Gear change noise!


USA GT - STAN WHITE

FORD
Mark IV Lifetime
Aug 13, 2007
32
Gardnerville, Nevada
Would like to hear from anyone that has done the 3.90 Gear Change. I have done three Gear Changes in the past. 92 Vett/ 97 Viper/ 2000 Viper. I never had a Noise Issue. With my 06 GT first 200 miles I was very pleased. The performance was just what I wanted. After first 200 miles I started hearing noise on deceleration seems to be getting louder the more miles I put on it. I would like some feedback from others that have made this modification. Thanks. PS I have a New GT Engine complete from Factory. Still on the pallet that I am willing to sell. If interested call 775 265 5333.
 

Shelby#18

GTX1 Owner/Moderator
Mark IV Lifetime
Le Mans 2010 Supporter
Dec 15, 2006
1,623
Nev./So. Cal./Minn.
Hello Stan,

I have changed the gears on two of my cars, and have not any noise issue. Did you give Stillen a call? Is it a grinding noise, or something else?
 

kmillen

Well-known member
Jan 29, 2007
504
Hi there Mr. White,

Just wanted to jump in and offer a little information on this.

During the testing of the 3.90 gear changes Ricardo informed us that there might be a little gear noise on some cars. We asked why, and they explained that because of the cut of the gear, some cars might experience a little whine on decel. We ended up shipping all of our inventory back to Ricardo and asked that they re-cut the gears and ask that they surface them so there would be as little noise as possible. They went through and serviced every gear set and all efforts were made to minimize the possibility as much as possible.

In fact, the first two cars that we did the gears on were both done with the original gear sets and we offered to do a free replacement on those gears if the customer desired. One customer said he liked the whine and wanted to keep it and the other customer did return to our shop for the revised gearset. However, those were the only two gearsets ever installed in car's with the original cut. After those two all of our inventory was returned to Ricardo.

Now, with that being said, we have noticed a little bit of gear whine on some of the 3.90 cars as well as factory cars with unmodified gearsets. As stated by Ricardo on numerous occasions, it is normal and not something to be concerned about. Especially if the whine is on decel. If the whine was noticable under acceleration then we would be a little concerned. Remember, this transaxle is basically a racing transaxle. It will have little noises and odd characteristics that are normal for transaxles of this type.

It is my understanding that Shadowman has driven the car after the concern initially came up and after discussing everything with our tech's and the Ricardo engineer's the noise is not a concern in regards to any mechanical issue presenting itself.
 
Aug 25, 2006
4,436
Hi Stan

I am glad that you were able to migrate through the posting process and I hope that you do so much more often.

Rick; FYI there is no grinding or mechanical noises but rather a bit of a whine on deceleration; I tended to the conversion and Stan and I have chatted about this at length; the noise was present in my gal after the conversion too however I never gave it much thought until Stan brought it up at which point I contacted Kyle and let him know of Stan's concern; in fact I stated if that if was able to be resolved that i wanted my gal tended to also. It was some time later that I visited Stan and went for a drive in his gal then again chatted with both Kyle and Sammy the service manager at Stillen with the support of Ricardo and they all deemed the noise to be normal per Ricardo’s standards.

All the best

Shadowman
 
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dbackg

dbackg
Mark II Lifetime
Jan 28, 2009
691
Tempe, AZ
What are the performance benefits of the 3.90 gears?

Thank you for the replies.

Plain English please.

No offense to our technical engineers out there. :biggrin
 

USA GT - STAN WHITE

FORD
Mark IV Lifetime
Aug 13, 2007
32
Gardnerville, Nevada
Gear change noise

I went with the 3.90 Gears because I felt that the stock Gears, 3.36 were to high. I like to keep my RPMs above 1500. With stock Gears I very seldom used Sixth Gear. As far as I am concerned the car is much more fun to drive with 3.90 Gears. I understand that Ford wanted to achieve low zero to sixty times, (No Shifting). To achieve this they chose the 3.36 Ratio. This is just my personel opinion. Not everyone feels the same.

Stan
 

BlackICE

GT Owner
Nov 2, 2005
1,416
SF Bay Area in California
It depends on how you define performance.

0-60 times worst.
1/4 times, worst for me, since I have to shift into 4th and I am a slow shifter.
road course, more fun can use more gears.
street use, more fun can use more gears and slow traffic is a much easier to drive in while reducing clutch wear.
driving on a lift, much easier too!

It is funny thought the gear noise was the blower whine and asked Shadowman why did my Whipple make more noise after the 3.9 gears. He said not the Whipple but the gears on decel.
 

GERMANORACING

GT Owner
Dec 4, 2006
132
Farmington CT USA
It depends on how you define performance.

0-60 times worst.
1/4 times, worst for me, since I have to shift into 4th and I am a slow shifter.
road course, more fun can use more gears.
street use, more fun can use more gears and slow traffic is a much easier to drive in while reducing clutch wear.
driving on a lift, much easier too!

It is funny thought the gear noise was the blower whine and asked Shadowman why did my Whipple make more noise after the 3.9 gears. He said not the Whipple but the gears on decel.

Has anyone tried running there car in a 1/4 mile with stock gear and then with the 3.90 gear and see the difference in et/mph
 

AZGT

GT Owner
Mark IV Lifetime
Dec 20, 2005
1,354
Scottsdale, AZ.
There is an old thread where I talked about the ratios. At that time, for performance, based on the normal calculations a 3:90 for our car seemed perfect. The choice of that specific ratio as an aftermarket is well supported.

It is nice. Drove a car with it. I like it.

They are good for performance. You don't find many hot rods with a 3:30. Always lower. I used to run 4:11, 4:56, and 5:38. Could pull out tree stumps with the 5:38.
 

Empty Pockets

ex-GT Owner
Mark IV Lifetime
Le Mans 2010 Supporter
Oct 18, 2006
1,361
Washington State
I used to run 4:11, 4:56, and 5:38. Could pull out tree stumps with the 5:38.


Aaaaaaaaah - the good ol' daze! I still have a set of 4:88's in the downstairs garage. Every now & then I stick 'em in a car for a while just for ol' times sake!

I vividly remember the night a friend of mine & I went up to Vancouver, B.C. in his brand new, 4:89 geared, 1966 Hemi Coronet (automatic). I think we "cruised" at about 40 m.p.h. all the way up there & back! :rofl:rofl:rofl
 

atspeed

LAST BLU
Mark II Lifetime
Le Mans 2010 Supporter
Jun 13, 2007
123
Berkeley, CA
I also noticed a bit more noise on decel with the 3.9 gears. In fact, what spooked me was that it seemed to come from the front of the car -- which made no sense at all to me at the time (resonance). After a quick chat with Shadowman, I felt more at ease and didn't bother worrying about it (he cited the exact same things in this thread that he did over the phone). I've done 3 very hard track days at Thunderhill since and not worried about it a bit. Parts are now spinning at different speeds with gears cut for an intent more agressive than stock. Leave it at that and love it. This is how the car was meant to be.

Michael