Needed to see the B44.3 chassis to make a new chassis for this project. got the chassis along with the original Bj4 chassis. it’s the first time to see the original version. and I can see the wheelbase is identical to Bj4 worlds edition.

B44.3 chassis is 4mm longer than B44’s. but still the Bj4 and B44 bodies fit the chassis. the structure is different for the front and rear bulkheads. Bj4 was built with Nitro TC3 parts. and B44 series has it’s own bulkheads and tranny, diff cups and more

you can check the wheelbase here

https://slowbean.net/2015/06/a-quick-update-for-retro-bj4/

And, the under tray came from B44.2 Bulldog body set from Pro-line
http://www.prolineracing.com/bodies/bulldog-clear-body-b442/

With some original Bj4 parts from Jconcepts, AE, and Losi

The kingpins from 870C through YZ10 are basically same shoulder screws. even you can find the replacements from Tamiya and Kyosho as well. and MX4 kingpins are flanged bushing (flanged sleeve) which are easy to assemble and hard to be lost

The flanged sleeves should be assembled from inside to out on the front C hubs.

But, YZ10 C hub has a bit small room for MX4 kingpins. and both assembled from top to bottom. like these pics

All done with titanium screws, and ready to run.

Found some for myself and friends recently. I had a few while ago. but haven’t seen them for a while

There were 2 different ZD-304S from Yokomo. the early one is more simple, and later one came with idler bearings

the first one is here. it’s very unique with 4 of 4-40 SAE flathead screws on the bottom. they are the same screws you can find from AE cars. and I’m not sure with the later version. I haven’t opened the bag yet

And, this is the later one.

Someone posted some decent pictures of the 2nd version on Tamiya club.
http://www.tamiyaclub.com/showroom_model.asp?cid=121643&id=23290

Hudy seems to make the best setup tools on the market. but we never had one for Yokomo YZ10 5mm axle yet. or simply I didn’t see

I got this 1/8 on-road setup tool for 12mm axles. and only thing I need was 4 of 5x12mm bearings. I ordered the bearings. then forgot about it. some metric and SAE bearings came from Avid RC for my Yokomo and AE buggies. but couldn’t remember why I got 5x12mm bearings with them. it took a while to figure it out.

The setup tool is this. Hudy 1/8 on-road setup tool for 12mm axle. and I just switched the front and the rear ones.

Then 1/2″ step bit job on the other side for 3/16″ axles.

Then some thin paper tape to hold the bearings securely

Done

The tool works for the old 834B through YZ10, RC10, and modern 4WD as well.

On the rear axles, 5x12mm bearings works fine for 5mm and 3/16″ both. the difference is small. and we just need the camber angles on the rear axles.

Also, this tool is a very nice display stand for YZ10

There are two different versions
ZC-300AF Aluminum front bulkhead
ZC-300FC Aluminum front bulkhead for Works ’93

those two are basically same, except for the caster angle.
ZC-300FC for Works ’93 has bigger angle as you can see from the last picture
if the caster is same with the magnesium bulkhead, it’s 300AF. you can see that without the header.

Probably, I posted this somewhere. and I’m doing this again to remind my memory.

it’s the simple comparison

’94 / ’95 / ’97 YZ10 front > ’94~’97 YZ10 rear = Works ’91 / ’92 / ’93 Front = Works Rear = 870C front long version (with outer mount hole on the front arms) > 870C Front = 870C Rear

so, there are only 3 different lengths from Yokomo from ’87 through ’97.
but, there are more than one model number for the same length. it’s about the solidity.

870C universal drive, ZC-421 (front long version ZC-422) are softer than ZC-422A which is Works F/R universal drive. but ZC-422 and ZC-422A still have the same length.

there are ZC-423, ZC-423S, and ZD-423. all they are for ’94~’97 YZ10 front and the differences are solidity as well. it’s just about the material

Yokomo keeps testing and making new parts for their current and next models. it’s the reason they keep changing the model numbers and making newer ones. I respect that

From left to right,
ZD-423 = post ’94 YZ10 front, super hard version (same length with ZC-423, ZC423S)
ZD-422 = post ’94 YZ10 rear, super hard version (same with ZC-422A which is for Works)
ZC-422 = 870C front long version (same with ZD-422, and ZC-422A)
ZC-421 = 870C F/R

the actual length from the end to the other end is
107mm, 101mm, and 96mm
the length from the end to the universal joint is 25mm