The joys of working on old tractors......

Sun Oct 06, 2013 1:40 pm

Been working on my 47: rewired, replaced head, front bolster, radiator, and front wheel section. Trying to fix leaks as I move to the rear. Cranked using auxiliary tank and drove around the yard some. It finally turned as it should :-:-): . Ran diesel in transmission to clean. Replaced trans fluid. Went to change the oil :censored: . Bolt going through filter appears to have been stripped a some time. Top oil cap has been broken from over tightening (sounds like something I would do :oops: ). Now when looking into the hole where the bolt attaches there is what appears to be a fitting that that may screw out for replacement. Will it come out? I have put a socket on it but do not want to make my problem worse. Thanks. Been keeping me out of trouble by spending so much time and money trying to get it fixed :D

Re: The joys of working on old tractors......

Sun Oct 06, 2013 1:52 pm

jworthington wrote: looking into the hole where the bolt attaches there is what appears to be a fitting that that may screw out for replacement. Will it come out?
There is an orifice in the bottom of the oil filter housing, where the bolt goes. Orifice is part of the oil pressure regulation.

I checked a couple of parts and service manuals and did not find it listed as a separate item.

Don't know if it will come out. I would leave it alone.

Re: The joys of working on old tractors......

Sun Oct 06, 2013 1:59 pm

I suspected that would be the answer :( . I will try to hold my mouth just right when I put it back on.

Re: The joys of working on old tractors......

Sun Oct 06, 2013 2:26 pm

I am ashamed :oops: . I should have looked this up first. The part I am referring to is 251 390 R1 on page 27 of the TC 37 manual I have. It is listed as Adapter, oil filter stud. It looks like a bushing. So maybe it can be removed?????

Re: The joys of working on old tractors......

Sun Oct 06, 2013 3:22 pm

Welcome to the "Joy of old tractors" club! LOL !! Can sympathize with you completely - thing is, when you have more than one you can change from one to the other(s) so you don't get bored or while waiting for parts!! Good luck. Dusty B

Re: The joys of working on old tractors......

Sun Oct 06, 2013 3:40 pm

I would just clean the threads and put it back in.

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Re: The joys of working on old tractors......

Sun Oct 06, 2013 3:45 pm

Your question about the filter bolt fitting at the bottom of the filter housing is a good one. I have never had a reason to deal with it, but I have noted that there is clearly what appears to be a large hex collared fitting at the bottom of the filter housing. You say your filter bolt is stripped so you obviously need to address the issue. Guys like Clark Thompson and others who have done major engine overhauls should weigh in on this one. Can you tell if the threads are stripped off the bolt rather than the fitting it threads into? If so, you may be able to clean up and restore the threads in the fitting by running a tap through the threads. The threads on the bolt appear to be straight and not pipe fitting threads. The way the filter works, as I understand it, is that it is a "bypass" system. This means that the filter housing is in the oil distribution circuit but rather than a positive filter system that filters all the oil before it is pumped through the lubrication circuit, the bypass system is on the side of the lubrication circuit. As such, even if the filter gets plugged, it will not impede the flow of oil through the circuit. The downside is that all the pumped oil is not immediately filtered before it is pumped through the lubrication circuit. The by-pass system filtration is continuous but slower and the filtered oil is returned to the crankcase after filtration rather than to immediately lubricate the engine. You will note that the bottom portion of the filter bolt on the Cub is hollow up to where a small orfice is found on the side of the bolt. It is through this small orfice that the filtered oil enters the hollow portion of the bolt before returning to the crankcase. It is important that this orfice be clean but not enlarged since its size controls the amount of oil passing through the filter while assuring that sufficient pressure is maintained to deliver oil through the internal engine channels to lubricate the engine. The orfice should be open and clean, however, otherwise little or no oil will get filtered. I will note that the oil in the filter housing drains out by gravity through this small orfice after you shut off the engine. This is why you do not immediately have oil pressure upon starting the engine since the pump must first fill the mostly empty filter housing before a build up of pressure can occur. Since the lower portion of the bolt is hollow, if someone were to torque the heck out of the bolt because he couldn't think of any better way to keep the cover from leaking oil, he likely could compress the hollow bolt, bend up his cover, and strip out the threads. Obviously, no such man handling of the filter bolt and cover is necessary if you have a new gasket and use common sense to make sure the sealing surfaces are smooth, straight, and clean.

Re: The joys of working on old tractors......

Tue Oct 08, 2013 11:42 am

Get a good 6 point socket and pull that baby out. If you can't find one to buy, take it to your local Vo tech machine shop class. That would make a nice little project for a student.

Re: The joys of working on old tractors......

Tue Oct 08, 2013 5:11 pm

Thanks guys! I have ordered a new oil cap and bolt (Ebay) and will try to clean the threads (using a magnet to catch filings) before trying to remove the bushing. Maybe I will get lucky.

Re: The joys of working on old tractors......

Fri Oct 11, 2013 6:04 am

Got my new bolt and oil cap in mail yesterday :eBay: . Tried the bolt and it would go in about a half turn and bind. Bolt had a burr so cleaned that off. Still half turn and bind. Took Dan's advice put a socket on it and pulled and it broke loose. Ran a tap on it and :{_}: the bolt now works. The fun part was putting the bushing back in since my hand would not fit in the hole. Tried a pair of long need nose pliers to no avail. Then it hit me :idea: use the bolt. So later today I am going to drop the oil pan and clean out. Add some oil and hopefully go for a longer drive.

Re: The joys of working on old tractors......

Fri Oct 11, 2013 8:28 am

Ah yes, working on these old machines and making progress, actually making improvements, is a bit like fine chocolate or really good ice cream, small bites to be savored! :D

Re: The joys of working on old tractors......

Fri Oct 11, 2013 2:12 pm

Pulled oil pan this afternoon. No metal in bottom :{_}: . But I did find about a half inch of the oil filter bolt :!: . Guess somehow it was broken off at some point but I'll be :censored: if I know how. Going to rebuild carb and hopefully get started again.