What's a Good Replacement Rear Diff for the E-Maxx? - Page 2 - RC-Monster Forums

TexasSP · 05.18.2009, 09:22 AM

Of course my 3905/E-Revo diffs have held up to 6s abuse quite well. If your cheap just try that first. I had issues previously with 3.3 diffs but these others in my maxx and e-revo have been great. If I start to have problems I will just go straight to the LST2 diffs and skip the others.

rawfuls · 05.18.2009, 10:18 AM

Hmm, I originally went the 3.3/3905 diffs, and I believe that is the one that is busted.

I guess if I adjust the slipper more, would it be more "gentle" on the diff? Or am I on the wrong track?

lincpimp · 05.18.2009, 10:33 AM

Do you mean new 3.3tmaxx, or old 3.3 tmaxx? The old 3.3 diffs are not as good as the 3905 diffs.

suicideneil · 05.18.2009, 02:52 PM

Slackening the slipper off would make life easier on the diffs, but, too loose and the slipper will melt...

Overdriven · 04:17 PM

Did you shim the diffs at all? Are all the bearings good, espeically the ones that support the ring gear/diff itself? I've put 3906/old 3.3-2.5 diffs through he'll with no problems when they are shimmed, even with plastic 3.3 cases. You only have to shim the pinion, but the driveshaft or cup must be attached. Why, any cup or shaft that uses the stock style drive pin helps determine the pinion depth, even some with grub screws do as well if they line up with the hole in the pinion. You can pm me for further explanation or if you'd like the hardly used pair of Integy cases with perfectly shimmed 3.3 gears/bearings I have no use for

I know what everyone says about integy, but I have no complaints with these cases.

rawfuls · 05.18.2009, 07:18 PM

Hmm, I guess it's time to use those shims then..

PM Sent Overdriven.

So on eBay, what should I be looking for, just regular 3.3 diffs?

Overdriven · 05.18.2009, 07:38 PM

If you're going the eBay route look for 3905 emaxx or 4908 tmaxx diffs. These models are said to be stronger, and are also sealed units like the revo. All 3.3 models have the 4 screw plastic diff cases so you can't tell that way. Best is to ask what model they were pulled from if they don't list the model number. Btw a pm will be there in a few minutes.

rawfuls · 05.18.2009, 07:39 PM

Not the 4909?

Great, waiting for the reply.

Overdriven · 05.18.2009, 08:47 PM

Quote:

Originally Posted by rawfuls

Not the 4909?

Nope, not the 4909. The 4909 got the Revo driveshafts and sealed pivot balls, and 4 screw diff cases, but not the Revo style sealed diffs.

The ones you want are the 4908 (and 3905 E-maxx) which have the Revo style Sealed diffs, which are in different housings due to the different size bearings used.

rawfuls · 05.20.2009, 12:47 AM

What about a rear spool?
So it should be a solid axle, right? Or am I thinking of something else...
Either way, is this a good or bad idea?

I don't race, just into bashing really.

TexasSP · 05.20.2009, 09:53 AM

The problem with spools is that for anything but off road it will give you issues. It is much harder on your drive train and drastically reduces turning radius. I have run with a spool and also used to use a positrac setup and much prefer tuning the diff action with diff oil. The other thing you may not realize is that with a spool you only get rid of the spider gears but still retain the ring and pinion. No way around that really.

rawfuls · 06.09.2009, 07:59 PM

To revive an old thread...
Would this work guys?
Revo 3.3 Spec diffs = the same thing as this link?
http://cgi.ebay.com/NEW-TRAXXAS-TMAX...lenotsupported

Gee · 06.09.2009, 08:31 PM

Quote:

Originally Posted by rawfuls

To revive an old thread...
Would this work guys?
Revo 3.3 Spec diffs = the same thing as this link?
http://cgi.ebay.com/NEW-TRAXXAS-TMAX...lenotsupported

No not necessarly. We were upgrading to Revo 3.3 specs before traxxas came out with the improved 3905 diffs. Take a look at these couple of links. The difference between the old ones and these are the metal pieces beef the differential up and make it more solid.

THis is the cup which is also has a seal, the metal side plates and takes a 2.5mm screw instead of a 2mm. The 3.3 specs don't
http://www3.towerhobbies.com/cgi-bin...?&I=LXTKN0&P=7

In this link the addition that the older diff don't have is on the left with the three holes in it. The diff Carrier Support I guess is what it is called.
http://www3.towerhobbies.com/cgi-bin...FVSEARCH=5382x

This is the ring and pinion gear to go with the other items. It's from the revo but also used on the newer emaxx. Major different is the size of holes is for a 2.5mm screw instead of 2mm.

http://www3.towerhobbies.com/cgi-bin...?&I=LXNZW6&P=M

If you are buying a set off of ebay make sure the differentials are the ones that were removed from the 16.8v e-maxx 3905

Overdriven · 08:35 PM

THe 4908 T-Maxx and 3905 E-Maxx have the revo spec diffs and should be the strongest. Its very hard to tell the difference from the outside of the case and the seller doesn't list the model # of the donor truck. However the seller's other items are all from a 4908 T-Maxx, but I'd ask him if they are or not to make sure. Don't assume anything

Gee · 08:41 PM

Here a set of aluminum cups already setup. Doubt they have the improved internal gears of the 3905 but they are an considerable improvement over stock. I ran a similar setup in my FLM maxx without any issues for some time.

http://cgi.ebay.com/ws/eBayISAPI.dll...m=120429907461

I'd guess the final price might end up close to be double of what the current bid is right now.

Is the 4908 T-maxx the improved on they put out after the 16.8 e-maxx? Makes sense they use the same beefed up diffs.