49 cub oil pump

[oldiron29]

Cub guy, this is a first for me on your site. I have been on yesterdays tractor many time, I have become very versed in the F series but some what new to cubs. I have 3 but have never had any problems. I change the oil and tune ups, hook up impelment and do baseck repairs. I bought a 1000 one arm loader I wanted to put on my 49. I bought the bypass block and I pulled out pistons and put new rod bearings and rings in tractor. All back together and running fine. My big mistake is I put the block on and to stop if from leeking I pluged outlet. so picked up oil and hydo pump primed and it went thud, oil dripping out of the oil pan. Any way broke the cam gear I pulled the front all apart got new cam gear seals and gaskets put it back together. I took out by pass block. She starts and runs BUT! I had 40 lbs oil pressure after rebuild, now I have
10-20 and very erract it dropsfast to 5 and than back up. Could the key in the oil pump be broken or is there something else it could be. Every thing was cleaned new filter relife valve is free moving. And now I will not put the by pass block on till the loader is on and I can hook up hoses.
Thanks for any help oldiron29

[Bigdog]

There are many others more qualified to answer this than I am but I think you may be onto your problem. Unfortunately, the only way to say for sure is to remove the pump and check it. I can't think of anything else that would cause those symptoms.

[John *.?-!.* cub owner]

Before you tear it down too much, pull the regulator valve and check for sticking or crud. It is the hex headed cap screw on the right side close to the front. another possibility would be one of the rod bearings spinning.

[Eugene]

I really don't have a good answer. I suspect you are going to have to disassemble the engine to disclose the problem.

An issue/item frequently causing low or no oil pressure after an engine overhaul is missing allen screws. The allen screws are used to plug the oil galleries. There is an allen screw under the cam shaft timing gear.

Check the allen screw(s) under the valve tappet cover. Simple check.

The woodruff key in the oil pump is pretty hefty. If that key is sheared - something would have had to cause the oil pump gears to jamb. In that case, most likely you would have no oil pressure.

Cam shaft broken behind the #4 cylinder cams - but I don't see that happening .

[Bigdog]

Eugene - since the force was great enough to break the cam gear isn't it an indication of a pretty severe shock to the engine? At least enough to have possibly sheared a key. (Just thinking out loud here. I'm certainly not qualified in any way to call myself a mechanic.)

[oldiron29]

Guy's thanks for all you help. Yes the force was hard enough to brake th cam gear into many piecs and I guess I will split it to check pump and I hope that is the problem or I don't no where to go after that. I hope it is the woodrif key and not the cam shaft. oldiron29

[Eugene]

I bought a 1000 one arm loader. I bought the bypass block and I pulled out pistons and put new rod bearings and rings in tractor. All back together and running fine.

My big mistake is I put the block on and to stop if from leeking I pluged outlet. so picked up oil and hydo pump primed and it went thud, oil dripping out of the oil pan. Any way broke the cam gear I pulled the front all apart got new cam gear seals and gaskets put it back together.

I took out by pass block. She starts and runs BUT! oil pressure 10-20 and very erract it dropsfast to 5 and than back up.

Eugene - since the force was great enough to break the cam gear isn't it an indication of a pretty severe shock to the engine? At least enough to have possibly sheared a key. (Just thinking out loud here. I'm certainly not qualified in any way to call myself a mechanic.)

Me to BD, just thinking out loud. I have read the original post several times. I think the hydraulic pump locked up - no outlet for the hydraulic oil. The locked hydraulic pump broke the cam gear.

The engine oil pump is located on the rear of the cam shaft. It doesn't really take a whole lot of torque to turn the oil pump. If the front of the cam stopped suddenly - I don't think the torque on the oil pump would shear the woodruff key.

I can envision that with the cam gear breaking, pieces of the gear catching and driving the camshaft backwards - towards the rear of the engine by several thousands of an inch. Driving the camshaft into the oil pump and oil pump case.

Just thinking out loud.

[Eugene]

Still thinking about this situation.

I would suggest tearing the engine down looking for damage other than the broken idler/cam gear. Check for damage to the camshaft, camshaft front journal and block bearing surface. Also check the crank, #1 main journal and bearing.