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6 cylinder with an oil leak, a few questions.

Posted: Mon Aug 09, 2010 8:51 am
by fergusont20
Morning

I have posted in this forum and not in my 6 cylinder thread hoping that someone can help me.

My major diesel has gearbox oil dripping/flowing through the bellhousing, originally it was overfull with oil, this has now been drained off to the low level, but with the engine running oil flows,but when engine is turned off the oil leak gradually stops.

I have split the tractor in half and checked inside the bellhousing, i originally thought the transmission oil seal was leaking, but upon inspection this does seem to be the case. When looking inside the bellhousing, to the upper right of drive shaft, there is what looks like the end section of a shaft about 1/2 " in diameter with a keyway cut in it. underneath this there was telltale signs that oil had been leaking through it and down to the bottom of bellhousing.
I then used an airline to put compressed air through the filling part where you pour in the gearbox oil, i could then feel compressed air and abit of oil come through the end of the shaft like piece which i mentioned inside the bellhousing. I guessed that this must be some form of overflow for the gearbox.and i could not see any other faults inside.

I put the tractor back together and drove it about 10 miles last week, but still got the oil leaking issue.

so i am wondering if there is a build up of pressure inside the gearbox and if there should be some form of pressure relief valve, or a drilled out bolt to let it breath.

Can anyone help me ?? or has anyone encountered the same problem??

Thanks Mark

Posted: Mon Aug 09, 2010 9:00 am
by fergusont20
Hang on a minute, i have just been reading Brian's oil thread at the top of the page, not sure if it is relevent to the questions i have asked above, but i think i have been assuming what each oil does,incorrectly.

I thought on a Major it was engine oil, then gearbox oil,then backaxle oil which operated the pto and the lift arms

But is it the gearbox oil which operates the pto and hydraulics?? and can this in anyway help explain my oil leak??? im not sure if it can

Mark

Posted: Mon Aug 09, 2010 7:28 pm
by Ian
The gearbox and backend oil should be separate

Posted: Tue Aug 10, 2010 6:03 am
by fergusont20
Thanks, i realise that.

Anyone??

Posted: Tue Aug 10, 2010 8:05 am
by Nick
my understanding of it was, as you say, engine separate, front gearbox seperate, i thought this just did the gears, and the backend because it takes 10-12 gallons of oil i thought this operated the hydraulic pump and pto (and link arms).
This oil leak sounds strange to me, i have never taken mine apart, but i would assume as you say that there is some sort of breather in the gearbox. Have you tried running it without the filler cap on?

Posted: Tue Aug 10, 2010 9:23 am
by Scruff
Hi,

One of the bolts that holds the front deisel tank bracket to the top of the gearbox has an extended head (left hand side sat on tractor). This has a hole up through it's shaft with two holes on opposite spanner faces. This, I believe, is the gearbox breather. Mine dropped oil out of the bellhousing until I found this one and unblocked it.

Now all is well. :D

I hope this solves your problem too.

Scruff.

Posted: Tue Aug 10, 2010 9:30 am
by Kiwi Kev
Ian wrote:The gearbox and backend oil should be separate
The gearbox and rear transmission are seperate compartments, but can use the same type of oil.

There is an oil seal between the clutch and gearbox, and an oil seal between the gearbox and the rear transmission. There are also oil seals on the PTO engagement gearbox(under the gearbox)
The PTO and the hydraulics uses the rear transmission oil.

If the oil is coming from the bellhousing, it would have to be from the clutch/gearbox seal or from the engine rear crankshaft seal.

The gearbox does have a breather, and if my memery serves me correct, it is the right hand bolt that holds the front bracket for the diesel tank. The breather should look more like a stud with 2 nuts on it.
Hope this helps
Kiwi Kev

Posted: Wed Aug 11, 2010 8:29 am
by fergusont20
Thankyou all for your help :)

It is definantly not the crankseal on the engine because the engine oil is currently black and needs changing, and the oil dripping through the bellhousing is milky,exactly like the oil in the gearbox.

I changed all the bellhousing bolts for new ones when I swapped the engine, so I'm hoping the oil leak is because I have no breather bolt.

When I am next with the tractor I will check, can you buy new breather bolts off the shelf?? Or have I just got to try a few local places??

Thanks Mark

Posted: Wed Aug 11, 2010 10:06 am
by Kiwi Kev
fergusont20 wrote: I changed all the bellhousing bolts for new ones when I swapped the engine, so I'm hoping the oil leak is because I have no breather bolt.
Thanks Mark
Mark
The breather is not one of the bellhousing bolts( to me the bellhousing is where you bolt the engine to the gearbox, with the clutch inside)
The breather is one of the bolts that bolts the front bracket of the fuel tank to the gearbox.
Kiwi Kev

Posted: Wed Aug 11, 2010 1:54 pm
by fergusont20
thanks Kev

I will take a look