Oil Dipstick Tube Broken in Block, 1972 350

[Larry M.]

Re: Oil Dipstick Tube Broken in Block, 1972 350

Joe,

If I end up removing the pan, yes, I'll post a photo of the tray.

[Larry M.]

Re: Oil Dipstick Tube Broken in Block, 1972 350

I just remembered I had some photos of the engine assembly from 1988. This is the only one that shows the tray:

engine0001.jpg

[Joe L.]

Re: Oil Dipstick Tube Broken in Block, 1972 350

I just remembered I had some photos of the engine assembly from 1988. This is the only one that shows the tray:

[ATTACH=CONFIG]67819[/ATTACH]

Larry------


Yup, that's the GM #3989075 windage tray as it should be. If you have a photo taken from the other side you'll be able to tell if the lower dipstick tube was installed.

[Larry M.]

Re: Oil Dipstick Tube Broken in Block, 1972 350

I stand corrected - there is also this photo showing the tray, and from the dipstick side of the engine. I can't see anything that appears to be a tube sticking down into the crankcase area.engine20001.jpg

[Joe L.]

Re: Oil Dipstick Tube Broken in Block, 1972 350

I stand corrected - there is also this photo showing the tray, and from the dipstick side of the engine. I can't see anything that appears to be a tube sticking down into the crankcase area.[ATTACH=CONFIG]67820[/ATTACH]

Larry------


I don't see it, either. However, it's possible it was installed at the time that the upper dipstick was installed, after this picture was taken. I sure hope that's the case.

[Larry M.]

Re: Oil Dipstick Tube Broken in Block, 1972 350

So if the lower tube isn't installed, it'll be more difficult to drive out the stub?

[Joe L.]

Re: Oil Dipstick Tube Broken in Block, 1972 350

So if the lower tube isn't installed, it'll be more difficult to drive out the stub?

Larry------

Yes, the lower tube has a flange on the top which seats onto a seat machined into the block. It's the flange on the lower tube that serves as the surface which contacts the upper tube in order to force it out. If there's no lower tube, then there's nothing to contact the perimeter of the lower end of the upper tube remnant. However, you still MIGHT be able to do it by using a lower tube and inserting the UNFLANGED end from below and driving it out. I've never done this but it might be possible.


GM#3951600(b).jpgGM#3951600(c).jpg

[Richard M.]

Re: Oil Dipstick Tube Broken in Block, 1972 350

I really think this would be a great application to use my favorite liquid tool..... CRC Freeze-Off. This will shrink the tube diameter, which is what you want to do. Any screw in extractor/puller is fighting the sidewalls and expanding the tube. I would not attempt that procedure.

This liquid tool will of course require a oil change after the process to remove the penetrant from the oil in the pan that is combined with the refrigerant in the ingredients of the product. Since the broken piece may have fragments already down in the pan, to me a oil change is a given.

This is how I would approach it.

Try to insert a small rubber plug into the bottom of the tube, just enough without falling into the pan. This is optional. It may be best without any blockage of the inner walls of the tubes length.

After seeing your photos, I would prepare the broken piece by using a small drift/pointed drift, tapping the exposed edges inward towards center. Try to create a smaller diameter top end. Cave the top edges inward. This may give you a "end-pull" without expanding the broken piece sidewall. Leave enough of a hole so you could insert a long sheet metal screw, say a #10, #12, or 1/4" x 3" or so. Test fit the screw by hand to create a mini puller.

Unscrew the screw. Place plenty of rags around the area leaving the tube top exposed. Wear eye protection. Maybe even a breathing mask as the product is pungent when used indoors.

Apply the Freeze-Off directly inside the sidewall of the broken tube. Shoot it at least 20 seconds as the instructions state. Maybe longer.

Insert your "puller-Screw" back into the tube. Use pliers to grab the head of the screw and give it a few tugs.

Maybe a 2nd or 3rd application.

My bet........it will eventually come out.

Rich

[Larry M.]

Re: Oil Dipstick Tube Broken in Block, 1972 350

Thanks; god top know that's an alternative.

Any idea how far the lower tube extends below the oil pan rail? I ask this in case when I drop the pan I see it, or a portion of it.

[Joe L.]

Re: Oil Dipstick Tube Broken in Block, 1972 350

Thanks; god top know that's an alternative.

Any idea how far the lower tube extends below the oil pan rail? I ask this in case when I drop the pan I see it, or a portion of it.

Larry------

As I recall, it extends about 2 to 3 inches below the oil pan rail.

[Richard M.]

Re: Oil Dipstick Tube Broken in Block, 1972 350

Joe, You are right in the range.

If a 283CI uses the same parts, here are some reference measurements I just snapped. It's a NOS tube 8 1/8" long, and when I drive it home all the way it'll be about 2 3/4" into the crankcase area.

The bored area for the upper tube is apx 1" deep before getting to the smaller ID for the lower tube.

P1100007.jpgP1100008.jpgP1100009.jpgP1100010.jpgP1100011.jpgP1100012.jpgP1100014.jpgP1100015.jpgP1100016.jpgP1100017.jpg

[Mark E.]

Re: Oil Dipstick Tube Broken in Block, 1972 350

Rich's method is probably worth a go.

But if you must resort to removing the pan, as mentioned earlier it's not a bad job in these cars since the pan sits behind the frame's crossmember. This means there's no need to raise the engine or mess with the motor mounts. I did this job not long ago (to replace the rear main seal and oil pan) and found the procedure less involved than changing spark plugs. To add to Joe's comment about merely unbolting the idler arm and lowering the steering linkage, I suggest referencing the service manual. It explains the complete procedure step-by-step.

I took Joe's advice and used the one piece Felpro oil pan gasket. I chose the kit with the plastic retainers to hold the gasket to the block, and installed it dry as per its instructions. Simple, clean and no leaks. The gasket is a bit thicker so you may need longer oil pan bolts. (My experience is with a big block; I understand Felpro makes a similar SBC gasket kit.)

[Tom B.]

Re: Oil Dipstick Tube Broken in Block, 1972 350

I threaded the tube with a tap then put a small slide hammer on the bolt I threaded in and it came right out.

[Larry M.]

Re: Oil Dipstick Tube Broken in Block, 1972 350

Thanks all who've responded. I appreciate your ideas and suggestions. I won't be working on the car till next Saturday. I have an idea I'm going to try, and I'll let you know the outcome. Even though I'm fairly confident I'll end up removing the oil pan, I'm holding off on that as long as I can.

[Larry M.]

Re: Oil Dipstick Tube Broken in Block, 1972 350

Richard,

Excellent photos and measurements; thanks.