Hey all, first post because I haven't had to do any strange work to my 2004 Acura TL, which has been quite nice after 4 cars constantly falling into disrepair. This car has been the best car decision I've made so far.

The other day, one of those road construction signs was put too much into the lane and I hit it just with my right side mirror. It still works surprisingly enough, but I've been looking for a replacement. The thing is, my left mirror has an LED bar, I'm assuming for the turn signal or parking lights. All the other 04 side mirrors don't have this though, so I'm wondering whether the left side mirror is newer or something. I don't want to replace the mirror with one that doesn't match, but I'm wondering if the wiring is different.

Anybody have some insight?

Also. Unrelated question: does anyone have something that can help me understand how in hell the helical great limited slip differential works on my car? I don't get it and YouTube isn't helping.

 

Hey, good to hear that you've had a positive experience so far with the TL.

So yeah, it sounds like somebody simply replaced the mirror with an 07-08 mirror which has the LED on the housing. I highly doubt it was ever hooked up and properly tied into your turn signal relay, but you never know. The 04-06 had simple mirrors without the led marker lights.

And quoting an ancient post on this site:

"When equipped with the 6-speed manual transmission, the TL features a standard limited-slip differential (LSD). This helical-gear-type LSD enhances traction during acceleration and reduces understeer in high cornering load situations.

A set of helical gears mounted within the ring gear carrier responds to wheel spin at either front wheel by directing torque from the spinning wheel to the wheel with the best traction. This system improves traction when cornering, and when negotiating slippery surfaces or surfaces where traction is uneven from side to side."

 

The purpose of a differential is to allow the wheels to spin at different speeds. When taking a corner for instance, the outside wheel has to travel a larger distance than the inside wheel. A typical 'open' or non-LSD differential achieves this, but as a downside it only will only send power to the wheel with the least resistance, or the one with the least traction. If your left drive wheel is on ice and the other is directly on pavement, the open diff will send 100% of the available torque to the wheel on the ice. Not ideal for traction. An 'LSD' or limited slip differential allows the wheels to spin independently the same was as an open differential but will lock the two wheels together when there is enough of a difference in speed between the two wheels. It limits the slip between the two wheels. In the same ice example earlier, once enough slip occurred between the two wheels, the LSD would lock and begin to send power to the wheel on pavement, improving traction. An LSD is a big upgrade in terms of traction.

The 'helical' part of the LSD in our cars just describes the type of mechanical means through which the locking is achieved. Helical/torsen, clutch type, viscous, e-diff, etc. There are lots of different types that have different traits, but they all aim to limit slip and lock the differential in some way.

 

So I'm guessing the 07-08 side mirrors are compatible with the 04-06 ones, just with the extra harness for the side marker?

 

Yes, they are directly compatible, you should be fine if you wanted to replace the mirror with another 07/08

 

Best of luck finding a used one in good shape if you go that route; had a bit of a time trying to find mine last week.

 

Look around, you never know...