Which pinion gear?

[84brat]

I have an old Subaru Brat that I have owned since it was new in 1984. It has a differential rear end. I have recently purchased a new motor without any pinion gears. I did try putting one of the old pinion gears I had on the new motor. When I accelerate, it is rather loud; as if the gears are too tight or binding. I am not sure how many teeth are on the differential gears but I would like to get the correct pinion gear to see if this solves the problem.

So, if the dif gear has:

48 teeth, what size pinion gear do I need?

50 teeth, what size pinion gear do I need?

52 teeth, what size pinion gear do I need?

Is there some standard size pinion gear that corresponds to the number of teeth on the differential?

Thanks for the help with this.id="size2">id="navy">id="Tahoma">[8D]

[ideal2k]

52T Spur = 16T pinion

50T Spur = 18T pinion

49T Spur = 19T Pinion

[mymonsterbeetleisbroken]

welcome to the site!

i'm guessing your cars diff is a frog/monster beetle/blackfoot gear as you say its got a differential rear end???

if changing the pinion to the correct size doesnt seem to help, the diff could be worn. the gears really should be quite free.

try spinning on back wheel, the other should rotate in the oposite direction, it will feel fairly tight but thats just how they are. if theres alot of play in there then worn out parts is the problem []

hopefully all my rambling is completley wrong lol, but if changing the pinion doesnt work - you know where to find us for more help []

[SonicCJ5]

When you install the motor do not use the cover. Leaving this off will allow you to see how the pinion meshes with the spur gear.

Also a side note you mention this is a brat they came with rs380 motors and an adapter with a different sized gear that might not work with a standard rs540.

[ideal2k]

What he is describing is the differential hop up kit for the Brat.

It was the same as the kit that came with the Frog as standard, basicly it has a two-piece spur where you can select three sizes of main gear, which is then held onto the drive gear by a C-ring.

[TAZ-NZ]

I got a NIP set of pinion gears etc for that setup, if it's what Ideal2k described.

it's got 3 aluminum pinions each with a different number of teeth (I haven't counted them)

a set of left and right diff steal bevel gears, and what looks to be a brass center gear for the counter gear.

I picked it up off ebay as part of an auction lot of brat/mudblaster parts. the bag is labeled X8412 frog gear set k1-k9 for 41

[ideal2k]

Oh yeah? Does it come with the spur gears and the C-ring? I'd want it.