Go Back   The Ford Barn > General Discussion > Model A (1928-31)

Sponsored Links (Register now to hide all advertisements)

Reply
 
Thread Tools Display Modes
Old 07-08-2020, 01:41 PM   #1
DBSHELTON
Senior Member
 
Join Date: Sep 2019
Location: Kountze,TX
Posts: 266
Default Rearend Leak

I have a leak between the Right Axle Housing and the Center Section. Is there any way to fix this without completely disassembling the rearend? Tightened the bolts and that didn't help. They weren't loose.
DBSHELTON is offline   Reply With Quote
Old 07-08-2020, 03:25 PM   #2
JOHN CT
Senior Member
 
JOHN CT's Avatar
 
Join Date: May 2010
Location: In my garage
Posts: 438
Default Re: Rearend Leak

I had the same problem after a rebuild. I removed paint from the seam Cleaned the area well and put a light coating of Permatex PX 90min Right Stuff on it itís been fine for a year now
__________________
31 Tudor
66 Bonneville
57 Chevy pickup 27 T roadster pick up
JOHN CT is offline   Reply With Quote
Sponsored Links (Register now to hide all advertisements)
Old 07-08-2020, 05:22 PM   #3
BRENT in 10-uh-C
Senior Member
 
BRENT in 10-uh-C's Avatar
 
Join Date: May 2010
Location: Eastern Tennessee
Posts: 9,578
Default Re: Rearend Leak

Quote:
Originally Posted by DBSHELTON View Post
I have a leak between the Right Axle Housing and the Center Section. Is there any way to fix this without completely disassembling the rearend? Tightened the bolts and that didn't help. They weren't loose.

Typically what we find is the housing flange is warped/bent which requires installing in a lathe to true the flange for a better seal. Unfortunately, you cannot do this operation without disassembly. Also, we find many housings are bent requiring straightening. I suspect this happened over the years as people threw chains around the housing to pull things, -or to be pulled out of places. How this affects things is the two rear hubs do not rotate parallel with each other causing the rear axle shaft to bend ever so slightly on each rotation. Not only is this tough on axle shaft longevity, this can also affect braking and tire wear because of the hub not in alignment.

I have placed a few pictures below showing how the housing flange is trued on a lathe. Notice how the area cleans up on one side of the flange yet not the opposite side. This is because some housings are tough to get 100% straightened. The housing tube is straightened using torch to heat and water to cool the area to shrink it back into alignment. The axle housing is held between centers and indicated off of bearing races on each end and in the tapered area of the tube. In the case of when a housing is within a few thousandths of being true, it does not hurt if the housing retains a slight bend as long as a new race is installed for the hub bearing as it will be machined where the centerline is corrected. I hope this makes sense.

.
.
Attached Images
File Type: jpg IMG_0908.jpg (66.5 KB, 85 views)
File Type: jpg IMG_2199.jpg (53.3 KB, 90 views)
File Type: jpg IMG_7262.jpg (50.4 KB, 83 views)
File Type: jpg IMG_0218.JPG (121.9 KB, 82 views)
File Type: jpg IMG_0222.JPG (96.9 KB, 80 views)
File Type: jpg IMG_2207.jpg (44.3 KB, 82 views)
__________________
.

BRENT in 10-uh-C
.
www.model-a-ford.com
...(...Finally Updated!! )

.
BRENT in 10-uh-C is offline   Reply With Quote
Old 07-08-2020, 06:04 PM   #4
Synchro909
Senior Member
 
Synchro909's Avatar
 
Join Date: Jun 2014
Location: Melbourne, Australia
Posts: 5,281
Default Re: Rearend Leak

Another source of a leak is someone chased the threads with an ordinary tap. I have a rear end the "restorer" did that to. I drained the diff and one by one, I removed the bolts, thoroughly cleaned the threads (male and female) and put them back with some Permatex #3 on them. That helped but it still leaves a little oil on the ground over time.
__________________
Accidents hurt. Safety doesn't.
Synchro909 is offline   Reply With Quote
Old 07-08-2020, 06:55 PM   #5
Tom Endy
Senior Member
 
Tom Endy's Avatar
 
Join Date: May 2010
Location: Southern California
Posts: 2,678
Default Re: Rearend Leak

There is an easy trick you can try that might be successful. drain the oil from the banjo and remove each of the 10 bolts on a side one at a time and coat the thread's with sealer and reinstall before removing the next one. Torque each bolt to 35 ft. lbs. If there are lock washers installed remove them and discard them.

