Saving grandpas grader

[Old Magnet]

The maximum rod journal wear is 0.007 in. The maximum clearance wear for journal and bearing is 0.013 in.

The s/n tag on the grader is about half way up the frame on the LH side.

Head torque:
Be sure to check liner projection before mounting the head.

[1_sparky]

It is a 3U504 0r 3U584 kind of hard to see in the back of a dark barn.

I measured the crank with a Starett mike and I took the rods to my buddies shop and he came up with 3.008. I don't know how he measured them because I was doing some electrical work for him at the time but I know his "inspection department" has been certified to do work for NASA and the Air Force.

So with .013 max play and I have .008 I guess it it will be good enough to play around with on the weekends? The mains were the last thing that he was working on so I am thinking they were good.

[Old Magnet]

Sounds a little shaky.....I'd review the numbers one more time.

[1_sparky]

A little update found a box of connecting rod bearings so I put them in. I used plastigauge on both the mains and connecting rods and all seem to be in the .006 range maybe a little tighter.
After polishing one of the liner counter bores they are all sitting at the same height of .005 I don't see anything in my book so I guess I am good to go and install the head any tips.

I have the oil pump that has been in a sealed bag along with the head from the machine shop. The tag says decked and new gears and shaft installed. Do I need to do any pre lube on this type of pump? I don't want to take it apart but it looks like there is some sort of thin grease packed inside of there.


I found the fuel pump over on his bench across the shop all disassembled. I found two new gears and a new pumping section 4b-9047. Any tricks on reassembly?

[rjh-md]

turn the oil pump up side down ,and pour clean 30 wt desiel oil in it ,and turn the pump shaft over to draw oil in to both sides of pump by hand ,install the pump ,and sucksion screen 3/8 nc bolts and L364 locks on each bolt and sucksion tubes
tighten bolts to 32 + or - 5lbs, lock by bending securly, 1 flat hex on each bolt head and bend down the middle tab in opposite direction against the housing .
Fuel pump , Sounds like you have the main body parts to the pump. Are there new bushings ,and a seal for the main shaft ? You may want to replace them at this time.
Check the bottom plate if its old to see if the old gears ,and dirt,water, have cut a circular pattern in the plate ,if its grooved more than a couple of thousands ,and can catch your finger nails ,you may want to replace it or rub the plate over fine 220 sand paper streched out over a piece of glass to sand out the grooves or take plate to machine sop and have it surface ground
Assemble the pump lubercating all parts with oil 5/16 bolts in bottom plate retain pump sections torque to 22 lbs when assembling ,check to see if pump turns over after tightening bolts if not you may have to ream shaft bushings .
2 -3/8 long studs,lock washers ,and nuts hold the pump to the fuel pump housing with a gasket
There,s a by pass valve bolted to the fuel pump and the fuel line from the tank goes to it .take valve apart ,and inspect,and clean the rubber seat ,spring ,and casting .
Good luck!

[Old Magnet]

0.005 is the high end of spec for liner height.....did you have them clamped down to take the reading?

[1_sparky]

rjh-md thanks for all the good info thanks.


OLD magnet I used an OTC #7106 tool set to measure the liners while torqued.

Since they are all consistently too high do you have a part number for some thinner copper shims for under the liners? Or are these old motors like the Lister diesels where you have to machine the top of the liner to get them into spec?

[Dandy Dave]

Nice to hear it is being saved. The correct way to say the model number is, "One Twelve" This model with the D-315 is the same basic engine engine that a D-4 6U and D4-7U used. It always baffeled me a little as to why Cat designated the smaller graders with the bigger numbers back in the day. The "Two twelve" from about 1948 and well into the 50's used the D-311 engine which is the same basic engine as the D-2 4U and 5U. My neighbor has a Two Twelve that has direct electric start. Suffix is 79C-42 which is a 1955. This option is rare. I wish he had some road work as I love to run a grader and have run the 212 in the past. The model 12 of the era used the same basic engine as a D-6.

With that much wear in the bearings you are on the edge, and I would replace them with a new set of standard bearings.

You can also look on the left side of the grader frame near the front where it bends downward to the front axle for a Brass serial tag. Unless the engine was replaced, the number should be the same for the engine. Dandy Dave!

[Dandy Dave]

I guess I should have looked at page two...According to my serial number book your machine is a 1948. Dandy Dave!

[Old Magnet]

I wouldn't say that 0.005 inches is to high, it's just at the high end of the recommended range. Being that they are all reading the same I'd leave it alone.

I don't have the part numbers for the shims (that I could find anyway). I believe the part numbers were supplied with Cat's counterbore tooling if you go looking.