D950 Gear Case SEAL OIL(15841-04140)

[jimybud]

I am planning to replace the oil seal (15841-04140) on the front of the engine of my D950.

a couple of questions:

Can I replace the oil seal WITHOUT removing the gear case?

What is involved to remove the PULLEY FAN DRIVE (15752-74280)?

Any details would be appreciated (i searched the forum and could not find any information on this basic procedure).

 

[Stumpy]

No and unpleasantness. No way to change the front seal without removing the cam gear case. I can't tell if you're motor is separate or part of a tractor but if it's in a tractor you've got some work ahead of you. I show how I did it on my L175 here. Start at post 25. The entire front axle assembly has to come off, thus a thousand other things do too.

To get that nut off you'll need a 46mm wrench or DEEP socket (a regular one won't clear the splines). 1-13/16ths also works. I opted to make a crows foot but most people don't have access to a mill so you're probably going to have to drop some change on a single use tool. Get someone to brace a screw driver between the flywheel teeth and the timing port to hold the crank. Then hammer the nut off, remove the pulley and it's key. The oil filter housing has to come off as well and the two governor springs must be disconnected. I think the alternator has to come off too, I don't remember but it should be obvious once you get into it. Take your time removing the case, mine was stuck on pretty good thanks to some corrosion on the internal water neck. Enjoy scraping that gasket and don't forget to replace the three orings near the oil filter and the one on the water neck.

 

[jimybud]

The seal will not remove from the front of the case? I was hoping that I could removed the pulley from the crankshaft and then remove the seal from the front similar to how I replace seals on mower gear boxes.

It seems odd to me that the design would be such that the entire case would have to be removed to replace a seal.

I also noticed there are some differences in the gear case between your two cylinder engine and my three cylinder.

Thanks for the consideration.

 

[bruceatlam]

It might pay to invest in a WSM -----

 

[Stumpy]

The seal is pressed into the case. There is no lip, at least on mine, so theoretically it could be pulled out in place. The thing is it's in there tight enough I have no idea how you'd do it. I wouldn't want to drill any holes and risk getting swarf inside the engine.

 

[jimybud]

The fact is not a lip is on the case gives me hope that I may be able to remove it from the front without case dis-assembly/removal.

Based on your previous thread, it sounds like a horror story if I have to remove the case to replace it.

I will post a followup with the results of my actions.

Separately, did the crankshaft pulley on your engine have three bolts in addition to the nut you had to remove (I could not quite tell from the photographs in your prior thread)?

 

[Stumpy]

Nope just the big nut. My pulley has two threaded holes in it that are to my knowledge used to bolt secure something to the front PTO spline but that's just what I've got, your's may differ. A service manual or even a free parts diagram from Messicks.com for a tractor with that engine will tell you more.

If I may ask how do you intent to get the seal out while it's still on the motor?

 

[jimybud]

I am presuming that I would be able to get it out similar to how I have removed freeze plugs on blocks and oil seals on mower deck gear boxes.

I take a punch and hammer and actually isolate on part of the seal and hammer it IN. The result of this is that the opposite side of the seal will actually come OUT some.

I then would take a small screw driver or other hook type tool and try to pull it the rest of the way out.

sometimes I was able to get it out very easy with this action. The last seal I had to remove I ended up damaging it pretty good as I had to hook it from the inside and pull it. My main focus is to be sure not to damage the shaft or the case cover.

Let me know if based on your experience if you think I may have success with the procedure of if you think the removal of the crankshaft seal would be different than the mower deck gear box seal.

 

[Stumpy]

Jimmy you are one lucky fellow. Your question intrigued me enough to pull my boots on and walk up to an icy barn in lieu of studying my Calculus to dig through the Bench of Lost Souls (*Parts ) to find my old front oil seal, cut it in half, and take a picture of it for you.

This is a profile of the seal, the front is to the right, the engine to the left. As you can see it's got a single band of steel with rubber molded over top that seals in the housing and a spring inside a groove in the rubber that provides additional sealing around the crankshaft bushing. It's not as rigid as I remembered (the rear definitely is) but it's not insignificant. Also if you look at this picture:

You'll see what looks like a big washer on the crankshaft. If I still had that case off I could tell you for sure but I believe that washer prevents the seal from being pushed any further back in the case. So it's wedged in there pretty good but you might be able to do it provided you hook that band with something and can pull it out straight. I'd be afraid of that band gouging the aluminum housing if you tried to cock it in the hole. Just be sure nothing falls back into the engine or you're taking the case off anyway to clean it out.

It's could work but personally I'd rather go with removing the case. Mitigating the risk of damaging that housing is worth the cost in part and time to me. That's just how I see it, hope this helps!

Matt

 

[Swamper]

Stumpy,
Nice work, great information. Definitely above and beyond. If the seal is installed from the front of the cover, there may be a shoulder in the bore that the seal bottoms against. I would be careful trying to tap the seal inward. It looks like a thin hook attached to a small slide hammer might grab the lip on the inside of the steel band. The cover itself would be protected from the hook. Shouldn't hurt anything to give it a try. My two cents.

 

[jimybud]

Thank you very much for the above and beyond effort. The additional photographs are wonderful.

It may be a week or so, but I when I complete the task I will provide feedback to this thread of my success/failure.

so the best you can tell, when the seal in in the proper position the back side of the seal is pressed up against the "washer" depicted in the photograph?

I may just try and hook it and pull it as recommended. Usually under this process the seal becomes destroyed but it will be going in the garbage anyhow.

 

[Stumpy]

As far as I can tell without taking it apart and looking again yes.

Good luck!