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Losi LRM Ball Bearing Differential

Posted: Wed Mar 16, 2016 10:36 am
by RCveteran
Remind me again what size the bearing in the center is to buy in bulk. Goes in the center of the A3021 diff gear.

a-6904 thin bearing's


Is it 1/4 x 3/8 x 1/4?

I'm not at my parts bin and have another order going. I'm embarrassed this has slipped my mind :lol:

Re: Losi LRM Ball Bearing Differential

Posted: Wed Mar 16, 2016 1:55 pm
by GoMachV
According to your post it's a .108 :mrgreen:
That makes it basically a 7/64 width
The 1/4"x3/8" part is correct

http://www.rc10talk.com/viewtopic.php?f=27&t=18950

Re: Losi LRM Ball Bearing Differential

Posted: Wed Mar 16, 2016 2:41 pm
by RCveteran
Too funny, I always search first and somehow missed my own knowledge! Man I'm smart. :mrgreen:

Re: Losi LRM Ball Bearing Differential

Posted: Wed Mar 16, 2016 7:08 pm
by aconsola
I've looked around and can't find a source for the bearings anywhere. The instruction sheet did say that they were custom bearings, and I think it may be that they were special ordered just for that application.

if you find some aside from the 2 losi part numbers posted, please let us know.

There are other options:
1The MIP change box kit came with a very thin plastic bushing to be used with a single standard bearing
2as mentioned in the other post There are 2 versions of the thorp right diff half, one has a deeper recess for the bearing than the other. about .16 vs .13"
aside from the recess depth the gears look otherwise the same. I checked my parts stash, the 5100 gear set, and 5102 right side gears are the shallow kind, and the 5110 transmission gear set has the deep recess and includes a ball bearing diff gear.

There is a seller on ebay that appears to have bought out the old thorp stock. he has right side gears out of packaging listed cheap. I asked him if he had one or the other version, and his reply was "
Thanks for asking but I have no idea ."

Re: Losi LRM Ball Bearing Differential

Posted: Wed Mar 16, 2016 8:54 pm
by RCveteran
I purchased a full thorp gear set from him. It's on the way and I'll check when I get it. I just bought the right different half of which you speak as well. We shall see.

I took a couple years off but I'm back and recall at one point I had built up a few ball bearing differentials which now I wonder what I did. Maybe I had NOS Losi bearings if I recall.

Someone on here bought my stash I had built all with ceramic balls and they were like butter smooth. Whoever you are, show yourself and give me my diff back :lol:

I'm not familiar with the MIP kit? More info please and I've never used the thorp stuff I have coming so what size bearing do I actually need for each option you mention.

Also, is it me or are there a lot less X2 parts on the bay than even a few years ago.

Re: Losi LRM Ball Bearing Differential

Posted: Thu Mar 17, 2016 8:11 am
by matt1ptkn
There are fewer parts on eBay... Most are in my stash. 8) But I have no input on the bearings. :oops: I've only used the Losi part #'s.

Re: Losi LRM Ball Bearing Differential

Posted: Thu Mar 17, 2016 8:59 am
by RCveteran
I had a fire sale a couple years back on enough NIP parts on the bay of X2 parts that most of you here probably have them all :lol:

Re: Losi LRM Ball Bearing Differential

Posted: Thu Mar 17, 2016 11:28 am
by aconsola
I think there are more parts on ebay now for jrx than a few years ago, problem is they are all listed individually for big$. It used to be you could find big lots of parts, or cars cheap which came with electronics and spares. now the start prices for cars is generally very high. There are a few deals to be had here and there, but I think there are more of us looking.

The MIP change kit gives the lrm a 2.6 internal ratio and includes a thin plastic bushing. it is the same thickness as the center of the gear. you would use this with a standard bearing, or use the gear without bushing but with 2 of the special thin bearings.

For the Thorp kit it depends what you actually have. you either use one standard bearing with the early parts, or 2 standard bearings if you have the later parts. Measure the right outdrive recess, or put a standard bearing in. if bearing is flush it is same as stock losi, if it is sunk down in a little then you can stack 2 bearings for a bb diff gear.

one note on the deep outdrive, the edge is not beveled like it tells you to do on the losi 3020 kit instructions, it really should be beveled or recessed so that the bearing on the gear is able to spin independent of the outdrive

Re: Losi LRM Ball Bearing Differential

Posted: Thu Mar 17, 2016 11:37 am
by aconsola
here are the 3020 instructions

Re: Losi LRM Ball Bearing Differential

Posted: Thu Mar 17, 2016 11:46 am
by RCveteran
That's really interesting. I never did the bevel cut on my Losi one and did not have an issue. Last time I ran run was with 13T Brushless. I did have ceramic balls in the diff and thrust bearing.

So I am clear 2 follow up questions?

1) On the Thorp as I have some coming, it will be either one 1/4" or 2 1"4" thick bearings?
2) Can you use the 1/4x3/8 bearing in the Losi part?

Re: Losi LRM Ball Bearing Differential

Posted: Thu Mar 17, 2016 2:55 pm
by aconsola
the standard bearings are actually 1/8" wide not 1/4. the inner diameter is 1/4, otherwise yes.

Re: Losi LRM Ball Bearing Differential

Posted: Thu Mar 17, 2016 3:41 pm
by RCveteran
I'm confused in my bearing nomenclature then so the standard losi ones then would be 1/4 (I) x 3/8 (O) x 1/8 (W) ?? Making sure we are talking same thing. Avid seems to have those readily available.

http://www.avidrc.com/product/9/standard-bearings/6/14-X-38-X-18-Metal-R168ZZ-standard-bearings.html

We're in the process of moving and I can't access my stash at moment to look.

Re: Losi LRM Ball Bearing Differential

Posted: Mon Mar 21, 2016 3:04 pm
by RCveteran
Is the above link correct?

Re: Losi LRM Ball Bearing Differential

Posted: Mon Mar 21, 2016 4:02 pm
by jwscab
yes, avid has the nomenclature right, the last dimension is the thickness, the std bearing is 1/8" (0.125"). the losi narrow is likely 7/64"

Re: Losi LRM Ball Bearing Differential

Posted: Mon Mar 21, 2016 4:42 pm
by RCveteran
Gil Losi are you listening? Who was the supplier for these things and what is the exact thickness?