Buying new diffs?

[paulyoung356]

i have an savage xl and the front and rear are both 43 teeth go to find them on the internet but theirs only 29 teeth diff and what would it do to the speed of the truck in top speed acceleration wise. thx if any one can help.

 

[Jam Racing 1]

both diffs should be the same gearing so do both ends if switching to 29 tooth diff gears and be aware you must also buy the 9 tooth pinions to go with them

43 divided by 13 is 3.30, 29 divided by 9 is 3.22 so by that you would be running the diffs at different speeds if you were to only do one end....

 

[Jam Racing 1]

http://www.ebay.com/itm/HPI-Savage-...-JOINTS-KIT-/381435221135?hash=item58cf4f948f

http://www.ebay.com/sch/i.html?_fro...TRS0&_nkw=hpi+savage+differential&_sacat=2562

scroll down the second link and there are a few diffs you can use that are right for your truck eg: 43/13

 

[rikkidy]

What makes a diff bullet-proof? The gears or the case or both?

 

[Jam Racing 1]

Supposedly the gears, but I am sure my pistol would make the term "bulletproof" invalid.....

 

[rcnut14]

Hmmmmm, i have an idea for new target...

 

[olds97_lss]

What makes a diff bullet-proof? The gears or the case or both?

Both really. The alloy cup, the machined large toothed gears (vs cast or compressed metal and smaller teeth) and the diff case itself all make the "bulletproof" diffs really strong.

I've had many savage's over the years and diffs were always a sore spot. With the originals, you had to take a lot of the truck apart to get a diff out and they had compressed metal ring gears with only 2 compressed metal spider gears in the cup. The cup was also plastic. Then HPI came out with a machined ring gear and started using 4 spider gears vs 2. Then at some point, they made the BP diffs with larger toothed machined ring/pinion gears, 4 spider gears and alloy cups. On my pre-X savages, I bought alloy diff cases as well and shimmed them very closely while using the machined small tooth gears. Was the only way to get a diff that would last you very long with a strong engine.

Now in my current savage X, I'm using the BP diffs and stock diff cases and haven't had an issue in many gallons of LRP28S3 running.