Hi all,

what would you recommend

I have a brand new primary gear and when fitting it up i only has just over 1 thou clearence and the book states 3 to 6 thou and i would like to run around the 5 thou.

the shim i have measures up at 115 thou, but when i look at carcraft book they only have a 120 shim.

do you know if i can get a 111 thou shim? if not should i just thin the shim down on a oil stone?

thanks

_________________


100% Pure A Series Turbo
Morris - The Original RedBull Racing

For such a small amount, I would oilstone it, or 400 wet n dry with WD40 on a piece of glass, wont take much!

You can also use the steel bit in front of the gear to change this clearance too, same deal, wet and dry on the back face for just a couple of thou'

What type of clutch you running, grey diaphram? rally plate?

The primary gear clearance is temp sensitive, the lower end; 3 thou is quieter, but given your application and potential heat, I agree with your chosen 5 thou clearance

Sounds like a power rebuild!!

_________________
Sir Alec! we are not worthy!

thanks Graham,

i have found mini spares have a 112 to 114 thou shim, i guess they are not overly confident in their machining....

I will oil stone it and see how i go, might do the gear and the shim to keep it even.

yes have been using a grey diaphram and a cerametalic plate for a while now and it holds what i previously made so will see how it goes.

its been off the road now for close to 6 months and have massive withdrawals.

_________________


100% Pure A Series Turbo
Morris - The Original RedBull Racing

'Oil stoning' or wet and dry can get the job done but keeping it paralell can be a real problem doing it that way.

_________________

[edited due to previous brain fart]
I hold it in my 4" lathe chuck, clock it up with a dial gauge and face off as needed.
If I don't have a 1275 one, I grab a 998 one and bore it out to fit.

_________________
DrMini- 1970 wasaMatic 1360, Mk1S crank, 86.6HP (ATW) =~125 @ crank, 45 Dellorto (38 chokes), RE282 sprint cam, 1.5 rockers, 11.0:1 C/R.

Just put your shim in a lathe and machine of what you need. We used to make them out of bar stock, whatever size required. You can also put the transfer housing in the lathe and take off metal if you have far too much clearence.

_________________
Have a Nice Day.
If already having a nice day please disregard.

Agree, it can be tricky, but not impossible!

Grant was only looking for 4 thou, I would rub gently in a circular motion, checking for taper as I went, should be possible?

Or, Grant, whip it down to Kev and shout him a beer while he does it!!

_________________
Sir Alec! we are not worthy!

Yes, I assume you mean to reduce excess clearance on the the idler gear when you refer to machining the casing, not the primary gear, which is unaffected.

What a great thing this forum is!

_________________
Sir Alec! we are not worthy!

No, definitely possible, just tricky!

_________________

i have been oil stoneing and oil stoneing and have taken off about 2 thou, but yes got to keep spinning in the hand if you know what i mean just to ewnsure i keep it square.
i'll get there.

thanbks guys always great help

_________________


100% Pure A Series Turbo
Morris - The Original RedBull Racing

when you rub it on a stone use a figure 8 motion, and turn it over regularly just incase it has a slight curve in it.

_________________
Research is the difference between speculation and investment. Anyone who copys some one else will always be second
www.minisprintgt.com

The other thing you need to be aware of is that not all transfer case gaskets are the same thickness. The original gasket is about 0.035" thick uncompressed but non genuine/aftermarket gaskets can be thinner. I have one that is only 0.027". So if you use a non genuine gasket of the wrong thickness your idler gear clearance will be wrong and it can even prevent the idler from turning.
The same issue can apply to diff side plate and engine to transmission case gaskets. These gaskets should be about 0.009" thick uncompressed.

Edit: Oops misread the bit about it being the "primary gear" and not the idler gear but the gasket info is still relevant.
RonR

_________________
68 build Mk1 Cooper S
72 Clubman GT project. Total restoration required