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Ford Freestyle CVT Transmissions

207 messages,  Last post on Dec 03, 2009 at 1:19 PM

You are in the Ford Freestyle Forum. Your Hosts are steve_ & tidester

What is this discussion about? Ford Freestyle, Transmission, SUV


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#103 of 207
Re: Other alternatives [barnstormer64] by tidester HOST
May 04, 2008 (11:51 pm)
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Replying to: barnstormer64 (May 04, 2008 11:06 am)

A mathematician cannot decide ...
 
A mathematician would say it's topologically equivalent to a Ford Freestyle and try to drive off with it like we did with this topic!
 
tidester, host
SUVs and Smart Shopper
#104 of 207
Re: Other alternatives [tidester] by stevedebi
May 05, 2008 (8:43 am)
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Replying to: tidester (May 04, 2008 11:51 pm)

Tidester-
You know, we went through this last year when Edmunds decided to break up forums into different topics instead of letting people determine where they wanted to post. There were fewer topics, but a bit more of a story line.
 
I point this out because you moved my "I prefer Freestyle over T-Rex" post from the Taurus-X forum to this one - but the post was really about the T-Rex, not CVT. Can we copy this message back to the Freestyle / T-Rex forum?
 
Not only that, but I note that the hosts keep having to tell people to post in an existing forum, which is a bit ironic when you think about it - we went from a very few forums to many, many forums, of which quite a number have 2 messages - the original and the host reply to post in a different forum.
#105 of 207
Re: Other alternatives [stevedebi] by tidester HOST
May 05, 2008 (10:14 am)
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Replying to: stevedebi (May 05, 2008 8:43 am)

I'm not sure which post you are referring to but go ahead and repost over there.
 
tidester, host
SUVs and Smart Shopper
#106 of 207
check engine light/accel issues by ct2ct
May 06, 2008 (9:38 pm)
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2006 FS-just over 38,000 miles, just out of warranty, i start to hear weird noises out of the engine, like a belt is loose. Then it starts roughly, runs roughly, especially in cold weather. It also had acceleration problems, not accelerating like it did originally. Sometimes had a pause and then kick with power. Further, when i put it in reverse, it had a disturbing acceleration, which could be very dangerous. Sort of lurched backward with too much power for just taking my foot off the break. It has now been in the dealer 2 times, for a total of 4 weeks. They have told me it is one issue and then another. They replaced the engine sensor light twice, check the PCM, the wiring and the coils. They alternate between telling me it is my problem for not changing the oil soon enough (went 14,000 miles before change) to telling me it is a computer problem or some other part. Now they are telling me it is a timing chain issue that will cost me $1600 or if that doesn't fix it, the whole engine needs to be replaced for a cost of $6800! This car is not that old, doesn't have that many miles on it. Is this just another transmission failure issue, like others I have read? Suggestions? I have liked the car, but I cannot afford to put in a whole new engine in it, especially if this is a design defect.
#107 of 207
CVT chain tension, how is it optimized for fuel economy? fordwrench by coldcranker
Jun 19, 2008 (6:12 pm)
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I've been trying to find out the sensitivity of fuel economy to CVT chain tension (clamping force on the cones). Specifically, is this tension/force just set, or is it somehow automatically adjusted? I don't see how this force is directly sensed, so is a certain hydraulic pressure simply commanded, with hope that the force/tension turns out right? In a nutshell, what is the control law/strategy for chain tension and clamping force against the cones? Any maintenance required? Below, a quote and link from ZF's Mini Cooper version of our CVT. I understand ours is very similar, ours having a torque convertor for smoother takeoffs from a standstill, and different control software of some kind.
 
I posted this in the Freestyle maintenance section in hopes of snagging an answer from fordwrench or somebody else that understands the internals of this. I communicated this question to the son of the engineer who led the original development for the basic ZF design, and he is asking his dad about this. I'll post his answer later should I get it and compare it with the brainiacs who might answer this here. I'm certainly going to learn something here, and hope you all will too.
 
