T500 Case Dowels

[Powderfinger]

I'm working on a Titan motor, the bike is a 73, the motor that was on it was from a later year and it had a welded repair in the oil pump area. It looked like someone used the little cast "walls" as a pry point to remove the pump and cracked the case. It looked like a decent repair but I ended up finding another set of cases from a 71 or 72. These look good but I notice the dowels for the crank bearings and pretty much all the other ones don't stick up near as high as the later cases. Some barely stick above the surface. They don't look to have been messed with, no grind marks or anything like that. I looked at some cases on Ebay and every set I see the dowels stick up as they are on my first set.

Has anyone noticed inconsistency with these dowels from case to case.

Thanks for any info.

[ConnerVT]

The T500 cases were recast some time in 1973, which changed the oil capacity from 1200cc to 1400cc (and I believe eliminated the drain bolts under the cylinders).

This may be another difference.

[Powderfinger]

The repaired cases are later ones, marked 1400cc, serial number T500 82402

The set I want to use are marked 1200cc, serial T500 49432

The later set the crank bearing dowels stick up about .090 maybe even a bit more. The other set the left and center stick up maybe .010 and the right side is pretty much flush with the case. Really nothing there to hold the bearing. No sign of damage or heat or modification, just short dowels.

I was just wondering if anyone else had seen this. It may have been an error by a machinist that made the holes to deep and the dowels are regular length.

I guess the bearings are not likely to move once everything is torqued.

[oldjapanesebikes]

What sometimes happens is the dowels are not lined up properly and get pushed in when the cases are torqued up. In really bad instances, they can be pushed through the casting. So long as they do protrude at least somewhat, and you get them correctly aligned, you should be fine.

And are you trying to mix an upper and a different lower ? Not usually recommended, as the cases are matched pairs, and are stamped - usually behind the drive sprocket - so you can tell.

[Powderfinger]

Thanks for the info. They are both matched sets. I've been cleaning both up trying to decide which set to use.

[oldjapanesebikes]

If you go with the earlier cases, just make the change to the weir height (if it already hasn't been done) as detailed in service bulletin T-3 which you can read here. And take a very close look at the 4th and 5th gears - spalling on the teeth is common.