Oil pump gear placement and grub screw

Rebuilding a 1968 109 with a 2.25L petrol. Had the block redone, crank and pistons installed by the machine shop. Refitted the camshaft, set up the timing with little issue. Now installing the oil pump drive gear.

Just trying to put the oil pump drive gear back in and final lined up the master spline, when I try to line up the hole for the grub screw, I have to lift the whole body of the drive gear up about the length of the hole to get it lined up, which means the whole thing will be resting on the grub screw, is this correct?

I never took apart the oil pump drive gear assembly and I don't have any bits that appear to go under under the gear for it to rest on.

Many thanks for any thoughts and advice.

Hi @ColinP

I just rebuilt my 2.25L Petrol engine and am in the process of putting it back in the car. Dropping the drive gear down through the distributor mounting hole and lining up the hole for the grub screw that retains it is one of the most frustrating parts of the whole rebuild, in my opinion. I think it took 20 attempts to get it to settle into place correctly, because it rotates as the helical gear meshes on the way down. I used a long needle nose pliers putting outward pressure on the inside diameter of that gear to help control it as it drops. When the hole is at the correct level for the grub screw, it is NOT all the way down, as you pointed out. You also have to have the correct #1 cylinder TDC so that when the drive screw settles into place, that slot on top is rotated 20 degrees from the "horizontal." THAT is the real challenge.

thank Dhagar

I watched Britannia Restoration for tips https://youtu.be/OpX4wrzrQF8?list=PL...BMbYuOSnCfyiIx. He replied to my question and also confirmed what you said. I feel much better now, I thought perhaps I left out a thrust washer or something! for future readers looking for the same answer to this rubric cube puzzle; Once you line up the hole in the horizontal, you can slide a screwdriver into the bolt hole below the grub screw hole, to lift the assembly up and align it in the vertical.

A friend taught me this method and I have used it several times now. It works like a charm. Turns an agonizing procedure into a 5 minute job. Make sure the bush on the drive gear is easy to rotate and put some "three in one" light oil on it. Install the gear with the "master spline" located at the two o`clock position when standing at the side of the engine. Advance the gear as you drop it in as it is aligning on a skew gear. Check that it is at the correct position. Using a pair of long needle nose pliers, grip the inside of the drive gear and with a bit of a twisting motion, move the gear up and down without disconnecting the gear. At the same time put a thin screw driver or a piece of wire inside the screw hole so that is just touches the drive gear bush. As you move the gear up and down the bush will rotate and you will soon feel the hole "arrive". Do not let the bush bottom out or the hole will not align, keep it just slightly of the bottom position and install the grub screw with a bit of loctite. Do not over tighten or you will bind the bush.Remember, there is a small oil hole opposite the grub screw hole on the bush. Not the hole you are looking for.

Brett

Hello. Just did this on my engine build. Here is what worked for me. Dumb luck : ). Just kidding.

Now that I have done this I see exactly why it is so challenging. If the drive gear assembly only had to rotate and not move slightly back up it would be so much easier. I dropped the assembly in and engaged the camshaft gear. To start I got the master spline thing lined up as the Haynes manual shows. I might have had an advantage here since my engine is apart. I used the oil pump drive to help push the assembly up/down while I got the master spline aligned properly. Once the master spline is right now the part to get the grub screw aligned. If you let the gear assembly bottom out you will notice that you will see a small section of the sleeve assembly through one of the oil pump holes to the left of the grub screw hole. I used a chop stick with a rubber band taped to the end to allow me to created some friction and rotate the sleeve assembly. Now rotate the sleeve and then push the gear assembly up with the oil pump drive. While doing this look into the grub screw hole and look for the hole to line up. Hope this makes sense. You basically can only rotate the sleeve but to see if the hole is right then you have to push up the gear assembly. Little bit of a process but eventually I got the hole in the right place then just hold the oil pump drive very still while you tighten the grub screw. Last make sure before you start that your timing is properly set with cylinder 1 TDC and the camshaft sprocket "P" aligned to the correct front cover bolt. Cheers, Tom

For the past 30+ years we've been using a HERBRAND 185 or PROTO #251 circlip installation tool, with parallel-expansion pantograph jaws and I'd swear they made a mistake when they designed them 'cause they are ABSOLUTELY IDEAL for fitting the distributor drive gear. They make the job a lot easier than falling out of bed and I've DONE IT SO MANY times; it's SO controllable that it makes the job a dream!!!!