center diff

[metal finisher]

what is the best way to lock the center diff? i know you can use silly putty but is that gritty like ware the gears faster or should i just jb weld it?

[Freeprawn]

I used glue.

It's a bit over the top though really as the diff is basically junk after.

One guy filled it with rags which seems a good idea.

I think I'm gonna try silly putty (blutack) next time though.

Has ayone tried anything better?

Nige

[Clubin]

I am going to JB mine.

[mynameismud76]

Sorry buddy, what is JB?

[VancouverHobbies]

2 part epoxy

[mooman007uk]

I got some blutack like stuff couple of days ago and also some plasticine I found at a craft store...will try the tack first as it seems stiffer

[Freeprawn]

I was thinking sand might work too lol.

Defo have to let us know if the blu tack thing works ;)

Nige

[metal finisher]

o.k thanks guys, hey moo what is blutack?

[mooman007uk]

it's the stuff that sticks up pictures /posters etc instead of using thumbtacks...like a putty...several different brands out there...i'll take a pic later and get the name of the stuff i'm using...

[mooman007uk]

so got my diff all done, still a slight bit of give, which is good but pretty much locked solid...enough for at least 2 diffs for 3 bucks...bargain...it cost me $20 for the 500K lube I had in it before

[Freeprawn]

Is that glue or like a non setting putty? Have you run it yet?

I NEED ANSWERS lol ;)

Nige

[mooman007uk]

it's exactly the same as blu-tack in the UK only white
haven't run it yet...was going to tonight til my th/br servo horn stripped...got it sorted so will run it tomorrow and see how it hooks up with no slip:punk:

[Pipeous]

I ran mine today with the factory locked dif (gears seized in the alloy case) and I like it. you lose brake bias but sure puts the power down. we ran on grass, high bite. when I got it onto the baseball diamond and did some donuts in the dirt was sweet all 4 wheels a tossing the rooster tails.

[Freeprawn]

Factory locked diff?? Do they do one?

I know a centre locked diff is ace, mine works fantastic, it's just cos I filled it with glue if anything breaks on it the whole thing is junk :o(

I'm hoping the blutac works, it'll be a right mess in there after it's been used but at worst we'll still be able to dig all the bits and bobs out of the goo :yahoo:

Nige

[mynameismud76]

Locking the centre diff, would this put more load onto the front..thereby taking some work off the rear diff?

Gone through 2 rear diff gears so far.. =(

[Freeprawn]

Umm, it might help a bit.

It's more about splitting the drive front and rear and ensuring both the axels always have drive rather than all the power going to the wheel with least grip though really.

When you drive a car with a locked centre diff the car feels like it pulls it's self out of corners more and cuts down on oversteer a bit.

I find with 4wd cars normally both the rear wheels usually have good grip, so I like to run quite an open (free) diff in the rear.

On the front, the inside wheel, when you go round a corner fast, usually looses grip and spins like mad. This is why locking the centre diff helps cos rather than loosing all the power to this spinning wheel you have the back wheels still pushing you along. Also this is why I like to run a very tight front diff to try to get power to the outside wheel.

Usually if your going through diff gears something is wrong, either you have worn bearings or something isn't shimmed right. To be honest the gears on the nutech are pretty good in my experiance. I have done a diff gear and input pinion, but this was because I have a bearing collapse and the mesh got screwed up.

Hope that helps,

Nige

[mooman007uk]

a locked centre will put more load on the rear...only reason i'm locking mine cos when my motor hits the power most of my power is going to the front as it has less weight on it...just boils the tires then and my truck doesn't hook up..i want both front and rear with equal power and no slip.

I've done several rear ring and pinions...there is a new plastic outer housing avaialble now that is thicker and has an extra bolt below the bearing...the first style cases allow side flex and this enables the pinion to push the diff sideways and ride over the teeth and bugger them....also once is does it once the inner pinion bearing hole in the case gets ovalled out making it easier for the new pinion to ride over the ring gear

i bought the cnc outer case...problem solved....the new plastic one should fix it too

[Pipeous]

my center dif seized up. the center gears on the pin don't spin anymore. so my dif is locked...