From the Mini Cooper CVT transmission article PDF file to download here..., page 21
 
"Pressure is supplied to the secondary pulley to ensure that there is always adequate clamping force onto the belt for all load conditions. A solenoid valve influences the secondary pressure control valve, optimising the pressure and hence the clamping force.
Optimisation of this pressure improves fuel consumption.
The working valves in this area are the secondary valve, the exhaust secondary valve, and a PWM solenoid secondary valve."
#108 of 207
Re: CVT chain tension, how is it optimized for fuel economy? fordwrench [coldcranker] by coldcranker
Jul 15, 2008 (6:51 pm)
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Replying to: coldcranker (Jun 19, 2008 6:12 pm)

I found some more info into what is going on inside these CVTs: In the June 2008 issue of SAE's "Automotive Engineering International" magazine, Hirofumi Okahara said he's "not satisfied with the current efficiency of current CVT metal link-type drive belts. We are developing more sophisticated sensing throughout the CVT to further optimize the degree of clamping force at the pulley and reduce pressure on the steel belt under running conditions", speaking about the Nissan CVT. The Nissan (JATCO) CVT may be similar in some ways to the Ford Freestyle (BMW MiniCooper, Audi ZF unit). Actually, it may well be that the Ford Freestyle/500 CVT is more efficient than the JATCO Nissan one, as it has been noted in the past (Car and Driver) that the JATCO CVT wastes some energy in internal hydraulic pumping losses. Depending on how clever the engineers are, it is possible the ZF CVT (Freestyle, etc.) doesn't waste as much energy internally. However, the clamping force Okahara speaks about critical to efficiency may be a problem in some Ford Freestyles, since it is difficult to gaurantee optimization in all production vehicles. I wonder if this is behind the inability of some Freestyles to get good MPG. Okahara wants more sensors in the JATCO unit to better measure and control clamping force.
Also see Technical CVT Paperor another Set of CVT Tech Papers. A lot of engineering/tech reading; not easy to understand. Anyway, I'll try to run Okahara's comments past one of the engineers responsible for the ZF CVT in our Freestyles to see if he thinks clamping force variations across many Freestyles could be a problem.
#109 of 207
WHO THE HECK changed the name of this forum? by stevedebi
Jul 16, 2008 (2:14 pm)
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The Taurus X does not use a CVT, and the forum should either be "Ford CVT", "Freestyle CVT", or just "CVT Transmissions".
#110 of 207
Re: check engine light/accel issues [ct2ct] by jjr4
Jul 16, 2008 (2:31 pm)
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Replying to: ct2ct (May 06, 2008 9:38 pm)

I have an '07 Freestyle (Manufactured in late '06) with 39,000 miles. I am having identical problems with acceleration, or lack of, and surges, or lurching forward and in reverse. Did you ever figure out the problem?
#111 of 207
Re: WHO THE HECK changed the name of this forum? [stevedebi] by steve_ HOST
Jul 16, 2008 (2:42 pm)
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Replying to: stevedebi (Jul 16, 2008 2:14 pm)

We were doing fine until Ford changed the Freestyle to a Taurus X and added the CVT.
 
How about we just drop the CVT?
#112 of 207
Re: WHO THE HECK changed the name of this forum? [steve_] by coldcranker
Jul 16, 2008 (4:26 pm)
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Replying to: steve_ (Jul 16, 2008 2:42 pm)

No, just drop the TaurusX from this forum and keep the "Freestyle CVT" association in this forum. The Taurus X does not have a CVT, and there is already another Freestyle/TaurusX forum to handle the other similarities in the vehicles.
 
To be clear, Ford used a CVT in the Freestyle from '05-'07, and the TaurusX from '08-on has a new engine, tranny, and front suspension, and otherwise the vehicles are almost identical (only front end cosmetic changes).

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