leaks around differential bolts

Bill Goddard

Bill Goddard

Well-known member
I have leaks from under the heads of 5 bolts in the lower half of the bolt circle of my differential pumpkin. Is there a fix for these leaks. They are as tight as I dare make them. Bill G
 
Someone may have chased them with a tap and removed some of the original metal.
Originally they were a slightly undersize thread to prevent leakage.
If it were mine I'd remove them one at a time and put some sealer on the threads like Silicone. Then re Torgue them and wipe away any leftover silicone sealant.
 
They should be torqued to 35 ft. lbs. What you can do is drain the oil and then remove each bolt one at a time and coat the threads with Indian Head gasket cement and reinstall.

Tom Endy
 
What I did to stop leaks on the bottom bolts of a 7 tooth steering column was to take some cotton thread and wrap it around just under the head. It would depend on how thick the tread is for how many turns to make, but it took a number of turns. I tried all kinds of things before the thread deal and nothing stopped the slow leak. I don't know why the same thing wouldn't work for the banjo.
Rusty Nelson
 
wrndln said:
What I did to stop leaks on the bottom bolts of a 7 tooth steering column was to take some cotton thread and wrap it around just under the head. It would depend on how thick the tread is for how many turns to make, but it took a number of turns. I tried all kinds of things before the thread deal and nothing stopped the slow leak. I don't know why the same thing wouldn't work for the banjo.
Rusty Nelson
Click to expand...

Yeh, that would probably work. The cotton might expand as it absorbed the oil and seal the thread just like hemp was used to seal threaded joints in galvanised water pipes.
 
I used Indian Head shellac just as Tom Endy suggested. This did not totally stop the seepage, but improved it to a manageable degree. My hands and fingers got really messy with the shellac, so I found it much easier to do with a helper--one person to keeping his hands clean to remove and reinstall the bolts, and one person painting the shellac on the threads with increasingly goopy hands. My differential is now slightly oily on the bottom from the seep, but seldom wet enough to drip. Before this treatment, I always had a huge grease spot on the floor and would have to top up the differential a few times each year.

W. Michael
 
when you chased the threads on the banjo housing you changed the pitch of the treads and that why they are leaking. install a good original banjo housing with original bolts. that should fix it. its lot of work. an old timer told me that me years
ago and he was right. evidently ford used a unique bolt and tread for that part and when you changed one component it leaks.
 
I tried everything

I finally rebuilt the differential

Side gaskets were in pieces

Made banjo surfaces flat and took very thin cut off of bell gasket surfaces, they were not flat, I have a machine shop

Now, every thing fine, no leaks

Try everything else first before disassembly

I am NOT a big fan of Silicone

My opinion

Chris W
 
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