[Shop-talk] Tractor Bearing Sizes

[Bob Spidell]

Getting the List back in the loop.

Tractor is a ca. 1953 Ford 851 (6V pos. gnd.). It's got a buck rake on 
front, and is not often used but indispensable when I need to buck brush 
out of my orchard. I'm doing a "poor man's overhaul;" e.g. valves, hone, 
rings and main and rod bearings, no need to pull the crank as it's a 
PITA and with new wear items it'll outlast me.

I've got the rod bearings out; I don't have machinist-grade measuring 
tools so if I can figure out what size bearings are in there--mains 
TBD--I'll just put new of same size back in. Does this look like a 
0.020" undersize bearing from the inscription? It's confusing because my 
ordering options all call them 'oversize,' when I'd bet money the crank 
and rod journals have been ground at least once ('oversize' vs. 
'undersize' depends on your perspective, I suppose, but generally 
'undersize' bearings are thicker for journals that have been ground, no?).

Bob

On 12/24/2023 11:47 AM, Jack Brooks wrote:
> Jeff beat me to the punch.  I also did this on a Triumph. My 1960 TR3. 
> It was fairly simple procedure.
>
> Jack
> ------------------------------------------------------------------------
> *From:* Shop-talk <shop-talk-bounces at autox.team.net> on behalf of Jeff 
> Scarbrough <fishplate at gmail.com>
> *Sent:* Sunday, December 24, 2023 10:19:50 AM
> *To:* Bob Spidell <bspidell at comcast.net>
> *Cc:* Shop Talk <shop-talk at autox.team.net>
> *Subject:* Re: [Shop-talk] Tractor Bearing Sizes
> 1.  Maybe?  I don't know about your particular tractor, but I have 
> rolled the old main bearings (on a Triumph), just by pushing on the 
> end without the tank and grabbing it on the other when it starts out.  
> New ones just roll in.  Requires all the caps to be loose.  If they 
> are sticky, you might get lucky by sliding a roll pin into an oil hole 
> in the crank and turning the crank to push the bearing shell out.  
> Note that this can introduce problems that you didn't use to have.  Be 
> governed accordingly.
>
> 2.  A good pair of sharp-pointed calipers may reach in the gap well 
> enough that, with a slightly dropped crank due to loose caps, you 
> might get an accurate journal measurement.   You could also use 
> Plasti-Gage with new bearings to see if you guessed correctly.  Could 
> be expensive if you guess wrong, though.  The shells *should* be a 
> guide, if you can find an accurate dimension for new shells.
>
> Sounds like loads of fun for the New Year!
>
>
>
> On Sun, Dec 24, 2023 at 11:57 AM Bob Spidell <bspidell at comcast.net> wrote:
>
>     Merry Christmas Shoptalkers!
>
>     I've pulled the head, pan and pistons from my ancient Ford 851
>     tractor
>     (it was burning and belching oil and, well, it was time). Head
>     actually
>     not in bad shape; all but one cyl pass the (liquid) 'leak down'
>     test--valves hold solvent in upside-down chambers--but I'll get a
>     valve
>     job anyway. Couple rod bearings worn but not bad, one pretty bad
>     and one
>     with all babbit(?) gone and copper substrate fragmented (prob
>     would have
>     seized in a few more hours). I plan to drop the main caps and,
>     hopefully, extract the upper shells without having to pull the crank.
>     Cylinder bores smooth but in good shape; I'm thinking ball hone
>     and new
>     rings.
>
>     My questions:
>
>     1: Can I tap the crank's upper bearing shells out, then replace upper
>     and lower w/o pulling the crank (not at option)?
>
>     2: Since I can't pull the crank, and it's not worth removing and
>     grinding/polishing anyway, can I determine what size bearings to
>     use--rods too--by just measuring the old bearings and getting an
>     idea if
>     they're over/under and, if so, by how much?
>
>     All answers appreciated.
>
>     Bob
>     _______________________________________________
>
>     Shop-talk at autox.team.net
>     Donate: http://www.team.net/donate.html
>     Suggested annual donation  $12.96
>     Archive: http://www.team.net/pipermail/shop-talk
>     http://autox.team.net/archive
>
>     Unsubscribe/Manage:
>     http://autox.team.net/mailman/options/shop-talk/fishplate@gmail.com
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://autox.team.net/pipermail/shop-talk/attachments/20231224/829fd246/attachment-0001.htm>
-------------- next part --------------
A non-text attachment was scrubbed...
Name: RodBearing.JPG
Type: image/jpeg
Size: 753297 bytes
Desc: not available
URL: <http://autox.team.net/pipermail/shop-talk/attachments/20231224/829fd246/attachment-0001.jpe>