Modifying a HB 1/8 diff to use 3.3 sliders - RC-Monster Forums

suicideneil · 06:16 PM

This is one of those things that occasionally gets discussed but not in any kind of detail, so I thought it would be nice if we could thrash out a 'how to' for future reference.

So far as I understand, you just need to remove the output shafts that have the cups built into them (?), and replace them with the 3.3 stub axles (with the threaded portion cut-off). The only thing Im not 100% clear on is how the larger spider gears then attach to the new out put shafts- is there a set-screw or pin of some kind that threads into the spider gear and hold the shaft in place? A picture would be great to illustrate, though I appreciate it does mean ripping apart a diff to get one (or two).

My reasoning for all of this is that I have noticed UE 6 spider diff cases are only $69.99 for two (?)- which is meant for using maxx diffs but ignore that bit, its the cases that are important here. If you then buy the HB 1/8 diffs that come with the needed bearings and pinions, all you have to do is combine the UE case & the HB diff to get the ultamite 'drop-in' diff upgrade for your E-maxx. Price wise it would work out at about $190 for a total truck, which is cheaper than a new UE 6 spider set, and cheaper than the FLM hybrid route too (buy about $10-15). I like this UE & HB diff idea since it means I wouldnt have to sell my existing FLM bulks in order to upgrade the diffs.

Any thoughts, tips & info on doing the shaft mod is most welcome.

EDIT:

These are the modified output shafts for the HB diff that Mike sells for the revo diff upgrade- I assume he might sell them seperately if I/someone asked nicely?....

lincpimp · 10.06.2007, 06:57 PM

According to the pic you posted, if those are modified 3.3 axles, then the threaded portion is cut off, then the groove is milled into the center, and then a hole is drilled at the other end(that goes into the diff). The diff out put gear is held on by a cross pin that slides thru the newly drilled hoe and the output gear has a slot milled in the backside that the pin engages onto. This is just the same as stock HB, so the pin and output gear are un-modified. It could be done by hand, however the hole would have to be drilled prescisely thru the center of the axle. Not sure if you really need the groove, but I think it has something to do with the o-ring that seals the fluid in the diff.

ClodMaxx · 10.06.2007, 07:02 PM

Quote:

Originally Posted by lincpimp

newly drilled hoe

must.....resist.....commenting.........

lincpimp · 10.06.2007, 07:06 PM

Quote:

Originally Posted by ClodMaxx

must.....resist.....commenting.........

Sorry meant to say "freshly drilled hoe"

Glad to see that people are reading my posts!

Serum · 10.06.2007, 07:22 PM

http://www.rc-monster.com/forum/show...ht=revo+slider

All you need to do now is shoot mike an email and ask him for 4 output shafts for 3.3 sliders for 1/8th diffs. He's got a bunch of them laying around.

mkrusedc · 10.06.2007, 07:24 PM

Quote:

Originally Posted by lincpimp

Sorry meant to say "freshly drilled hoe"

Glad to see that people are reading my posts!

You guys make my day...

Serum · 10.06.2007, 07:33 PM

Boy... I must have missed that part.

It all adds:

your kermit in heat avatar.. A fresh drilled hoe..

One pervert typo for sure..

suicideneil · 10.06.2007, 07:36 PM

Hole man, its hole, not hoe! Im a bad influence around here. Anyway, thankyou Serum for that info- I knew I read/saw that thread a long time ago but couldnt find it for the life of me. In any event, I shall try and find some UE diff cases, then order the diffs & shafts from Mike; the 2nd part is easy, the 1st part isnt given UE wont sell to people outside the USA..... **grumble grumble**

ClodMaxx · 10.06.2007, 07:41 PM

Quote:

Originally Posted by Serum

Boy... I must have missed that part.

and here i thought you were trying to be the bigger man by ignoring it. glad to see i was wrong...

neil, i'll shoot you a PM.

suicideneil · 10.06.2007, 08:11 PM

Ow, you got me. PM replied- I love this forum so much, everyone is so helpful!

squeeforever · 10.07.2007, 03:23 PM

Neil, why not just get some FLM bulkless? Probably about the same price as a used set of UE cases.

suicideneil · 10.07.2007, 04:42 PM

After I did my sums (again) I discovered the FLM bulkless route would have been cheaper, but not by that much so....
Im lazy is the trouble- I already have FLM bulkheads which I like alot, and I didnt really feel like selling them & buying whole new bulkheads & diff combo. Daft I know, but thats just me :P

crazyjr · 10.07.2007, 06:39 PM

My HB diffs for revo conversion had the threads already cut, all i had to do was install. On Ue diffs (Emaxx) i cut the threads off and put the pin through the hole on the thread side, install in diff then drop the gear on shaft and line pin to slot, then finish assembly. its really easy

suicideneil · 10.08.2007, 11:54 AM

Cool, does sound nice & simple. I emailed Mike and he said I could buy the needed output shafts for $5 each, so $20 to do two whole diffs, which is ideal for people who run 3.3 sliders/ cvds etc. I also bought some diff fluid - 7k for the front & 5k for the rear to get me started with-, some of the 10x12x0.2mm shims to adjust the pinion depth if necessary, and some cups for the centre dogbones that mount onto the pinion output shaft; the stockers are 6mm, but the HB uses an 8mm pinion shaft so I have that covered. Just have to wait a few weeks and hopefully I will have everything I need to bulletproof the drivetrain completely & enable future upgrades of the BL motor & esc setup.

suicideneil · **It is done... -** 10.25.2007, 08:55 PM

First off, a big thanks to Mike for the diffs and modified output shafts, they really are nifty little items. And a big big thanks to ClodMaxx for all his help with getting me the UE ultralite cases- life saver dude.

Thats a nice lot of parts.

Stunning quality; I was going to polish them, but there really isnt much need to be honest.

One HB 1/8 diff.

Remove 4 screws holding the ring gear onto the cup.

Remove spider gear from shaft, slide out pin & remove shaft. Replace pin into modified shaft.

Insert shaft into ring gear, O-ring seal holds it into place which is handy.

Replace spider gear onto shaft.

Remove grubscrew from diff cup, this allows you to slide out the pin & withdraw the output shaft.

As before, insert pin into new output shaft, drop it into position, and replace spider gear. Replace remaining spider gears, fill cup with diff fluid, and screw ring gear back into place.

I found that two 8x10 shims was perfect for setting the pinion depth.