I had my buggy out like one day I did the vids on that wet old track. I decided not to run anymore until I got all the alloy cases as mine was a pre production model. glad I waited as the play in the case was huge on the outdrive area. I ordered front cvds and alloy dif cases right away. a strong drivetrain is essential. rear cvd's are next for me

[GLYNSAVAGE]

ive got a knackerd centre diff,may have to fill it with something and try this out :punk:

[mynameismud76]

Pipeous,

Took my front diff out..was leaky.

The same pin was stuck, didn't file the grooves before installation =(

After a little heat persuasion, it popped out =)

Fingers crossed, it's not leaky anymore..for a while anyways

[hugo]

Hi Guys,

I am new to big scale drivin and bought a TB II last week, had my first drive out in the mud today. Really impressed with it!

But indeed I need to do something about the centre diff. seems like I have front wheel drive now (ootb).

Also the steering is really bad with all the spinning of the front wheels.

For now gluing the center diff all together seems a bit harsh, other people suggested thick silicon oil (K1000).

If I do not want to block it what would be my best choice of oil?

tx

hugo

[Clubin]

Welcome, I am running 120 in my centre diff.

[mynameismud76]

Hi Hugo,

I'm running a 50-50 mix of 500k and 100k...about 250k in effect.

Welcome to the forum buddy =)

[Clubin]

Hi Hugo,

I'm running a 50-50 mix of 500k and 100k...about 250k in effect.

Welcome to the forum buddy =)
Krap 500k You'd need to cut that into cubes and jam them in. LOL

[mynameismud76]

Nah, just squeezed it between bum cheeks while I took the centre diff out and apart..just enough time to soften it up..only by a little LOLOLOLOLOL

[mooman007uk]

I still spun up the fronts with 500k...and now doing it with the tacky crap...guess I didn't stuff it in tight enough so not going to mess with it anymore gonna weld the spiders to the pin and lock it solid.

[Clubin]

I agree, the centre realy needs a spool.

[Freeprawn]

Bugger :(

Tacky cack don't work.
500k don't work.
Glue is too peminent.

How would you hold the gears in place when you weld them?

Silicone sealer is worth a pop maybe, but gonna be destructive like glue.

Wish someone would make a spool :(

Hmm could try cutting access holds in the case and putting 2 part epoxy directly on the gears, Might try this next.

Nige

[mooman007uk]

the tack should work if it's jammed in tight enough.
I'll weld the spiders to the shaft in place...or tack them in the diff then pull them out and finish the job...then i can always just pull the spiders and swap them over if i want slippage in the centre.

i don't like the idea of glue...when you come to replace the diff cups it could be a pain...gas jockey used rags stuffed in his and it works fine...this actually maybe the best way to go thinking about it...locks it solid and super easy to remove...think I'll try that first before i weld em

[Freeprawn]

Don't get me wrong I hate the glue idea. But I'm struggling to come up with ideas how to lock it solid.

The rag thing could be the way forward then!! That would defo be worth a try if he's had a good result with it.

[mooman007uk]

I'll be trying the rag method today.. hope it works good cos pulling my cage, motor and centre diff is getting a bit old now:no:

[Freeprawn]

At least you can still do stuff to your diff, mines just a solid lump of glue at the mo lol :damn:

[Pipeous]

I liked the 100k until mine seized up. we are also talking a buggy compared to an mt. thing is we all drive rc's different and setup is a personal choice. on a track I like having a center dif. setting brake bias really helps get around a tight corner as I tend to set more back brakes than front so the arse can slide around when brakes applied. straight line speed is such a small percentage of a track

[Minimax]

I was driving home this evening and I was thinking about the subject.

As we use alot of plaster (fireproof plaster to cast metal in), this could be something which is hard enough never to let go. On the other hand it is removable (with sandblasting or hard work picking bits out).

