revomaniac

I am changing my top cap to the ITS ribbed unit.
In my bravo manual it assumes no one has been in your drive before and you are using the same cap.
My question is how do you verify what the gear lash is?
Seems like I have .005 difference between race sufaces on the 2 caps?

Opinion?

Mr Gadgets

Rev,
there is a couple of different ways of measuring the lash. To do the upper gear, Merc's process is better to look at installed height. It is a fairly long winded process that uses several special tools. If you measure your two caps and find .005 difference, then using the corresponding race shim will put the gear back where it was and you will be no worse than you were with the stock cap. It would take a small book to explain it.. Well supplement 28 does a nice job.. I measure case & cap depth, pinion centerline and start from there then I measure the lash with a flag and shaft in the lower gear and then calculate the upper one and check it by feel. I have used a cap with a hole in it and use the dial indicator that way, but it is not very accurate. The new Merc method will put a gauge on it and give you some hard numbers. My new set of tools will be arriving monday.

I hope that helps. Like I say there is a lot to be concerned about, but just shimming for the diff in the cap and you will be back where you started..

Dick

revomaniac

Thanks for the reply.
I took a lot more time measuring the difference between the 2 caps and now determine I need a thrust washer that is .042 thick instead of .061.
Does such a thing exsist?
You mention race shim. Where do I purchase those?
If so where?

Mr Gadgets

Rev,
that doesnt sound correct. The races, I call them shims, come in different sizes.. 051", .054" .057. and then .058" to .068" In one thousanths steps. The part number is 23-8645960xx. The xx being the size of the shim you need. The 23-864596061 would be the .061" shim.
But you shouldnt need a .042" shim. Is your drive a Standard Bravo or an X type? There is .010" difference between the two caps, usually. And how are you measuring the caps? I use a depth mic with two 1" parallel bars to make the measurement.
If you want, you can give me a call and I can tell how I do it and see it that helps you out..

Dick
616-335-8446.... please not after 9pm est.. thanks

revomaniac

Thanks Mr. Gadgets.
I am using a digital caliper as I cannot find my depth mic from work.
I will borrow one tommorrow and remeasure.
I agree something does not sound right.

The drive is an OM style bravo, not x.
Dave.

revomaniac

Just for anyone's info, the only way you can measure this is with a depth mic.
After finding my depth mic the two caps measure out exactly the same.
Thanks Mr gadgets for the help and part numbers.
Cheers.

Mr Gadgets

Hey Rev,
What did it measure? .255" or .265"? If it is OM ..it should have the X gears I believe.. running late.. sorry I didnt get back to you.. last nite. Caught a nasty cold.. Now that summer is here.. !!!
Dick