Tom Endy
Tom Endy is offline   Reply With Quote
Old 07-08-2020, 07:03 PM   #6
Dick M
Senior Member
 
Dick M's Avatar
 
Join Date: May 2010
Location: Ukiah, CA
Posts: 357
Send a message via Yahoo to Dick M
Default Re: Rearend Leak

Sponsored Links (Register now to hide all advertisements)
Same reply as #2 except I used JB Weld. Ten years later and no leak....
Dick M is offline   Reply With Quote
Old 07-09-2020, 04:26 AM   #7
DBSHELTON
Senior Member
 
Join Date: Sep 2019
Location: Kountze,TX
Posts: 266
Default Re: Rearend Leak

Thanks for the tips. It seems to be leaking from bolt holes.
DBSHELTON is offline   Reply With Quote
Old 07-09-2020, 06:01 AM   #8
john charlton
Senior Member
 
john charlton's Avatar
 
Join Date: May 2010
Posts: 936
Default Re: Rearend Leak

The bolts are a machine fit and are very carefully made they are not a common UNF bolt . I am not sure if the reproductions are made to the same tolerances so could be you have repro bolts installed by someone because they look pretty . No lock washers should be fitted .

John in Suffolk County England .
john charlton is offline   Reply With Quote
Old 07-09-2020, 06:28 AM   #9
old31
Senior Member
 
Join Date: Jan 2016
Posts: 1,318
Default Re: Rearend Leak

Quote:
Originally Posted by Dick M View Post
Same reply as #2 except I used JB Weld. Ten years later and no leak....
I love JB, but I would have guessed that it would be to brrittle to work on this application. I would have reached for Perm2.
old31 is offline   Reply With Quote
Old 07-09-2020, 07:46 AM   #10
BRENT in 10-uh-C
Senior Member
 
BRENT in 10-uh-C's Avatar
 
Join Date: May 2010
Location: Eastern Tennessee
Posts: 9,578
Default Re: Rearend Leak

Quote:
Originally Posted by john charlton View Post
The bolts are a machine fit and are very carefully made they are not a common UNF bolt . I am not sure if the reproductions are made to the same tolerances so could be you have repro bolts installed by someone because they look pretty . No lock washers should be fitted .

John in Suffolk County England .

John, you have hit on something that many are not aware of. The former Roy Nacewicz bolts were manufactured correctly however I cannot speak for other vendors, however it is typically not the bolts that are the problem. The Differential Housing's hole thread pitch that Ford used was a Class 4 which is a size that is typically not used commercially any longer since the advent of thread locking compounds. I think most pitches go from Class 1 - 5 with a Class 5 being almost a locking fit. The standard bolts will seal when the holes are threaded with a Class 4 cutter. Below is a PDF I made off of my A-4025 print that shows the specs for the holes.

.
.
Attached Files
File Type: pdf Threads.pdf (1.58 MB, 60 views)
__________________
.

BRENT in 10-uh-C
.
www.model-a-ford.com
...(...Finally Updated!! )

.
BRENT in 10-uh-C is offline   Reply With Quote
Old 07-10-2020, 06:22 AM   #11
DBSHELTON
Senior Member
 
Join Date: Sep 2019
Location: Kountze,TX
Posts: 266
Default Re: Rearend Leak

Thanks guys. I went ahead and ordered a new set of bolts from Bratton's. Will try just replacing the leaking bolts and add some kind of sealer.
DBSHELTON is offline   Reply With Quote
Old 07-10-2020, 07:01 AM   #12
Jim Baskin III Pa.
Senior Member
 
Jim Baskin III Pa.'s Avatar
 
Join Date: May 2010
Location: Lock Haven Pa.
Posts: 244
Default Re: Rearend Leak

I use clear Flex Seal.Guaranteed to stop the leaks
Jim Baskin III Pa. is offline   Reply With Quote
Old 07-10-2020, 04:33 PM   #13
john in illinois
Senior Member
 
john in illinois's Avatar
 
Join Date: May 2010
Location: Illinois
Posts: 1,942
Default Re: Rearend Leak

Read post 10.

John
__________________
Welcome each day
john in illinois is offline   Reply With Quote
Old 07-11-2020, 12:13 PM   #14
norcalal
Member
 
Join Date: May 2010
Posts: 56
Default Re: Rearend Leak

Maybe I just got lucky, but I hand filed the trumpets flat where they mate up to the banjo housing,and 11 years and many miles later no leaks. Whatever you do use original bolts without lock washers.
norcalal is offline   Reply With Quote
Old 07-11-2020, 12:29 PM   #15
BRENT in 10-uh-C
Senior Member
 
BRENT in 10-uh-C's Avatar
 
Join Date: May 2010
Location: Eastern Tennessee
Posts: 9,578
Default Re: Rearend Leak

Quote:
Originally Posted by Tom Endy View Post
If there are lock washers installed remove them and discard them.

Tom Endy
Quote:
Originally Posted by norcalal View Post
Whatever you do use original bolts without lock washers.

While we all agree that the bolts originally did not have lockwashers, the use of lockwashers should not have any affect on whether it will leak or not, ...providing everything is within specification.

Think about it, if the gasket mating surfaces are truly flat and parallel, -and if the threads are the proper size, the 600 wt. lube will not penetrate the threads nor the flange area.
__________________
.

BRENT in 10-uh-C
.
www.model-a-ford.com
...(...Finally Updated!! )

.
BRENT in 10-uh-C is offline   Reply With Quote
Reply

Thread Tools
Display Modes

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Sponsored Links (Register now to hide all advertisements)


All times are GMT -5. The time now is 05:10 PM.