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Thunderbird712 Member
Joined: Mar 26, 2012 Posts: 189 Location: Lexington Park Maryland (Southern Maryland)
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Posted: Sun Aug 17, 2014 10:23 am Post subject: 200 ft/lbs torque to much for the pinion nut |
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After replacing the front and rear diff pinion seals I torque the nuts down to 200 to 220 ft/lbs and now I cant roll my frame telling me its torqued to much. I do have to figure out which diff was causing the problem or possibly both but is a lower torque setting for these nuts possible? To note these seals were never replaced since I had the jeep. Also I have never taken them apart. The diffs were operating fine with no noise or obvious signs of issues during an inspection before I started my restoration. So I have no idea what they were torqued to before. The other thing to point out is there is no felt seal in the rear diff. Would this cause the issue? _________________ TJ
53 M38A1 (project)
3/28/45 MB factory restoration project |
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Thunderbird712 Member
Joined: Mar 26, 2012 Posts: 189 Location: Lexington Park Maryland (Southern Maryland)
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Posted: Sun Aug 17, 2014 10:25 am Post subject: |
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Sorry in case some one misses my signature it is a m38a1 _________________ TJ
53 M38A1 (project)
3/28/45 MB factory restoration project |
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OKCM38CDN Member
Joined: Feb 17, 2012 Posts: 530 Location: Del City, OK
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Posted: Sun Aug 17, 2014 11:34 am Post subject: |
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If I remember correctly the torque is 200-220 ft/lbs...
try that... _________________ Hal, KB1ZQ
TSGT, USAF (Ret)
1952 M-38 CDN CAR 52-31313
1952 M-100 Strick #104
1951 Willys Wagon (For Sale)
1954 Willys M38A1 201001205
Tornado Alley
Del City, OK |
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Thunderbird712 Member
Joined: Mar 26, 2012 Posts: 189 Location: Lexington Park Maryland (Southern Maryland)
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Posted: Sun Aug 17, 2014 12:53 pm Post subject: |
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You know I forgot to mention that I had tried that. I saw a previous post by WesK about using the 120 ft/lbs and that the 200 was to set everything. At 120 everything works fine. I continued to read up on it more and kept seeing the 200 #. I am just not fimiliar enough to say 120 will be enough. I do however believe what Wes said is ok. Thats why i wanted to post the question to see if anyone else had gone with the lower torque value. Still reading through some more posts, other forums, and other literature on the diffs to learn. Thanks! _________________ TJ
53 M38A1 (project)
3/28/45 MB factory restoration project |
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wilfreeman Member
Joined: Mar 13, 2006 Posts: 1079 Location: Richburg, SC
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Posted: Tue Aug 19, 2014 2:45 pm Post subject: |
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I racked mine down with a ½" impact, not even thinking about how much torque it was putting out, now I can't even get the nut back off to torque it correctly. I probably galled the threads. I will try again with a ¾" impact when I get the chance to work on it again - already tried a few methods I have found on the net with no success. Just think about it before you do anything as dumb as me! I would go with the 120# and see if you have the correct play, then go from there. _________________ Matt
1953 M38a1
1964 USMC M38a1
'51 USMC M100 trailer, '54 M100 trailer, '90 M101a1 trailer
Http://wilfreeman.wordpress.com (M38a1 build blog)
http://m38a1usmc.wordpress.com (USMC M38a1 rebuild blog) |
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wesk Site Administrator
Joined: Apr 04, 2005 Posts: 16253 Location: Wisconsin
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Posted: Tue Aug 19, 2014 6:09 pm Post subject: |
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I don't recall advocating 120 on the axle companion flanges. I recall that 120 was for the transfer case front and rear companion flanges.
The book calls for 200 to 220 ft Lbs then insuring the bearing is shimmed properly to maintain a rotating friction of 10-25 In Lbs. That is not a lot of rotating resistance and if set correctly to that spec the pinion should turn with no more then 10-25 In Lbs of rotational torque. I am betting your bearing preload is much higher than 10-25 In Lbs. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php |
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jimm Member
Joined: Nov 01, 2011 Posts: 199 Location: Escondido, CA
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Posted: Tue Aug 19, 2014 9:11 pm Post subject: |
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I agree with Wes that your pinion assembly is probably not shimmed correctly. You have to measure the torque to turn it without the differential installed in the axle, i.e., no other load on it than the bearing preload. It can be tricky to measure that low of torque because you need to do it as you are rotating the pinion slowly but smoothly (breakaway torque will be a little higher than rotating torque).
