stock gears?

mob said:

what does traction lock do?

Click to expand...

it is the limited slip ability of the rear end. as far as i know, all 8.8's came with Trac lok.

ALWAYS jack the car up and count driveshaft revolutions compared to 1tire revolution to determine your rear axle ratio. Unless you are absolutely certain of the entire history of the car since it was new, examining axle tags or VIN numbers won't always give you the right answer. MANY of these cars have had gears swapped, or complete axles swapped over the years.

Once you've determined what you've got (and as others have said - if they haven't been changed, they're likely to be 3.08's or 2.73's) then decide on your replacements. If you've got 2.73's in there now - you'll notice a big difference with either 3.55's or 3.73's. There's only 5% difference in engine speed between the two - you can almost toss a coin to decide. If you have 3.08's - I'd go with 3.73's just because they offer a bit more of a change from where you're already at, compared to going with 3.55's.

As JT says, Traction Lok is Ford's trade name for it's limited slip differential. This device allows power to be divided between both rear tires for more traction, while still allowing the inside tire to turn more slowly than the outside tire when you turn the car. There are lots of ways to provide this function - the TracLok uses springs/clutches to do it -- and those units do wear out. While changing your gears, it's the ideal time to freshen up the springs/clutches in the TrakLok. Those units also require a special anti-friction additive for the rear end lube - be sure the additive is in the dope that's used, or gets added separately. Otherwise that unit will make lots of shuddering/chattering noises especially when turning sharp corners at low speeds. For cars without TrakLok, or when the unit has failed, burnouts result in only one tire (right rear) providing the power. Which cuts your traction in half -- not what you need when you've multiplied your applied torque by about 30% with a 2.73 to 3.73 gear swap.

My 88 GT had 3.08's. I put in 3.73's, and noticed a good difference, but wished I had gone with 4.10's. This was about a 1-2 yrs ago. I rear end needed some work recently so I decided to put in the 4.10's I've always wanted. Installed yesterday...I love them!! I'm only turning 2900-3000 rpms at 75-80mph which is where I like to cruise on the interstate. 5th gear is cool now.

If anyone would ask me, as a general rule I'd tell them to go up a whole number when upgrading gears...you have 2.73...go to 3.73...you have 3.08...go to 4.10's.

If you ask me people over analyze when it comes to the top end and fuel milage issue. Its really not that bad and for the little bit of tradeoff, you get a heck of a lot of driving enjoyment. This is coming from a guy who has spent the last 2 years putting 500 highway miles on a week @80mph.

You'll have much more percieved torque, so if you get lots of wheel spin, get some decent tires. I installed the BFgoodwrech tires on Friday too....THEY HOLD....unless I drop the clutch on them. Tire rack had them for about $100 a tire.

I just filled up my tank tonight and I think I got 230 miles out of my tank where I usually get a little over 200. Gosh, I may be getting better gas milage!

go with no less than 3.73...If I had to do it all over again I would definately go with 4.10...not much difference in driving rpms but a nice gain in performance...

theres always that good 3:90 for the 373/410 undecideds