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Discussion Starter · #1 ·
2014 with 90K miles. For the last few thousand miles I have had a surging/ pulsing under light throttle application. It's almost rhythmic at about 1 second intervals and I can see it moving the tach slightly. Finally got around to making an appointment yesterday at an independent shop in Tulsa and what do you know, car won't turn over this morning.

Any ideas?
 

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Discussion Starter · #6 ·
Update: Battery was bad so I replaced. Unrelated to surging. Had dealer change transmission fluid and perform computer reflash. Did not fix the problem. Waiting to hear if Acura will throw in some goodwill on replacing torque converter.
 

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Dang, let us know if that TC is really shot. The TSB implied that the TC never really breaks/fails, but it is really just sludgey fluid causing the problem. If that's not it, maybe prolonged use with higher than designed heat loads does indeed cause a failure.
 

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Discussion Starter · #9 ·
Still waiting to hear from regional rep. The service advisors and lead tech both admitted that failed TC's are a well known issue and Acura has been taking care of customers pretty well on replacement.

My MDX is 99% highway use and never towed. I can't imagine an easier life on a drivetrain.
 

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At this rate should everyone up to 2015 model expect a dying tq around 100k?
I wouldn't conclude that at this point. Just because 'some' vehicles have an issue with a particular component doesn't usually mean 'all' same model vehicles will have the issue - it's usually not the case unless there's a gross design problem. Of course there 'could' be a gross design problem that just hasn't affected many vehicles yet due to the fact that probably not many 2014s have hit around 90K mileage yet but I sure hope this is more of a one-off. Mine's only at 40K miles in 4 years so it'll be a long time before I hit 90K most likely.

Neoshi - maybe you know whether or not the TC changed significantly or at all between the 2nd gen 2013, for example, and the 2014. I don't know if it has or not but sometimes subtle design changes have the potential to cause problems, including the fluid used. OTOH it could be a spate of poor welds or defective bearings or some part from a vendor with some tolerance off or something.
 

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Honda torque converters are simply not big enough for the amount of Overdrive the Transmission via Software is asked for...
In order to push big MPG numbers Honda finds itself lugging the engine quite frequently and thus the Torque Converter get loads of heat, heat that in Honda Software is "OK" until it doesn´t and the TC craps out for abnormal accelerated wear in the fins.

My theory:
I particularly found this issue in a lot in post 2010 models... Seems that when Honda introduced the 6 speed they were already under pressure to push bigger MPG Numbers thus they required to lug the engine more and more (6 Speed has some quirks between 1st and 2nd often skipping one or the other), My 5 Speed MDX is often guilty of this in Full AUTO but you have to be really gentle with the Throttle otherwise the engine will easily REV to 3000K but since I started driving it on SS 90% of the time I got used to hold 1st gear longer anyway so no biggie, After 1st to 2nd the lugging issue is not that relevant as the MDX likes to downshift easily.

I will advice any of you to not let the MDX take off and shift into second before 2500RPMs, If you can spin it to 3000RPM or more the better, After this Grade Logic wont allow you to cook the TC in steep hills or down hills. TC lock up can happen in the 5 Speed at gears 3 through 5, In the 6 Speed TC lock up happens from 4 to 6.

I dunno about the Software programing on the ZF 9 Speed but I hardly doubt it will cook the TC with the TITANIC Sized gear spread it has. This issue was more relevant to the in house Honda 5 and 6 Speedo.
 

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The TC mostly remained the same until 2015. Minor improvements over time but the design was the same. Honda doesn't really change their designs much and simply evolves them a bit. The 5 speed and 6 speed use a lot of similar components iirc and a lot of 6 speeds are merely 5 speeds with overdrive 6th.

I'm actually worried about folks who don't diy the atf changes (i know you will mdxstang lol) or just don't think to bring in their mdx to drain and refill every 60k (actually less if you don't have the reprogramming to reduce the heat). This seems like a good amount of people (outside of our forum of course lol).

Well we shall see i guess. A part of me didn't like how the zf performed in the beginning, but still trusted it more than the proprietary tranny after the last tranny fiasco in the Odyssey. It was the first of two tranny fiascos actually.

Sent from my Pixel using Tapatalk
 

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^
The 6 speed does not have an Extra Overdrive..
5th and 6th ratios are Identical to the 5 Speed Trans 4th and 5th gears.. The 6th extra gear is a new LOWER 1st gear so it has an extra lower gear than the 5 Speed Trans.

So more easy to understand All gears together (5 Speed) vs 6 Speed:
LOW GEARS > 1st (N/A) > 2nd (1st) > 3rd (2nd) > 4th(3rd) > OVERDRIVE GEARS > 5th(4th) > 6th(5th)

In contrast the new ZF Transmission takes that to a WHOLE NEW LEVEL...
IIRC the ZF Trans does not directly relate to the 6 Speed until 4th gear so it has a whopping 3 extra low gears and the Overdrive Gears are way past the 6/5 Speed Trans, ZF 9th Gear is so ridiculously overdriven that its very hard to get there without exceeding the speed limits in all USA for our Speed Limits 8th gear will be the most used Gear.
 

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She goes under the knife Thursday morning to replace torque converter. Acura has offered to pay half of the $2600
Honda transmissions have always been weak. $2,600 is not bad. Is it the dealer doing this or a transmission shop. A lot of dealers are not allowed to open up a transmission. Usually they just swap them out.
 

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A lot of dealers are not allowed to open up a transmission. Usually they just swap them out.
The torque converter on at least most trannies is a separate component where the actual trans doesn't need to be 'opened up' to service/replace. Usually one just needs to drop the trannie and then the TC slips off the shaft at the end of the trans. On a normal front eng rwd vehicle it's not usually that difficult to replace. I don't know what the effort would be in an MDX. I'd expect a dealer to be capable of replacing just the TC and it'd save Acura a lot of money vs replacing the whole trans + TC.
 

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The torque converter on at least most trannies is a separate component where the actual trans doesn't need to be 'opened up' to service/replace. Usually one just needs to drop the trannie and then the TC slips off the shaft at the end of the trans. On a normal front eng rwd vehicle it's not usually that difficult to replace. I don't know what the effort would be in an MDX. I'd expect a dealer to be capable of replacing just the TC and it'd save Acura a lot of money vs replacing the whole trans + TC.
Good point.
 

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Acura? That fiasco was Honda spread wide... It affected: Pilot, MDX, Accord, Odyssey, CL, TL... It was the biggest PR Nightmare Honda ever faced in its entire life and not even the ZF Fiasco comes close to it.

Also that link makes it believe Torque Converters failed? Nope that wasn't even the issue, TCs didn't even get affected by the flaw in design the original BXWX transmission had.
 
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