The Product Bulletin dated Sept 21, 1965 gives the info you're all looking for, on the 933G .. listed under "New model features - a digest of improvements" ..

In short .. this is the "new product release" info, for the "new" 933G, identified as S/N 42A5918-up.

The improvements are listed as follows ..

1. New turbocharged engine - D320T. Similar to that used in the 922B (59A series) .. 60 FHP at 1900 RPM.

2. A new final drive support which is mounted on the track roller frame and which extends back to the final drive cover. This gives support to the "new design" FD cover, which reduces deflection and extends FD component life.
The "new design" FD cover appeared on the 933G (no S/N given).
The "new design" FD covers are directly adaptable to all machines from 42A1-up. It is not considered economical to try to adapt these improvements to earlier 933's.

3. With the above design improvement, new track roller frame guards are used. These TRF guards are not interchangeable with earlier TRF guards, nor vice-versa.

4. New main relief and tilt relief hyd valves with increased relief pressure settings. Main - 1650 psi .. Head end tilt - 1800 psi .. Rod end tilt - 2050 psi ..
It is not recommended that these new valves be used on earlier 933 models.

5. Larger bucket. The largest bucket available with the 933F was 1 1/8 yds. The 933G now has a 1 1/4 yd bucket available. This new larger bucket has an extended heat treated cutting edge, and new tooth groups with adaptors that bolt only to the cutting edge are required.
It is not recommended that this bucket be used with earlier 933 models.
In conjunction with the new larger bucket, a 500 lb counterweight that was previously offered as an attachment, is now standard.

6. Stronger FD gears. The FD pinion and mating gear have deeper case hardening to improve wear resistance. The new pinions and gears are directly adaptable to all 993F's.

Thanks OzDozer for that info.
Regards
Martyn
The next question is about the plant the G's were built.Aurora, Why were the 933gs built there? was this factory just a loader plant? Would love info on Aurora,as the Cat Peoria factory is world famous.

The serial number books I have show the 933G starting at 42A6181?, I saw my first one around 1966, we were converting them from donkey engine to direct electric start at Bowmaker Plant, although the last couple we supplied to British Rail in 1968 went out with donkey engine start, the last time I saw one of them was at Yeovil around 1974 when I re-fitted a donkey engine.
british Rail also had the first 951 I ever saw, serial number 89A72 supplied in November 1964, before then they were using 955 12A machines, 5R series D6's and a 3T D7 at Stoke Gifford tip.
A strange thing I found out today, the early 933F 4" bore engine was still known as the D311 despite having no common parts with the old D2 engine, it was not called the D320 in the 933 before it became the D320T in the 933G.

What that D311 was your talking about was the new D311 and had the compact inj. pump housing on the right and was very similar to the D330 engine and yes they both were a completely new engine back then and the D330 replaced the D315 D4 engine and other applications.The D333 replaced the D318 like the D6 9U and other applications used too.

The "new" D311 was called the D311H .. to distinguish it from the earlier D311 that was fitted to the D2's, and the 933, when the 933 was first released, in Feb 1956 .. and yes, it was a totally redesigned engine ..

Seems we're still left with the dilemma of the D320T showing up at 42A5918 and the 933G designation later at 42A6164....unless I missed something. If this is correct the D320T arrived under the model "F" designation:confused:

OM - I thought the Product Bulletin info I wrote up, explained it in full. I guess you did miss it.

The "new" 933G model was introduced at 42A5918, as the PB advises .. along with the new D320T engine.

If you wish, I can scan the PB and post it on the BB, so you have a 'hard copy' to refer to ..

Hi OzDozer,
Works for me:) Just trying to get past the various bits of bogus serial number and model designation information. Sometimes you can't even believe the Cat literature:rolleyes:
Thanks for the copy offer but it's not really necessary.

I have been in contact with a guy that works at the Aurora Caterpillar plant.I have asked him if he can get hold of photos on the Traxcavator production at the plant.I hope to get over to the USA next year to meet up with John Drott junior.
Martyn

I gave the 933 a good run yesterday,the starting engine clutch problem has been sorted by taking up the slack in the linkages.The weather in the UK has been very wet,not as bad as in the Southern USA.