The Ford Barn

Lawrie · 03-26-2025, 04:00 AM

The trans on my pickup has been leaking, it leaked about a 6in diameter pool in a month while I was away.
I decided to look at it, it was coming from the back of the cluster gear shafts I did an oil change to the 600 wt oil, the trans was way quieter ,but still leaked.
So today I pulled it out and stripped it down.
I find there is a .006 gap between the shaft and housing, the shaft is .750 but the housing is .006 larger.
My fix tomorrow is to clock the housing up on the mill, bore it out .080 oversize, then turn up a sleave and press it in ,then bore that to the shaft size.
Will post some pics tomorrow on the job
Lawrie

Joe K · 03-26-2025, 06:24 AM

Given your size you're probably talking about either the cluster shaft or the reverse idler. I like to turn a "groove" and fit an 0-ring on the shaft - although the parts houses sell a "cover/gasket" that can be used in this area.

Cutting a groove in the lathe I discovered how "hard" the cluster shaft is. Case hardened, perhaps. I finally resorted to doing the groove with a tool-post grinder - not my fave since it puts grit all over the ways of the lathe.

Joe K

Y-Blockhead · 03-26-2025, 07:46 AM

The vendors sell those two shafts with the groove already cut into them

Joe K · 03-26-2025, 07:58 AM

Quote:

Originally Posted by Y-Blockhead

The vendors sell those two shafts with the groove already cut into them

At that time (20 years ago?) the grooved shafts were not available - and its a logical extension and I considered it far better (likely tighter) than the cover/gasket.

In this case it appears the hole has worn. There is nothing to keep the cluster shaft from turning other than the friction in it's hole. Some rebuilder instructions look to have the shaft "tight" in the hole - so tight it won't drop of its own weight when you hold up the case. Tightening the hole IS probably the best initial solution. I would go on to a positive seal since that's the part that Henry obviously left out.

Joe K

Y-Blockhead · 03-26-2025, 08:13 AM

Quote:

Originally Posted by Joe K

At that time (20 years ago?) the grooved shafts were not available - and its a logical extension and I considered it far better (likely tighter) than the cover/gasket.

In this case it appears the hole has worn. There is nothing to keep the cluster shaft from turning other than the friction in it's hole. Some rebuilder instructions look to have the shaft "tight" in the hole - so tight it won't drop of its own weight when you hold up the case. Tightening the hole IS probably the best initial solution. I would go on to a positive seal since that's the part that Henry obviously left out.
Joe K

OK, but we are in the present day and the grooved shafts are available now so why grooves them now?

The cluster shaft and reverse idler shaft should not be turning there is a retainer at the back of the transmission.

Joe K · 03-26-2025, 08:23 AM

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Quote:

Originally Posted by Y-Blockhead

OK, but we are in the present day and the grooved shafts are available now so why grooves them now?

Worthy query. It is well you brought it up. That is the point.

Joe K

Y-Blockhead · 03-26-2025, 08:37 AM

Even my Mitchell Transmission leaked from those sfafts. I installed the "Transmission Seal Kit" to stop the drips. https://www.snydersantiqueauto.com/p...8999&cat=41756

I don't like drips... so dry it is rusting.

Lawrie · 03-27-2025, 12:46 AM

Job finished today,
bored and sleeved the trans housing and then bored the sleave to .7505 inch.(sleave made from old ford axle shaft )
Came out really nice ,
Tomorrow will reinstall the trans,

deuce5wndw · 03-27-2025, 07:41 AM

Lawrie what about a counter bore and put a small seal on the shafts? Is there enough meat in the case for that? I looked at that on the V8 cases and think it would work.

Lawrie · 03-27-2025, 03:24 PM

Once I have sleeved the bore back to the correct size, there is no need for an o ring.
I have resleaved a couple of my spare V8 boxes and they dont leak after, my 33 has done a pile of miles with one fitted,
There would be enough metal to fit an o ring in, but on. the model a case the bore is only .700 long so it would reduce this by the thickness of the o used.
my sleave was .830 OD ,there would be enough room on the boss of the case for a seal.
Lawrie

03-26-2025, 04:00 AM	#1
Lawrie Senior Member Join Date: May 2010 Location: Qld, Australia Posts: 4,529	Leaking transmission The trans on my pickup has been leaking, it leaked about a 6in diameter pool in a month while I was away. I decided to look at it, it was coming from the back of the cluster gear shafts I did an oil change to the 600 wt oil, the trans was way quieter ,but still leaked. So today I pulled it out and stripped it down. I find there is a .006 gap between the shaft and housing, the shaft is .750 but the housing is .006 larger. My fix tomorrow is to clock the housing up on the mill, bore it out .080 oversize, then turn up a sleave and press it in ,then bore that to the shaft size. Will post some pics tomorrow on the job Lawrie

03-26-2025, 06:24 AM	#2
Joe K Senior Member Join Date: Jul 2010 Location: Cow Hampshire Posts: 4,610	Re: Leaking transmission Given your size you're probably talking about either the cluster shaft or the reverse idler. I like to turn a "groove" and fit an 0-ring on the shaft - although the parts houses sell a "cover/gasket" that can be used in this area. Cutting a groove in the lathe I discovered how "hard" the cluster shaft is. Case hardened, perhaps. I finally resorted to doing the groove with a tool-post grinder - not my fave since it puts grit all over the ways of the lathe. Joe K __________________ Shudda kept the horse.

03-26-2025, 07:46 AM	#3
Y-Blockhead Senior Member Join Date: Jul 2011 Location: Redondo Beach, CA Posts: 6,641	Re: Leaking transmission The vendors sell those two shafts with the groove already cut into them

03-27-2025, 07:41 AM	#9
deuce5wndw Senior Member Join Date: May 2010 Location: Liberty, KY Posts: 987	Re: Leaking transmission Lawrie what about a counter bore and put a small seal on the shafts? Is there enough meat in the case for that? I looked at that on the V8 cases and think it would work.

03-27-2025, 03:24 PM	#10
Lawrie Senior Member Join Date: May 2010 Location: Qld, Australia Posts: 4,529	Re: Leaking transmission Once I have sleeved the bore back to the correct size, there is no need for an o ring. I have resleaved a couple of my spare V8 boxes and they dont leak after, my 33 has done a pile of miles with one fitted, There would be enough metal to fit an o ring in, but on. the model a case the bore is only .700 long so it would reduce this by the thickness of the o used. my sleave was .830 OD ,there would be enough room on the boss of the case for a seal. Lawrie