3 speed transmission bearings

[roadster36]

I am starting the rebuild on some transmissions if have and noticed that there are several choices for transmission bearings available. The vendor has listed bearings that are open on both sides (stock), bearings open on one side only, and bearings that are totally sealed and closed on both sides. The vendor states that closed bearings cut down on rear transmission leaks. Has anyone used these ? I know that most of the r leaks I have had over the years were from the countershaft not the bearings. Thank you - Dennis

[Lawrie]

Be careful and check the circlips and grooves on the bearings,and the fit of these in the housings,check for end float .
lawrie

[JM 35 Sedan]

I don't have any idea which vendor your talking about who's making recommendations for different types of transmission bearings, especially the part about using totally sealed bearings closed on both ends. Probably the only vendor I would listen to about where to use a totally sealed & closed bearings on one of these early Ford 3 speed top loaders, would be Mac Van Pelt.

[Mac VP]

This is my opinion on sealed bearings for the old 3 speed transmissions.

For the front ball bearing, it's not necessary to use a sealed type, particularly if the trans uses the 1937-48 front bearing retainer (which houses a pressed in lip seal). If your bearing retainer is the 32-36 type, or the 49 and newer retainer, it won't hurt to use a sealed ball bearing. I recommend prying the plastic seal out of the inner side so that gear oil can always lube the bearing. We just install the 78-7050 retainer with the lip seal.

The rear ball bearing is a different matter. For several reasons I don't recommend using a sealed bearing. On closed drive transmissions, it's my contention that Ford intended for some gear oil to get past the oil slinger, and migrate through the ball bearing to mix with the grease in the u-joint area. This cavity is sealed with the paper gaskets and cork strip. If properly sealed up this area should not allow any leaks of significance.

On open drive transmissions (i.e.: pickup trucks) I believe the rear bearing should also be the open type. A bit of gear oil is necessary to lubricate the output shaft splines (in the slip yoke). Any excess oil would be retained by the rear oil seal in the rear bearing retainer housing.

Rear leaks are more common if the trans gearbox case is not sealed up well. We've found that the biggest source of leaks here is the failure to seal the passage for the countershaft lock pin. This is open to the inside of the case. Remove the pin, clean the passage of oil, clean the pin, and use a good sealer on the pin, and over the ends of the pin after reinstalling.

Stay away from synthetic gear oils....they tend to find tiny crevices easily. Watch for driveline slope on lowered hot rod applications. The rear end oil can run right down the torque tube and overfill the transmission.

These are just my opinions and are subject to change with my next whim.

[Terry,OH]

I agree with Mac on the front bearing, since I always replace the early front bearing retainer with the later style with a seal but I use a bearing with one metal SHIELD on the U-joint side only. I use a 0-0 grease in the u-joint and do not want transmission lube to mix with it. The metal shields on the bearings can be removed with ease by picking them out with a small screwdriver. I would not use rubber shield bearings since they are more for moisture and do not know how the shield material would react to long term exposure to petroleum products.
Just two slightly different views.

[Talkwrench]

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As Mac said.. What do you think the top roller bearing on torque tube and turtle gets most of it lube from.

[JM 35 Sedan]

After giving more thought today to the original post here, my thinking now on the use of sealed and/or shielded ball bearings on the front or rear of these transmissions, IF I could even find these bearings, would be:

On the front input drive bearing, I would use a seal on the outside/front of this ball bearing and a sheetmetal shield on the inside of this same front bearing. On the rear output shaft bearing I would use a sheetmetal shield on both sides of this bearing. Thoughts being, the shields on either of these two bearings, will or should by design allow gear oil to come in and go out of the ball bearing area, but should keep most of the of the potentially damaging debris from entering these ball bearings with shields from either the gear box side or the U joint side. I use John Deere Corn Head Grease in the U joint housing, and I know this mixes well with small amounts of gear oil that will make it through that rear bearing.

[big deuce]

Anyone have a part# for front bearing either metal shielded or rubber?

[nickthebandit]

Why not stop questioning what to use. Pay attention to Mac Van Pelt, and buy what he recommends. Mac knows of what he says. Whether you buy from Mac, or elsewhere, He will always give you the correct advice.

[big deuce]

I've reached out to Mac, just no response yet.

[pistonbroke]

If you do not allow transmission oil to pass through the rear bearing, you will destroy your U joint, speedo drive and driven gears and burn out the mid drive shaft bearing. Unfortunately, been there done that and got the bill for the transport of 1100 miles. That's about how far it took at freeway speeds. All that from listening to someone that liked to hear himself talk but knew nothing. I wish I had taken pictures but I was too PO at myself for not seeing the obvious. Tim

[big deuce]

I plan to have rear bearing open, to lubricant speedometer gears on open drive rear mount.

[FlatheadTed]

A Model A club member seized the roller bearing on the Front of the drive shaft on his Model A through lac of lube there it was on a cross country run .Model A is basically the same concept as the v8 there , Mac VP x2 here .Ted

[Oldcarbearings]

Front bearing FORD part number: 51A7025,
Listed in our bearing application catalogs as " drive shaft rear",


Aftermarket part numbers: NDH 43208 (BCA/FAFNIR/L&S/MRC ) 6208,
Mainshaft rear : FORD 51A7065 = NDH 43306 (BCA/FAFNIR/L&S/MRC) 6306,BOTH bearings are open type NO circlip/snap ring groove or snap ring,
If you need circlip/snap ring type add " N" to above aftermarket part numbers, these just have the groove &NO circlip or snap ring add " NR" to above part numbers, sealed or metal sheilded type: 6208 2RSNR, /6208 ZNR (metal sheilded one side) ZZNR (sheilded both sides).