Since the assembly is made up of very stiff pieces of steel and cast iron, a little shimming goes a long way. You want to creep up on the right amount of shims from no drag/preload. More shims are the equivalent of making the case longer (or the shaft shorter) and increase the preload. When you get close to the correct preload torque, adding the thinnest shim (.003") will make a noticeable difference. You may even have to take out some and add others, e.g. minus one .005" plus two .003", to get the increment you need. _________________ Jim McKim
1952 M38 son-father project
Slowly turning rusty parts into OD parts |
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Thunderbird712 Member
Joined: Mar 26, 2012 Posts: 189 Location: Lexington Park Maryland (Southern Maryland)
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Posted: Wed Aug 20, 2014 4:18 pm Post subject: |
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While I was reading up on the issue I came across this previous post
http://www.willysmjeeps.com/v2/modules.php?name=Forums&file=viewtopic&t=6761
First off I misread the torque value in the post. Second I could be wrong in my assumption it was about the diffs. That was the only post i read mentioning a lower torque value so i tried it as well as asked the question about it. Anyway as I said the rears have never been taken apart by me and the last owner was the greek army. So they could have been previous rebuild incorrectly but I have never had any issues with them. I got my answer about the torque. I have some more stuff to figure out before I go ahead and take things all part. Thanks for the help. _________________ TJ
53 M38A1 (project)
3/28/45 MB factory restoration project |
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wesk Site Administrator
Joined: Apr 04, 2005 Posts: 16253 Location: Wisconsin
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OKCM38CDN Member
Joined: Feb 17, 2012 Posts: 530 Location: Del City, OK
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Posted: Wed Aug 20, 2014 9:18 pm Post subject: |
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Sorry, I am mistaken, I read one thing and made an assumption, well you know what happens when you do that... _________________ Hal, KB1ZQ
TSGT, USAF (Ret)
1952 M-38 CDN CAR 52-31313
1952 M-100 Strick #104
1951 Willys Wagon (For Sale)
1954 Willys M38A1 201001205
Tornado Alley
Del City, OK |
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wesk Site Administrator
Joined: Apr 04, 2005 Posts: 16253 Location: Wisconsin
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jimm Member
Joined: Nov 01, 2011 Posts: 199 Location: Escondido, CA
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Posted: Wed Aug 20, 2014 9:45 pm Post subject: |
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wesk wrote: |
The book calls for 200 to 220 ft Lbs |
Wes,
Just for clarity, which book are you referring to? The civvy repair manual? I can find no reference to a specific torque for the yoke nut nor the preload drag in either of the M38 and M38A1 power train manuals (TM 9-8014B and 9-8015-2, respectively), and don't see the yoke nut listed in the table of torques you posted from the civvy manual. _________________ Jim McKim
1952 M38 son-father project
Slowly turning rusty parts into OD parts |
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wesk Site Administrator
Joined: Apr 04, 2005 Posts: 16253 Location: Wisconsin
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Posted: Wed Aug 20, 2014 10:12 pm Post subject: |
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The best book to fall back on when the TM's come up short on hard data. The Army's unit motor pools didn't rebuild axles. They order a depot overhauled unit and exchanged it. That's why the field level TM's lack so much hard data. The Army depot doing the overhauls would have had in house pubs which would include Willys and Spicer factory manuals to address the overhaul issues.
That is why I loaded the important chapters from the civvy manuals in my photo album. Some day I'll get them all scanned and PDF'd and loaded on the downloads page. I have advised the use of the civvy factory manuals to backup our inadequate TM's ever since day one (2002) of this web site and day 1 (1996) of the M38 Yahoo group.
The TM 9-8015-1 and TM 9-1804B both only address the pinion bearing preload as a check for slight drag and adjust shims as needed note.
TM 9-8015-2 on page 180/181
TM 9-1804B on page 132
In the old referenced post you mentioned replacing the 3/4-16NF-2 nut every time which is really not required unless the Hug Nut fails a run-on torque test. _________________ Wes K
45 MB, 51 M38, 54 M37, 66 M101A1, 60 CJ5, 76 DJ5D, 47Bantam T3-C & 5? M100
Mjeeps photo album: http://www.willysmjeeps.com/v2/modules.php?set_albumName=Wes-Knettle&op=modload&name=gallery&file=index&include=view_album.php |
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jimm Member
Joined: Nov 01, 2011 Posts: 199 Location: Escondido, CA
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Posted: Thu Aug 21, 2014 10:02 pm Post subject: |
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I thought that was the book you meant. I bought a copy after we rebuilt our axles, so I must have used your scanned info, which was very helpful at the time.
'Twern't me that mentioned replacing the nut every time - that was Bretto If you had to replace it after one use, you'd go through a bunch of 'em just trying to get the pre-load set! _________________ Jim McKim
1952 M38 son-father project
Slowly turning rusty parts into OD parts |
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