Upgrade Mega/BLS plastic transmission to BLX metal

[Ekfchan]

Here's an update...
.

I took the entire differential and transmission apart and actually everything seem to be ok. However when I put it back together, and tried to tighten the slipper nut, I noticed that it popped back up when I really tightened down the spring. I think that the threads on the nut are worn. Looking at some Traxxas forums this seems to be a common situation. Perhaps that is the reason why it was slipping.

On a bigger note, when I put it back together, this spur with spin but the wheels would not move at all. Checking the differential when I turn a wheel one way the other wheel turns in the opposite direction and all the gears on the transmission are meshed correctly. So I have no idea at this point. Maybe a pin is loose somewhere or I forgot a pin?

 

[LunchBox]

The opposite spin in the wheels when u turn is correct, that's the diff working. I have never had the nut or shaft strip out on the slipper clutch. If this is the case if don't get any tension on the slipper clutch your wheels will not spin.

 

[Ekfchan]

I am almost sure it is a broken pin in this gear...

The transmission gears spin freely when turning the spur shaft by hand if half the case is off. Once some tension is added by putting on the top half of the case it is much harder to turn the shaft and the shaft will turn without the attached gear, since the gear is attached to the shaft by a pin if the cross pin was not broken they should not be able to move independently.
. But... I can't seem to get to the pin. How do I remove the gear?

 

[ajdragon]

Hi

You should be able to pull the gear right off the end of the shaft.

 

[Ekfchan]

Pulling - and pulling - STUCK. Trying to pry off but worried about the plastic

 

[LunchBox]

U have to pull the bearing and the e clip off to pull the gear off

 

[Ekfchan]

U have to pull the bearing and the e clip off to pull the gear off

Hi Lunchbox

I was thinking that but below the bearing, you can see it in the pic, there is a ring that seems to be attached to the shaft. There is no such ring in the manual or exploded diagram.

 

[LunchBox]

I belive that is a spacer that should just slide off. My old mega diff is out in the work space I'll take a look but I wouldn't be till late 2moro evening

 

[mrbelloso]

Here is the exploded view:

 

[ajdragon]

Hi

Use a flat head screw driver and a hammer to tap the gear off the end of the shaft. The pin is more then likely sheered off and is holding the gear in place, so stand the shaft up on the big end and then put the flat edge of the screw driver against the side of the gear and start tapping until it comes off.

 

[Ekfchan]

Thank you everyone - before reading the last replies I had dropped it of at the LHS. They confirmed that it is most likely a broken pin. Will confirm and update when I receive it back...

 

[Ekfchan]

Thank you everyone - before reading the last replies I had dropped it of at the LHS. They confirmed that it is most likely a broken pin. Will confirm and update when I receive it back...

Got it back. Part 310597, which is the transmission great on the slipper shaft had melted on the inside where the pin sits. LHS said I should gear down... Am on 3500 vxl brushless with stock gearing. They said gearing down would help, like switching to 38p 54/13.

However, getting home, checking things out, it seems like the Diff is too loose? For example, when I turn one wheel slowly the other moves smoothly in the opposite direction like it should. But when I spin one wheel quickly, there is a sound inside and both wheels move in the same direction.

See video

Is that normal?

 

[LunchBox]

Got it back. Part 310597, which is the transmission great on the slipper shaft had melted on the inside where the pin sits. LHS said I should gear down... Am on 3500 vxl brushless with stock gearing. They said gearing down would help, like switching to 38p 54/13.

However, getting home, checking things out, it seems like the Diff is too loose? For example, when I turn one wheel slowly the other moves smoothly in the opposite direction like it should. But when I spin one wheel quickly, there is a sound inside and both wheels move in the same direction.

See video

Is that normal?

I run a traxxas velineon vxl on one of mine with 57/13 and my son loves it! I rebuilt the diff with I thin 50,000 diff oil and my wheels spin in the same direction when spinning by hand slowly! I thin the diff oil Arrma uses is a little to thin and needs to be thicker!

It's a full on wheelie machine now!

 

[Ekfchan]

I run a traxxas velineon vxl on one of mine with 57/13 and my son loves it! I rebuilt the diff with I thin 50,000 diff oil and my wheels spin in the same direction when spinning by hand slowly! I thin the diff oil Arrma uses is a little to thin and needs to be thicker!

It's a full on wheelie machine now!

Hi Lunchbox,

So would that mean my Diff action in the above is normal? Spinning quickly they move in the same direction. Slowly it does what it is supposed to and go in opposition.

 

[LunchBox]

I may be wrong cause I'm am sort of a newbie still..... But seem right to me!

 

[justatree]

I may be wrong cause I'm am sort of a newbie still..... But seem right to me!

Hmmm.... mine did that when it was new but now it is weak... I spin it fast on one side and the other side hardly moves... do I need to put new diff oil in my diff?

 

[Walter]

Open it up and find out. If you've never been in there it is probably only partially filled with grease and would benefit from some new diff oil.

 

[justatree]

Open it up and find out. If you've never been in there it is probably only partially filled with grease and would benefit from some new diff oil.

Right, I don't even know where it is hiding in lol will need the manual I guess... and some diff oil ofcourse

 

[Walter]

Hi Lunchbox,

So would that mean my Diff action in the above is normal? Spinning quickly they move in the same direction. Slowly it does what it is supposed to and go in opposition.

Probably normal. In the video it sounds like your spur and pinion are what is making the noise. Take off the spur cover and do it again. Try holding the spur gear in place when you do it. Then open the diff and check it out... as with justatree above it will probably benefit from some oil.

 

[LunchBox]

The most def! Open it up cause they barley put anything in it stock! If u have been running hard them it use a rebuild! The diff is hiding in the gear box and it isnt really as hard as u think it would be! You can also find in this thread somewhere how to take the gear box out of the truck! @justatree