Am i the first EVER to be unimpressed with a gear swap??!!!

[bloopbloob]

Finally got my 3:73's in today, and i have to say i am somewhat dissapointed! I notice it revs a bit faster, and can spin 'em a bit easier, but nothing too drastic! Maybe i was just expecting too much? Put in new axle bearings, trac lock rebuild (modified stack), swapped speedo gear (white driven gear), and royal purple synthetic. i didn't put friction modifier in also....
other than watching rpms, i can't really notice much difference as far as SOTP accelleration goes....
also, whats the break-in procedure for this? don't launch hard and give it a few hundred miles and heat cycles? or does it really matter?

 

[MustangOwner]

Finally got my 3:73's in today, and i have to say i am somewhat dissapointed! I notice it revs a bit faster, and can spin 'em a bit easier, but nothing too drastic! Maybe i was just expecting too much? Put in new axle bearings, trac lock rebuild (modified stack), swapped speedo gear (white driven gear), and royal purple synthetic. i didn't put friction modifier in also....
other than watching rpms, i can't really notice much difference as far as SOTP accelleration goes....
also, whats the break-in procedure for this? don't launch hard and give it a few hundred miles and heat cycles? or does it really matter?

You didn't? Your suppose to have it. Its like a whole 5 dollars at the ford dealership. Spend some of your money, you can't take it with you! Its just gears, its not a supercharger. Its not a engine mod, it just helps take offs so you can run it at higher rpms. Its not gonna shread off 3 secs on your time slip. Yes, they make a big difference, but you can't expect to much from it

 

[bloopbloob]

You didn't? Your suppose to have it. Its like a whole 5 dollars at the ford dealership. Spend some of your money, you can't take it with you! Its just gears, its not a supercharger. Its not a engine mod, it just helps take offs so you can run it at higher rpms. Its not gonna shread off 3 secs on your time slip. Yes, they make a big difference, but you can't expect to much from it

i still have the bottle. I talked to a guy that does only performance ford work for the last 20+ years, and he talked me into the idea, saying for the kind of driving i will be doing, the benefits of no FM far outweigh the negatives. He said the only time you'll notice is at higher speeds on corners you will hear a noise in the diff for the first while. The royal purple has some FM in it to begin with i believe, and the clutches were also soaked.
I was just expecting the swap to throw me back into the seat at least a LITTLE harder, but i don't really notice a change at all....

 

[HISSIN50]

I'm with Bloop^2.

It's easy to add FM but hard to remove it. If you don't get chattering, I agree that leaving it out isnt a bad idea (I don't use it with Redline LSD gear oil, for instance, as it has modifiers in it already IIRC).

There is a break-in for gears - I'd probably follow it after all that work was done. Some guys do a burnout leaving the shop but why not play it safe.

 

[Grn92LX]

Maybe its possible you had gears in it already? Count the teeth and do the math and see what ratio you had.

You don't break in gears, but if you changed bearings you can give them a heat cycle or 2.

I swapped from 3.73's to 4.30's and there was a diffrence but it wasn't earth shattering either.

 

[gtcobra302]

What gear ratio did you have before, if you went from 3.55 or even 3.08 to a 3.73 then you wont notice that much difference. I went from a 2.73 to a 3.73 and almost **** my self. It depends on how drastic the change was, and it is worth the money to do it right, especially here.

 

[JKidd]

Certain synthetic gear oil does not require friction modifiers to be added...so that doesn't sound too crazy.

As far as break in, I'd give them 200 miles. Maybe not necessary but I'd want any wear patterns to be settled in to gently as opposed to banging the crap out of them.

When I went from 3.08s to the 3.73's I noticed a huge difference. It felt as though I added at least 50 hp to the motor. Maybe you had 3.55s in there already...maybe you're expecting too much. Not sure...but there was a very noticeable difference in acceleration...IN ANY GEAR. That's what was nice. No matter what speed/gear I was in, acceleration improved noticeably.

