Diff build

[Lee Martin]

Enjoy!!!

http://www.trfracing.co.uk/page_1265187551237.html

:thumbsup:

[makinwaves]

Nice guide Lee.

Can I ask why you remove the lugs from the pulley? I had a lumpy feeling diff when I built the 511 and wondered if it may have been the lugs, but chickened out of lopping them off.

[Lee Martin]

no need for them. Need the balls to work, not fail on the lugs

[DCM]

sometimes, it can stop you getting the correct tightness on your diff, they are there to stop the pulley from wobbling, but end up getting in the way.

[makinwaves]

Cheers guys, they will be lopped at the next rebuild.

[chrispattinson]

Excellent guide, thanks.
Just one question, I understand it is important to get the thrust bearing the correct way round. From looking back on previous threads, it appears the curved side faces the screw head. I seem to have trouble identifying the curved side, is this the side where the brass centre insert protrudes a little more?

[simoncrabb]

I'd never spotted those dimples before, but rarely had an issue with them, I suspect they wear in a bit!

I wonder why they are there, they aren't all the way around...

I'll chop em off in future tho.

[DCM]

Excellent guide, thanks.
Just one question, I understand it is important to get the thrust bearing the correct way round. From looking back on previous threads, it appears the curved side faces the screw head. I seem to have trouble identifying the curved side, is this the side where the brass centre insert protrudes a little more?

the brass center sleeve, one side has a square shoulder, the other side is rounded, rounded side goes to the screw head, otherwise you can cut the head off.

[chrispattinson]

the brass center sleeve, one side has a square shoulder, the other side is rounded, rounded side goes to the screw head, otherwise you can cut the head off.

Thanks DCM

[94eg!]

You know it's a million times easier to sand the diff rings if you use the female outdrive as a ring holder. A small dab of grease will keep it stuck to the outdriveso it doesn't fall off if you pick it up. Only using your finger creates uneven sanding pressure across the face and is a PITA as well. Muchmore even sells a magnetic tool for prepping diff rings. Of course it costs money that could be better spent on other things...

http://www.redrc.net/wp-content/uploads/2009/02/muchmorediffmaster-2.jpg

I also use a little blob of bearing/machine oil on the sand paper to act as a lubricant when sanding the rings. This keeps bits of abrasive from getting imbedded into the metal. Just clean them with detergent or motor spray when your done. Buttery smooth diffs every time...

[mikeyscott]

The front diff tighter than the rear etc. is this the general rule of thumb on 4WD?

[94eg!]

The front diff tighter than the rear etc. is this the general rule of thumb on 4WD?

Yes that's for both touring and off-road.

[DaveG28]

The front diff tighter than the rear etc. is this the general rule of thumb on 4WD?

It's something I've always tried to do, just to give a slightly safer split in power handling wise (tho I've always guessed at that being the effect!)

[mikeyscott]

Yes that's for both touring and off-road.

Need to rebuild the front diff anyway so cheers.

[5POINTSTAR]

I have read this thread and have learned nothing new :p

[Lee Martin]

Superstar!

[T4miy4 Guy]

You know it's a million times easier to sand the diff rings if you use the female outdrive as a ring holder. A small dab of grease will keep it stuck to the outdriveso it doesn't fall off if you pick it up. Only using your finger creates uneven sanding pressure across the face and is a PITA as well. Muchmore even sells a magnetic tool for prepping diff rings. Of course it costs money that could be better spent on other things...

http://www.redrc.net/wp-content/uploads/2009/02/muchmorediffmaster-2.jpg

I also use a little blob of bearing/machine oil on the sand paper to act as a lubricant when sanding the rings. This keeps bits of abrasive from getting imbedded into the metal. Just clean them with detergent or motor spray when your done. Buttery smooth diffs every time...

Great post thanks !

Andy :thumbsup:

[chrispattinson]

Ive followed the guide to the letter, and must admit my diffs are smoother than ever before..... however.

After running in on the bench for the required few minutes, the diff did spin for about half a second when I spun the wheel (Ive never had a ball diff do this before without slipping).
Sure enough, the diff must have backed off a bit, or bedded in during this period, as it did slip, as Lee predicted in his guide.

However, when I nip it up by the tiniest amount, where it doesnt slip, it no longer spins as freely (which I expected).

Are you guys ending up with a diff that doesnt slip (when holding the spur and trying the rear wheels), and at the sametime get a very free diff action where the wheel will spin for 1 second?
It seems I can have a slipping diff that spins for 1 second, or a non slipping diff that doesnt really spin, but still has a smooth diff action.

Any thoughts?

[simoncrabb]

Which balls and thrust did you use Chris?

I've found a big different in steel balls & thrust v ceramic balls & thrust. The latter is a whole lot more free.

(And ceramic balls and a steel thrust sits somewhere in the middle.)

[Lee Martin]

if it doesnt really spin much this is not too bad. its only bad when diff slips. my diff at present is slipping for only 1/2 second. not much at all really. feel free to have a 'feel' of mine ;)

[chrispattinson]

Which balls and thrust did you use Chris?

I've found a big different in steel balls & thrust v ceramic balls & thrust. The latter is a whole lot more free.

(And ceramic balls and a steel thrust sits somewhere in the middle.)

