JasperGT

So I went to the drag strip to test out my new cam setup. All was going well on my would be best run ever, when instead of shifting 1-2-3-4, I shifted 1-2-3-2 with the 3-2 "up-shift" happening at ~90mph. As soon as I went into 2nd, the wheels locked up, and I immediately depressed the clutch, shifted to neutral, and coasted to the finish line with a 13.5 at 80mph.

Anyways, the transmission, clutch, and drive shaft all seem fine (so I'm very lucky in that respect), but now it seems to me that I have the dreaded gear whine. It only happens during deceleration, but it sure is annoying.

So I guess I'm looking for some advice in what to do. I'm thinking that I should take it to a gear shop, and see if they can reinstall the gears to get rid of the whine. If I did that, I would obviously have them inspect the gears to see if there is any damage. If there is, should I stick with my 4.10s or move up slightly to 4.30s? All comments are welcome, so let me know your thoughts!

deekum1627

sorry to hear this jasper. if you didnt have whine before and now have it the ring might of cracked it happend to me, my shop did fix it tho. i would def take it to a shop to look at it that is the most annoying sound ever.

siggyfreud

In the M3 world we called that "money shifting" because generally it bent valves and cost a lot of money to repair . If you got away with just dmging gears, you're lucky.

FYI this can most often be avoided with proper shifting technique. On a 3-4 shift, don't grab the shifter like a bottle, or even with your hand centered on top. Instead, use the palm of your hand, but have the back of your hand facing towards you, and push the shifter away and down.

http://www.shortshifter.com/techniques2.htm

VistaGT

If you don't do much highway driving I would do 4.30s. I've always wanted a little extra than the 4.10s and the highway rpm really isn't that bad with them usually 2500-2700. Especially with the cams I think the 4.30s would work nicely. I remember JDM jr's saleen had 4.88s??? I think? It could have been 4.56 but either way that's a lot of gear and it was his street car.

Riptide

Get it to a driveline shop and have them take a look at it.

I'd go with 4.30s if I were you. Worst case scenario you can put a larger tire on.

cummins cowboy

I wouldn't want to just assume this is in the rearend, the axle in our cars is actually pretty darn heavy duty, it might be in the transmission.

the advice about shifting above is correct, don't hold the shifter like a BEER CAN, at least after you are out of first and second.

JasperGT

I'm definitely gonna have to try that.

I'm gonna take my car over to Real Street Performance, and have Jay drive it around to get his take on what he thinks has happened. We'll have to see what's going on...

jdog78

I did exacly what you did a few weeks ago, and I had the same problem. Had the same locking issue and all. I still had my stock gears. What happened is there was damage to the teeth in my rearend. The problem is not your tranny. People were telling me this when my problem happened. I was able to get my problem fixed under warranty. I beleave they needed to replace some parts that cost a total of about 90 bucks. If you need anymore specific info, just ask and I will look at the work order to see what they exactly said.

JasperGT

Thanks for the info jdog78. I'm pretty sure that something is up with the gears, but I'm not too worried. The transmission feels fine, so I don't suspect that there is any damage there. I'll be out of pocket for all the work since these are aftermarket gears if there is any work that needs to be done. Sounds like its turning out to be an expensive trip to the track. lol

AmericanSpeed

LOL, me and my brother were at the track with him and right when he explained what happened, that's what my brother called it (drives the 335i)

The most expensive trip is the first one, causes you to spend all sorts of money on your car...