B4 vs B4.1 diff and bearings

[grelland]

Hello there.

I have just ordered a vega conversion kit for B4, but I have a question.

My car is a B4, not B4.1, but as I understand the gearbox for the vega is designed for the B4.1. What is actually the difference?

I understand the B4.1 uses metric bearings, but is it enough just to swap the bearings, or do I need a new diff also? I looked at the listings at losipartshouse, and from what I can see, the outdrives have the same part no for both the B4 and B4.1...

Anybody out there that can shed some light on this for me?

[TheReferee]

from my research on getting the C4.1 there is a difference between the outdrives, the b4.1 can use the gear diff from the sc10 so the gearbox is slightly different to the b4. which means you need the b4.1 outdrives which are different, as the vega uses a bespoke aluminium gearbox they may do a 4.1 or a b4 sized one, best to ask them that question

[MRD]

I'm pretty sure there's both a B4 and B4.1 conversion kits, so just order the B4 version

[nicVEGAchildJR]

On the b4.1 the bearing are metric and the diff is 4 mm wider
You will need to buy a new diff
What surfaces do you race on????

I can give you setup help if you need just pm me and I have setup sheets if you need

[grelland]

It is only a B4.1 kit listed on the website, at least.

No big deal, I need a new diff ayways

I will run on astro, and setup tips will be highly appreciated

[Richard Lowe]

The B4 used imperial bearings, the 4.1 uses metric and also has a new gearbox case + T plate. You only need the newer outdrives and bearings to convert the B4 diff itself to metric.

B4 bearings - #6903 (3/8" x 5/8")
B4 outdrives - #7667 and #7668

B4.1 bearings - #9832 (10x16mm)
B4.1 outdrives - #9852 (pair)

[TheReferee]

Originally Posted by nicVEGAchildJR

On the b4.1 the bearing are metric and the diff is 4 mm wider
You will need to buy a new diff
What surfaces do you race on????

I can give you setup help if you need just pm me and I have setup sheets if you need

perhaps you should list your achievments and experience, regional and national results, then people could decide if you are someone to take advice from.

[Roel]

Originally Posted by nicVEGAchildJR

On the b4.1 the bearing are metric and the diff is 4 mm wider
if you need

How is it wider? The main diff gear and most other parts are the same parts as on the old B4.

And for some reason only the diff bearings are metric, the bearings of the top shaft and idler gear are still imperial..

[grelland]

thanks guys,

from the pictures, it seem that the outdrives are changed, with a flange, so that the bearing sits further out.

A new diff is on its way, just hope it gets here before the vega