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4wd auto trac - 4wd manual

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Old 05-08-2011, 01:19 PM
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Default 4wd auto trac - 4wd manual

Hey guys, I will be changing my 4wd system first of all because they are a pain in the butt to be dealing with chains sliping, actuator going off and all that but the most important thing is that I heard that when you put it on let's say 4wd HI to race or something, the PCM gets that info and reduces his power to the drivetrain, and honestly I can feel it!
And people say that with the manual shifter the PCM never gets that info and the truck's power remains the same..
Has anyone heard of this or does this make any sense to any of you guys?
Does any of you know who has the whole setup (shift lever, linkage, t-case) for sale?
Who knows what kind of t-case should I be looking for(model) or if any of you has manual 4wd in his truck would you do me a huge favor and check out what model does your t-case is?
Thank you guys in advance!
Old 05-08-2011, 01:35 PM
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on what truck? i have a 05gmc sierra z71 their is no loss of power.. i mean yea some gets lost when spinning the front wheels but it makes up in case u spin on 2wd.. i launch on 4hi and switch it out on the go.. ive got great time at the track on stock tires.
Old 05-08-2011, 01:40 PM
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I ran low 12's last year using my auto-trac transfer case, and expect to be in the 11's with it this year. I wouldn't even consider the swap you are talking about doing.

I don't know anything about the rest of your setup, but if you really want to make a change, consider a swap to the AWD setup. Check out Midnight's thread on his swap, here's a link. https://www.performancetrucks.net/fo...&highlight=awd

I believe he is selling the setup that he removed, if that is truly what you want to do. Send him a pm if you want.
Old 05-08-2011, 02:09 PM
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Ok guys so what people are telling me about the power loss is not true?
I do Sand drag racing most of the time guys and there is a LOT of trucks with the chain in the t-case slipping and all sorts of things! That's why I want to replace mine before that happens.. It will be going in the truck in my signature.. Also, is there a difference between the ratio in my current 246GM t-case model and the one that goes with the manual setup??
Old 05-08-2011, 02:17 PM
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All of the transfer cases have chains in them. Maybe the guys are smoking the clutch pack in the auto-track t-cases. That would make more sense to me. Also, I wouldn't consider the AWD t-case for sand drag racing. In fact, I wouldn't want the auto-trac either.

I think you'd likely be best off to swap to the manual shift t-case.
Old 05-08-2011, 02:33 PM
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Yes sir that's why I'm looking for the manual shift setup, because we always race in 4wd LO In the sand and like you said, AWD is not an option and Autotrac is not tough enough..
Old 05-08-2011, 02:36 PM
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I know Midnight(Jake) has the parts you are looking for.
Old 05-08-2011, 03:08 PM
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My truck has the vato track. Been 1.37 60' with it. Only trouble I have ever had out of it was when I tried switching to 2wd on a 10sec pass it burned up the fork. Since that I leave it in 4. The power loss you feel is prob the drag ftom 4wd, or in the tune. 4wd robs alot of power.
Old 05-08-2011, 03:34 PM
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I see no problem at all running the autotrac in teh sand, just dont run it in the auto mode, thats where people have problems with the clucth in it. My autotrac is going on 12 years old and has had a lot of hard miles and power put through it offroad with no problems. Ive gone through mud holes pulling my deer stand, feeder, corn and 4wheeler on a 150 shot with a cammed 5.3 and was in 4lo with no problems, other than covering everything on the trailer with mud.

The autotrac tcase is very strong if you know how to use it, dont shift out of 4hi under a lot of power and dont use the auto function, other than that its good to go. I think Stock48 is a testament to the strength of it. Sure the chains get loose after a while but so do the ones in awd and manual cases too. They all suffer from the same pump clip issue too.
Old 05-08-2011, 09:23 PM
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Sand drags in 4 Low are a whole different ball game than our drag racing in 4 Hi guys. I'd have to check to be sure, but I think the clutches are being used no matter what in hi or low range. Definately a weak point for his purposes.

If you've ever ridden a 4 wheeler on hard pack, then sand, you'll notice alot more drag when running in sand. It's alot harder on drivetrain parts than you think. Especially with the sand drag tires they are using.


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