discodave

A few days ago I got my FRPP 4.10 Gears with Trac-Loc installed and now I have a few questions for those who are smart on this subject:

1. After the install I used my tuner to put in the correct gear ratio in order to recalibrate the speedometer. Worked great, no issues with that. Here's the question here: Are custom tunes Gear Specific? I've noticed on some sites like Brenspeed, Bama, etc., that they ask for your gear ratio when asking for a custom tune. Since my gear ratio has changed, is the tune I have now ok or should I get a new one?

2. My car (I think all the 2010s have it) has Traction Control, with a Traction Control button. The default is "Traction Control On" and if you hit the button the "Traction Control Off" light is displayed. This came stock on my car and I never really used it. Now that I have a Trac-Loc (Limited Slip Differential), what's the purpose of Traction Control? Maybe I don't understand the Traction Control function enough to know this.

3. When the shop installed my gears and Trac-Loc they didn't put in friction modifier. I noticed a noise in the back (kind of a "whoomp" "whoomp" sound) that only happened while make sharp, slow right turns. So, I called "Randy's Ring and Pinion", the place that I ordered everything from) and told them about the sound, and the first thing he said to me was "Did they use friction modifier?". Long story short, I went back and they added the friction modifier and said that there shouldn't be any issues, and to give it a week or so for the friction modifier to work itself into the gears. The noise is still there but I'm waiting and will go back there if it doesn't go away. My question here is: Since they didn't add the friction modifier until a full day after the install, should there be any issues that could come up because of it?

4. The gears do make a sound, but I wouldn't necessarily call it a "whine". It kind of sounds like a faint noise and only happens when I accelerate. As soon as I let off the gas the sound goes away. It really just sounds like the gears turning. It's not loud, but I can hear it. I don't mind it at all, but have read that the gears should make zero noise just like stock. The guy showed me in the paperwork that came with the gears a line that said something along the lines of "These gears WILL make SOME noise". The owner of this shop builds racecars for people and has a great reputation, which is why I went there in the first place. Question here is: Should I worry about the faint sound coming from the rear when accelerating?

Break in Period: This shop said that the break-in period isn't necessary, but can't hurt. I got specific instructions from Randy's Ring and Pinion that said to baby it for the first 200 miles or so before you "get on it". I've been doing that so I can't report on how it's "really" gonna feel once I do see what the gears can do. I can say this... Even when going light on the gas, I get to my desired speed MUCH faster and with VERY LITTLE effort, which is much different than the 3.31 gears I had in there before.

Sorry for writing this book, but these are questions that I haven't been able to find on this forum.

Your response will be GREATLY appreciated.

7up

Congrats on the gear install!

Break in period: I've been told a (somewhat) different routine.

The gears need to initially go through several (2 to 4?) heat cycles. The heat cycles were explained to me as driving about 15-20 miles at various speeds/RPMs, then letting it cool down for about 1½ to 2 hours. After the heat cycles, try to stay easy on her for about 500 miles.

I'm guessing a lot of this is subjective in who you talk to. Sometimes I'm thinking a shop will tell you a routine which is "better safe than sorry." And when it comes to that all important rear gear, I can't fault them for that in the least.

A gearhead (literally speaking) -- I'm admittedly not. So I will watch this thread closely.

discodave

You know, the break in period makes sense, but I'm not convinced it's that necessary. I'm doing it just to be safe.

I've read several threads where people do it and have no problems and others where they have had problems. I think it comes down to the gear install and how well it was done. The guy at the shop said he installs gears in his racecars (and toys) and opens it up the same day, and he's never had a problem.

Torch Red GT

Traction control has nothing to do with your traction lock, its just a system that stops you from burning out or losing traction in the rain. If you want to drive fast in dry weather then you can take it off, but in the rain or any stormy weather you should keep it on.

also when i installed 3.73 in my v6 i ran with my old tune with adjusting the gear ratio my self and later on i got it re tuned for the correct gear ratio, and it makes a big difference so i believe gears require a re tune

7up

That's actually good to know. You really don't want to get too wrapped up in breaking in the gears in some EXACT prescribed method, lest you develop an ulcer or somethin'.

But I am in complete agreement with one thing: the installation (supposedly) makes all the difference in the world. Gears, from what I've been told, will whine more often than not from an incorrect installation -- and too many folks end up blaming it on the gears themselves.

Now if you're using an unknown manufacturer for the gears and the quality of their material is subpar, that's a different story.

discodave

So are you saying that if traction control is on (and it always is) both of your wheels won't engage at the same time? i thought that was the whole purpose of the trac-loc. i do understand traction conrol and i understand trac-loc, i just am not clear on how they work together.

7up

I'm dropping by a shop tomorrow; I'll see if I can dig up some info on this.

We're talking about the FRPP gears here? (Obviously, since that's what you installed.)

And there was FRPP paperwork that said they will make some noise?

Interesting. I've seen the install instructions (you can download them from FRPP's site), and they don't mention anything about noise.

I wonder exactly what paperwork he showed you. See if you can find out.

FastDEW

The smaller the pinion becomes in relation to the ring gear, you will have some more concern about noise. But this is really pretty normal. So a 4.10 will have a little more noise than a 3.73 but if setup properly they will both be very quiet. A slight noise is nothing to worrry about.

As for break in, the heat cycle is more important. You can really beat on the car after the first 3 heat cycles and never have it cause a problem. The big issue is to heat cycle so that it sets the steel. Heat treating that is.....

The pattern will wear in over time. You can go out and floor the car and it really isn't going to matter much. Heat cycles are most important.

GT_n00b

I too would like a definitive answer on this. Thanks for any input.

discodave

Thanks for the info. I have put her through at least 6 of these cycles so far. Drive then cool.... So it should be ok for me to not baby the throttle so much now right?