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Benjamin

Cummins L10 / Voith V-Drive Questions

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I have some questions about the Cummins L10 engine and its common transmission, the Voith DIWA D863.2-W7. This winning combo lasted from 1986 to 1994.

Among them:

1. Were there any Canadian TA's that specified the L10 and Voith in the angle-drive (aka V-drive) layout? There, only one manufacturer offered such a configuration: New Flyer, since they made buses in both T-drive and V-drive layout. But here in the U.S., we had two more manufacturers cataloging this powertrain in this layout: Flxible and Neoplan (the latter, like New Flyer, built buses in both T-drive and V-drive layouts).

2. Regarding the V-drive layout, was the L10 laid down on its side (a la the Volvo B59 and B10R series)?

or

If there was one solution the Toronto Transit Commission could have done with its 1990 New Flyers with their Cummins L10 engines and ZF Ecomat 4HP500 transmissions circa 2000: they could have specified the Voith D863.3-W7 or, at least, the Allison VR731R (final "R" means reverse rotation, also called "RH"). But instead they chose to procure the old-fashioned V730's from a bunch of their retired 1977-81 GMC New Look buses. I wonder if that is because of the fact the VR731R/RH is electronically-controlled and the L10 at the time of original production was mechanically-controlled?

~Ben

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Mostly because they had a lot of spare V730s and parts kicking around.

They did have to order in new rotation reverser assemblies though.

Interfacing an electronic Allison to a mechanical engine is no big deal, the biggest adaptation was attaching a cable operated electric switch to the fuel " throttle" lever for downshifting on hills.

Older Allisons achieved this by installing a brass piston in the valve body that teed off the air supply for the fuel lever. Since the old L10s used compressed air to manipulate the injection pump lever, the old air style downshift was a logical choice, but had they wanted to or had the budget they could've gone electronic. More labour to run the wiring harnesses up front for the keypad and stuff though.

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I have some questions about the Cummins L10 engine and its common transmission, the Voith DIWA D863.2-W7. This winning combo lasted from 1986 to 1994.

Among them:

1. Were there any Canadian TA's that specified the L10 and Voith in the angle-drive (aka V-drive) layout? There, only one manufacturer offered such a configuration: New Flyer, since they made buses in both T-drive and V-drive layout. But here in the U.S., we had two more manufacturers cataloging this powertrain in this layout: Flxible and Neoplan (the latter, like New Flyer, built buses in both T-drive and V-drive layouts).

2. Regarding the V-drive layout, was the L10 laid down on its side (a la the Volvo B59 and B10R series)?

or

If there was one solution the Toronto Transit Commission could have done with its 1990 New Flyers with their Cummins L10 engines and ZF Ecomat 4HP500 transmissions circa 2000: they could have specified the Voith D863.3-W7 or, at least, the Allison VR731R (final "R" means reverse rotation, also called "RH"). But instead they chose to procure the old-fashioned V730's from a bunch of their retired 1977-81 GMC New Look buses. I wonder if that is because of the fact the VR731R/RH is electronically-controlled and the L10 at the time of original production was mechanically-controlled?

~Ben

Didnt this result in these buses constantly cooking transmissions, because the engine was too powerful for the transmission?

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Didnt this result in these buses constantly cooking transmissions, because the engine was too powerful for the transmission?

Shaun,

http://www.cptdb.ca/...e=Voith_DIWA.3E

I wish there was information here about the Voith DIWA.2 series, which predates the DIWA.3 series.

According to the tables the above link takes you to, the 270-hp Cummins L10 would greatly have worn down a D851-W7.

The older Allison V730 was only acceptable with engines up to 262 hp and 752 lb-ft of torque (by 1982, the torque limit was upped to 812 lb-ft). A typical L10 in a 40-foot bus produces 270 hp and 860 lb-ft of torque.

By comparison, the original ZF Ecomat 4HP500 used in original production of the 1990 New Flyer D40's was only approved for engines up to 1100 Nm of torque (812 lb-ft). Roughly takes up to about 300 hp.

http://apps01.zf.com...mat2_Bus_EN.pdf

(wish we had info here about the original HP500, HP590 and HP600 transmissions that predated the ECOMAT-2 series)

~Ben

Edited by Benjamin

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you forgot to convert the kw from the wiki to the hp for the L10. once converted, the transmission is rated to 294 hp.

The .3E units are less reliable than the .3's or the .2's most .3E units have been overhauled early and modified with improved parts.

The .2 units were almost indestructible.

the .3 units were around in the late '90's - early 2000's. the change to the .3E happened around 2002 or so.

Shaun,

http://www.cptdb.ca/...e=Voith_DIWA.3E

I wish there was information here about the Voith DIWA.2 series, which predates the DIWA.3 series.

According to the tables the above link takes you to, the 270-hp Cummins L10 would greatly have worn down a D851-W7.

The older Allison V730 was only acceptable with engines up to 262 hp and 752 lb-ft of torque (by 1982, the torque limit was upped to 812 lb-ft). A typical L10 in a 40-foot bus produces 270 hp and 860 lb-ft of torque.

By comparison, the original ZF Ecomat 4HP500 used in original production of the 1990 New Flyer D40's was only approved for engines up to 1100 Nm of torque (812 lb-ft).

http://apps01.zf.com...mat2_Bus_EN.pdf

(wish we had info here about the original HP500, HP590 and HP600 transmissions that predated the ECOMAT-2 series)

~Ben

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Putting in a larger than standard spec. Heat exchanger, and larger transmission sump can help. So can reducing the servicing interval.

Transmission failures are largely cumulative, due to overheating and burning range clutches, not snapping shafts and the like.

