About 4:10's

[9COBRA7]

I hear so many different opinions about these gears. Some say there a good street gear and others say if you do 4:10's then your gonna need axles, then trans, etc. Well whats the truth here, I have a 97 cobra. What are these gears actually like. I know the whole sport of racing is to race and breakin things goes along with racing, but I wanna keep the breaking things to a minimum right now. I have been in a car with 4:10's and I love em, as soon as the guy lifted his foot off the clutch I could tell a difference. Also, with the torque setup the cobra has and everything, what are 4:10's like on the Xway?

 

[2k1Cobra]

Well, I have a 01 Cobra and everyone told me the same thing and I too have had 4:11's before. What I was told was that they are potentially a threat to tearing up your rearend but it just depends on how you drive it. With street tires, your gonna be spinning anyways so there wont be too much pressure back there. The only way I can see tearing everything up is if you put a really good clutch and a good set of drag slicks and go out to the track and launching at 5k, then you're gonna break something. As far as the highway, at 70mph I used to be around 2k rpm and now I'm at about 2500-2600. I really dont mind though bc I know that I can launch on pretty much anyone, it just matters how long I can stay in front!! Anyways, if you're worried about the highway rpms or breaking something, you could probably go with 3:73's or 3:90's, but 4:10's are the way for me! Hope this helps out.

 

[DirtySanchez]

I hear so many different opinions about these gears. Some say there a good street gear and others say if you do 4:10's then your gonna need axles, then trans, etc. Well whats the truth here, I have a 97 cobra. What are these gears actually like. I know the whole sport of racing is to race and breakin things goes along with racing, but I wanna keep the breaking things to a minimum right now. I have been in a car with 4:10's and I love em, as soon as the guy lifted his foot off the clutch I could tell a difference. Also, with the torque setup the cobra has and everything, what are 4:10's like on the Xway?

The only gripe I hear about 4.10's is that you'll have to shift into 4th shortly before the traps in the 1/4 mile. 4.30's are better for drag racing. If you want a detailed comparison of two gears, check out http://www.svtoa-atlanta.org/cgi-bin/trans.cgi

 

[99SVTAddict]

Agreed with above post. 4.10's are a GREAT street gear, but 4.30's are better for the track. I recently swapped my 4.10's for 4.30's when I put the solid axle in.

The 4.10's aren't going to eat up your clutch or tranny...sticky tires and high RPM launches will do that.

4.10's minimum...DON'T even think about 3.73's....4.10's or 4.30's

 

[dark_cobra_01]

What do you guys think of replacing the IRS Half Shafts when doing a Gear swap to 410's ?? Is it a waste of money, or a good investment for running sticky's in the future?

I've read some scary stuff on busted up stock half shafts and think right now that it would be worth the investment of getting aftermarket half shafts ..Everyone knows that once you start to mod something there's always something else to go with it .. In this case, doing the gears is more than likely gonna tempt anyone to get sticky tires and so forth..

Opinions ??


DC

 

[SnakeBite98]

bottom line is if you go to the track every weekend you should go with 4.30's, but if you're like me and go 2 times a month then go with the 4.10's, they'll treat you better on the street.

 

[99SVTAddict]

You will want aftermarket 1/2 shafts if you are running sticky tires and gears. They finally started selling stronger replacements once again.

I finally just went to a solid axle though...sick of the IRS, hop, and even with better 1/2 shafts there's still a decent chance for failure after a given time (depends how much abuse you throw at it).

 

[dark_cobra_01]

Thanks for the input 99 ...

One more question:

I know this sounds dumb but when I'm pricing up the install of gears do I have to add in the price of a rebuild kit for the pumpkin.. or does the shop usually have all the gaskets and stuff to do that as part of their installation price ..

I could see this going either way:

1. I buy the kit and drop it off with the ring and pinion ...

or

2. they say don't worry we got all those lil pieces for you around the shop and it's included in our price...

What's the usual scenario ??

 

[2k1Cobra]

I took mine to a Mustang Performance shop and they told me that if you go with Ford Racing gears, you dont need the the rebuild kit bc they were designed to replace the stock gears. If you go Richmond or something else, you need the rebuild kit bc they are designed to go into anything. I stuck with FR bc I didnt really have the extra 100 bucks to spend on the kit for Richmond.

 

[99SVTAddict]

What he said...go with Ford Racing gears (I would call GEF Racing) and talk with them there. Make sure that it comes with the shim kit and all that. I have all my work done by a Mustang shop and just had them order all the parts.

Gear installs on our 99+ Cobra's aren't cheap because of the IRS...at least that's what everyone says. I think it ended up costing around $500 or so in labor but I can't really remember. 4.10's are a great gear, but just so you know, you may get a slight vibration at 80+ mph. I had the shop order an aluminum driveshaft as well as they said it eliminates the vibe. I never had a vibe following their advice. If you go with 4.30's make sure the shop really knows what they are doing. 4.30's have a tendency to whine.

Last thing, don't forgot to get the speedo recalibrated. This can be done by chip or a speedcal. I went with the chip as I had them install longtubes as well and needed it anyway.

 

[dark_cobra_01]

So, there should be shims in the FRPP box with the ring and pinion ??.. I ask this because everytime I see a FRPP ring and pinion set in a box "online" it looks like there's nothing else with it but the ring and pinion..

------

I'm not new to the gear swap issue either, I've looked through the issues of swapping to .410's now for almost 2 years.. I'm familiar with all the websites and threads describing vibration issues, runout, driveshafts, half shafts etc etc etc ... (this turned me off to a gear swap last year since it looked like there was just too many issues.) And I always said that I would only use a shop that can understand all these issues even if I had to print out all the websites and discuss it with the shop owner..

So as of today I've decided that this is the year I'm gonna do it...

And I do know for sure I'm gonna use FRPP and not Richmond or something aftermarket... FORD RACING ONLY !!!

I saw an ad in 5.0 from Gene Ford that has .410's for $139.00.. That seems like a deal to me.. anyone deal with them before ??


DC