UGOTWS6D

Just kind of curious about what exactly causes the 10 bolt to break when changing gears to like a 4.10, etc. Does the rear break only from launching the car hard or will it hold up if you drive it normal and don't do 4-6K clutch dumps? Or does the rear just go due to the lower gears being weak and having less teeth?
Also, is a 3.73 a good "all around gear" in a M6 or a waste of time going from a 3.42? Seems to be mixed opinions from what I've searched. Thanks

monte383sbc

iTrader: (15)

all of the above, the 10 bolt in our camaro's and firbirds are a tiny 7.5'' rear, and arnt as tough as 12 bolts and 9'' rears since they are bigger, but to get to your answer when you put gears in a 10 bolt it puts more strain on the rear kinda like more torque, also with a stick car compared to a auto car the stick is guna have more instant snap to the rear like when you dump the clutch but the auto will be a little easyer on it, ive seen guys run in the 10's with a 10bolt with auto vehicles, but its a ticking time bomb, do some research and it will tell you everything you need to kno about 10bolts, what do you plan on doin with your car?

VandykeT/A

In my opinion having 4.10s instead of 3.42s wouldn't exactly make it more likely to break. If its gonna break then its gonna break no matter what gear ratio is in it.I have 4.10s in both of my cars and I haven't had any problems but I'm biting my nails everytime i take one of them to the track. As long as you do'nt beat the **** out of it i think you'll be ok. And I've had 3.73s in a M6 and it helped some but their no way I'd put them in another M6 car. I say 4.10s at least.

monte383sbc

iTrader: (15)

o ya look in the stickys theres allot good info there, will help you in the long run trust me lol, if you drive your car like i do you will be breaking stuff especially with slicks and a stick!!!!!!

projectX

iTrader: (51)

Yeah man google a pic of the 7.5 ring and pinion compared to say 8.8 ridiculously small.

UGOTWS6D

Well, it's honestly a garage queen with 2300 miles on it. Just something I've been thinking about to go with the cam and wake it up some more, but I dunno. I don't wanna go blowing the rear up in this car tho. I was looking at 3.90's...a lil more jump than a 3.73 but not as aggressive as a 4.10 maybe? Like I mentioned, I don't race the car. I also am on drag radials, so by just changing the gears alone, puts more strain on the rear?? Or do you have to shift it hard and "shock" the rear pretty much to chance blowing it apart?

My whole thinking behind this is that I get some cam surge at very low rpm's (not really a big deal) and I thought a lower gear would get rid of that by keeping the rpm's up, plus it would be a blast to run 2nd and 3rd around town just cruising. I understand what you're saying tho as it is a small rear end and asking it to handle 400+ rwhp is like trying to get a boy to do a man's job. I know most on here look at the gears from a track perspective, but I was just thinking that a gear change wouldn't be hard on my car for what I do with it. I don't know that much about gears and even after looking at searches, there's ALOT of differing opinions.

UGOTWS6D

Did the 3.73 make it pull much harder than the 3.42, or was it about the same? I've read some good things about 3.90 but looks like Motive is the only one that makes that ratio and I have no idea if Motive is a good brand or not....some of the people that posted in threads say they whine like crazy and a few claim no problems

killagt

iTrader: (3)

I have 3.73 on mine m6,and I feel it getting more slack after many thousand miles, time to save up for a 9 or sell it and stick with my trans am.

FirstYrLS1Z

iTrader: (4)

UGOTWS6D

Wow....the 12 bolt really dwarfs the 10 bolt

Bob@BruteSpeed

iTrader: (16)

Motive makes good gears and are typically quiet. Bob

VandykeT/A

3.73s helped enough to tell a difference. It still seemed like the gears took a while to wind out. With 4.10s your rowing through the gears alot faster. It also makes it to where you can use 6th gear alot more. With 373s i was still using 5th alot. And every set of gears I've ever put in anything were motives. All of them started out silent and picked up some noise after abuse but alot of it could have been the install to.

flintwrench69

iTrader: (11)

I have heard the ring gear & pinion teeth can break because its small. This has a better chance of happenning on a 4.10 gear set as the pinion has less teeth but it can happen on a stock rear too. There is a good chance it could happen if you "hook" & run anything better than a 1.7 60' or if your doing the high rpm clutch dumps. It will still last a good while if your slipping the clutch on launches & normal driving.
My car had 3.73s in it when I bought it so I cant say how much better it is but most will say not much. I have 4.11s now & its a lot torquier & a very noticeable difference. With 3.73s I would bog on launches sometimes but not with 4.11s.

RedWS6 00

I'll let you know.I have the 3.90's. Not installed just yet, having probs with lack of tools getting the pinion in. Hopefully done tommorow and will be running in the gears for a few hundred miles. I've got M6 and it was 3.42 gears. I went with the thinking 3.72 wouldn't be very noticeable, but 4.10's maybe too agressive, so I went in the middle with Motive 3.90's.

UGOTWS6D

Yeah def let me know how those gears turn out for you, and I'm like you...i'm afraid a 3.73 isn't enough of a jump to make it worthwhile.

Would the 3.90 be stronger (using that term loosely for the 10 bolt) than the 4.10? So, if and when, the 10 bolt does decide to go, is the damage mainly to the gears itself so you just put a new set of gears in, or is there other damage to the axles, etc to where you can't salvage anything and have to replace the entire rear end??

02 BLK WS6

iTrader: (11)

10 bolts behind an m6 are a ticking timebomb.

A 10 bolt can live behind an auto but nothing geared numerically higher than a 3.42 or ring gears start shredding teeth.

Camaro9969

iTrader: (12)

It makes me wonder besides the reason they wanted to save weight.........why the hell didnt gm make a 12 bolt an option at the dealership with these cars????

Bob@BruteSpeed

iTrader: (16)

Money, I'm sure they made a lot more money using the puny 10 bolt that was already being used in production. Bob

therealcreeper

iTrader: (37)

because if they had to do research and development on 2 different rear ends for the same car the car would cost more overall. had it been an option it probably would have cost just as much as buying an aftermarket one.

if these cars were heavier and more expensive than they were people would have complained just as much as now that everyone knows how crappy the rear is

FirstYrLS1Z

iTrader: (4)

The 7.5/7.625 10 bolt is fine for GMs' intended use/how used for the car. I don't think(I could be wrong) even SLP had a 12 bolt option for the SSs' and birds. WE are the ones that cause it to need a 'beefier' rearend. Enhanced traction,sticky tires,more horsepower,power adders.