3.90's
06-26-2007, 11:17 AM
#22
3rd Gear Member
Join Date: Mar 2007
Location: Philly
Posts: 821
RE: 3.90's
3.90's are perfect for me, they pull like a raped ape. 1st gear is still usable, I've driven my buddy's Mach with 4.10s and first gear might as well not be there. If I spin its because I wanted to. I don't do much highway driving, but the few times I have I've cruised along at 3k-ish RPMs. I can cruise around town at 2k RPM in 4th gear.
The gears we the most noticable mod I have done. Really made the car a different animal. I can actually get a length off the line on my dad's 99 Cobra but he pulls me in after I hit 3rd gear. Damn his free-spinning 4v!
The gears we the most noticable mod I have done. Really made the car a different animal. I can actually get a length off the line on my dad's 99 Cobra but he pulls me in after I hit 3rd gear. Damn his free-spinning 4v!
06-28-2007, 11:47 AM
#24
3rd Gear Member
Thread Starter
Join Date: Aug 2006
Location: PA
Posts: 550
RE: 3.90's
got my car back. the 3.90's definately made a big difference. sorta ticked though, cuz the guy charged me $400 just to put the gears in. that was labor, new bearings, bushings, and lube. the gears are wining in mostly 4th and 5th between 1800 and 2500 rpms. is this common until they mesh? my 3.73's never did that.
06-28-2007, 11:57 AM
#25
3rd Gear Member
Join Date: Mar 2007
Location: Philly
Posts: 821
RE: 3.90's
Mine have a little bit of whine to them, but the guys at Evolution said it is common with the Motive 3.90s since the tolerances that Motive makes their gears to is tighter than the Ford parts. I watched them set the backlash and pre-load and the gears mesh perfectly so I'm not worried about them.The whine is so slight that when driving around you can't even hear it overtireand other road noise.
06-28-2007, 02:27 PM
#26
5th Gear Member
Join Date: Mar 2007
Location:
Posts: 2,441
RE: 3.90's
ive always been told that gear whine is NOT normal, but that was from people with FRPP gears, dunno about motive but i think they are one in the same. i had 4.10's with the blower and even in my auto all i did in first and second is spin.. so im hoping 3.73's or 3.90's will improve that a little bit.
06-28-2007, 03:21 PM
#27
3rd Gear Member
Join Date: Mar 2007
Location: Philly
Posts: 821
RE: 3.90's
Honestly I don't know if its actually the gears whining. Its not the classic gear whine where it whines while under load, it whines once I get up to about 40-50 mph which leads me to believe its my noisey tires or maybe the new bearings breaking in. After 500 miles I drained the gear lube and looked at the gears and they were still lined up greatwith no metal shavings in the lube. So I'm not worried about it, the guys at Evolution know what they are doing.
06-28-2007, 06:03 PM
#28
2nd Gear Member
Join Date: Oct 2006
Location: michigan
Posts: 463
RE: 3.90's
i personaly installed my 3.90s and the backlash, preload, and gear pattern were all good with 0 slop(endplay). there was still whine. i think it could be a bearing, i reused the carrier bearings because they looked great. i get the whine above 40. its a light whine and can be ignored.