Give them time to get settled (physically and mentally) and then see if you still feel the same.

 

[Strype]

Finally got my 3:73's in today, and i have to say i am somewhat dissapointed! I notice it revs a bit faster, and can spin 'em a bit easier, but nothing too drastic! Maybe i was just expecting too much?

Dude the previous owner of your car probably had 3:55's in it already cause I've never heard someone say they weren't impressed with a .2 second difference in the 1/8 mile for $200- I don't even know what they add in the 1/4

 

[bloopbloob]

i went from 2:73's to 3:73's, but it sure doesnt feel like i added 50 hp! maybe 10....

 

[bloopbloob]

car was COMPLETELY stock when i bought it, and i checked the code on the diff tag a long time ago. it was 2:73, but i'll have to go count the teeth i guess. At 120km/h, in 5th i'm about 600 rpm's higher than before.....

 

[rj95svt]

I went from 3.08's to 3.73's and it's noticeable but not drastic. If you can feel a difference then it did something because most bolt ons will not do much for seat of the pants feel I think you was probably just expecting a little to much.

 

[Strype]

car was COMPLETELY stock when i bought it, and i checked the code on the diff tag a long time ago. it was 2:73, but i'll have to go count the teeth i guess. At 120km/h, in 5th i'm about 600 rpm's higher than before.....

Then congratulations are in order- you are the first person I've ever met who actually was disappointed

 

[stykthyn]

should have spent the money on a ketchup induction system

 

[Strype]

 

[Dean85GT]

I can agree with this...I went from 2.73s to 4.10s and I was also unimpressed. You guys hype it up way too much

 

[GT Drifter]

You don't break in gears, but if you changed bearings you can give them a heat cycle or 2.

Um...yes you do.

Your supposed to drive the vehicle from 30 mins to heat the gears and oil up. Then you let it cool down. Do this 3 or 4 times then change the oil out, check out the gears and pull it back together with new oil. Then you drive it conservatively for 500 miles. After the 500 mile mark passes you change the oil and inspect the gears again. Put it back together and put new oil in.
Now you can beat on it like you normally would.

 

[Strype]

Um...yes you do.

Your supposed to drive the vehicle from 30 mins to heat the gears and oil up. Then you let it cool down. Do this 3 or 4 times then change the oil out, check out the gears and pull it back together with new oil. Then you drive it conservatively for 500 miles. After the 500 mile mark passes you change the oil and inspect the gears again. Put it back together and put new oil in.
Now you can beat on it like you normally would.

+1 but you can go w/o the oil changes

 

[fiveohwblow]

+1 but you can go w/o the oil changes

Thats what I did.

As for the SOTP difference, it wasnt there for me, but I went from 3.27's to 3.55's and I certainly wanted more...

 

[25thmustang]

Um...yes you do.

Your supposed to drive the vehicle from 30 mins to heat the gears and oil up. Then you let it cool down. Do this 3 or 4 times then change the oil out, check out the gears and pull it back together with new oil. Then you drive it conservatively for 500 miles. After the 500 mile mark passes you change the oil and inspect the gears again. Put it back together and put new oil in.
Now you can beat on it like you normally would.

Hmm, never did that on a single gear swap, and have a bunch of Mustangs that run fine, make no noise or clunking, and nothing out of the ordinary.

 

[Grn92LX]

Um...yes you do.

Your supposed to drive the vehicle from 30 mins to heat the gears and oil up. Then you let it cool down. Do this 3 or 4 times then change the oil out, check out the gears and pull it back together with new oil. Then you drive it conservatively for 500 miles. After the 500 mile mark passes you change the oil and inspect the gears again. Put it back together and put new oil in.
Now you can beat on it like you normally would.

Oh so wrong. You give fresh bearings a heat cycle or 2, you are not breaking in gears. Been there/done that 500 miles for a gear "break in" rofl