Oil leak

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Ralph Harvey
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Oil leak

Unread post by Ralph Harvey » March 20th, 2021, 10:43 am

I have an M151A1 that has a good oil leak somewhere around the oil pan or transmission. I plan to pull the power pack in the next few weeks(live in northeast unheated building cold floor) and I am not sure if it is a pan gasket or seal. What seals are the most common to fail? Any special tool for seal replacement? Is there any other area I should check?
Another problem I have is the first start of the day I want to go into reverse and get grinding teeth. I have to find another gear that it will go in. Then back to reverse and it goes in fine. Is this a clutch adjustment or a worn fork? It just seems the transmission needs to synchronize first.
I am just gathering information so when I start I will know better what to look for.
I am also looking for a left hand side curtain.

Thank you

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rickf
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Re: Oil leak

Unread post by rickf » March 20th, 2021, 10:51 am

There are several usual places for oil leaks in that vicinity. You need to see if it is running from somewhere else to where you see it. The rear of the valve cover is a common spot since the valve cover has a metal lip inside and out for the gasket to ride in and sometimes the lip gets hung up on the head and the cover does not seat. Rear main seal is another spot to check, you can pull the inspection cover under the flywheel and see if the oil is coming from behind the flywheel or if it is coming from the front seal of the transmission. Last but not least are the transmission output seals for the shafts and the transfer case shifter rod seal. So as you can see there are a lot of places it can leak. You can narrow it down by determining if it is motor oil or gear oil and then search the appropriate area.
The shifting into reverse is perfectly normal, same with first. It is an old style transmission that is not synchronized in first or reverse and sometimes you just need to bump things a bit to get the gears to line up.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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Horst
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Re: Oil leak

Unread post by Horst » March 20th, 2021, 11:09 am

as Rick said, perfectly normal to have some work for 1st or reverse as they are not synchronized. But you should not get any grinding, you would just not be able to get into the gear. Grinding means your clutch is not fully separating, you might want to check the adjustment (free travel of the pedal that is). Once you decide to adjust your clutch, be careful to not overdo it and entirely remove the adjustment rod from the fork.
Horst

1972 USMC M151A2 w/ROPS (ex Barstow) and M416
1962 M201 and trailer
1966 GTO,1982 E350 Skoolie, 1987 SJ413, 1987 911
Gone: 2xM35A2c, Unimog 404S, Hanomag AL28, DKW Munga

Ralph Harvey
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Posts: 11
Joined: February 17th, 2020, 11:54 am

Re: Oil leak

Unread post by Ralph Harvey » March 20th, 2021, 11:46 am

Thank you for the information. I will let you know what I find when I start.

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