Senton Diff and diff cover dramas

[linkupipm]

Hi All

I've read a lot of this forum but only just joined.

Own a Senton - ran it close to 20 times, mostly stock - 4 cell only.

I have had a number of parts replaced on warranty by Tower, most recently one of these:

http://www3.towerhobbies.com/cgi-bin/WTI0001P?I=LXECNS&P=8#technotes

I got this as I managed to lose a tooth on the rear diff pinion, which killed the rear diff crown gear as well.

I've build the diff perfectly as far as I can tell, but I just can't make it fit?!?!?! It slots into the diff case OK, then I pop on the over and as soon as the cover is tight, the diff won't spin.

I've tried it in the front and rear diff housing, one with a new diff pinion and the other with a slightly worn one, and tried both the front and rear diff covers at both ends - all combinations yield the same result -

- when the diff cover is tight, the diff stops spinning.

The crown gear is noticeably taller (ie, has longer teeth) than my other stock F/R diff, but it's brand new so I'd assume it should be?

Have Tower sent me the wrong diff - it's marked as a Typhon replacement... are those parts compatible?

I'm at a loss as to what I'm doing wrong... any help would be greatly appreciated!!!!

 

[TwiZted SkullZ]

Typhon and Senton use the same diffs.
Sounds like the diff bearings might not be seating in the diff housing correctly causing it to bind up
when you tighten the housing screws.
Another thing,did you put the diff in backwards?

 

[linkupipm]

The bearings are definitely not seating right - you are correct there. I've tried it in the front and rear diff housing, so it's the diff, not the housing.

Not in backwards I can assure you of that! In fact the diff still won't house correctly with the whole housing removed from the chassis.

I believe my issue is that I've been accidentally sent a kraton crown gear instead of the senton one. Everything else is identical to my existing diff, but the crown gear itself has longer teeth.

Does anyone know how 'tall' the teeth are for the senton crown vs kraton crown gear (that is, the height of the teeth) so I can measure and confirm I have the wrong crown?

My parts were labelled as senton parts - have checked numbers - but that crown is just way too juicy to fit the diff case with the senton's 13 tooth input gear...

I'm considering getting some slimmer bearings for the diff - 8x16x4 (rather than 8x16x5) and running with the kraton crown - at least until I can get the correct senton one - the big kraton crown seems identical to the senton one, just longer teeth!

Has anyone done this or an I heading into new territory here?

 

[TwiZted SkullZ]

Here's the Kraton crown gear,does it look like this?
It does look a little different/wider than a Senton....both have 43t.
http://www.arrma-rc.com/part/AR310497

 

[linkupipm]

I believe I have one of each - my Senton came with 2, and I was posted parts (under warranty) to replace one that died.

It was marked as a AR310441 (senton crown) but I think it must be a AR310479 (kraton crown) as it simply won't fit the diff housing with the 13t senton input gear.

Comparing senton gear to (suspected) kraton gear, they are a very close match. Both fit the same diff housing (AR310427) so one can't be much bigger than the other. They connect to the same diff unit, and they are the exact same diameter. The kraton one just appears to have longer teeth...

I wonder if anyone out there could measure the height of a AR310441 vs AR310479 so I could confirm I have the wrong part?