ShadyPhi

iTrader: (9)

Ok, I'm back to confuse you guys some more ( or maybe confuse myself some more.)

I ordered some Motive 4.10 gears for the stock GM 7.5 10 bolt.

Got the gears, opened the package and started counting teeth.

37 on the ring, 9 on the pinion. 37/9 = 4.11 !!!!

So I thought I got the wrong damn gears. I called up Motive, (just to verify this was a mishap) and they told me that my gears are FINE, and go ahead and put them in!!! He said they will work fine!! I couldn't believe it!

The guy was obviously busy, and I could tell he had to go, so I didn't get a chance to ask more questions. That is why I'm posting here!!

So, now I'm stuck with, why does the box say 4.10 when they really are 4.11 gears?? Motive says I'm cool, but I don't like how the math doesn't equal the package numbers!!

Ah!!

What to do?

00PewterSS

iTrader: (3)

Install them and don't worry about it. Maybe the teath on the pinion are thicker and thus cause the ratio to be 4:10, I dunno. Manufacturers seem to use the numbers interchangably. The real ratio could be determined from measuring the middle of the gear to the center of the contact for both the ring and the pinion and dividing. Again I wouldn't worry about how they denoted it.

Brian

co.6z28

iTrader: (1)

4.10, 4.11 same **** put'em in

MattIROC

iTrader: (19)

put them in, break them in however you want, then enjoy them.

12secSS

iTrader: (30)

Actually they are different! 4.10s are a ratio of the pinion to ring gear, where the pinion has 10 and the ring has 41 teeth. 4.11s have 9 teeth on the pinion and 37 on the ring. This is how the ratio is derived, not by "measuring the middle of the gear to the center of the contact for both the ring and the pinion and dividing.". Also, the thickness of the gear has nothing to do with the ratio, it does affect if it is a 2-series or 3-series. Either way, you should be fine. The 4.10s are stronger than 4.11s due to more teeth to contact on the pinion ... much like 33-spline is stronger than 26-spline.

ShadyPhi

iTrader: (9)

I almost think 4.11 gears are stronger because the 'thickness' is greater than the 4.10's....

But your way also makes sense..... oh well.... I know it will work ok, so I'll throw em in this weekend!

Thanks for the reply!

Ric

Depends on how they put fewer teeth on the pinion... if they make the pinion smaller and keep the same thickness, then you have a weaker pinion. If they keep the pinion tha same size and thicken the teeth up to compensate, then you have a strong(yet loud???)gearset. I didn't know they made 4.11s for the 7.5".

Were it me, I'd raise he!! with Motive till I got what I ordered in the first place.

Nittany_marine

iTrader: (7)

I had the same dilemna a while back, and just slapped em in, and forgot about it...lol Good luck with them!

badazz81z28

iTrader: (6)

Are you really worried about the .01? come on be serious.

GuitsBoy

iTrader: (4)

The strength issue has been debated in both directions, but essentially there are the same ratio. You couldnt tell the difference by driving the car with one or the other. My motives were 4.10s with 10/41 teeth.

Z95m6

iTrader: (1)

Who cares, they should be stronger. As the ring gear is where the 10 bolt usually fails and yours should have thicker, stronger teeth.

mcflyz28

I just broke three teeth off a set of 37 tooth 4.11's, they did last two years and I'm not easy on them.

00PewterSS

iTrader: (3)

Good info... I didn't know they really did make diff ratios for 7.5". Anyway ,I was being sarchastic about the measuring thing... because "technically" that would be the real mechanical ratio, but obviously that isn't the way that they ratio gear sets.

Now I'm curious if I have a 4:10 or 4:11 in my car. I didn't put it there, and I don't feel like removing the cover to find out.

Brian

HOSS

iTrader: (12)

its going in a 10 bolt, 4.10's will break just like the 4.11's will......its just a matter of time...i got 4.11's fun stuff, i dread the future

dug

iTrader: (10)

I wondered the same thing. I was gonna buy a set of used motives but passed because they were the 37 9 and not the 41 10. I think the 41 10 would be stronger. Without looking at the 2 gear set together before you can really tell.

What I really want is the 43r 10p for 4.30 gears. Too xpensive though.

HotRodNeil

I think we're splitting hairs. It really shouldn't matter, both in ratio and in strength. It's sort of like arguing which is faster, an A4 or manual.