CAT engines and ZF 12spd trans ?

Topic: CAT engines and ZF 12spd trans ? (Read 1144 times) previous topic - next topic

CAT engines and ZF 12spd trans ?

August 13, 2018, 03:51:33 am

I read a post in a another section that discussed Newell coaches. I was curious and went over to the Newell site to take a look.
I saw a few coaches that had 625HP C 15 CAT engines and wondered how reliable these are.
I also saw some units had a ZF 12 spd. transmission, what a great idea if they are reliable. I had a ZF transaxle in a DeTomaso Pantera years ago that was rock solid( probably turn into scrap after a minute behind a 625hp CAT). I was surprised to see a ZF and not a Allison coupled to a 625hp CAT. Some Newells had Cummins and Allison power trains.
Anybody have insight into these engines or transmissions?

Re: CAT engines and ZF 12spd trans ?

Reply #1 – August 13, 2018, 08:46:12 am

My experience only came from a few rvs. I was told Allison would not approve their trans for use with these high torque, high hp engines. I was told some were de tuned to get Allison mfg approval. I was told to expect 5 to 5.5 mph. I was told to expect rough shifting with ZF transmission. Caterpillar got out of the hiway and rv engine business in 2009.

I also found this post which may lead you to other conversations:
At Least 15 Lawsuits vs. Cat on ACERT Diesels Include Trucks, Buses - Fuel...

Re: CAT engines and ZF 12spd trans ?

Reply #2 – August 13, 2018, 09:01:15 am

Quote from: Jack Lewis – August 13, 2018, 08:46:12 am

I also found this post which may lead you to other conversations:
At Least 15 Lawsuits vs. Cat on ACERT Diesels Include Trucks, Buses - Fuel...

Interesting reading! I liked the last paragraph, which (perhaps) illustrates the principal of "Survival Of The Fittest". (color added for emphasis)

"Cat left the truck- and bus-engine business at the end of 2009 when ever-tighter federal emissions limits made compliance increasingly expensive. Meanwhile, the market for vendor-supplied diesels was shrinking as truck builders used more of their own engines. Cummins is now the only independent engine supplier to commercial truck makers."

Re: CAT engines and ZF 12spd trans ?

Reply #3 – August 13, 2018, 09:23:11 am

I am wondering if Cummins did not use their "corporate average" to meet some of the epa regulations.
They had one big advantage over Cat and DD, they had been building epa compliant smaller diesels for years.
One reason pre 2007 engined gliders are so popular.

Re: CAT engines and ZF 12spd trans ?

Reply #4 – August 13, 2018, 10:21:44 am

The big CATs made too much torque with over 2000 ft-lb with the twin turbos for the Allison torque rating so the ZF semi automatic was installed. I talked to a fellow in Puerto Penasco with one and said there was a maintenance issue with the twin turbos and the way they were mounted on the engine. If you wanted an Allison, the CAT had to be derated before it could be delivered with the full automatic Allison.

Discussion at: Opinions on the ZF 12-speed?

As far as Detroit Diesel goes, after Mercedes (MTU) purchased Detroit, the famous 60 series Detroit was morphed into the DD13, 15, 16 as well as some new smaller diesels in the DD series. They do cost a little more but have an extremely long B50 life. The engines are used throughout the world with an OM designation if in a Mercedes truck/bus and a DD designation if installed in many U.S. vehicles including Freighliners. And yes, the 2 cycle 6V-92TA is still produced and used in most all parts of the world except highway use in the U.S. Note that since the 6V-92TA does not meet the latest smog standards, MTU can't advertise complete engines on this web site but does supply complete new engines to the military and most other countries.

Check out the latest Detroit engines here. The DD13 is featured here as it's about the size as installed in motorhomes. Others are at the top of the page as well as a link to the 2 cycle page. Detroit DD13 Engine | Demand Detroit
and Detroit Legacy Engines | Demand Detroit

ZF makes this transmission all the way up to 16 speeds. I sure wish I had one in our U300!

Pierce

Re: CAT engines and ZF 12spd trans ?

Reply #5 – August 13, 2018, 11:03:29 am

IF (no first hand driving experience on the ZF) is the same ZF we rode in high end buses in Europe, it is a SEMI-automatic, not an automatic.

Meaning that you have to let off the throttle to shift. So much slower in acceleration, as turbo boost goes away at each of the many shifts.