Im using ceramic main diff balls, and steel thrust...... What parts make up the ceramic thrust race?

if it doesnt really spin much this is not too bad. its only bad when diff slips. my diff at present is slipping for only 1/2 second. not much at all really.

Cheers Lee, it does feel smooth and free, it just doesnt spin..... so maybe it's ok.
I cant wait to get to Worksop this weekend to try it out,

feel free to have a 'feel' of mine ;)

:lol:
First year of doing nationals (if I get in) this year, so I'll probably be able to feel yours at Talywain. :lol:

[5POINTSTAR]

Which balls and thrust did you use Chris?

I've found a big different in steel balls & thrust v ceramic balls & thrust. The latter is a whole lot more free.

(And ceramic balls and a steel thrust sits somewhere in the middle.)
Thank you for the info :). I'll be building my first Ceramic balls/thrust diff...

[mole2k]

How much running do you guys find you get between diff rebuilds ?

[simoncrabb]

Im using ceramic main diff balls, and steel thrust...... What parts make up the ceramic thrust race?


Ceramic thrust race is an aftermarket part by JAAD or Square or someone else I can't remember the name of. Demon lists them, but been struggling to get them in the UK lately.

http://demonpowerproducts.co.uk/product_info.php?products_id=2697

The steel one is good enough really, but, you know.

[Fredrik Emilsson]

I have read this thread and have learned nothing new :p

If you already know so much maybe you can share something useful with us instead?

[DCM]

Think he is just being a smart arse lol

[F-1]

Hello! Today has begun car building,I have seen what the diff pulley loosing between diff outdrives, it is normal?

[GRIFF55]

It will be fine. that is how they are when the lugs are cut. Superb:thumbsup:

[Migs]

hey, are you guys happy enough with the standard diff screw and nut, anyone tried any from another manufacturer, i had a nut fail on me basically which stripped the threads on the screw, i saw hpi have a 25mmx2 diff screw, i just wished my losi ones would work so i could just stick an allen driver in the diff outdrive to adjust the diff setting rather than uncoupling a ball cup and doing the adjustment then putting it back together and chekcing etc, maybe ive been spoiled by losi in that regard, now its got me thinking, i wonder if the losi stuff will work in it..hmm

[simoncrabb]

That 2mm diff screw has been around in Tamiya ball diffs for years and years in TA05s etc. They 'upgraded' it in the 416 diff, slightly sturdier screw with a big slot in it, and a machined nut, that doesn't fit in the 501/511 outdrives.

I've not snapped either, but others have, can strip the head off if the thrust is the wrong way round.

All in all, I think most are happy with it?

[94eg!]

That 2mm diff screw has been around in Tamiya ball diffs for years and years in TA05s etc. They 'upgraded' it in the 416 diff, slightly sturdier screw with a big slot in it, and a machined nut, that doesn't fit in the 501/511 outdrives.

I've not snapped either, but others have, can strip the head off if the thrust is the wrong way round.

All in all, I think most are happy with it?

I still don't get the whole "directional thrust bearing" thing. I've built loads of Tamiya ball diffs and never paid attention to the direction of the thrust (as the manual says nothing about it). I've never had trouble stripping or breaking the 2mm screw either... :confused:

[simoncrabb]

I still don't get the whole "directional thrust bearing" thing. I've built loads of Tamiya ball diffs and never paid attention to the direction of the thrust (as the manual says nothing about it). I've never had trouble stripping or breaking the 2mm screw either... :confused:

Secretly I never take any notice which way round the thrust is either ;) :D

[mikeyscott]

You know it's a million times easier to sand the diff rings if you use the female outdrive as a ring holder. A small dab of grease will keep it stuck to the outdriveso it doesn't fall off if you pick it up. Only using your finger creates uneven sanding pressure across the face and is a PITA as well. Muchmore even sells a magnetic tool for prepping diff rings. Of course it costs money that could be better spent on other things...

http://www.redrc.net/wp-content/uploads/2009/02/muchmorediffmaster-2.jpg

I also use a little blob of bearing/machine oil on the sand paper to act as a lubricant when sanding the rings. This keeps bits of abrasive from getting imbedded into the metal. Just clean them with detergent or motor spray when your done. Buttery smooth diffs every time...

Anyone know the part number for the Tamiya diff ring holder thing?

[Rich D]

Its made by muchmore Mike, not Tamiya. If i recall correctly, the 502x uses different diff rings to the 511 too.

I have got one, but it took some finding.

511 and 416 touring cars use the same diff rings.

HTH

[mikeyscott]

Its made by muchmore Mike, not Tamiya. If i recall correctly, the 502x uses different diff rings to the 511 too.

I have got one, but it took some finding.

511 and 416 touring cars use the same diff rings.

HTH

Ok cheers. Running 511 :)

What thrust race are people using, caged or non caged?

[Rich D]

Ok cheers. Running 511 :)

What thrust race are people using, caged or non caged?


I just use the std kit one, filled it with associated black grease. Balls are LazyRC ceramics with MuchMore diff grease. Diffs have done a full outdoor season of Nationals and are still as smooth as when i built them. I use vinyl diff protectors and some sponge in the outdrive to protect the thrust race from dust and grit.

[mikeyscott]

Cheers bud :)

[Rich D]

any time Mike