Schumacher Mi4
#2941
Tech Master

I have seen it said that if you use the plastic insert provided, but not the alloy ring / sleeve that it's ok. Otherwise, the slot is far too big.
#2943


#2944

I can confirm that the Spec-R diff with inserts but no rings "works" on an Mi4LP. Double check to make sure the blades aren't bottoming out. I can't vouch for long-term functionality, as I only ran a few race events with a car like that before I upgraded it to CX axles. I also can't vouch for the 3/3.5, since I've never run those cars.
As for the front... The gear diff will work in the front of the LP. The pulley is more offset than the spool, though, so the belt gets a bit of angle to it. It does seem to clear the top-deck OK, though (barely). The gear diff actually has even more pulley offset than the stock ball diff, too, so you get a bit of angle in the belt to the rear as well.
I did notice that for some reason when I set the front gear diff to the low position, it was binding on something really badly. I didn't figure out why, though, and just put it back to high, since that's where I normally run my diffs.
EDIT: You can also get this gear diff http://www.spec-r.com/default/index....roducts_id=209 if you don't need the slider inserts and rings. It'll save a few bucks over the Schumacher part #.
-Mike
As for the front... The gear diff will work in the front of the LP. The pulley is more offset than the spool, though, so the belt gets a bit of angle to it. It does seem to clear the top-deck OK, though (barely). The gear diff actually has even more pulley offset than the stock ball diff, too, so you get a bit of angle in the belt to the rear as well.
I did notice that for some reason when I set the front gear diff to the low position, it was binding on something really badly. I didn't figure out why, though, and just put it back to high, since that's where I normally run my diffs.
EDIT: You can also get this gear diff http://www.spec-r.com/default/index....roducts_id=209 if you don't need the slider inserts and rings. It'll save a few bucks over the Schumacher part #.
-Mike
#2945


as stated, Schumacher lists the spec R gear diff on their web site and it is for the Mi4CX I know I have two of them, or should I say, I just sold my CX with two of them.
btw, its not a front gear diff, just a gear diff, it fits both ends of the car
#2946

I can confirm that the Spec-R diff with inserts but no rings "works" on an Mi4LP. Double check to make sure the blades aren't bottoming out. I can't vouch for long-term functionality, as I only ran a few race events with a car like that before I upgraded it to CX axles. I also can't vouch for the 3/3.5, since I've never run those cars.
-Mike
-Mike
#2949

I never ran the gear diff on carpet.
I would build diffs with 2000 in the rear and probably around 500,000 and just play with it, keep good notes, the car may suck the first heat, but be good the second and awesome in the main, keep track of that, then change the diff lube and keep track of that, may be you have to have 2 or 3 diffs, one for each round.
#2950
Tech Fanatic
iTrader: (3)

just asking a question SkyPilot. "Those guys" have had their kits about a week and a half so maybe they had heard about the diff not fitting perfectly in the LP and thought it was a fitment issue with the CX by mistake. I made reference to a "front gear diff" because I thought the SpecR was designed as a "rear gear diff". Anyways
Might have to go gear diffs front and back. Less diff maintenance would be a plus.
Might have to go gear diffs front and back. Less diff maintenance would be a plus.
Last edited by BrodieMan; 08-30-2011 at 01:29 AM.
#2951

I would not run the gear diff in the front as when i trial fitted one in my car it makes the belt sit at a funny angle which i would assume cause's all sorts of problems the more power you have. The car is known for chewing belts in modified as it is anyway. Also the bottoming out in the low diff positions is a pain in the ass if you do not run on any high levels of grip as you need the low diff positions to get good traction.
#2952
Tech Regular

I use gear diff in front and rear at My mi4cx,
500.000 in front and sch 70 in rear works very Well
500.000 in front and sch 70 in rear works very Well
#2953

just asking a question SkyPilot. "Those guys" have had their kits about a week and a half so maybe they had heard about the diff not fitting perfectly in the LP and thought it was a fitment issue with the CX by mistake. I made reference to a "front gear diff" because I thought the SpecR was designed as a "rear gear diff". Anyways
Might have to go gear diffs front and back. Less diff maintenance would be a plus.
Might have to go gear diffs front and back. Less diff maintenance would be a plus.
#2954
Tech Fanatic
iTrader: (3)

cool, I took it too literally I suppose.
On the topic of diffs, I was watching the vid of Chris Grainger building an LP ball diff. He uses loads of diff grease but I'm sure he knows what he's doing
I take it Schumacher ball diffs hold their setting much better than others, for example my JRX-S Type R. I'm always checking my diffs, readjusting, rebuilding. Mi4 diffs seem to be, tighten, back off 270* & race. Looks like you have to take the Mi4 diff out to adjust it our can you adjust it on the fly like my Losi? Can't wait to start this build, two more days.
HPI Pro 4 springs. Are these the springs that loads of people are using when they mention HPI Silver etc. I come across HPI spring references all the time so I'm assuming they are good. After JRX-S Type R springs I think I'll go with Schumacher springs that are quickly identifiable being entirely painted different colours LOL
On the topic of diffs, I was watching the vid of Chris Grainger building an LP ball diff. He uses loads of diff grease but I'm sure he knows what he's doing

I take it Schumacher ball diffs hold their setting much better than others, for example my JRX-S Type R. I'm always checking my diffs, readjusting, rebuilding. Mi4 diffs seem to be, tighten, back off 270* & race. Looks like you have to take the Mi4 diff out to adjust it our can you adjust it on the fly like my Losi? Can't wait to start this build, two more days.
HPI Pro 4 springs. Are these the springs that loads of people are using when they mention HPI Silver etc. I come across HPI spring references all the time so I'm assuming they are good. After JRX-S Type R springs I think I'll go with Schumacher springs that are quickly identifiable being entirely painted different colours LOL
Last edited by BrodieMan; 08-31-2011 at 03:38 AM. Reason: multiple spelling Fails
#2955

Ive found that minimal grease works better than slathering it in there like in the Grainger Video. Here is a link to a good rebuild article when the Mi3.5 was out. Diff is pretty much the same these days anyway's. I was getting around 30 runs before rebuild in boosted stock doing it this way.
http://www.actionrc.com.au/downloads...ateMi3Diff.pdf
As for the Springs the pro 4 springs are the ones everyone uses. I have found Xray springs much better with either 2.8 all round or 2.8f/2.6r an awesome combo and on my home track kit springs are also faster than the Hpi's. I have found the HPI's to be a waste of my money...
http://www.actionrc.com.au/downloads...ateMi3Diff.pdf
As for the Springs the pro 4 springs are the ones everyone uses. I have found Xray springs much better with either 2.8 all round or 2.8f/2.6r an awesome combo and on my home track kit springs are also faster than the Hpi's. I have found the HPI's to be a waste of my money...