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Hi folks,

First time here! Have an MTD rider, 13HP tecumseh OHV 130 engine, 1997. Severe oil leakage is seen right where the engine base sits on the black steel MTD frame base. I even added tracer dye, and its glowing with a blacklight. Im guesssing its the lower (main?) engine seal.

I peeked under there and looks like I first have to start by unbolting the pulley, right?

Thanks!

As a rule it isn't a bad job. If it is leaking oil on the pully it should come right off. Drill a small hole into the old seal and install a self taping screw into it. The old seal should pull right out. Now just tap the new seal in with a small hammer.

reynoldston said:

As a rule it isn't a bad job. If it is leaking oil on the pully it should come right off. Drill a small hole into the old seal and install a self taping into it. The old seal should pull right out. Now just tap the new seal in with a small hammer.

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Thnaks, reynold! Geez, thats all there is to it?? Great!! Now, that pulley- it comes off easy by unscrewing a bolt? set screw? other?

Thnaks!!

There is just a bolt that holds the pulley on. Like reynoldston said with all the oil dripping on the pulley it should come off easy. Key word is should.

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OK, I get it, Car! Thnaks!!

Hi Guys,

Well, that pulley is not "pulling right out". The 16mm bolt head , upon turning to loosen, turns the pulley/crank shaft spinning round, of course. Looks like no way around wrapping one of those chain "strap" wrenches around that pulley, right?

But that is a chore. Man, there are 2 stud like "guards" which prevent the belt from jumping the pulley notch, of course, and as a result, its so hard to get up in there with the wrench/chain.

Oh well, I will not give up. As long as Im on the right track, right guys? Other ways to do this?

Thanks!

Most of the mtd's have studs that have a 1/4 hex on the end and they unscrew with a 1/4 wrench. they have a 1/4-20 thread on the end that screws in to the frame. Just make sure you get them back into the correct holes in the frame because most have more than one. An inpact wrench is the easiest way to remove the bolt that holds the pulley on.

If you have access to a 1/2 drive air gun it will come off easily. I have had a lot of success using this method when I remove the electric clutch.

Big thanks, guys. Yeah, I thought of a impact gun. But cant get one easily. I will try harder with my chain /strap wrench. I will let yous know what happens!!

Oh, anybody have a rough idea of the torque for that 16mm/5/8" bolt for after when I put it back together?

50 ft/lb torque for the pulley bolt

Thanks Ile! Will come in handy at time of assembly. But, now- trouble: I did get the pulley bolt off with help of the strap wrench, but now pulley wont drop down. Even tried to gently pound on it downward (hard to do). Should I try a long pry bar and keep prying downward? I was hoping to maybe find/feel for a set screw/key stop, but nothing.....

Thanks!

There has to be some kind of shop manual for this mower......Im still searching..........

OK, sprayed PB blaster, jiggled back and forth, up/down. pulley came off. Then, peeked up there and could not see any sign of oil. Dang.

So, I ran the engine at idle for about 5 minutes, and waited another 5 min, and no signs of oil drips at the oil seal!! Geez, maybe its not the seal!

Peeked around, and there is black crud around head gasket. Maybe its that. But again, no "oily" drips from head area. Where am I loosing oil from? I have no choice but to put pulley back on, clean/pressure wash the entire engine/deck/rider, and start from scratch. I will mow maybe for 10-15 min, then inspect closer with uv light/Flash Gordon glasses. I doubt it comes from the head, right? Cuz leaky head shouldnt ooze oil anyway- just loose power/hard starting. I dont have that.



Any tips still appreciated, as I have not solved this mystery, guys.

Thnaks

heres a picture of the leak so far- note the tip of the silvery awl point. that is the oozed oil leak so far with dye. That oil spot is drivers side, rear engine. Not far behind the oil filling tube (no leaks around tube/base of tube)

OK, heres the link to a bigger picture- easier to see the oil/dye:

oops. sorry- trouble with picture.....Oh well, hope small picture is adequate....

It looks like you did all the hard work. A seal is cheap and easy to change so why in the world would you not change it. This would at the lease give you a new lower crankshaft seal for less then five dollars.

reynoldston said:

It looks like you did all the hard work. A seal is cheap and easy to change so why in the world would you not change it. This would at the lease give you a new lower crankshaft seal for less then five dollars.

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Geez, your right, reynold. I have no problem with that. Still, nagged about why the oil sela looks "dry" with the oil slopped around. I will yank the seal/put new, and go from there.

Thanks, Man.

As far as the oil leak goes. Could it be leaking from the crankcase vent, or could the vent be pluged. Also another spot is the crankcase split or have a cover. Could the bolts be loose to this. Could the top crankshaft seal be leaking. Realy not that many places on a small engine that can be leaking oil. I had a older tecumseh leaking oil in my repair shop this pass fall that the valve cover case was broken but I don't think you have the same model engine.

