• Welcome to RCTalk! 🚀

    Join the #1 RC community where hobbyists connect, share, and get expert advice on RC cars, trucks, boats, drones, and more!

    • ✓ Friendly & passionate RC enthusiasts
    • ✓ RC tips & troubleshooting
    • ✓ Buy, sell & trade RC gear
    • ✓ Share builds & upgrades

Spider Mod Nessesary?

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, and others.
S

SpitFireV12RR

RCTalk Addict
Messages
743
Reaction score
0
Points
0
Location
Orlando
RC Driving Style
I'm getting a Savage 25(Yay!) and I was looking at HPI's site and then the Spider mod and the savage 25 has 6 differential gears. Is the Spider mod for the new Savages or is it just for the old .21?

P.S. I think the 21 had only 4 diff gears, right?
 
the norm for the savage ss & the new rtr .25's are 4 gear diffs

the older savage's had 2 gear diff's ...if your truck has the 2 gear diff's you should get the 4 gear upgrades ...unless you are useing a low power engine like the stock hpi .21
 
lol this is a funny subject. I upgraded my savage to the spider mod. Now I replaced everything, from the cup to all of the gears and even the pinion and that bigger gear.( I also installed these just before I broke a new motor in) My front diff was fine no problem at all. But my rear was a mess. I dont know what was wrong with it but everytime I would run my savage the rear would just blow out the gears (inside) would chip. I replaced it everytime with a new case and new gears. After the 4th time it happen I went back to the old style(2 gears) and I havnt had a problem since. Also after I installed the new diffs everytime I took it easy for about 1.5 tanks
 
ohh there ARE after market diffs for sale with up to 8 gears if i remember right (might just be 6) ....but the norm & all you should really need are the 4 gear diffs

imo
 
the rtr's used to ...from what i read the rtr's are now shipping with the 4 gear diff i belive
 
Some of them have two installed, but are supposed to come with them in the box for you to install, along with the cam type servo saver.

They should (now) be installed from the factory.

The four spider diff mod is supposed to make your differentials less prone to stripping out under massive power/hard braking. They really noticed this with the savage ss (.25 engine) that the increased power had an adverse effect on the differentials (particularly the rear) and the brakes on the front.

In the original design, the spider gears inside the differential were the weakest point in them, so with an upgrade at that point collectively makes the differential stronger when installed correctly.
 
Clarification... The original had 4 gears total inside the diff cup. 2 that went to the outdrives (wheel axles) and two spider gears on a shaft. So, technically, they are a 4 gear diff.
The new diffs have 6 gears inside the cup. 2 that go to the outdrives and two sets of spider gears (4 spider gears) on two shafts that cross each other in the middle. There is a notch in the shaft so they interlock.

I've had longer lasting diffs when I run the 4 spider/6 gear diff setup ass oposed to the 2 spider/4 gear setup.

Keep in mind, there are diffs that have 6 and 8 spider gears inside + 2 gears that go to the out drives. None of which are made by HPI.
 
i bought my savage 25 NIB from my lhs a couple months ago. They come with the cam style servo saver and 2 extra bevel gears per differential. The cam servo savaer and 4 bevel gear mod, arent installed though. You have to do it yourself.
 

RC Builds

Back
Top