Timken crankshaft bearing set Up 2003 -up

This piece was written in 2011 and updated in 2020

Some things are just good and you shouldn't touch them. The timing crankshaft bearing is certainly one of them. I've been doing this job for a while and I've never found this part broken in a motorcycle. It has been unchanged in every Bigtwin since 1969 and a somewhat smaller version in the Sportsters. So the Shovelhead, the Evolution model and yes, even in the new Twin Cam block the crankshaft on the left was stuck with the Timken bearing set. On the right everything was changed, from loose rollers to fixed bearings, which got bigger and bigger. But not on the left, the old familiar and very robust bearing just remained. To their horror he was suddenly out of the Bigtwins in 2003 .....

The beautiful double bearing was replaced by a single one and after some minor changes, the same bearing is currently on the left and right side of the crankshaft. The bearing has quite a bit of clearance, which is a good thing, as Harley currently mounts crankshafts with a decent 1 to 2-tenths swing, especially in the post-2007 models with the longer-stroke crankshafts.

The quality of this bearing has been whispered here and there, and especially among the suppliers of fast kits, there is not really any praise for the crankshaft suspension of the models from 2003 and after. S&S says in their own catalog that their crankshafts are for the double Timken bearing and not for the 2003 type and later. The strange thing is that they make crutches with the side of a 2007 and later, because that is different in terms of splines. So they don't immediately say that you have to mount a Timken, but with a detour .... The next sentence is then, that you should use the Screaming Eagle bearing which is actually the same as the original, but now with a coating on it. and therefore stronger. Personally I have built several 124 ci blocks with the Screaming Eagle bearing from Harley and I have not seen them broken yet. I do read quite a few nasty messages on google but yes, what is true on the internet?

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Jim's has been making a conversion kit for some time where, with the help of some tools and molds, you can mount the old timken bearing in a new type of crankcase. Screaming Eagle now has the same set in their catalog. With astonishment I see in the same Screaming Eagle catalog a 113 ci kit and even a 120R engine and kit, all right, a 2 liter from Harley-Davidson, with a lot of power, where this is not lower then again? Politics and costs will certainly play a role in this story as well. Enough talking now, I now have a 2011 103 original Harley engine and I am going to ramp it up to 124 ci and now have the double timing lower with the Screaming Eagle set. Funny thing is that the Screaming Eagle set was made by Jim's ...

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The set is a nice plastic box that costs a lot of money. The insert that goes into the crankcase has to be bought separately. Above you see the insert.

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The kit consists of an attachment that you screw onto the crankcase.

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Furthermore, a milled attachment to which you mount the insert and which, with the help of guide pins, fits nicely straight into the attachment that is screwed to the crankcase. If you are going to assemble the bus, you apply a lot of locktide to the bus, and on the thicker part grease, to press the bus into the aluminum crankcase without eating.

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Press well under the press.

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The dimensions of the drills to be used are milled into the press plate, so that you can always drill exactly at the right depth.Very useful.

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Furthermore, there are holes in the plate to make the oil supply and return and to drill the holes to fix the cases.

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Of course all drills are included and the tap, with a handy tool for straightening.

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You can also mount the insert without the screaming eagle box, but then you need a milling machine or something similar, and this tool is quite handy, because it is not really a difficult job.

 

When you eventually mount the Timken bearing in the Screaming Eagle bush, you have to determine the play and fill it with the correct spacer. The bus contains a fixed ring instead of a snap ring. The crankshaft can now be mounted as usual !!

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