Contour Enthusiasts Group Archives Forums General Troubleshooting I have a rattling transmisson - Part 2 - Answer from Ford

I posted mid June regarding a rattle in the tranny area when idling and when slowly acclerating....here's what the Ford Mechanics gave me....

service #08925

"Manual transaxle equipped contour/mystiques may exhibit neutral gear roll over noise (light metallic rattling sound from transaxle) which occurs only at idle with the transaxle in neutral and the clutch pedal up. This noise results from natural torsional characteristics of the powertrain. advise customers who come in with this concern that vehicle durability will no be affected. no design or service actions are planned to address this concern."

So its been documented.....hopefully some stats will come in stating that something needs to be done.... I have a hard time believing "Natural Torsional Characteristics of the Powertrain" sounds like a brush off to me.

You pay all that money for a rattlin tranny....

oh well live and learn

Nope,in this instance Ford is correct.The MTX75 has 'gear rollover' as do a lot of current transmissions,its nothing to worry about ...the only time it sounds worse is if you fit an aftermarket clutch with a 'solid' Vs torsional damping spring in a stoc clutch disc, the springs help to dampen the rollover noise.

Yeah, I noticed that in my Focus after I took my radio out. I never noticed it in my Contour but I never really knew what to listen for and the exhaust note probably covered up the noise.

That's a load of BS from them! Why didn't my car have the noise when it was new? And why did it progressively get worse throughout time and mileage? They are just trying to hide from admitting that it's a crappy designed tranny. It's because they know that many people will just milk more miles out of their tranny problem (if they were to think it's normal) right through the extended warrantees, plus, by saying that, they could hopefully avoid a potential recall campeign for this trans. Don't listen to that bulletin. You gotta remember, that in this day and age, everyone (it seems) is a liar. Every word is spoken based on the 'best interests' of the people speaking the words.

My trans had it at 35,000 and never changed,it now has over 90,000...sounds the same as it did at 35,000

So then it's normal for it to GROWL loud when you are at lower RPMs accelerating in first, second, and third gears, and while yout just idling in nuetral (like mine does)? It's especially loud when you are driving next to a building or in a drive-thru

Drive-thrus are the worst for hearing rollover,dont get it in mine normal driving,only in idle in neutral...

First 50+k miles in mine it never had it.

Put in the grizzly clutch (stiffer clutch disc "bump springs" compared to stock) with the lighter SVT flywheel and now I have it. No big deal 'cept the car sounds like poop at the drive through. If it really bugs me I'll just step on the clutch.

same hear. Never had the noise but put in a grizzly clutch and it started. Drive-thru's are defiantly the worst!

I've had a couple of people ask me what that noise is and I just tell em "Its the clutch biting" They both thought that was neat actually.

I thought it was a prob with the clutch at first but you guys told me it was normal.

It use to bother me, but not anymore....kinda cool I think

-neal

Gear roll over noise is a normal condition. Over the last twenty years or so, it has become more common. I will try to explain.

Manual transmission engineers have a choice when designing the gears. Fatter but streighter teeth are stronger and will take more load, but they are noisier. Thinner and more curved teeth are quieter but are not as strong and will not take as much load.

I first became aware of gear roll over noise in the 60's when the strongest Muncie 4 speed transmissions used in Corvettes were known as "rock crushers" because the transmission sounded like you were grinding gravel. The (I can't remember if it was the M20 or M22 that was the stronger, noisier one) noisier trans was used in the L88 option which was only intended for competition use, not street use. The L88 was a monster big block that made much more horsepower than the street version. The L88 did not even have a fan shroud and would overheat on a hot day in city traffic. It was not intended to be driven under such conditions, so noise was not considered a problem.

The "rock crusher" trans shared many components with the normal Muncie trans, but differed in the gear cuts. I don't mean that the gear ratios were different, because there was a normal Muncie with the same gear ratios. Thus they were able to make a stronger trans with minimal engineering costs AND WITHOUT A SIGNIFICANT DIFFERENCE IN WEIGHT.

As the auto industry started to become more and more concerned with fuel effeciency, every component in the car went on a diet. To keep the transmissions as light as possible and still strong enough to get the job done, more and more transmissions were designed with a bit of roll over noise. US small cars were not alone in this. The Ranger manual trans used in the 80's was made by Mazda and had gear roll over noise. Many Ranger owners needed to be educated to the fact that the noise was not harmful. The European made ZF 5 speed manual trans used in F350 trucks at about the same time were even noisier. None of these are as noisy as the old Muncie "rock crusher".

So you are not alone in being concerned about the noise. You are also not alone in having a hard time accepting the explanation of experts. If you don't believe Terry, one of the most knowledgable persons on the MTX-75 transmission, I don't know who can help.