dragonbat13

It seems as though when I bought my XL in 2011, the BP diff ring and pinion that is in it was considered machined steel. Now HPI lists the BP 29/9 as sinistered steel. Thats the same thing as the super heavy duty ring and pinion, the ones with the smaller teeth. I think it was something like 43/13 on the super heavy duty. Same ratio, just different size teeth.

Anyway, did they change the materials on the BP 29/9 diffs?

It also seems that the BP diffs came down in average price on ebay. It used to be that a BP diff with cup in the bulkhead was almost 50 dollars. Now you can get them for about 35.

What is going on with these diff sets?

sparky 25

The machined steel bulletproof diffs are still available to buy and come stock on the savage flux trucks,

Machineing steel is costly compared to pouring powder into a mould and heating it to fuse together (sintered)

The sintered steel bulletproof diffs are what comes stock on the nitro savage x and savage xl,

These are still much stronger than the original small toothed Diffs that used to come on the savages,

But the machined steel Diffs are not nesessary for the nitro vehicles and using sintered is also cheaper to produce.

llkoolskillet

Now IDK if the newest versions of the XL have sintered or not but since 09 the XL has had machined steel BP diffs.