Greetings all:

I have my Triumph gearbox apart for a refresh and while going thru the various tolerance checks,one of the thrust washers is too thin by 0.015 inch. This part retains the 1st gear axially on the trans shaft. This part is no longer available in any thickness - originally this part was available in 4 thickness ranges. http://i290.photobucket.com/albums/l...arretainer.jpg The existing thrust washer is hardened. Since there is no rotation on this part (unless the mainshaft bearing seizes and then I have much bigger issues). I am thinking of using a 0.015 thk round steel shim as a spacer between the bearing inner and the existing thrust washer. This part would not be hardened (Rockwell B85). http://www.mcmaster.com/#catalog/118/3244/=iqlzxw Does anyone see an issue with this?

The other alternative is to turn a thrust washer on the lathe out of some mystery steel. Problem is that I have a difficult time parting off and keeping the cut square. I do not have access to a surface grinder.

On Mon, 6 Aug 2012 20:19:41 -0700 (PDT), aribert n
wrote:

Greetings all:

I have my Triumph gearbox apart for a refresh and while going thru the various tolerance checks,one of the thrust washers is too thin by 0.015 inch. This part retains the 1st gear axially on the trans shaft. This part is no longer available in any thickness - originally this part was available in 4 thickness ranges. http://i290.photobucket.com/albums/l...arretainer.jpg The existing thrust washer is hardened. Since there is no rotation on this part (unless the mainshaft bearing seizes and then I have much bigger issues). I am thinking of using a 0.015 thk round steel shim as a spacer between the bearing inner and the existing thrust washer. This part would not be hardened (Rockwell B85). http://www.mcmaster.com/#catalog/118/3244/=iqlzxw Does anyone see an issue with this?

The other alternative is to turn a thrust washer on the lathe out of some mystery steel. Problem is that I have a difficult time parting off and keeping the cut square. I do not have access to a surface grinder.

It'll be fine sandwiched between the original shim and the bearing.
The original is hard because it has to bear on the retaining ring.

--
Ned Simmons

"aribert n" wrote in message
news:b2e5b9a9-f1eb-4ea1-b9b8-
The other alternative is to turn a thrust washer on the lathe out of
some mystery steel. Problem is that I have a difficult time parting
off and keeping the cut square. I do not have access to a surface
grinder.

How about turning a full-thickness replacement from the head of a
grade 8 bolt?

jsw

The ID is 1.0 inch, I don't have any bolts much larger than that.

wrote in message
...
The ID is 1.0 inch, I don't have any bolts much larger than that.

Old lawnmower blades?

On Tue, 07 Aug 2012 09:46:50 -0400, Ned Simmons
wrote:

On Mon, 6 Aug 2012 20:19:41 -0700 (PDT), aribert n
wrote:

Greetings all:

I have my Triumph gearbox apart for a refresh and while going thru the various tolerance checks,one of the thrust washers is too thin by 0.015 inch. This part retains the 1st gear axially on the trans shaft. This part is no longer available in any thickness - originally this part was available in 4 thickness ranges. http://i290.photobucket.com/albums/l...arretainer.jpg The existing thrust washer is hardened. Since there is no rotation on this part (unless the mainshaft bearing seizes and then I have much bigger issues). I am thinking of using a 0.015 thk round steel shim as a spacer between the bearing inner and the existing thrust washer. This part would not be hardened (Rockwell B85). http://www.mcmaster.com/#catalog/118/3244/=iqlzxw Does anyone see an issue with this?

The other alternative is to turn a thrust washer on the lathe out of some mystery steel. Problem is that I have a difficult time parting off and keeping the cut square. I do not have access to a surface grinder.

It'll be fine sandwiched between the original shim and the bearing.
The original is hard because it has to bear on the retaining ring.


I think that the first question is "how did the spacer get to be
0.015" too thin? Did it wear or was it originally assembles that way?
If the latter then the next question is "how long has it been that way
and did it shift all right ".

