anybody run 3.90s in an M6 car with 10 bolt??
#1
anybody run 3.90s in an M6 car with 10 bolt??
I currently have 4.10s but they have some noise. I just installed several sets of 3.73s for some people and they all came out quiet as stock. I was thinking maybe I would go to a 3.73 since they are easier to get quiet "for me anyway" but after having 4.10s I'm afraid I may not like them. I think a 3.90 would be a nice gear but I don't know anybody that run them. What do you guys think of the 3.90?
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the 4.10s i have done have been the Motive stock in the blue box. The 3.73s in my car are the Motive Performance in the orange box. All have been super quiet so far. I initially try the factory shim first. It seems to set back lash a little on the tight side like .006. I mocked it up with old hollowed out bearings that are slip fits and do a wipe pattern and it always so far has turned out great. then on final assembly with new bearings i check the backlash and wipe pattern again and they look good so i roll with it. Every one has been quiet.
#5
I have Motive 3.90's. They have some whine on deceleration, but are perfectly quiet on acceleration.
I've heard both sides of the story, starting to wonder if the whine is because of the installer.
I've heard both sides of the story, starting to wonder if the whine is because of the installer.
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I have Motive 3.90's. They have some whine on deceleration, but are perfectly quiet on acceleration.
I've heard both sides of the story, starting to wonder if the whine is because of the installer.
I've heard both sides of the story, starting to wonder if the whine is because of the installer.
I agree that the whine has more to do with the install than the gear set. I installed "thick" 4.10s from US Gear (aka Strange) in mine and they were just as quiet as the 2.73s they replaced, which were also very quiet. I had read that the thick gears should have been noisy, and that the 4.10s were noisier than the higher gears, but I have no complaints.
If you measure the backlash, preload, and make sure your wipe patterns are good, the gears should be quiet. If you abuse the gears, they will probably start making noise. I missed a shift at WOT one day and got some nasty wheel hop, and now my gears whine a bit on "drive."
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My cousin ran some 3.90 gears in his M6 SS. They were a nice gear and he was happy. They were motives and were pretty quiet. He said they made a slight noise but I drove the car and didnt hear anything.
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I think the different size is due to the different size carriers. Make sure that you get the gear for the series carrier that is in your car as the ring gear thickness is different between a 3 series and 4 series carrier.
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Yes. The F-bodies came stock with either a 2-series (with 2.73s) or a 3-series carrier (everything else). The 2-series carriers require a "thick" ring gear.
Also, the variation in the teeth on the ring gear is how you get the gear ratio. A set of 4.10s has a 41-tooth ring gear and a 10-tooth pinion, 41/10=4.1. Read the sticky at the top of this forum for more information. The series refers to the carrier, and the 7.5in refers to the ring gear diameter, I believe.
Also, the variation in the teeth on the ring gear is how you get the gear ratio. A set of 4.10s has a 41-tooth ring gear and a 10-tooth pinion, 41/10=4.1. Read the sticky at the top of this forum for more information. The series refers to the carrier, and the 7.5in refers to the ring gear diameter, I believe.