Urambo Tauro

1995 Mustang GT, 170,000 miles

In the process of upgrading to Cobra brakes (starting with the rear), the axle-shafts must be removed to install new brackets. I just changed the differential fluid a couple years ago, so to prevent changing it again so soon I am taking the opportunity to completely overhaul the whole pumpkin.

• The stock 2.73 gears will stay.
• Traction-Lok will be rebuilt with Ford Racing's M-4700-C carbon kit.
• All bearing and seals are being replaced.
• Cover is being replaced with a TA Performance girdle.
• Fresh Motorcraft synthetic fluid and friction modifier

I am starting to put things back together, and found the oil slinger slightly mangled. I seem to have snagged it with my seal puller. Instead of beating it back into shape, I just got a new one from the local Ford dealer. They don't cost much anyway.

What is this oil slinger for? It looks just like a washer.

Also, the old pinion seal wore a slight groove in the pinion flange. Instead of buying a seal saver kit, I'm replacing the whole thing with an FRPP flange for just a few more dollars. In accordance with the instructions, I marked the old flange in relation to the driveshaft, and in relation to the pinion. But since the new flange has no such markings, how do I install it to the correct degree?

88 orangepeel notch

Just curious as to why your sticking with the stock gears ? In another thread you said you may start on engine mods next for a little more power. A gear swap now would be a better improvement in performance than ANY engine bolt on mod. And I don't want to hear about how you may drop 1 or 2 mpg with a swap. That's a bunch of crap lol. Your right foot determines gas mileage more than anything else.

Sorry I couldn't help with your questions, but someone will chime in with an answer for you.

dawson1112

Doesn't matter how the pinion flange is installed. Its not degreed it just slips on. Some times guys like to mark the drive shaft and pinion before removing the drive shaft but you will be fine.

I agree, with orangepeel up there, if you have the rear differential apart and are going to overhaul it then go to a 3.73 gear ratio. That change alone will give you a lot more torque off the line.

the oil slinger is a washer for all intent purposes. Its supposed to keep the oil pooled up inside the bearing and help lubricate that outer pinion bearing.

Urambo Tauro

I'm aware of the advantage in swapping gears. This car is and will remain a daily driver. By keeping the stock gears, the revs will remain low at speed. This not only provides that marginal MPG advantage, but makes freeway cruising more pleasant. I've been toying with the idea of replacing the exhaust at some point, and one of the things I really want to avoid is a droning noise. I suspect keeping the revs low with stock gears will help.

I didn't think there was a reason to keep the degrees matched. But I marked it anyway per the instructions. I did a head-gasket job on a different car a few years ago, and followed the directions to return each push-rod to its original location. I obeyed without knowing the reason, figuring there was some minuscule thing about it that could develop issues later. Instead of pursuing a reason, I simply trusted the directions and stopped worrying about it.

Looking at the parts, I can't find any mechanical point-of-reference to match the pinion to the flange. But the flange does have those two offset holes that I can align with the yoke to match the original flange position. The rust pattern on the old flange will show me how to line them up. Using that reference narrows the mounting options down to two. I could bolt it up one way, or turn it 180° and mount it the other way (if that even matters).

raven_ghostwolf

I understand wanting to keep the 2.73 ratio it is what my 87 has in it, and it was great on the highway I could hit 24 mpg easy and still pull mid to high 14's. But you might want to consider finding a 3.27 set for a bit more punch and still decent mpg with out the droning noise your worried about. My 83 Capri has them and I still average 18+ MPG. I have Hooker shorties on it with and off-road x pipe and the stock tails from my 87LX and it has a nice tone cruising at 75mph+. I have a set of 3.27's waiting to go into my 87 when I am able to get back into the rebuild on it. Just an option to consider since your going to be doing the rear end anyway.

Urambo Tauro

My short-term plan is to finish my suspension and brake upgrades. But if the car is still around and in good shape when it hits the 25yr mark, I'd like to splurge on it with actual power modifications. I wouldn't rule out a gear swap from those long-term plans.

Until then, I am satisfied with the stock gears. I don't hypermile, but somehow have managed a personal best of 26MPG. The car usually gets closer to 23, but even after my eventual upgrades, I'd like to keep the average MPG at no less than 20.

I've noticed that Ford Racing offers a wide range of gears. I find it particularly surprising that they offer both 3.27 and 3.31 ratios. That's not much of a difference. How do you settle on a number?

silver91gt

Don't fear the gear. a set of 4.10's will wake it up for sure.

The most fun I had in my car was when it had 4.30's.

raven_ghostwolf

For me I created a spreadsheet that computes my speed by factoring in my tire size, rear gear ratio and the ratios for each forward gear in my transmission and motor rpm. I put in my stock configuration to see what speed I am at in each gear at any given rpm. I then looked for the same speed in the next gear to see what my rpm drop would be and where that would place me in the power band. I then put in my planned configuration and compared.

Now for 1st - 4th that helps me guess-timate how I would accelerate compared to each configuration. For 4th & 5th, maybe even 6th if I want to spend that kind of money, I can accurately see what RPM I would be pulling for any given speed during highway cruising.

Yeah I can be a bit of a nerd/geek at times. That is how I decided upon 3.27 for my desired results for my 87.

My Capri came factory with 3.27's and has been a nice conformation for me with what I was thinking for my intended plans for the 87.

One quick example that I can give is, with a stock 2.95 1st gear in the T5 transmission and a 3.55 gear, I can achieve practically the same result with the Z spec T5 first gear 3.35 and a 3.27 rear gear. While the 3.55 has a slight advantage pulling thru the rpm band in 2nd & 3rd, once into 4th and 5th the 3.27 rear gear has the advantage of a higher cruise speed at lower rpm's.

Bit long winded here but that is how I made my choice for my plans.

88 orangepeel notch

Yes, a bit long winded lol, but we'll said raven.

I'll simplify........... Install 3:55/3:73 gears now. 3:73/4:10 if your cars an auto. You will not be sorry, nor will your mileage drop thru the floor, and the drone is dependant on which exhaust you go with.

We are all very smart here and know everything about Foxbodys.........lol.

Urambo Tauro

Even though now is a good time for gears while I have the thing open, I'm going to file this away in my long-term plans for the time being. Thanks for the advice!