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Yes, if you include the sacrificial splined input shaft. Breaking hard parts are normally the end result of a failure started somewhere else. My range of exposure is centered largely around allisons. I have serviced and installed voiths as a complete unit at s&n diesel, but while they were certified to perform warranty approved rebuilding by voith, only a specially selected pair of technicians handled that.

Which brings up the Achilles heel of voith, at least in southern Ontario, IMHO.

While they are well made, Voith is very clear in their warranty terms that they will only accept complete units for rebuilding themselves, or by a warranty approved 3rd party. Voith will not even normally sell you internal components unless through those channels. In a nutshell, voith is much stricter who it lets open up their product.

Allison, and historically ZF, will honour transmissions rebuilt by customers, provided the technicians have been trained in certain proprietary seminars. One exception to this is the rebuilding or ZF drop box rear axles, used on Orion 6s, van hools, and nova lfses. In Ontario, they are normally overhauled as a complete unit by Tarten equipment.

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Since this is about the Cummins L10 engine, what is the difference with it's CNG counterpart the L10G, given that it is operated on Compressed Natural Gas, not with diesel.

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On the l10g, Lower Compression ratio, ignition coils, spark plugs and distributor primarily. No fuel injection pump or injectors.

Fuel is introduced in the intake manifold, before the cylinders.

There are other differences, but those are the obvious ones.

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There was also a Cummins L10 diesel engine (pre-CELECT) rated 240 hp and 870 ft-lbs of torque, and Canadian TA's usually went with the 240 hp version instead of the 270 hp version.

~Ben

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There was also a Cummins L10 diesel engine (pre-CELECT) rated 240 hp and 870 ft-lbs of torque, and Canadian TA's usually went with the 240 hp version instead of the 270 hp version.

~Ben

But why less hp? Our Neoplan's AN440's have the 270 hp version

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But why less hp? Our Neoplan's AN440's have the 270 hp version

Less fuel burn is a very large part of it. As well, generally Canadian transit agencies were slower to adopt features - such as air conditioning and wheelchair lifts - that had large parasitic power losses/draws and thus required more powerful motors.

Dan

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Less fuel burn is a very large part of it. As well, generally Canadian transit agencies were slower to adopt features - such as air conditioning and wheelchair lifts - that had large parasitic power losses/draws and thus required more powerful motors.

Dan

Then thats why we have higher L10 hp, the Neoplan's (and Flixble Metro's) used to be the kings of freeway and express service, going more than 65 mph on the transitway/freeway and having the AC on full blast during the hot days, and it gets hot alot during the year.

Is it now obligated in Canada to order air conditioning? Or does it continue to be an option?

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Is it now obligated in Canada to order air conditioning? Or does it continue to be an option?

It is still an option, but one that many Canadian agencies are now taking. Passenger and driver comfort trumps the added expenses of fuel and maintenance.

Dan

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In the U.S., as I previously said, the L10 was quite ubiquitous in the Flxible Metro series, from 1986 to 1994, and since it was also often paired with the Voith D863 V-drive transmission, raises the level of that ubiquity further. I mean, to get the most reliability from a power standpoint when the HVAC is on during the summer months, the 270 hp version is suited.

~Ben

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When the L10 first went into transit buses, only the 240hp version was available. A couple of years later, the 270hp variant was introduced, and the older 240hp engines could be rebuilt at 270hp. Santa Clara did this with their 1986 models, which started out as relatively slow buses but were faster after rebuilding. I'm not sure when they upgraded -- just that they were quicker circa 2001 than they were in 1986.

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In the U.S., as I previously said, the L10 was quite ubiquitous in the Flxible Metro series, from 1986 to 1994, and since it was also often paired with the Voith D863 V-drive transmission, raises the level of that ubiquity further. I mean, to get the most reliability from a power standpoint when the HVAC is on during the summer months, the 270 hp version is suited.

~Ben

The Dennis Dragons with L10 and Voith do sound the same as the Flxible Metros from 1986 to 1994. Even VTA repowered their L10 Flxibles to ISM, the sound doesn't change much.

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The current Voith DIWA series is revision ".5" and the current models are D854.5, D864.5 and, most recently, D884.5. The D884 is intended for use with engines making up to 375 hp and 1600 lb-ft of torque.

~Ben

you forgot to convert the kw from the wiki to the hp for the L10. once converted, the transmission is rated to 294 hp.

The .3E units are less reliable than the .3's or the .2's most .3E units have been overhauled early and modified with improved parts.

The .2 units were almost indestructible.

the .3 units were around in the late '90's - early 2000's. the change to the .3E happened around 2002 or so.

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THREAD BUMP

In regards to Cummins/Allison V-drive, there are at least two TA's here (in the USA) that come to mind:

New York City MTA ran ten 1996 model NovaBUS RTS-06's (40 feet long) with the M11 CELECT Plus coupled to the Allison VR731RH (units 9140-9149), although 9141 had been given a Detroit Series 50 EGR engine in later years.

Greater Dayton RTA (until 2003, it was called Miami Valley RTA) of Dayton, OH, ran 60 1997 model NovaBUS (35 feet long) RTS-06's (units 9701-9760) with the same powertrain as NYC MTA's RTS-06's numbered 9141-9149, although in the case of GDRTA the M11 CELECT Plus was rated 330 hp (as opposed to 280 hp) and thus the VR731RH transmission had to be modified to accept the higher HP rating.

~Ben

Edited by Benjamin

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What were the main differences between the T-drive and V-drive Voiths used in Gilligs vs. Flxibles (besides the T vs. V layout)?

All I can think of is as with all V-drive transmissions, strange sounds will come out of the rear axle and interplay with that of the transmission.

~Ben

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