Absolutely the extra gears would come in handy in the mountains, particularly for one familiar with multiple gear shifts/keeping a close eye on engine RPM.

Re: CAT engines and ZF 12spd trans ?

Reply #6 – August 13, 2018, 11:25:44 am

I have the C15 with the Allison tranny. The coach has about 124,000 miles on it and both are doing fine with no problems. I have put 30,000 on it since I bought the coach about 2.5 years ago. My C15 is pre-CERT so the CAT mechanics say it is a keeper. The ZF12 tranny spooked a lot of Newell drivers for it did not operate like an Allison or like their car's transmission. Those drivers that learned to use the ZF12 properly enjoyed them for they got 2050 ft lbs of torque and climbed the steep grades without much fuss. When they bought a newer coach with the Cummins and Allison they were disappointed with the lack of torque and HP they were used to but they enjoyed the amenities of the newer coach.

Re: CAT engines and ZF 12spd trans ?

Reply #7 – August 13, 2018, 11:37:30 am

Quote from: Pierce & Gaylie Stewart – August 13, 2018, 10:21:44 am

The big CATs made too much torque with over 2000 ft-lb with the twin turbos for the Allison torque rating so the ZF semi automatic was installed.

Brett,
Yes, I mentioned the "semi-automatic" aspect in the first sentence. I've ridden in quite a few ZF semi-automatics in Europe and Mexico and never found them having many shortcomings. The massive low end torque means only a momentary hesitation on shifts and acceleration from a stop was quick. That was probably a reason CAT went to two turbos on that engine. The two turbos are smaller and take almost zero time to spool up so boost is almost instantaneous. Diesels frequently do this in marine use as the two turbos bring in max torque a hundred or two earlier than a single turbo engines.

Since most all big rigs have manual transmissions, you can listen to them shift up and down on highways. Not much of a lag. I think part of the reluctance is the small clunk at a standstill if shifting from neutral to first gear. Since only three percent of Americans buy manual transmissions, it's easy to see why we like the seamless operation automatics offer. But at a price!! 80 percent of Asian and Europeans purchase manual transmissions today. How many big rigs have to watch transmission temperature or worry about coolant getting into the ATF via the transmission cooler?

Anyone have a ZF that wants to trade for our Allison?

Pierce

Re: CAT engines and ZF 12spd trans ?

Reply #8 – August 13, 2018, 11:44:39 am

Pierce,

Assume your Allison is the 4 speed, not the 6 speed of the 3000 and 4000 series.

Agree, more gears are GOOD.

Re: CAT engines and ZF 12spd trans ?

Reply #9 – August 13, 2018, 12:05:48 pm

Brett,

Yes, unfortunately. Otherwise I would not complain so much

(or is it "whine/whinge/snivel"?) Even some six speed Cummins 8.3 can pull away from us if we get caught between ratios on some grades and we could improve on already good MPG with a taller final drive.

I still remember going to the MBZ dealer in North Hollywood to get a manual transmission gasket set. I went back in the parts room and where there was a small box where all the four and five speed manual transmission parts were. The rest of the room was automatic parts. The MBZ manuals did use type A suffix A ATF.

Pierce

Re: CAT engines and ZF 12spd trans ?

Reply #10 – August 13, 2018, 12:18:08 pm

Quote from: Pierce & Gaylie Stewart – August 13, 2018, 12:05:48 pm

Brett,

Yes, unfortunately. Otherwise I would not complain so much (or is it "whine/whinge/snivel"?)/

Pierce

Pierce,

Can this whining be corrected with WINE?

We also had a 1967 MB 230S MT (many, many moons ago). Yes, ATF in the transmission.

Re: CAT engines and ZF 12spd trans ?

Reply #11 – August 13, 2018, 12:23:16 pm

Had a 1995 BMW M3 that used ATF in the manual transmission
John

Re: CAT engines and ZF 12spd trans ?

Reply #12 – August 13, 2018, 12:33:49 pm

Pierce, If you had been driving my 210 hp. 530 lbs. torque dt466 engine that is in my crane you wouldn't be so enthused about manual transmissions. After shifting this RT613 Road Ranger 13 speed for the last 25 years, I think I am getting Corpal Tunnel syndrome in my right wrist. Luckily I am pulling the plug on Sept. 27 and retiring.