However, it will weigh a bit, and that will be a bad thing for braking... I see it as a big flywheel, with a big momentum....

if lubricating the side of the diff casing, it would be relatively easy to remove the poured plaster

[mooman007uk]

reason i want to lock mine is I just can't get the power from my motor down to the ground...the front spins up so the tires are dinner plate sized and the back goes nowhere...got all that hp and can't use it...i will miss the inabilty to bias my brakes...i had mine set same as pipe...more rear so i could slide the back into a corner and then just nail it...but then watch my front wheels let go...
i wish i'd just stuck rags in to start so i wouldn't be stripping it down again, gas jockey said it worked perfect so i deceided to try something else:damn: go figure??...sometimes i'm well lacking in the smarts dept

[VancouverHobbies]

Moo, it was a Smartech center diff I stuffed full of rags not the Nutech.

[mooman007uk]

it should work in the nuey just the same..maybe a bit harder to get it to bind up between the teeth...might require little strips...gonna try it today...

[mooman007uk]

ok I found a nice diff lock material...nylon string...i dug up some el cheapo, crap,builders line thats twisted and not braided ...stuffed a bunch in the diff and twisted it as i did so...bolted it together, turned it about 1/2 turn and it locked solid...had a test run in the driveway and I now have a spool...now i got some drive to the ass end when i nail it:punk:

here's the string i used

http://i729.photobucket.com/albums/ww294/mooman007uk/nutech%20parts/DSC01658.jpg

http://i729.photobucket.com/albums/ww294/mooman007uk/nutech%20parts/DSC01659.jpg

[Pipeous]

LOL Chris must be shaking his head at these home brew mods but hey man if it works, who cares?

[mooman007uk]

cost about 1 penny for a spool:omg:

see how it holds up but can only image more string getting drawn into the gears and keeping things locked up

[mynameismud76]

Came across this:

http://www.badhorsie.com/products/diff-lock-grease.html

Worth a shot?

[mooman007uk]

it's for trucks under 10lb...if blutack don't do it not much will..as they say 1001 uses for string now there's a 1002 LOL

[Pipeous]

ofna sells dif lock too. it's super thick. I tried it in an 8th scale and could barely turn the dif with allen wrenches in the outdrives to hang onto

[mooman007uk]

went out for 1/2 tank last night...string works real good...i prefer the centre locked up so next time i pull the diff i'll weld the spiders to the shaft to make it more permanent, finally getting some power to the ground off the line:punk:...i got gazillions of nuey diff gears so easy to swap back to regular diff if need be...fg diff stuff and rear cvd's also performed flawlessly...ready to go give some flyin lessons at gas jockey's tomorrow:band:

[VancouverHobbies]

I'm interested to see how it performs with the center diff locked, I like the way my other models behave with a spool. Anyone else local to the area is welcome to join us tomorrow, just give me a pm for directions :)

[Clubin]

I'm interested to see how it performs with the center diff locked, I like the way my other models behave with a spool. Anyone else local to the area is welcome to join us tomorrow, just give me a pm for directions :)
I'd love to come and bash with you guys, but it is just a little too far. Take some vid for us will ya? Post em on youtube?

[mradlin]

I might be making it out there in July. I'm just waiting to hear back from work.

[Pipeous]

I actually am liking the spool setup. it's more like all my electrics. most don't even have a center dif. wish I could come out but I am picking up the paint tomorrow so I can start the buildings here. for 3 weeks I'll be going like a madman. I took the day off from the dealership today to go buy a new paint gun for my sprayer and get my stuff ready... this is good money for me too. and the neighbours are supposed to paint the gutters down but I said I'd do the rest for beer. should have my garage full of 24's this month. I'll bring some ales along when I come over for a weekend and just sleep in my car LOL

[mooman007uk]

be good to get a bunch over...we had 4 yesterday which was good...3 most of the time cos my truck was not happy yesterday...mostly the rear diff/fg cups and cvds popping out....only nutech thing really to break was a rear hub, after more than 30 tanks on it with much hardship it was bound to happen sooner or later...also had electrical issues with a bad switch, an alloy ball end seize, servo horn strip, and my string in the centre diff didn't hold up so running open for most of the time ...it's either getting welded now or some of that steel putty that's similar to JB stuffing in it... when it was locked at first it was way better to drive, centre diffs are nice to save drivetrain stress but rubbish IMO for traction as all the power unloads up front , and you can't go hot into a corner, brake and swing the ass end round and power out anywhere near as tightly as you can with a centre spool

