Ok guys, here the dilema...I'm pretty sure the entire dif unit (housing, finned alum cover, drive flanges, whole nine) Will bolt into the earlier cars. Now with the 04 tranny, you'd replace the companion flange, because the 03 driveshaft uses smaller bolts. I'd assume the dif end of the driveshaft on the 04 uses the bigger bolts as well, so we'd need to use an 03 dif flange. Here's the catch...By removing the stock 04 dif flange, we would be disturbing the wear pattern. In the past, I've used a beam style torque wrench to loosen the nut, in an effort to preserve the pattern on non-S2000 cars. With distance collar style setups like the S2000, I can almost guarantee the pattern will change a fraction, and cause a gear whine.
Now here's the other side of the coin...I'd like to get a complete 04 dif from Hardtopguy. Now this dif is from an in-transit new car wreck, and would only have 7-20 miles on it. In this case, would pattern preservation be a concern, because the pattern is not fully worn in yet?

Xviper, feel free to move this if I'm off on the forums...And while you're at it... your input would be great

EDIT...If I had an 04 driveshaft and tranny flange, it would solve the problem, but hopefully we can figure this one out...

 

I just had a '04 diff installed in my '00 and have no problems. it drops right in. as for the other part of your post, I dont know.

 

I can confirm that the input flange on the diff is unique for 04-05.

edit: spelling

 

what does this mean? my mechanic bolted mine up wit no problems that I know of. should I be concerned?

 

It means it's a different part number for 04-05 cars.

Edit: looking at the part list some more...
04-05 cars have 10x62mm bolts from the prop to the the rear diff input flange, <04 is 8x65, so evidently he did more than just "drop in" a diff.

 

Billman, since the 04 diff you'd be getting is practically new, I'd install th 00-03 flange.

1st measure the pinion turning force with a beam-style torque wrench. (You're going to need an inch pound wrench) Then swap the 00-03 companion flange to the 04 diff. Then slowly torque the pinion nut down untill you get a matching turning force reading.

The service manual lists a pretty big torque range when intalling the pinion in the diff housing. You pretty much tighten the pinion nut untill you reach the correct turning force for just the pinion.

You'll have to replace pinion nut, as it's a nylon insert locknut.

 

I disassembled and reassembled my '02 diff with 4.77s twice, and didn't notice any problems from changing the wear pattern.

 

Thanks for the replys guys, good stuff...I've done this with a small beam wrench on other cars, a few came back with a whine. I think with the low miles on the 04, we should be good.

Thanks on confirming the dif flange. I know the 00-03 has a 6mm allen socket head on the bolts, anybody know if this was stepped up too? Please say 8mm

oakfloor....I'm assuming they used your original dif flange, it would be the only way to make it work.

 

well its on my car, and I been driving it, however it still makes the same whining noise so I thought it's the tranny?. it is a '04 diff with 600 miles. so now Im still confused. any help is greatly appreciated. thanks

 

It may be your tranny. My tranny was always pretty noisy until I changed AWAY from Honda tranny oil. Now that I'm using GM Synchromech Friction Modified, I don't hear any tranny noise.