Cheers,
John B.

"John B." wrote in message
...
On Tue, 07 Aug 2012 09:46:50 -0400, Ned Simmons
wrote:

On Mon, 6 Aug 2012 20:19:41 -0700 (PDT), aribert n
wrote:

Greetings all:

I have my Triumph gearbox apart for a refresh and while going thru the
various tolerance checks,one of the thrust washers is too thin by 0.015
inch. This part retains the 1st gear axially on the trans shaft. This
part is no longer available in any thickness - originally this part was
available in 4 thickness ranges.
http://i290.photobucket.com/albums/l...arretainer.jpg
The existing thrust washer is hardened. Since there is no rotation on
this part (unless the mainshaft bearing seizes and then I have much
bigger issues). I am thinking of using a 0.015 thk round steel shim as a
spacer between the bearing inner and the existing thrust washer. This
part would not be hardened (Rockwell B85).
http://www.mcmaster.com/#catalog/118/3244/=iqlzxw Does anyone see an
issue with this?

The other alternative is to turn a thrust washer on the lathe out of some
mystery steel. Problem is that I have a difficult time parting off and
keeping the cut square. I do not have access to a surface grinder.

It'll be fine sandwiched between the original shim and the bearing.
The original is hard because it has to bear on the retaining ring.


I think that the first question is "how did the spacer get to be
0.015" too thin? Did it wear or was it originally assembles that way?
If the latter then the next question is "how long has it been that way
and did it shift all right ".



Possibly there probably was a second spacer, oftentimes these kind of things
were intentionally designed with a loose fit and then the actual gap was
measured during the assembly process; finally, the appropriate shim was
selected and installed....

In fact, anyone that's rebuilding automatic transmissions is going to have
on hand (or at least he SHOULD have ) certain kits containing parts that are
commonly known as "selectables"...

--Basically, these are clutch plates that are a bit thicker (or thinner)
than your stock plates...if you need an extra .005 then you pull out one
that's say, .060 thick and replace it with a .065.

Then again, on the part pictured, it might not really be all that
important--it's a helical gear and so depending on exactly where it is in
the gear train, an extra .015 or so really may not be a big issue when it
comes to the actual amount of force that is developed when it impacts
against the snag ring as the throttle is suddenly let off.

As spares become No Longer Available, gearboxes are built up from several parts boxes. The excess axial play has been there for the last 8 years (20K miles). I was not observant enough when I dismantled my worn but functional trans and a parts box. The issue with this trans was a slow upshift from 1-2 (1 sec pause during upshift) and major difficulty on both a 3-2 & 2-1 downshift. Over the past 5 years I found NOS 1st gear and 1-2 shift hub along with a newly reproduced 2nd gear. Synchros back in the late 90s were garbage -supposidly good quality now. All the other axial tolerance checks are in spec on the low side.

I bought 0.015 thk round shim from McMasterCarr. I considered turning a thrust spacer but my inability to part off square and to tolerance means that I would end up filing & lapping the thrust washer to tolerance (but probably not a uniform cross section). I really want a surface grinder or access to one.

On Wed, 8 Aug 2012 10:02:58 -0700 (PDT), wrote:

As spares become No Longer Available, gearboxes are built up from several parts boxes. The excess axial play has been there for the last 8 years (20K miles). I was not observant enough when I dismantled my worn but functional trans and a parts box. The issue with this trans was a slow upshift from 1-2 (1 sec pause during upshift) and major difficulty on both a 3-2 & 2-1 downshift. Over the past 5 years I found NOS 1st gear and 1-2 shift hub along with a newly reproduced 2nd gear. Synchros back in the late 90s were garbage -supposidly good quality now. All the other axial tolerance checks are in spec on the low side.

I bought 0.015 thk round shim from McMasterCarr. I considered turning a thrust spacer but my inability to part off square and to tolerance means that I would end up filing & lapping the thrust washer to tolerance (but probably not a uniform cross section). I really want a surface grinder or access to one.

