MM 445 oil pressure

[Jeep1980]

Hello, I have just acquired a real nice 445 from my uncles estate. We don't know a whole lot about how deep the restoration on the tractor went. I believe it was only a cosmetic restoration and nothing mechanical was done. It's been sitting for about 5 yrs due to his health at the time and I'm just starting to get it ready to use again. I filled it with propane and it starts and runs great. 3pt works and the ampli torc works. The problem I'm having is the oil pressure acts funny on it. Upon start up it builds 35lbs of pressure and will slightly raise with rpm increase but at about 1/4 throttle it starts to lose oil pressure. It never drops below 20psi but this seems opposite of what it should do. I attempted to adjust the external regulator on it and it seems to be working. I got an increase in pressure at idle but the pressure still falls with rpm increase. Just wondering if anyone has suggestions on what to look at next.

 

[J.Wondergem]

Are you running 15-40 oil? Did yo change the oil filter yet? The rule of the thumb is 10 pounds of oil pressure for every 1000 RPMs.

 

[MMDEL]

It is possible the pick up screen is partially plugged and when you rev it up it calls for more oil and if the screen is plugged the oil can't get through. Basically the pump is cavitating and of course the pressure would fall. Unfortunately you have to take the cover plate off of the side to look inside the crankcase. You might be able to drain the oil let it drip drain overnight and then go up through the drain hole with a borescope to look around an see what the inside looks like. Being an LP it really should not be gunk ed up. You can buy a borescop that hooks up to your smart phone for around $20 at Amazon. Also I would have to check, that is the same block as the Z and I think at the front of the oil pump ahead of the oil filter canister there is Pipe plugs . The one goes straight through a passage that feeds the oil pump. If you stick your finger in there it would give you some idea if it is real clean or gunky.
MMDEL

 

[SWMolines]

This has been mentioned here previously. The high detergent oils available today can loosen old slug in engines that were not using HD oils in the past resulting in plugged pick-up screens.

 

[Jeep1980]

Well, I haven't changed the oil in it yet. I know it doesn't mean much but the oil on the dipstick looks good even on a white paper towel. Not being able to verify it's age and hours since the last change I'll do that this weekend. Probably going to go ahead and pull the pan off it too just to clean it out. At least then I'll know for sure what it looks like as far as sludge.

 

[MMDan]

Well, I haven't changed the oil in it yet. I know it doesn't mean much but the oil on the dipstick looks good even on a white paper towel. Not being able to verify it's age and hours since the last change I'll do that this weekend. Probably going to go ahead and pull the pan off it too just to clean it out. At least then I'll know for sure what it looks like as far as sludge.

There is no pan to remove on that engine series-just a large side cover on the left side to get access to the crankcase.

 

[Jeep1980]

I will take that off and have a look this weekend. I'll let you know what I come up with.

 

[Jeep1980]

I've found a combination of things I believe are contributing to my oil pressure fluctuation. The o ring on the floating pickup is deteriorated and sticking the pickup so it did not move without encouragement. Also there was a fair amount of sludge on about half of the pickup screen. I've got everything cleaned up and am going to re assemble later today. Thanks for the help so far. I'll let you guys know if I run into anything else.

 

[Jeep1980]

Drove it around for awhile tonight to get it warmed up. It hold 40-45lbs of oil pressure throttled up now. After about 20 min of driving the rear main seal seems to have decided to leak pretty good. Time to figure that one out now.

 

[SWMolines]

Regarding the rear main seal leak, I'd check the fluid level in the tranny and TA be certain they are not over full.

 

[molinegb]

Drove it around for awhile tonight to get it warmed up. It hold 40-45lbs of oil pressure throttled up now. After about 20 min of driving the rear main seal seems to have decided to leak pretty good. Time to figure that one out now.

I would lower oil pressure to 25-30 warmed up.

 

[T.R.K.]

Regarding the rear main seal, I am thinking a 445 crank will have a felt seal with a spiral groove machined in the crank. If this is the case, it won't work with a more modern lip seal. You have to install another felt seal.

 

[molinegb]

Regarding the rear main seal, I am thinking a 445 crank will have a felt seal with a spiral groove machined in the crank. If this is the case, it won't work with a more modern lip seal. You have to install another felt seal.

Is a felt seal but lip type can be used with a speedy sleeve

 

[T.R.K.]

I wonder what a approximate 4 inch speedy sleeve would cost. A speedy sleeve for a shaft about 1-1/8 dia. was $50.

 

[Duane Kaufman]

Hi All,
I didn't know what a Speedy Sleeve was:

SKF Speedi-Sleeve​

This thin-walled sleeve [0,25 mm (0.01 in.)], developed by SKF, is simply pushed in position over the worn area, providing a counterface surface that is optimized for radial shaft seals.​

https://www.skf.com/us/products/ind...smission-seals/wear-sleeves/skf-speedi-sleeve