M151 Differential Rebuild

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Rossco
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M151 Differential Rebuild

Unread post by Rossco » February 14th, 2017, 4:24 am

Kia Ora all

Some guidance please?

While waiting for my body parts to come back from being chemically dipped I have stripped down and cleaned both front and rear differentials as part of my restoration process. Generally I was very surprised with the overall state of them and apart from the condition of the oil seals (old hard rubber and some leaks) and the two side bearings on the rear diff being rough (I suspect this is due to them not being set up properly when last rebuilt/played with) most parts are re usable.
So I will fit new side bearings and seals as part of the rebuild

However, as expected I have some questions

The front diff has no shim fitted behind the large pinion bearing and the diff housing is this normal or should there be one??

The pinion/shafts on both diffs are highly magnetic, why would this occur and is this normal?

On both diffs both the drain and and filler plugs have magnets in their centers is this also normal practice? I am use to the magnet being only on the drain plug?

How critical is it to retain/re-apply the red oxide paint on the inside of the diff housings - one side cover has virtually no paint finish.

Then if so then what sort of paint does one use?

Thanks
Rossco
1973 M-151A2
1960 Seagrave LAFD Hook and Ladder Fire Truck
1953 M38A1 Jeep
1998 Ford Escort XR3i
2007 Ford Focus ST 2.5

199th mp
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Re: M151 Differential Rebuild

Unread post by 199th mp » February 14th, 2017, 6:57 am

army buck wrote a very good article on this, which you may also find helpful.
http://www.g838.org/viewtopic.php?f=3&t ... aul#p39599

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rickf
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Re: M151 Differential Rebuild

Unread post by rickf » February 14th, 2017, 8:36 am

I don't remember if he mentions the paint in the article or not. It is not required but it is a nice touch and it seals any imperfections in the castings. It is called Glyptol.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Rossco
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Re: M151 Differential Rebuild

Unread post by Rossco » February 14th, 2017, 2:53 pm

Rick

I had previously found the excellent post by Army Buck covering the rebuild of the 151 differentials on the 838 site - and what very a clear and concise guide it is.

I will let you all know how I get on plus any further questions I may have

Rossco
1973 M-151A2
1960 Seagrave LAFD Hook and Ladder Fire Truck
1953 M38A1 Jeep
1998 Ford Escort XR3i
2007 Ford Focus ST 2.5

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rickf
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Re: M151 Differential Rebuild

Unread post by rickf » February 14th, 2017, 6:38 pm

Although I have built hundreds of regular automotive differentials I have never done one of these. I have one that blew a seal and emptied out on me on a trip and before I knew it it was smoking, literally! I plan on rebuilding that one sometime when it gets warmer out.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

Rossco
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Re: M151 Differential Rebuild

Unread post by Rossco » February 15th, 2017, 3:00 am

Rick

I am very surprised to hear that, I thought you had repaired/rebuilt MUTT's from stem to stern? I have played around with cars for a quite few years now, having starting off as a young motor mechanic working on European imports. I don't have a lot of experience rebuilding diffs but the guide provided by "army buck" is excellent so I do not see any major problems - I will certainly let you know if I need help!
Have to say the 151 diff is very robust and appears to be over engineered for the power it needs to cope with.

Regards
Rossco
1973 M-151A2
1960 Seagrave LAFD Hook and Ladder Fire Truck
1953 M38A1 Jeep
1998 Ford Escort XR3i
2007 Ford Focus ST 2.5

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rickf
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Re: M151 Differential Rebuild

Unread post by rickf » February 15th, 2017, 11:04 am

I have never heard of a differential or transmission breaking due to load in an M-151.
1964 M151A1
1984 M1008
1967 M416
04/1952 M100
12/1952 M100- Departed
AN/TSQ-114A Trailblazer- Gone

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