Big Twin lower Bearing numbers

[byacey]

Does anyone know what the bearing numbers are for the driveshaft and pinion bearings OMC part # 0376858 and #0378578? These are for a 40952R.<br />Thanks

 

[Paul Moir]

Re: Big Twin lower Bearing numbers

378578 is a Torrington "Drawn cup" full complement roller bearing, ID .625" OD .875", length ~ .750 overall. P/N BH-1012, it is still manufactured (pretty cheap usually). Dang near impossible to remove without destroying usually. Mar the ends and the needles won't roll properly.<br /><br />I belive the other is Torrington BH-1412, another drawn cup roller bearing. ID .875, OD 1.1875, length about .750". Double check that those numbers match yours, I'm not 100% on it (going by my '65 33hp in parts). Another cheapo still being made. <br /><br />EDIT: Uhh, sorry, that's the upper pinion bearing (376856), you're after the lower one with the loose rollers right? Mine's got torrington AG28493 on it, and appears to be a special bearing made for OMC. It's still listed as available from BRP and pretty cheap, but I couldn't find it from Torrington. If you want dimentions, I'll be able to furnish them.<br /><br />You'll find most the L/U bearings are dead straight standard & still manufactured. The reverse is a standard 6xxx series ball bearing (~2 or $3) and the forward bearing is a Timken tapered roller bearing (~$40 canadian for the cone & cup).<br /><br />Hope that helps!<br /><br />PS - Timken and Torrington are now one, it seems, since 2003. Also, got my wave shaper finally started - 30% duty cycle at 500RPM, approching 50% around 1000rpm. Well simulated, anyway - thank goodness for crutches. Didn't have materials to prototype, and since the stores are closed here Sundays I couldn't get them. Will report soon though.

 

[byacey]

Re: Big Twin lower Bearing numbers

Thanks Paul,<br />Actually I am after all the bearings. My pinion gear bearing surface is a little rough, I wonder how much I can polish this without loosening it up too much?<br />Do you have a specific number for the ball bearing close to the prop? I can't seem to find a proper number for this bearing. I priced out the tapered roller bearing for the back of the prop shaft, and I can get it here for about $30.00. I priced out forward and reverse gears plus the clutch dog. The local dealer wants about $300.00 for the forward gear and $96.00 for the clutch dog.Reverse gear was considerably cheaper?? at $221.00. Bottom line buying all the parts from them including the bearings is about $1100.00 going by their prices. I think I am going to build up the rounded edges with weld and mill it square with a vertical mill.

 

[Paul Moir]

Re: Big Twin lower Bearing numbers

Funny thing is, I don't think there's any difference between the reverse and forward gears. Once you press the bearing out of the forward gear, it looks a lot like the reverse. Swapping is possible too. <br />I think there's a thousand things you could do, and they would all improve the original design. Weld them up, machine them down, throw a couple degrees on the ears for positive engagement (all mine seem to measure 90°, but other brands often use a ° or two). Swap forward & reverse. Even find a good set of used ones.<br /><br />Reverse (ball bearing) is a 20mm ID, 52mm OD, 15mm wide. Standard unsheilded 6302 Ball bearing (any manuf.). Heck, even Princess Auto's got this one in the form of 6302-2RS, which has rubber sheilds & is packed with grease. My 28hp has this bearing with the sheilds popped off and the grease washed out. PA wants $4.19.<br /><br />$30 is a good price for the forward tapered roller bearing. I think I pay $37. Now that's for both the cup and cone, which have different p/ns and are sold seperately. One (I guess the cup) is a lot cheaper than the other.

 

[byacey]

Re: Big Twin lower Bearing numbers

Thanks Paul - Yep, the price is for the race and bearing. The only difference I can see between the forward and reverse gear is that one has an oil hole drilled through the side. I might just swap them around and mill a slight negative angle as you suggest. I would like to see exactly how much the clutch dog lobes engage with the gears when in gear, but I don't think thats possible with the gearcase lower cover removed. A person would have to measur the shift rod travel and figure the amount of engagement the fork provides, and take into account the slop that the fork has.

 

[byacey]

Re: Big Twin lower Bearing numbers

Hi Paul, Can you send me a private email? I would like to talk about these bearing measurements.<br />Thanks<br />byacey(at)interbaun(dot)com