Moab's and GRC

[easyrabbit]

Hello RockHeads,

Well after some broken linkage (ends actually) and tweaks to make GRC a little stronger after the 12.5" upgrade kit, I am out hittin the rocks. I am pretty new to all of this so do not have much to compare my GRC too, but it seems to handle quite a bit. I tip over more than I would like and the gear ratio is a little high even with the Integy 55 turn motor in there. Looking forward to spending another 70 bucks for that new gearbox from PTI (this week??).

OK, on with the question. I used the Redrocks and they were not the greatest performing crawlers but did give GRC a bit of ground clearance. Now I am using Moab's on Axial rimms and they grab much better (not a much as I thought they would but better). However I have lost all that ground clearance which hangs me up much more and easier than with the RedRocks. Are these for certain rocks or something because the fun factor dropped considerably with this "upgrade"

Has anyone had this problem or have any suggestions on how I can fix this problem?

Many thanks in advance,

Mike

[K_B]

This should help:

axle clearance

But really, if you enjoyed it more with the Red Rocks, use the Red Rocks then. Just because everyone and their mother runs Moabs doesn't necessarily mean you have to too. Although there is usually good reason why a particular tire is popular, the terrain will dictate what works best.

[easyrabbit]

Many thanks (again). Sounds like I have a bit more tweaking to do.

Now it seems my dogbones are slowly (but quickly) being sawed off LOL need to shim them up or something. Any idea how to do this properly?

Also, my shocks way too mushy. I saw that someone made a mod to mount shocks higher but I do not have that level of metalworking equip. Tighter shocks?

So many tweaks needed to get this truck right. I like it but if I can not get it tough Enoch for my driving, it will have to go.

The more I use it the less I like its gear reduction. Any tips in that area would be greatly appreciated as well.

Many thanks!!!

M

[K_B]

To save your dogbones, try lengthening your links a bit. If the links are threaded all the way into the rod-ends, back 'em out so that they're only about 75% of the way in. Then adjust the collars upwards on the shocks to lower the ride height a bit.

This will pull the dogbones out of the drivecups so that they have a better range of motion and the edge of the drivecup won't dig into the dogbone.

The tweaks required to get this thing right is the one reason people either love or hate this truck it seems. The gearbox makes all the difference in the world on these things too. If you don't wanna drop the coin on the PTI box or the RC4WD box, you can use a cheaper GD-600 airplane gearbox, but you have to get a special pinion from RC4WD or file the output shaft down to fit standard pinions. Plus the GD-600 isn't nearly as stout.

[easyrabbit]

Thanks for your responses!

At the moment I am having a hard time keeping the dogbones in. I have two hole options with the stock (extension kit). The back hole and the shocks were soft so I moved it to the outer. The outer hole made the shocks stand straighter and lifted the truck a little but moves the end of the dogbone a close to the edge of the outdrive. This and the angle to the axle is causing it to cut a small ring around the end of the dogbone where it rubs against the edge of the outdrive. Does that make sense? I can send pictures (would post them but have not figured out how yet).

I think I will switch the holes back so that the angle is not as severe and pushes the dogbone a little further back in to the outdrive.

Since I am actually trying to lengthen the dogbone, do you know what I would use and where/what end of the dogbone I would place it?

Many thanks!

[curve]

I wouldn't spend the $70 on a gear reduction from pti when you can buy a gd600 from tower hobbies for $13 and it is nothing to fit in there.

[easyrabbit]

Originally Posted by K_B

To save your dogbones, try lengthening your links a bit. If the links are threaded all the way into the rod-ends, back 'em out so that they're only about 75% of the way in. Then adjust the collars upwards on the shocks to lower the ride height a bit...

Many thanks for this info. I did as you suggested and it worked. I also needed to do this in general as everything is looser and working better.

NOW, after putting a little stress on G-Dog, I noticed that the front plate starts to bend and hit the servo arm. After bending this back a few times it finally snapped right off. I am now looking for a different bumper that can handle some abuse. After that I think this truck will be solid enough to handle some decent "crawl bashing" and serious crawling as well.

Will keep you posted and thanks again!

[easyrabbit]

Originally Posted by curve

I wouldn't spend the $70 on a gear reduction from pti when you can buy a gd600 from tower hobbies for $13 and it is nothing to fit in there.

MANY thanks for this Info too! I will check this out for sure!

[Skeeno]

The GD600 is much cheaper and works, but it needs to be modified. You need to mill the output shaft from 5mm to 3mm so standard pinions fit. You may also get 5mm pinions, but the selection is limited. You will also have to remove some of the plastic to get it to fit in the motor mount. The GD600 will also sit about 1/2" higher than the stock motor.

The PTI gear reduction is more expensive but needs no modification and does not raise the CG. I prefer the PTI GRU for the CG reasons.

[easyrabbit]

Yes thank you for that input. I have been researching using the GD600, the mods, CG etc... since reading the post. Spending a little extra cash on the proper part what fits/looks correct is probably the way I will go. IF they ever release the thing!

I do have a spare Traxxas Stampede trans sitting here. Has anyone tried using that on a GRC?

Originally Posted by Skeeno

The GD600 is much cheaper and works, but it needs to be modified. You need to mill the output shaft from 5mm to 3mm so standard pinions fit. You may also get 5mm pinions, but the selection is limited. You will also have to remove some of the plastic to get it to fit in the motor mount. The GD600 will also sit about 1/2" higher than the stock motor.

The PTI gear reduction is more expensive but needs no modification and does not raise the CG. I prefer the PTI GRU for the CG reasons.

[K_B]

Using the 'pede tranny would certainly solve the gear reduction problem and would be stouter than the GRU/stock tranny setup. But it's pretty heavy and to keep the chassis near stock width, you'd have to mount the tranny vertically, which again, raises your center of gravity a bit. But it's worth a shot I think, especially since you have one sitting around.

For what it's worth you could this instead of the GD as well:

http://rc4wdstore.com/index.php?cPath=61