Hey all qucik question was thinking about changing my gears and was wondering what is a good set to get?? I did win a set of 4.10's but the guy said he dropped it on the ground and broke a tooth!!! So needless to say i got to get my money back and find another set. But is 4.10's something i want and what should i expect??
What are you talking about? the rear end is plenty strong with street tires. Why else wouldn't it be worth it? I am sticking with the 7.5 until I break it. That won't be anytime soon either. The 7.5 is at least 60lbs lighter than the 8.8 too.
I laugh at all the horror stories about how hte 7.5" is just looking for an excuse to break. I have had 3 turbo 2.3L cars and a 79 Capri with a 360 BHP 302 with a SROD and 3.45:1 7.5" rear. I have never broken one. If your running a supercharged V8 or racing it then I can see having the extra protection but a mild hipo street car does not have a history of breaking the 7.5" rear unless you abuse it and these same guys break 8.8" rears too. Why do you think Ford put a 7.5" rear behind the SVO when they could just as easily have put a 8.8" rear under it? Because they didnt need it and they wre worried aobut it. The 8.8" in the T-bird was also in a significantly heavier vehicle.
Why do you think they put the 8.8" under the '86 and later 5.0's? Because the '86 Motor had 210 BHP and '87-89 had 215 compared to the wimpy 180 BHP of the '85 and lower 5.0's which had the 7.5. I have broken a 7.5 Racing once, it wasn't even during a launch, i was under full throttle at about 40 MPH and broke 4 teeth off the pinion and 6 off the ring gear. But, unless you plan to top 250 or so HP and it sees daily abuse, i would just stick with the lighter 7.5.
You are a rarity. When most 7.5's break, it is the spider gears. Also, I guarrenty that the damage was done earlier (on a launch with sticky tires perhaps?), which left hair line cracks in those teeth, and while "racing" at 40mph, you finished the breaks. Again, for anyone that doesn't use sticky tires, and doesn't race it, 7.5's are great.
Ford switched to the 8.8" because they cant prove the rear wasnt abused when some idiot does a 6000rpm holeshot and sidesteps the clutch with aftermarket rims and tires. Ford has to cover even those breakages. I drove my 302 Capri daily for 5 years but I didnt do hole shots, I didnt abuse the crap out of the cars. I had P265/50-15 tires rear and P215/60-15 front. I did my share of burn offs and low speed accelerations runs. I have seen where someone on this board broke a 8.8" rear with a turbo 2.3L. Im still trying to figure out how.
That would definately be impressive breaking the 8.8" with a 2.3L Turbo. The 7.5" i broke never saw sticky tires, but did see regular agressive holeshots. Again, unless you plan to build some decent power, the 7.5" will usually suffice for a while.
As stated the spider gears usually go,........ from doing burnouts with an open differential. 8.8 has bigger clutch packs, spiders and more support, cheaper readliy available gear selections. I have yet to find a good cheap set of 4.10 or higher in 7.5" but 8.8, right here in my local hi performance catalogue.
If you have an open diff (non trac lock) you are spinning the spider gears to beat hell. So in short, yes you are doing damage.
>>is that the stock one for the 91 stangs? how long would i have before i break it << That's kind of a loaded question. How could anyone guess? That's why you will get people saying leave it in there, it's good enough. It may never break on you and you will be one of the people praising the 7.5" cause it stood up to your abuse.
spinning any open rear end like that will result on eventual spider gear failure. The 7.5 is still MORE than strong enough for a 2.3 NA though. I have done a lot of tire spinning with my car over the last 4 years, and I havn't had any rear end problems yet.
I think we agree buff, but what I'm saying is if you break it don't rebuild it, replace it! Or if you wanta change gears, just swap the whole thing. The gear selection and availability of 8.8 alone is worth it to me, not to mention when you get to 4.10 or lower the 7.5 fades away. 4.10's on a little 7.5 the teeth are tiny shavings.
