Rear Pinion Seal Woes

1952 - 1968, M38A1, M170, questions, discussions, regarding anything related to the M38a1 series.
Post Reply
Apolloblackcat
G-Private
G-Private
Posts: 5
Joined: Fri Apr 19, 2019 9:02 am
Location:

Rear Pinion Seal Woes

Post by Apolloblackcat » Mon Sep 27, 2021 10:31 am

All,

I have recently replaced a leaking rear pinion seal with a new one from John at Midwest I included the paper washer and felt seal in the re-build.
I parked it up after a quick run and this evening noticed the ominous drip of oil cascading over the UJ of the prop shaft. I tightened the nut to about 40/Ibs torque

Could someone please confirm that the nut should be torqued down to 220ft/Ilbs and the reason why this should be so high? Am I correctin that its something to do with the pre-load?

Thank You
Nic


User avatar
Jeeps4Brains
G-Lieutenant Colonel
G-Lieutenant Colonel
Posts: 1058
Joined: Wed Jul 20, 2005 9:56 am
Location: Upstate SC

Re: Rear Pinion Seal Woes

Post by Jeeps4Brains » Tue Sep 28, 2021 7:10 am

Did you put any kind of sealant on the pinion splines and the yoke/flange splines?

I have seen gear oil migrate along the splines and leak.
45' MB, ??' MBT, 47' CJ2A, 48' CJ2A,
51' M38 #1, 51' M38 #2, 51' M100,
52' M37, ??' M101A1 (1st Gulf War Vet),
53' M38A1, 53' M211, 65' M151A1, 67' M416,
MVPA #31724

Apolloblackcat
G-Private
G-Private
Posts: 5
Joined: Fri Apr 19, 2019 9:02 am
Location:

Re: Rear Pinion Seal Woes

Post by Apolloblackcat » Tue Sep 28, 2021 9:32 am

Jeeps4Brains wrote:
Tue Sep 28, 2021 7:10 am
Did you put any kind of sealant on the pinion splines and the yoke/flange splines?

I have seen gear oil migrate along the splines and leak.
No I did not I suppose that is why it is dripping from the prop journal, the surround of the seal is dry where it meets the casing, I could try the sealant route.
Thank you for your reply

Regards
Nic

JMZ421
G-Second Lieutenant
G-Second Lieutenant
Posts: 545
Joined: Sat Jun 02, 2012 2:21 pm
Location: N.E. Ohio

Re: Rear Pinion Seal Woes

Post by JMZ421 » Tue Sep 28, 2021 9:38 am

I can only tell you what I did on my M38 a couple years ago and I torqued to 180 foot lbs. I got that from an old timer on this site and I have had zero issues. I used a piece of long flat iron and drilled a hole in it and attached to the yoke to prevent from turning and I got the 180. Prior post is correct. Need to place that permatex near the front of that yoke so does not get pushed in. I also sealed around pinion seal before tapping in.

John

Apolloblackcat
G-Private
G-Private
Posts: 5
Joined: Fri Apr 19, 2019 9:02 am
Location:

Re: Rear Pinion Seal Woes

Post by Apolloblackcat » Tue Sep 28, 2021 10:03 am

JMZ421 wrote:
Tue Sep 28, 2021 9:38 am
I can only tell you what I did on my M38 a couple years ago and I torqued to 180 foot lbs. I got that from an old timer on this site and I have had zero issues. I used a piece of long flat iron and drilled a hole in it and attached to the yoke to prevent from turning and I got the 180. Prior post is correct. Need to place that permatex near the front of that yoke so does not get pushed in. I also sealed around pinion seal before tapping in.

John
Thank You John

Regards

Nic

Apolloblackcat
G-Private
G-Private
Posts: 5
Joined: Fri Apr 19, 2019 9:02 am
Location:

Re: Rear Pinion Seal Woes

Post by Apolloblackcat » Wed Sep 29, 2021 9:18 am

JMZ421 wrote:
Tue Sep 28, 2021 9:38 am
I can only tell you what I did on my M38 a couple years ago and I torqued to 180 foot lbs. I got that from an old timer on this site and I have had zero issues. I used a piece of long flat iron and drilled a hole in it and attached to the yoke to prevent from turning and I got the 180. Prior post is correct. Need to place that permatex near the front of that yoke so does not get pushed in. I also sealed around pinion seal before tapping in.

John
John what Permatex type do you recommend? Which works best???

Regards

Nic

JMZ421
G-Second Lieutenant
G-Second Lieutenant
Posts: 545
Joined: Sat Jun 02, 2012 2:21 pm
Location: N.E. Ohio

Re: Rear Pinion Seal Woes

Post by JMZ421 » Wed Sep 29, 2021 12:57 pm

I used Permatex #3, that blue stuff. John

Apolloblackcat
G-Private
G-Private
Posts: 5
Joined: Fri Apr 19, 2019 9:02 am
Location:

Re: Rear Pinion Seal Woes

Post by Apolloblackcat » Wed Sep 29, 2021 1:12 pm

JMZ421 wrote:
Wed Sep 29, 2021 12:57 pm
I used Permatex #3, that blue stuff. John
Thanks John

Nic


Post Reply

Return to “M38a1 Technical Knowledge Base”

Who is online

Users browsing this forum: No registered users and 5 guests