Re: CAT engines and ZF 12spd trans ?

Reply #13 – August 13, 2018, 01:11:32 pm

Quote from: craneman – August 13, 2018, 12:33:49 pm

Pierce, If you had been driving my 210 hp. 530 lbs. torque dt466 engine that is in my crane you wouldn't be so enthused about manual transmissions. After shifting this RT613 Road Ranger 13 speed for the last 25 years, I think I am getting Corpal Tunnel syndrome in my right wrist. Luckily I am pulling the plug on Sept. 27 and retiring.

I bought a MBZ 406D van in Frankfurt years ago. It had a 2 liter 4 cylinder engine that was the bottom end of what they offered. I purchased a rear end out of a larger MB truck and stuck it in the back. I knew it would be needed as when on a test drive, it was all done at 50 mph and when it saw a hill ahead, it automatically started slowing down. It was a long trip from Frankfurt to Bremerhaven and the ship.

We did make it from Lake Tahoe to Puerto Vallarta in two days driving most of the time. I think I got CP syndrome just from shifting on the trip.

Shortly after that, I put a turbo on a normally aspirated 300D 5 cylinder engine and installed the taller rear end. Had to put the radiator underneath as the 5 cylinders were too long for the engine compartment. It had the same body as the 309D MB buses you still see in some towns. It weighted just under 5000 lbs after I took the two seats out to weigh it for registration so no commercial plates required. After the conversion, it got 23-24 mpg on the highway at around 65.

Our RAV4 toad is a five speed. Love shifting it. Would buy a new 6 speed with a diesel but while it's available everywhere else, not in the U.S. Bummer. My daughter has one in Brisbane, OZ.

Chuck, looking forward to meeting you at Oh Ridge June Lake campground sometime after you retire. Nicest area in the U.S. in my meager mind.

Best in retirement. Congratulations!!! (nice photo with the fish)

Pierce

Re: CAT engines and ZF 12spd trans ?

Reply #14 – August 13, 2018, 01:17:45 pm

The fish came out of Lake Lundy, I'm sure you know it.

Re: CAT engines and ZF 12spd trans ?

Reply #15 – August 13, 2018, 02:20:34 pm

Quote from: wolfe10 – August 13, 2018, 11:03:29 am

IF (no first hand driving experience on the ZF) is the same ZF we rode in high end buses in Europe, it is a SEMI-automatic, not an automatic.

Meaning that you have to let off the throttle to shift. So much slower in acceleration, as turbo boost goes away at each of the many shifts.

Absolutely the extra gears would come in handy in the mountains, particularly for one familiar with multiple gear shifts/keeping a close eye on engine RPM.

most motorcycles have straight cut gears, so clutch is typically only used when stopped or shifting into 2nd. most recommend to "lift" momentarily while shifting. "quick shifters" are available that kill the ignition for milli-seconds when it detects the start of shift lever movement, but most of these engines are low mass. This would not work on a high mass diesel with no "ignition". with 12 speeds I would think the rpms would only need to drop about 100 rpm. I would love to have a two speed rear end our auxiliary overdrive to go with my 4 speed automatic.

Re: CAT engines and ZF 12spd trans ?

Reply #16 – August 13, 2018, 04:01:05 pm

Phred, I had a Kawasaki 500 triple with forged pistons w/dykes ring, modified ports, clip-ons, mag wheels with road racing tires, disk brakes, etc. Just under 3 seconds 0-60. No chance of using the clutch as that would be the last thing you ever did. Just get low over the clip-ons, roll the throttle off a little for a hundredth of a second and hit the shifter. Even then, it would keep the front wheel off the ground part way through 3rd gear. Just lean a little to change lanes.

Did you know that a 2 cycle motorcycle's engine turns the opposite direction from most 4 cycles bikes? Any bike with a chain or belt between the engine and transmission turns the opposite way from a 2 cycle with gear between engine and gearbox. 2 cycle bikes lift the front wheel when accelerating, 4 cycle bikes push the front end down.

Chuck, we were at Lundy Lake three weeks ago. Great looking little store. See photos.

Re: CAT engines and ZF 12spd trans ?

