LRM transmission 'options'?

[Bormac]

I'm rebuilding a couple of LRM transmissions and wanted to ask what mods are available to make them a little more reliable?
I have heard there is a better centre ball diff arrangement but have little info on it.

Can anyone recommend the parts requires to install a slipper also?

Thanks- Jason

[Charlie don't surf]

Standard hydra top-shaft fits a B4.whatever slipper if I'm not crazy-

[Bormac]

Thanks Reg.
What about a hardened ball diff centre gear? It seems the top input gear chews the standard gear to peices.
I am sure Ive heard of a diff that sports extra bearings or something....

[LosiXXkid]

This is the Thorp centre gear with bearing....

http://www.ebay.co.uk/itm/Team-Losi-JR2-JRXT-JRT-PRO-Aluminum-Diff-Gear-With-Bearing-Thorp-Dirt-Burners-/380691921705?pt=Radio_Control_Parts_Accessories&hash=item58a301bb29

You can also opt for the the aluminium diff halves like these...

http://www.ebay.co.uk/itm/Team-Losi-JR2-JRXT-JRT-PRO-Aluminum-Diff-Gear-Set-By-Thorp-Dirt-Burners-/360632348031?pt=Radio_Control_Parts_Accessories&hash=item53f75ced7f

You can also get Thorp LRM outdrives which are made from machined Delrin but I can't find a link for them.......errr...yes I can!

http://www.ebay.ca/itm/Vintage-THORP-Dirt-Burners-Losi-JRx2-JRxT-Junior-2-T-Delrin-Output-48P-Gears-NEW-/191024405956?pt=LH_DefaultDomain_0&hash=item2c79f11dc4&_uhb=1

[LosiXXkid]

I'm rebuilding a couple of LRM transmissions and wanted to ask what mods are available to make them a little more reliable?
I have heard there is a better centre ball diff arrangement but have little info on it.

Can anyone recommend the parts requires to install a slipper also?

Thanks- Jason

You can fit the Losi A-3120 slipper shaft that will allow you to run the Hydra-Drive or dual disk slipper. My comments in this thread should help also....

http://www.rc10talk.com/viewtopic.php?f=27&t=33592

[Bormac]

Great advice. Thank you.

[highwayracer]

Hello Jason,

The only upgrades that I've used are an A&L slipper, ball bearing diff and an A-main top gear. The reason the top gear eats the diff gear is because over time, the gearbox begins to wear out where the bearing sits near the spur. When gear mesh is adjusted on the pinion, it pushes the top shaft further up...which increases gap between the other gears.

Racing back in the day is different than it is now. Back then, I rebuilt/replaced everything because parts were available and I was able to get everything at a high discount (50% off). Since these parts aren't that easy to get, that may not be possible today (especially for you guys that actually run your cars ) . What you can do is modify the trans slightly by using a flanged bearing inside the motor plate. By doing this, there are now 3 bearings supporting the top shaft. The motor plate will not wear...keeping the top shaft in the correct location.

Hope this helps.

Regards,
Roger

[Bormac]

Wow Roger, I would never have thought of the 3rd bearing to slip in to the motor plate, great idea.
What size flanged bearing do I need? I want to give that a go along with the bearinged diff and a slipper also.
Thank you- Jason

[hondaman]

Roger that's a great idea.. I used an old tamiya bearing (frog small bearing) for a spacer for my b4 slipper to stop the binding and that works great but it doesn't support the shaft.. the flanged bearing would solve this.. looks like time to take some measurements..

Shawn