Series 60 maintenance

[Jim Blackwood]

With these engines beginning to show up in bus conversions and all the fearmongering about bull gear failure I thought I'd post what I've learned and start a maintenance thread that can hopefully benefit everyone.

It appears the issue with the bull gears is not the gear itself but the bearing, which can fail without warning anywhere from  about 1/3M miles upwards. The bearing fails and then the teeth begin to break off, at which point there is a limit to how far the vehicle can be driven.

I've learned there is a way to do a periodic inspection, say every 100K miles or so, that isn't particularly hard, especially with the front of the engine as exposed as it is in a bus. You simply remove the accessory drive and use a prypar against the gear to check for any play to the front or rear. The accessory drive is a pulley with a 5 bolt flange on the front of the gearcase, which runs the alternator. Uses an o-ring for a gasket. Now I haven't done this myself yet, but as it should be a timken type bearing there should not be any play as timkens are run under preload. Maybe someone else can recommend how much deflection you should see. So anyway if you do that once and it looks good it'll be years before you have to do it again and will give great peace of mind about the gear drive I would think. That's my plan anyway.

The bearing itself can be removed and replaced but the retaining nut has to be torqued to 1000 ft/lbs and there have been instances of early failures after just bearing replacement so most people just buy the assembly. I suppose it is probably an exchange/core type situation.

Hope I got that mostly right, please make corrections as needed.

Jim

[luvrbus]

Lot of time the series 60 starts to run crappy because with the play on the bull gear it throws the timing sensor off or you can even lose the pin,if you not are sure I would replace the bearings and be done with it costly yes but worth it takes about 16 to 20 hours a after market gear and bearing are around a 1000 bucks, from DD double the price  ,that nut is one place I do use my Proto multiplier lol   

[Jim Blackwood]

Andy has done the bull gear on his truck a couple times now. On the inspection, not counting flex if there is any lateral movement in the bearings they need replaced as they will not last much longer. (How much is much?) He confirms the approx. $1000 cost for the assembly but says he paid that at Freightliner which is DD if I understood correctly, and he recommends exchanging the assembly rather than just the bearings.

I think I should be able to get the maintenance records on the bus, and maybe I'll get lucky on the bull gear.

Jim

[luvrbus]

When the bearing gets sloppy it increases the wear on the gear so it is best to replace the gear too,I pay Wiiliams $1845.00 for the kit it also includes the crank gear and hub that is way I replace a bad bull it's JMW you are there anyways the idler gear I replace the bearing because it is adjustable with the cover on 

[chessie4905]

Seems like those series 60 aren't quite the best thing since sliced bread after all. Especially now that they have been discontinued for a few years too.

[luvrbus]

Seems like those series 60 aren't quite the best thing since sliced bread after all. Especially now that they have been discontinued for a few years too.

They are good engines the early 11.1 and 12.7 had a few hiccups,but they ran 6 to 700 thousand miles before the bull gear needed attention.That is about 2 overhauls in the life span of a 2 stroke 

[lostagain]

I ran a 12.7 S60 in a hockey team's 95 D3 for several years. It had about 1/2 million kilometers. It ran and ran without a hickup. Only thing I did was adjust the valves once. The Webasto in good working order is a necessity, because the S60 doesn't warm up unless pushed hard. Just idling or even driving around town doesn't bring it up to operating temp. The Webasto warms it up quickly and keeps it at around 190F. I have driven several 1990s and 2000s buses with the S60/B500, and they are quite trouble free.

JC