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oEmails (Dave Baker) wrote in message ...

I am not sure what grade bolts were in there but I put grade 5 back
in. (new bolts) The threaded portion the bolts go into are in the
transmisison casing itself which i assume is cast iron. I was more
afraid of stipping those out than anything.

Can I get by with 20 ft lbs?

If you think you know more about the engine's design and requirements and bolt
theory than the guy who designed the engine then by all means carry on. If you
replace high tensile bolts with pieces of **** and do them up to half the
required torque and it all falls apart don't be too surprised.

Tsk, Tsk, Dave. Bad form.

However, having bits of knowledge that you may not, having spent some
12 years working in Case transmission plant, and he DID say "in the
transmission", here goes. Rule number one, tractors, especially old
ones are WAAAYY overbuilt. Bearing retainer, which I will assume is a
retainer holding the bearing in a blind bore, or a bore/ counterbore
in the transmission housing, and probably four or more bolts, is
probably overkill to the extreme. I believe he said it was the
intermediate shaft, and the only thrust forces on it are going to come
from the helix of the gears, assuming they're not spur cut gears. The
35 ft/lb sounds like it was intended to be self locking, no lock
washer, not a common practice, but IH did a lot of things that were
not common practice.

A further guess, the retainer is cast iron, and the bolt pads are
probably about the same thickness ad the bolt diameter, meaning that
if anything breaks, it will be the cast iron beneath the bolts. Also
meaning that the weakest point, even with grade 5 bolts is going to be
the cast iron. I'd have to say that if he used a lock washer to
prevent it backing off, torqued to the 20 ft/lb, it will probably last
longer than what is going to be the next thing in the transmission to
go, more than likely a bearing somewhere, or the teeth off a gear.
Tractors of yesteryear were made with being able to field service them
in mind, and they knew that more than likely the service was going to
come from a farmer with hardware store parts. Chances are that the
bolt size and length were picked to be able to use something they
already used in an other application, if it was a higher grade, in the
lots they buy in, price difference isn't going to even make a dent,
where having several different similar bolts with different numbers
will make keeping the inventory cost more than using a higher grade
than is really needed. This applies to older tractors, the newer
ones, manufacturing cost is a higher priority than availability,
reliability or serviceablity. Then we wonder why the small farmers
are selling out in droves.