bene

iTrader: (16)

Does it make any noise on a certain speed?? Your gains ET? How much did you lose on gas mileage highway and city driving? How well will this gear go with 3200/3600 stall? What stuff do I need to complete the swap of my 2.73 gear to this 3.42 gear besides an install kit and well rear end fluid? Appreciate w/ any constructive input. BTW, I'm not doing this by myself I'm planning on paying someone who knows their ****.

TDP

iTrader: (23)

Usually the "thick" gears made for a 2-series carrier will make noise. The right way to do it would be to get a 3-series diff, and GM 3.42s. Even used GM 3.42s will work fine.
I had 3.42s in my old 99TA with a Yank PT4000 stall and it was absolutely perfect! I still got 265 miles to the tank.

bene

iTrader: (16)

Shiat really? Fack. Looks like I'm going to be hunting for 3 series gear and a posi diff.

bene

iTrader: (16)

Anymore input? TTT.

MCBRIZ28

iTrader: (2)

Thats the way I went when I changed from 2.73 to 3.42. I think I lost 1 mpg with gear change still get 25 mpg on highway and 19 to 20 in town if I keep my foot out of it. Did pick up 2 tenths et.

bene

iTrader: (16)

Did you use strange gears or use the stock 3.42s and a new/used 3 series posi? Can you please give me more info? If you use strange 2 series 3.42s, does it whine or make a noise on a certain speed?

bene

iTrader: (16)

TTT!!!!!one!!!!one!111

chicane

Interesting. I would love to hear an explaination on this one.

bene

iTrader: (16)

Please do.

TDP

iTrader: (23)

Theres no good explanation that I know of, except that it has been my experience. I've done well over 1000 gear installs, and I quit using the "thick" gears for the 7.5, because they usually whine. I never have any problems with the AAM 3.73 or 4.10s in a 7.5 10 bolt. They are a much better quality than any aftermarket brand. Unfortunately AAM does not make "thick" or "thin" gears. They just make the correct gear for the correct carrier.

This is the rare case that factory (AAM) gears are better than any aftermarket brand. The AAM gears are installed in EVERY rear wheel drive GM vehicle. That is millions of vehicles every year, and how many of them whine when new from the factory....VERY VERY few. They go through a lot more QC than Motives, Richmond, etc etc

People can argue with me all day long, but I am speaking from experience. Just my 0.02

chicane

In my experience of 15+ years and somewhere in the nieborhood and north of 10k differentials later, I have never experienced a thick gearset make noise just because it was a thick gearset. Sounds more like an assumption without any technical knowledge to back up that claim.

This has been covered before, time and time again. There are QUITE A FEW manufacturers that supply the OEM manufacturers... its not solely AAM. They are under contract by 'the big three' and are used for production runs to meet the demand.

As for your statement about the QA from other manufacturers, that doesnt fly either. I know for a fact that USGear, Percision and Richmond have excellent QA that even rivials the OE on many levels. If your statement was true, every racing vehicle on the planet would be running AAM gearsets. Obviously, that isnt the case.

I do agree with you however, on purchasing a replacement 3-series carrier for use with a ratio change. I myself would use either USGear or GM 3.42's if it were up to me.

bene

iTrader: (16)

So the best bet for me to use is GM gear since I never heard of USGear. That means I have to switch my LSD to a 3 series carrier unless I can use some kinda of adapter. Is there an adapter for 3 series carrier 3.42 in use w/ 2 series LS differential? If I do "need" to change my LS differential to 3 series carrier, do I need to get one for a traction control equip car like mine? I've heard of 3 channel and 4 channel units but I don't know which is which.

bene

iTrader: (16)

TTT, sir.

TDP

iTrader: (23)

All I have to say is that everyone has their own opinion.....and you know how the rest of the saying goes

I do not believe any of the above statements. If they are facts, prove it. Sounds more like speculation and opinions to me...

BTW, just because of all the internet know-it-alls and arguing, I am going to go out of my way to prove what I believe to be true.

chicane

DO NOT... use a ring gear spacer. That is a bandaid, waiting for failure to happen.

All available 7.5" differentials have the provisions for a reluctor ring (aka tone ring). This will not effect the three or four channel ABS system, since the differential will have the provision for the reluctor ring and the three channel system. The four channel system take inputs from both the axles and not just the differential itself.

It would be in your best interest to ditch the idea of using your old differential carrier (posi) in this case. By the time you get all the associated widgets and work done it will have cost near the same as it would be to purchase the correct parts.

BTW, USGear under contract has made more 7.5" gearsets than the others combined. The majority of these were for GM in specific ratios that were considered 'problem children'... which were designed with complex hypoid cuts (that were different from previous manufacturers) to null inhearent noise and other problems from other manufactured gearsets.

TDP

iTrader: (23)

Agreed. It takes away the "press fit" the ring has on the carrier, causing an unnecessary weak point.

chicane

Ok... you dont have to believe anything I stated.

But then again, you have built what... 1000 diffs ?? It would seem to me that you havent really seen all that much in the differential industry over the past 15-20 years. It also seems, that you, actually... are in the position to back up your claims and prove differently. I have the credentials, the resume and the degrees to back up my claims.... but, what is it again that you are bringing to the table ??

15+ years of building performance differentials, doing failure analysis for Ford, GM, Chrysler and Toyota... not to mention working hand in hand with GM DT engineering supporting factory racing efforts and building 10 to 1 against you. Huh. Experience is 9/10's.

You want facts... if you actually knew things by sight, I would not have to prove anything to you... you would already know. If you can actually tell me that you have never seen an OE GM gearset that came from the USGear foundry... then you havent build half of what you have stated. USGear was contracted by GM specifically for various ratios, specifically for the 93-02 F-body. The only visual differences between them, was the finish machining and a GM part number stamp.

Its kinda funny... that the Ford 8.8 was the same. Same gear, different finish, different part numbering.

As were many of the DANA and CMD sets during the same time frame.

But you knew that already.....

bene

iTrader: (16)

Okay, w/ those being said as far as your recommendation on ditching the idea. What is the best 3 series differential carrier (posi) that can be had (mainly on street/rarely on track). I have heard that traction control equipped cars has 4 channel rear, so I guess I have 4 channel. Will I have to get a posi made for a 4 channel rear?

I guess what I'm trying to figure out here guys if you could please do help me is... What are the correct parts for me to have for 3.42s? Posi brand, gear brand; type, etc for a mostly street driven car.

koolaid_kid

iTrader: (21)

bene, I have the Strange 3.42 gear set in my 2 series carrier. They have always made noise, which I found curious. Last year, I took off the cover to replace the gasket (I have an aluminum cover with the reinforcing bolts). When I looked at the gear wear, I discovered that the mechanic did not set the gears up correctly. I now have a new set waiting to be installed.
I have 5 years machinist experience, and I don't quite understand why thick gears would make more noise, if they were set up correctly. The answer could be the tolerances used versus stock. Another remote possibility could be the hardness of the material used. However, I do not have the experience of the experts on this thread, so I decline to offer an opinion.

bene

iTrader: (16)

Thanks for your input Koolaid_kid. Any input is good input as long as its constructive.