Reply #17 – August 13, 2018, 05:42:39 pm

Looks like there is a difference between a CAT C-15 and a C15. The twin turbo seems to get poor reviews compared to the older single turbo engine. As soon as emission standards came on the scene the durability seems to have dropped.
Interesting.
That 12spd ZF intrigues me, or maybe its the 2000# of torgue available with the big CAT.

Re: CAT engines and ZF 12spd trans ?

Reply #18 – August 13, 2018, 07:35:56 pm

Looks like fuel supply is part of the problem but the high operating temps required to pass smog caused much of it. The guy I talked to was not that happy with his and said it was not that fast especially considering the high horsepower rating. Said his old Eagle was quite a bit quicker.

Here is a video of the ZF-AS Tronic automatic transmission. Note that it has no torque converter, heat exchanger, etc. It does have twin countershafts. Looks slick to me. I saw the same exact modern bus last month in Cairo. Got a photo of the back but stuck in traffic so no front shot.

We had a late Crown firetruck with a twin countershaft 5 speed. Nice shifting.

https://www.youtube.com/watch?v=RWBmUZ6VJmI

Actually driving the ZF-AS (Astronic): https://www.youtube.com/watch?v=RWBmUZ6VJmI

Pierce

Re: CAT engines and ZF 12spd trans ?

Reply #19 – August 19, 2018, 11:03:04 pm

Semi-trucks have been using autoshift and auto clutch transmissions for years. They are fully automatic versions of a traditional "manual" transmission.

Re: CAT engines and ZF 12spd trans ?

Reply #20 – August 20, 2018, 11:52:53 pm

Quote from: John and Stacey – August 13, 2018, 12:23:16 pm

Had a 1995 BMW M3 that used ATF in the manual transmission
John

My 1973 Barracuda 4 spd is auto fluid from the factory.

Re: CAT engines and ZF 12spd trans ?

Reply #21 – August 21, 2018, 07:21:31 am

Looks like a good start, why not go ahead and make it a dual clutch transmission with the ability to autoshift or paddle shift..... Honda is going great guns with this trans in several of their motorcycles including the new Gold Wing.

Re: CAT engines and ZF 12spd trans ?

Reply #22 – August 21, 2018, 01:48:51 pm

At the other end of the power scale I had a VW Rabbit diesel N/A years ago. 48 HP and 58ft/lbs torque. 50 mpg. Engine looked like a sewing machine. Trick was keep the revs way up. Car did not accelerate but "gathered speed" as a friend said.

Keith

Re: CAT engines and ZF 12spd trans ?

Reply #23 – August 21, 2018, 04:53:17 pm

Quote from: Keith and Joyce – August 21, 2018, 01:48:51 pm

At the other end of the power scale I had a VW Rabbit diesel N/A years ago. 48 HP and 58ft/lbs torque. 50 mpg. Engine looked like a sewing machine. Trick was keep the revs way up. Car did not accelerate but "gathered speed" as a friend said.

Keith

Had one as well. Bought it as a "boat car" to use to resupply the boat. Ended up driving it from FL to New England. Slow, but, yes 50 MPG. Other small diesels were a Datsun Sentra diesel 53 MPG and a Puegot 504 diesel 35 MPG, but very comfortable as was a MB 200D.

Re: CAT engines and ZF 12spd trans ?

Reply #24 – August 21, 2018, 05:00:19 pm

Quote from: Keith and Joyce – August 21, 2018, 01:48:51 pm

At the other end of the power scale I had a VW Rabbit diesel N/A years ago. 48 HP and 58ft/lbs torque. 50 mpg. Engine looked like a sewing machine. Trick was keep the revs way up. Car did not accelerate but "gathered speed" as a friend said.

Keith

Quote from: Keith and Joyce – August 21, 2018, 01:48:51 pm

At the other end of the power scale I had a VW Rabbit diesel N/A years ago. 48 HP and 58ft/lbs torque. 50 mpg. Engine looked like a sewing machine. Trick was keep the revs way up. Car did not accelerate but "gathered speed" as a friend said.
Keith

I had a couple of them. The first was a German model with the 1500cc engine and relatively short final drive. It handled really well and was fairly quick. I did a lot of highway driving from SoCal to Santa Fe so the short final drive was tiresome. I got rear ended so the next was a U.S. built 1600cc diesel model. More modern dash, much taller final drive but with a soft ride and poor handling. Was very quiet on the highway and did get 50 mpg. Later turbo diesels were much faster.

Pierce

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