[mooman007uk]

so string was no good, turned into dust, tried steel epoxy putty similar to JB weld...didn't work either so i ended up welding the spider gears to the shaft (needs alot of heat to get the weld wire to melt into the hard gear and the pin that is of unknown ingredients:confused:)
took it for a spin and I now have a prpoer locked diff and i like it...my truck launches like a raped ape:yahoo:

[banners]

I am working on a diff lock. I've tried one way and it failed. If it works in it's mk2 guise it will be available to buy. Testing is underway :excited: it's had a tank so far and I deffo like it more that way.

If successful you get to keep the internal gears as spares :yahoo: :punk:

[mooman007uk]

a steel tube with an ID the same as the cup shafts with a pin notch at either end would be a super simple locker slide in locker, could even weld a ring over the notch so it wouldn't spread apart :good idea:..just came to me..must have had enough coffee to kick start the noggin

I way prefer the centre locked...actually getting all the power to the ground now:)

[banners]

I am nodding - the kiss principle is usually best imo although tube doesn't quite have the hardness to stop it distorting. 2 tanks and it had chewed through 90* of movement that way. I did try that way first. MK2 has a subtle change lol!

Pics hopefully for the weekend if successful. I'm stripping the ctr diff (again :) )after another tank or two.

[mynameismud76]

Cooooooolll..sub zero!!! :punk:

[banners]

well a bit of an update on my findings, this works fine, a few have been trialled and work fine but there is fear it maybe placing strain on the other 2 diffs when in the plastic housings - alloy may be fine

http://i491.photobucket.com/albums/rr280/banners-ng8/ftxpunisher/mods/25062010292.jpg

5 tanks or so and it came out as clean as it went in. It makes the car more responsive to drive, but I'm just messing about and not racing

[mooman007uk]

nice job,
nutech have now designed a spool for the centre which should be available soon.
even round a track I prefer the centre locked. If you have the V3 plastic diff cases with the large metal insert and thicker pin slot then everything should hold up just fine...only extra stress that may break diff cup pins is landing off jumps with high wheel speed....as yet I've not had a problem

[banners]

Cheers mate, it's performed well, no problems with mine but Nige at FreePrawn has had a few issues with the locked centre - he glued his completely!

2 rear diffs and a front was his punishment for such an act!

[mynameismud76]

My only concern with any plastic diff gearboxes is the groove that slots the pins for the two gears are not strong enough. =(

[mradlin]

Where can we get one from?

[mynameismud76]

PM sent =)

[banners]

One of mine? PM Nigel @ FreePrawn (http://www.freeprawnracing.co.uk/), see what he can do Mike ;)

[mynameismud76]

Yes buddy, I think Mike means your diff locker.

It sure is a well made piece of kit!! :punk:

[aidensere07]

Yea since the nutech one proberbly costs 3x more than the one banners has made, i ran it at testing other day and it was fine!! :punk:

[mradlin]

It sounds really promising. I look forward to hearing the test results. :punk:

[Pipeous]

I like it Banners, simple and functional. I got to like locked center difs after racing electric 4wd's (no center dif at all) and my 8th scale needed thick or the front tires were pizza cutters.

[Freeprawn]

I'll get them listed in the shop A.S.A.P.

They are £22.50.

If anyone want's one in the meantime Send me a PM :o)

Nige.

[mradlin]

I'll get them listed in the shop A.S.A.P.

They are £22.50.

If anyone want's one in the meantime Send me a PM :o)

Nige.

PM sent. ;)

[Freeprawn]

Link for interested peeps :)

http://www.freeprawnracing.co.uk/blackbone-punisher-destroyer-diff-locker-bb2.html

Nige

[mooman007uk]

My only concern with any plastic diff gearboxes is the groove that slots the pins for the two gears are not strong enough. =(

the new case with the large metal insert has more plastic where the pin slots ..i ran one in the rear for a few tanks, it's in the centre now, and it's holding up alot better

[mynameismud76]

That's good to know, just a little uneasy about running plastic diff gear boxes in the rear or centre.