Here's a project:
The car howled in any gear. On the gas or off. If you let it float at neutral throttle, the noise goes away. Ahh... must be the ring & pinion. Too much backlash? Terrible noise really. Must look into it.
Step 1: Whip out the transaxle:
Bit of character on it. Time for a bath. Sometime I'll give a rundown on how to clean things in an enviromentally conscious way. Right now I'll just try to throw up some images and see if I can get it all to work. A sketch of pages to come if you wiil
Nice line from the back. Complex little assembly.
Ooh. There's the ring gear. Hmm.. doesn't look too bad for all that noise. No broken teeth anyway.
Aah! Open. Been wanting to look at one of these for years.Took awhile to get to this step, I'll tell you.
Nice thing inside. I wonder where the noise is.
Bit cleaner now. What a project to contemplate.
Nice old piece. Alot of detail. Imagine making the mold & cores out of sand to cast it
It would be too easy if it just came apart. Time to make a bunch of special sockets for those ring nuts. That's a whole other page to put here in the engineering section: how to remove ringnuts. I've been trying to find a good fast way to get tools made for years and every one is an argument. I used to start with an old socket, a hacksaw and a file. It was always heartbreaking (or at least momentum robbing) to find one of those darn nuts in the way of getting something apart. I never much cared for leaving a big footprint by using a chisel, so another sidebar distraction starts. Here's this weeks version of a solution.
So where did the noise come from?
Turns out this nice pinion bearing had a rumble in it. If you look at the path of the drivetrain it makes sense
you would only hear it when moving.. Hmm. I thought it was the ring & pinion but maybe not. well, getting it out involves the torch, the press, pullers, some excitement, and the chance to reshim the pinion depth as the new bearing will perhaps change that setting. Of course the shim lies under the pinion, so it's torch, press & pullers each time you change the shim pack...
Some nice looking axles, they of course needed another socket to be removed from their hubs
Here's part of the process:
A summary of the ones needed on this project so far..
There was bigtime runout in one of these hubs.... More work to sort out (the bearing was seated at an angle)
Setting up the carrier bearing preload involves a lot of shimming and these darn hubs are a press fit in the case.
The factory suggests warming the case in an oven, a bit impractical 6 or 8 times in a row.
Drilling the hub & threading it at 2 opposite points allows the hub to become its' own puller with the use of 2 bolts..
About time to stop taking pictures and assemble this thing
Time for the brakes & clutch. Will it ever end. 37 hours to get here counting trying to cross reference bearings, find material to make special tools (and making them) May as well document it so someone else can appreciate it in 5 minutes on their computer.......
Speaking of bearings, I find it interesting that most metric bearings have inch size balls in them. Say you have a $600 Lamborghini wheel bearing that is a bit loose. Interestingly enough they can be reloaded with new balls ( I think it was 15/32" and they tighten up & the noise goes away. ) Doesn't work with a pitted race, but is an amazing trick in a pinch.
The pinion bearing here needed replacement (sure buddy, go find one of these, it's not a standard size in any catalog...)
but the intermediate bearing below had a split race and was loaded with 9/16" balls. A handfull of new ones tightened it up nicely. Why on earth are vintage metric bearings filled with these inch balls? I've seen it over and over. Anyone have a suggestion?
Below is an email from Bruce Carr pointing to a plausable explanation.
Thank you Bruce !
In your Flaminia transaxle rebuild, you wondered why
metric dimension bearings have inch-dimension balls.
It's pretty simple, actually.
The tooling, manufacture and production of British
System (inch-dimension) bearings and components
In fact, mass-production of British System bearings
predates even the agreements which established one
standard metric system (there had been several).
For a very long time, all precision ball bearings were
inch dimension, and made in England or the U.S.
Paralleling that, Connecticut developed into the world's
primary source for high-precision bearing balls.
Why? Because the equipment to make precision balls
was invented and developed there, which spawned the
standalone precision ball manufacturing industry. Which
spawned the ball bearing industry, which remained
firmly rooted in Connecticut for decades.
And so production of precision balls continued (and
continues today) in inch dimensions. Changing the
equipment, the installed base, etc., etc. would be
pointless and offer no benefit to the engineering or
An excellent parallel is the automotive tire and wheel:
While the installed unit's envelope dimensions are
(usually) metric, the base structure is inch-dimension,
based on billions of dollars of installed inch-dimension
engineering and manufacturing infrastructure built up
worldwide over many decades.
(we're working up a cleaner explanation, with pictures,
for www.BearingMuseum.com, but that's my best effort
Bruce A. Carr, President
On to the Brakes!
While waiting to finish, here's what's in the driveway today:
And on a friday afternoon we now have a runner. Totally silent transaxle, both on & off throttle.
Just a delight. Too bad it took 52 1/2 hours of shop time. No backtracking or mistakes, just a very complex piece of machinery. It was nice to work on, & now it's nice to drive. Onto the next project. I'll try to document that Urraco water pump soon. It was also a very complex & interesting piece to massage back to good health.