Good luck Nick

reynoldston said:

As far as the oil leak goes. Could it be leaking from the crankcase vent, or could the vent be pluged. Also another spot is the crankcase split or have a cover. Could the bolts be loose to this. Could the top crankshaft seal be leaking. Realy not that many places on a small engine that can be leaking oil. I had a older tecumseh leaking oil in my repair shop this pass fall that the valve cover case was broken but I don't think you have the same model engine.

Good luck Nick

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Thnaks, Nick. I need all the tips I can get. Update: I popped in a new bottom seal. Im back to square 1. test drove it (mowed about 5-10 minutes), and stopped, looked, and dang, oil leak at the same spot!!!

Now, I undid the pulley assembly again(easy this time), and no leakage at the main seal! Only spot with oil collecting was at that spot I pointed out in my photo!! Yeah, right at the tip of the point of the aluminum awl I placed for reference. I cant figure it out. There is no engine "split" there, and no other oil leakage/seepage/migration (not even from the filler tube area).

Take another look at that photo. its between the engine and the frame base. AND, its not coming from the lower crank seal.

This is an unsolved mystery, people..........

Oh, just for the heck of it, is that vent near the carb? Still, if so, no leakage anywhere visible there that would eventually run to the area where I see the oil collect- like I said- mystery.

in the picture all I can make out is the engine mounting bolt. I would have no Idea where the engine is leaking oil. The crankcase vent is as a rule around the air cleaner because some of them vent into the air cleaner but not all. By chance could you have a cracked crank case? I would say clean everything up real good and start from there. I mean with a pressure cleaner. I have had a real hard leak to find before that I have even put white paper under what ever I am working on. I have found that oil will travel. I have found that sometime a oil leak can be very hard to find.

reynoldston said:

in the picture all I can make out is the engine mounting bolt. I would have no Idea where the engine is leaking oil. The crankcase vent is as a rule around the air cleaner because some of them vent into the air cleaner but not all. By chance could you have a cracked crank case? I would say clean everything up real good and start from there. I mean with a pressure cleaner. I have had a real hard leak to find before that I have even put white paper under what ever I am working on. I have found that oil will travel. I have found that sometime a oil leak can be very hard to find.

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Thanks, Nick, for continued support. Yes, I did use a pressure washer. And, to go further, I pre soaked the entire engine and base with engine cleaner. It is squeaky clean. There was absolutely no oil residue left on the machine. Only then did I start it/mow 5-10 minutes to retest, and found the leak. Now, regarding photo, one doesnt have to see the oil (I admit, photo is not big enough), but the point of the picture is more to point out (literally, the point of the metallic awl) the LOCATION of the seepage. I dont know how it would help more to see the oil- the point is the same. How can oil SEEP to that area?
Thats why I gambled and replaced seal first, as I couldnt imagine any other leakage source (no biggee, and I have a new seal), but still, leak at that point where aluminum aloy engine base meets the frame of mower.

There are also no seepage from engine wals, so I assume as a result, no cracks on engine. I observed all this with oil leak test DYE, and uv light with special eye glasses. Fluorescence shows up ONLY at base- no other place.

Geeez, I may have to yank engine and place on my bench- I guess thats also not a big deal, right Nick? Im out of ideas.

Thnaks, Man.

The oil has to be coming from someplace. I am just guessing from other engines I have worked on. I know some engines the case splits in haft and some have just a cover. To seal this crank case some companies use a gasket and a lot of the newer engines now use a anaerobic sealer. Seeing that yours is a newer style engine I am going to guess your case is put together with the anaerobic sealer. If this is so your engine would have to be disassembled and resealed. One of many company's that make this sealer is Permatex and it is called Anaerobic Gasket Maker. (Not cheap) Before I did anything if it was me I would want to find the leak frist what ever it took to find it.

OK, Nick. Guess thats it for now- I need to do detective work- best to get it on the bench, I figure. I will let you know what happens....

Thanks, Man!

slightly off track
I had (10 years ago)a new 14.5 B&S (not a filter/pressure lube setup) just splash lubrication got too much oil in the crankcase and(the pressure) popped the paper gasket at the base of the motor
Just me $.02cdn

weewilly said:

slightly off track
I had (10 years ago)a new 14.5 B&S (not a filter/pressure lube setup) just splash lubrication got too much oil in the crankcase and(the pressure) popped the paper gasket at the base of the motor
Just me $.02cdn

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Too much oil in crankcase sure would be a reason for a oil leak, not off track at all good idea.

Whew, I know its been waaaaay long time ago, but believe it or not, havnt had much opportunity to run mower during winter.....LOL

So, I figured out it was the o ring at base of the plastic poil dip stick tube!! tested it about 2 mowings the last few weeks, and didnt want to conclude too early, but that surely wqas the culprit. Anyway, you guys were a huge help here. I will be back!!!