, it may be better to leave a little more material and fill the area with JB Weld or epoxy.
Just for giggles, here is the clearance with Losi LST tires. 2 1/2" here!
So that's it. I know guys in the 1:1 world that spend many hours grinding axle housings to gain an inch of clearance. You can gain the same thing in scale in less time in scale. Happy krawling.