What..no machine shops in your area? Go in on a Tuesday morning with a
box of donuts and ask if they could grind your spacer flat.

flattening out a spacer takes maybe 3 minutes on a surface grinder.
Hell..stick it in an envelope and send it to me with 50 cents for
postage back and Ill do it.

Gunner

wrote in message ...

I bought 0.015 thk round shim from McMasterCarr. I considered turning a thrust spacer but my inability to part off square and to tolerance means that I
would end up filing & lapping the thrust washer to tolerance (but probably not a uniform cross section). I really want a surface grinder or access to one.

You'll probably be fine, even if it does eventually end up in pieces in the bottom of the case...(which probably won't happen so long as it was properly heat treated for use as a thrust washer)

But in the future, I would suggest using a pair of spacers that are fairly close to one another in thickness rather than having one of them be thin enough that it might easily tear or crack in use.

wrote in message
...

I bought 0.015 thk round shim from McMasterCarr. I considered
turning a thrust spacer but my inability to part off square and to
tolerance means that I would end up filing & lapping the thrust
washer to tolerance (but probably not a uniform cross section). I
really want a surface grinder or access to one.

Material that thin doesn't stick to the mag chuck very well. I have a
lot of trouble grinding 0.025" hacksaw blades. When the wheel grabs
the work it launches it at ~60MPH. Also you can overheat and soften
it.

Used to have lots of machine shops, now there are a few less. I just don't know any one in the business. It has been 8 years since I worked for a co.. that had a shop that I had access to. I rarely used a surface grinder, its the TIG access that I miss the most.

Thanks for the offer, I intend to reassembled this Saturday, that's why I am looking for a commercial solution that will function & last. The 0.015 thk round shims arrived yesterday. I found some M42 & O-1, both 1.25 dia. -the existing thrust spacer is 1.375. If I wanted to try to part off.

Thanks all for your suggestions.

wrote in message
...
Used to have lots of machine shops, now there are a few less. I just don't
know any one in the business. It has been 8 years since I worked for a
co. that had a shop that I had access to. I rarely used a surface
grinder, its the TIG access that I miss the most.

Thanks for the offer, I intend to reassembled this Saturday, that's why I
am looking for a commercial solution that will function & last. The 0.015
thk round shims arrived yesterday. I found some M42 & O-1, both 1.25
dia. -the existing thrust spacer is 1.375. If I wanted to try to part off.

Thanks all for your suggestions.

To make a precision washer on a lathe from a bar, drill the center hole and
face the end of the bar. Sand to remove turning marks if needed. Part-off a
little thicker than needed. Double side tape the flat side to the faceplate
or another flat-ended bar (or superglue if the washer is small). Face the
second side to the correct thickness and sand if needed.

"anorton" wrote in message
m...

wrote in message
...
Used to have lots of machine shops, now there are a few less. I just
don't know any one in the business. It has been 8 years since I worked
for a
co. that had a shop that I had access to. I rarely used a surface
grinder, its the TIG access that I miss the most.

Thanks for the offer, I intend to reassembled this Saturday, that's why I
am looking for a commercial solution that will function & last. The 0.015
thk round shims arrived yesterday. I found some M42 & O-1, both 1.25
dia. -the existing thrust spacer is 1.375. If I wanted to try to part
off.

Thanks all for your suggestions.

To make a precision washer on a lathe from a bar, drill the center hole
and face the end of the bar. Sand to remove turning marks if needed.
Part-off a little thicker than needed. Double side tape the flat side to
the faceplate or another flat-ended bar (or superglue if the washer is
small). Face the second side to the correct thickness and sand if needed.

Sorry, I forgot some details: make the center hole well undersized to start.
Then before facing the second side, use a live center to hold the washer
onto the tape on the face plate. Face the second side. Then remount the
washer in a chuck and drill the center hole to size.

anorton

The purpose for an undersize hole? Is this so that the live center and lathe bit are not trying to occupy the same space?