I just installed my Motive 3.90 gears on the weekend. I bought them last summer after my Richmond 4.10's broke, but it took me awhile to get around to installing these (had the A4 tranny go in the meantime, and swapped to the T56! )

Anyway, I thought I'd post my "preliminary" experience with them so far .

The installation went well, except for the fact that I had to put a second washer behind the pinion nut when installing it. With only 1 washer, the pinion nut was bottoming out and not even taking up the slack between the bearings, let alone putting pre-load on the crush sleeve. After installing the 2nd washer, it torqued up perfectly, and I was able to get some pre-load on the pinion .

Beyond that, everything installed beautifully ... the pinion depth was within a few thousandths of their spec, and I was able to get the backlash set to .005"!! I was very happy with that.

My first drive was just around the block, to test the gears, the freshly rebuilt T56, and the newly installed headers and Magnaflow catback!! Yeah, I know, a lot of stuff going on all at once. BUT, the thing that I didn't hear from, was the diff . It is silky smooth, and dead quiet!

Thus far, the furthest I've been is the ~15 mile drive into work, but EVERYTHING seems to be working good, doing what it's supposed to . The gears provide a nice pull off the line, and in 6th gear, cruising at ~70 mph, they put the revs almost bang on 1800 RPM, which is pretty much identical to the factory A4/2.73's, cruising in 4th/OD!!

I have full intentions of getting down to the track as soon as I can to try out the new setup, but as far as these 3.90's go, so far I'd highly recommend them to anyone looking for gears in the ~4.00 range .

 

Did you put a solid pinion spacer in there instead of a crush sleeve?

Ken R.

 

No, just a crush sleeve.

 

Im glad to see the gears arent making any noise. I know a couple of years ago strange wouldnt sell these gears b/c they mader so much noise.

 

I just noticed last night driving home, cruising on the hwy in 6th, with my radio turned down , there was the faintest whine in between acceleration and coasting ... I mean, if you slightly lift off the throttle instead of maintaining speed, but not enough that the car goes into full deceleration mode either ... just a faint whine ...

... I'm still more than happy with that!!! Even my old 4.10's had a very faint whine under hard acceleration that would only go away completely in that "in between" spot, which isn't where the throttle normally is anyway. These 3.90's are pretty much "perfect" IMO .

 

Just a quick question a little off topic (ha! hi-jack my own thread! ) ...

... anyone know who makes/made the true 4.11 gears for a 10-bolt?? I know that somebody makes them, but can't find it listed anywhere. I "think" they are also made by Motive, but they're listed as "4.10's" except I think they're the ones "Made in Italy"??? Sound familiar to anybody?? Just curious how a person would be able to get them?

 

The Motives I got for my 95 were 4.11s, but when I got them they were listed as 4.11s as well, not sure if they just listed them as 4.10s now or if they actually changed their design.

 

You may want to switch over to a solid spacer if you do track duty. A few hard launches and it will probably get noisy on you.

Ken R.

 

What RPM do you spin at 65 and 80 also? Yes, I run 80 often.

 

I know what you're saying, but I'm not too concerned about it right now. My 4.10's held up ok 'til I took the car out on a road course ... behind the A4, there was no way to control the shifts (ie: rev matching) so the downshifts were all very harsh off the corners, and it snapped a couple teeth off the pinion ... I really don't believe that a solid pinion spacer would have saved the day?!

Me too! As of yet, I haven't got the computer re-tuned yet, so the speedo is still way off, but going by http://www.f-body.org/gears, looks like 80 mph is around ~2050 RPM .

 

Thats about where 90 sets with the 3.42's.


Thanks for the link BTW