4.10 gears in automatic done

[fartingchicken]

I had a guy here in Honolulu put in 4.10 gears in my automatic. Cost was $550. I'm surprised at how quickly it shifts. By about 25 or 30 mph it is in the top gear. Acceleration is noticably faster. What are you folks paying for the ring and gear? It is a Ford gear.
I see I'm going to have to ask the mechanic about whether he reset the speedometer. What did the gear do to the speedo reading? I've got a tuner coming.

I did notice a problem- first, the speedometer is showing too fast. I'll call the guy and ask why he didn't fix that. What is the speedometer fix for a 4:10 rear end? Secondly, there is a noticable roaring; not real loud, when going about 60 or 65 mph. It's obvious that it must be a gear issue. Ideas? Thanks.
Looks like from reading this http://www.moddedmustangs.com/ring-and-pinion-gears-the-ultimate-debate.html that the SCT tuner I'm getting will reset the speedometer? No gear needed?

 

[kooldawg6]

You're speedo is WAY off! The SCT does have where you change your rear gear ratio. Plus the tuner will make your trans shift much better! I have absolutely no noise from the rear swap after 17K miles.

 

[stang8urimport]

I basically sold my 07 Black GT because Ford, nor anyone else, could fix the gear whine. It sucks.

 

[fartingchicken]

thanks

The low roar/rumbling is like a jet reversing its engines, or wind noise, but not as loud, of course. Is that the sound you had? It does move quick now.
Thanks for the responses!

 

[cowtown]

Definitely need the tuner for gear change, your car's going to be a bit off until you get that adjusted.

 

[stang8urimport]

I had a pronounced whine from 65 up. Dealer changed the whole rear end, and the gears a couple times. I finally had 4.10s put in, and it still whined. So I said f it. And I traded it in lol

 

[fartingchicken]

whine

So it was a high pitched whine and not a rumbling or roaring?

 

[stang8urimport]

Correct.

 

[scupking]

So it was a high pitched whine and not a rumbling or roaring?

Yup, I had 3.73s put in my 01 GT auto a few months back and that’s what it does. It’s not that bad so I don't mind it much. If my exhaust was quieter then I would probably mind.