Experienced with gear installs? Please read.

[Jrgunn5150]

He's saying the run-out measurement was off. Meaning that the ring gear is just like you said....its not "true." Picture laying the gear on a perfectly flat surface...you'd have gaps under it. This can cause whininig. If the gear isn't true, there isn't really any amount of shimming you can do to fix it. The carrier itself could be warped or it could have been improperly tq'd. I've got motive gears in my car and have zero issues but every car is different. Gears a strange beast. Sometimes they just fall in...sometimes you fight them all day and night. It could be a pinion depth is off or back lash is off or a combo of both...but if he is saying the runout is off, that could be your problem. The crappy part is once they've got a pattern worn into the, you might be stuck with a set of noisy gears till you get new ones.

That's not run out, in technical terms, although it probably is what the guy is talking about. Run out ould be if it wasn't perfectly round, looking at the end, what Ryclef described is flatness.

At any rate, have them replaced, the casting is defective, and should have been caught in the machine shop.

 

[Wes8398]

Well now I'm thinking that maybe it had something to do with the install. It's buggin the hell outta me, but I don't know what to do about it right now. I called Brenspeed today, talked to an installer/tech, and told him that my installer told me that the ring gear seemed like it was out of round when he was doing a measurement of some sort. He said a ring gear being out of round is pretty unlikely, although possible. He said they've only ever had 2 approved "return authorizations" with Motive (meaning Motive inspected and agreed there was a flaw). He said that if my ring gear were out of round, they (the shop or Motive themselves) would likely have had a pile of complaints for all the gears that came from the same "lot". Makes sense to me. He also said that if the ring were out of round, I would likely be getting a howl at all times, not only on deceleration.
I would ask my guy to re-install them, and I'm sure he would, but I'm told that the gears quickly get a wear pattern in them, and once they do, they'll be noisy anyway, even if adjusted perfectly. ... grrrr ..

 

[Jrgunn5150]

Yeah, it seems unlikely to me that there would be excessive runout in them too. If there is, and you can tell by placing a dial indicator on the end facing you, and rotating it (it should be probably like .005, or less), then it is a casting/machining problem. If not, then it was the installer's fault.

 

[Wes8398]

Anything in particular that I can suggest to the installer? I don't wanna say too much since he's the guy who knows what he's doing, but if I can make it easier on him, I will mention any "tips". And he's gonna need another crush sleeve if he's gonna re-do it, right?

 

[Jrgunn5150]

Honestly, no. I suspect the guy installing your gear's, is Billy Bob Bo Brains lil brother Bubba, and isn't bothering to use any shims other than the ones stuck in there at Dearborn. Most installers actually do that, you can get away with it about 8 times out of ten, and that's what they count on.

IF, it's not flat, like he is saying, then he could try using a stone or something to flatten it out. Honestly it would have to be visibly warped to not be able to fall into the acceptable range. On the flip side, I deal with castings all day long, and there are no "lot's" I get a shipment from the customer, 5 good, one bad, 8 good, 2 junk, right in the same box, lol.

You said he did it once, and got a measurement of 2.5, then again and got a measurement of 3. I'm guessing he was saying .0025, or two and a half thousandths, and then .003, three thousandths. Either way, way to tight for backlash, which explains the howl.

If, all my guesses are correct, he needs a shim of .005 on the passenger side, in addition to whatever is in there now. He will also need a new crush sleeve.

 

[Wes8398]

Thanks again. When I talk to him I'll point out to him that the suspicion is that the backlash is adjusted way too tight. Regarding the use of the shims, I did give him an entire install kit which included shims....guess that doesn't mean he used 'em though.

 

[Steven]

should have gone 3.73s. Ive had 3.73s and 4.10s in my auto 98. The 3.73s are junk compared to the 4.10s. Never hit the limiter, never had a problem with it.

 

[Wes8398]

should have gone 3.73s. Ive had 3.73s and 4.10s in my auto 98. The 3.73s are junk compared to the 4.10s. Never hit the limiter, never had a problem with it.

Assuming you meant "should have gone 4.10s." ... What gear I chose really isn't the subject of interest here, but thanks for your input. Like I said, I'm more than happy with the 3.73. And without a shift kit or a tune to change shift points, I find it VERY hard to believe that 4.10's don't put you on the rev limiter when you're not manually shifting. With the 3.73's I'm seeing my car shift at barely under 5500 rpm. With the stock gear, it was shifting at about 5200 rpm. From all the reading I've done, every car is different though, regarding what gear they have problems with the rev limiter with. I had lots of guys from here tell me that they were hitting the rev limiter with 3.73's.

Anyway - I'm happy with the 3.73's. The car is rarely raced, and when it is it's auto-crossed; meaning that traction with 4.10's would probably have been an issue. It's driven on the highway enough that I know I wouldn't have been happy with 4.10's.

 

[Jrgunn5150]

Thanks again. When I talk to him I'll point out to him that the suspicion is that the backlash is adjusted way too tight. Regarding the use of the shims, I did give him an entire install kit which included shims....guess that doesn't mean he used 'em though.

Yeah, I mean, maybe he did, maybe he didn't, maybe he did it wrong, I dunno, I'm not there. Even if the gear is warped to .005, he should still be able to shim it so it falls in an acceptable range.

 

[Wes8398]

Thanks again. When I talk to him I'll point out to him that the suspicion is that the backlash is adjusted way too tight. Regarding the use of the shims, I did give him an entire install kit which included shims....guess that doesn't mean he used 'em though.

Yeah, I mean, maybe he did, maybe he didn't, maybe he did it wrong, I dunno, I'm not there. Even if the gear is warped to .005, he should still be able to shim it so it falls in an acceptable range.

Agreed. We'll see what he's got to say when I speak to him.

 

[ryclef331]

I'm not trying to piss in your cornflakes here but I just installed my second set of motive gears from Brenspeed...3.73 and now 4.30's and I haven't had a problem. I honestly think it was an installer error.