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Old 11-12-2006, 05:39 PM
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TopCatGr58 TopCatGr58 is offline
Join Date: Jul 2002
Location: Portsmouth, Va.
Posts: 12,621

John said:
A couple of things I discovered when doing my swap: 1) Do not remove the small phillips head screw on the flange where the four mounting studs protrude through, and in fact, place a couple of washers on two of the studs, and run nuts down on them snugly. This will prevent the pinion from coming out of the housing when pulling the drive shaft/oil seal out, and possibly disturbing the shimming of the pinion. In place of a slide hammer to pull the driveshaft, you could clamp onto it with a vise grip, and strike the vise grip with a hammer. That will drive it out.
2) Another tip is that the large 1/2 inch washer that Maximan calls for can be substituted with the washer that is in use on the XS11 FD. It is the correct size, and it completely covers the oil return holes. Maximan cautions about reinserting the pinion back in place so that the oil holes line up. Of course if you do not remove the pinion from the housing, then this caution is needless, but if it does come out, everything will realign when you line up the hole for the small phillips head screw when reassembling the FD.
It truly is an easy swap over, and you will enjoy higher fuel economy, and less wear n' tear on your engine at highway speeds.
In regards to the copper spacer:
Chop used it becasue it was readily available. However...I would seriously consider a steel or bronze spacer. I have not checked mine (copper) since the install but I will in a few days to see if there is any noticable wear. In any case i am going to replace the copper with a bronze spacer.

I was in an oilfield supply store the other day and stumbled upon a perfect spacer. It is a rocker arm bushing for a 346 Fairbanks Morse engine. It is made of bronze instead of copper and actually fits a little better than the copper tubing and the wall thickness is about 1/2 mm thicker. Being made of bronze it should be more durable.

The copper will work but I think this bushing would be a better long term solution. You should be able to get one at any oilfield supply. It is readily available through Arrow Specialty Products. Arrow Specialty can be found on the net. They have offices in NY and OH and other places but most Oilfield supply store would be able to get this common part for you. The Arrow part number is 1009 for a 346 Fairbanks Morse.

You'll have to cut it to length. But you'd have to cut the copper collar to length too.

Arrow Specialty Products handles these parts. The Arrow part number is 1009 in their catalog.

Arrow Engine
2301 E Independence
Tulsa, OK 74110
Phone: (918) 583-5711

But you can probably call these guys and ask for parts:

Then tell them you need a rocker arm bushing for a 346.


One thing I've picked up on that everyone should be aware of. I did not realize this when I wrote up the procedure.

The torque on the pinion retainer nut IS CRITICAL. As is the preload.

I suggest following the manual. After installing the larger washer to seal the spooge holes on the drive coupling be sure and torque the pinion nut to the specified torque...54-61 ft-pounds for a type one, 75-105 ft-lbs or there about for a type two. Then double check the bearing preload with the appropriate inch-pound torque wrench.

On a type one it is about 10 inch pounds.

On a type two (read 850) it is 3.4 to 4.3 inch-lbs.

If the bearing preload is not within the specified range damage could result as I found out on mine.

After the 3000 miles trip to west Texas I pulled the drive for inspection. There were some small metal shaving on the magnetic drain plug and the pinon assembly was very loose. MY BAD!!!

I chucked that drive and installed another. This time around I torqued everything back to spec and the bearing preload was fine.

HOWEVER... should you button everything up to spec and the beaing preload is not close to the specified torque in the should replace the expansion spacer (a crush washer) that is between the pinion gear and the retainer nut. These are only $10 and will assure you the right tolerances are maintained.

So far I know of no one that has had this problem and simply re-torquing everything back to spec should work fine without having to replace the expansion spacer. At least it worked for me on the second drive.