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View Full Version : 4.30 gear in IRS.


xanavisilvia
12-22-2003, 01:34 AM
I would like to put 4.30 gears in my 99 Cobra. I was wondering if there will be a lot of vibrations and noise after this mod? Do I need to conver to solid axle?
And, how hard is the swap?

tcrews
12-22-2003, 02:12 PM
If they are installed properly you will not have any additonal noise/vibrations or whatever.

Your driveshaft will need to be indexed properly when reinstalled but that's pretty much it.

From what I've read, the IRS suspension gets in the way making it a bit more difficult (expensive) to install vs. the older live-axle models.

Gears should cost in the $160 range and install can vary depending on who does it....expect in the $400 range for labor (IRS).

flynfink
12-22-2003, 05:05 PM
I've got 4:30's in my 99'.. Love them. Total install with a few new bearings, electronic ratio adapter and the gears was around $900.. Runs great. A little noisier that the stock setup. No vibration issues.

97BlackSnake
12-23-2003, 05:38 AM
I'm thinking about putting 4.10's in my 97 Cobra. What can I expect for installation? Also, is there anything else I should do at the same time? What should I do about speedometer recalibration and how much will that cost?

Thanks for any help!

Sorry for the hi jack!!

tcrews
12-23-2003, 08:24 AM
Should cost you around $200 for labor to install the gears. Gears again can be had for around $150+ so expect $350-$400 total.

To correct the speedo there is only one way to get it accurate, that is with an abbott ERA or Dallas Mustang Speedcal (either around $160). They are adjustable so you can dial in for your new gear change. They tie into your wiring between the tranny's speed sensor and the EEC-V and convert the signal coming in to what it should be.

'99 and up cars can have their computer chipped to handle gear changes for the speedometer, earlier cars can not.

Lumpydogs
12-23-2003, 08:28 AM
Dallas Mustang makes a great little speedcal product to adjust your speedo and odometer. All you do is tap into a hot line, i.e. the cigarette lighter from the shifter bezel. Drop the prewired lines down through the shifter hole and plug in. It's really simple and fast. Mine works great. All you need to do is jack up the car
to have easy access to the plugs.

You can program this unit to work on just about any combination of gears. I checked my speedo to the mile markers on the freeway and a watch. It was right on at 60 mph.

That's what I did. However, other folks have used chips or
speedo gears.

Good Luck

p.s. Had DTS (Drive Train Specialist) install my 4.10 gears. They did a great job. I think they are a semi-national operation.

smashedheadcat
12-26-2003, 01:01 PM
I'm still a fan of the speedo gear. While not the most accurate way to do it, at less than $20, it's the cheapest. It's what all the old 5.0's used from the beginning. I know they can come apart, but keep in mind, the stock piece is hard plastic too.

Josh

flynfink
12-26-2003, 02:45 PM
Josh, 99 and up have no speedo gears.. Just a wire to the computer.

tcrews
12-26-2003, 03:26 PM
Originally posted by smashedheadcat
I'm still a fan of the speedo gear. While not the most accurate way to do it, at less than $20, it's the cheapest. It's what all the old 5.0's used from the beginning. I know they can come apart, but keep in mind, the stock piece is hard plastic too.

Josh

It's not that it's plastic its that it doesn't 'mesh' properly as the teeth count/spacing is wrong. For 4.10s you have to use a Dodge part and I've seen too many chewed up (and now those pieces are in your tranny). For 4.30s....you'll be too far off to want to use a plastic gear that'll do nothing but help you get tickets, throw off your mileage tracking and possible damage your tranny :)

Also...most 5.0s stuck with 3.55/3.73 ratios........and the plastic gear works fine for that. 4.10s, 4.30s, 4.56s and 4.88s....not really a standard gear in the 5.0s :)

smashedheadcat
12-27-2003, 05:45 PM
Originally posted by flynfink
Josh, 99 and up have no speedo gears.. Just a wire to the computer.

Yeah..... I forgot what year we were dealing with. Thanks though. :)

smashedheadcat
12-27-2003, 05:50 PM
Originally posted by tcrews
It's not that it's plastic its that it doesn't 'mesh' properly as the teeth count/spacing is wrong. For 4.10s you have to use a Dodge part and I've seen too many chewed up (and now those pieces are in your tranny). For 4.30s....you'll be too far off to want to use a plastic gear that'll do nothing but help you get tickets, throw off your mileage tracking and possible damage your tranny :)

Also...most 5.0s stuck with 3.55/3.73 ratios........and the plastic gear works fine for that. 4.10s, 4.30s, 4.56s and 4.88s....not really a standard gear in the 5.0s :)

In defense to that....... There are two plastic gears. The simple one to get to, and then the other one that's a tailhousing pull away. I've always been affraid to pull a tranny apart, but after doing it, it's very simple. The drive gear just slides right off, and you replace it with a correct one. The driven gear is a sinch to swap out (as you know i'm sure). All I'm sayin is the old speedo gear correction has a few more ratios available by switching the 2 gears instead of the 1 gear. But, like you've said from the beginning, you won't have that precise accuracy you'd get with a speed cal or equivilent.