I'm suppose I'm deranged but.....

blk smoke lb7

<-----Lots of green $
Nov 8, 2010
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belvidere,ill
The gear ratio would be way to high,reminds of when they did the stock v6 top speed run with a 90 s 10 pickup at Bonneville motor and trans bone stock rear end gears were altered it ran something like 169 or something i dont recall now but they had to push it with another truck to 60 so they could use 1st gear.
 

Kspen90

<<<got turbos?
Jul 14, 2011
1,433
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Burleson, Tx
The gear ratio would be way to high,reminds of when they did the stock v6 top speed run with a 90 s 10 pickup at Bonneville motor and trans bone stock rear end gears were altered it ran something like 169 or something i dont recall now but they had to push it with another truck to 60 so they could use 1st gear.

You would stay in the normal 1:1 ratio and drive normally until you were at the top end of 6th, shift the transmission to neutral, shift the transfer case to 1 : 2.72, then shift the transmission back into 4th and it should act just like a 7th gear.
 

Kspen90

<<<got turbos?
Jul 14, 2011
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Burleson, Tx
I couldnt tell ya. As soon as i get my tcase from levi to rebuild, ill know how they use the pump inside

Let me know how it works when you get it back and wether or not it could be reversed if necessary. I wish I just had one laying around that I could tear apart :(
 

DAVe3283

Heavy & Slow
Sep 3, 2009
3,727
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Boise, ID, USA
Jeeps have used 2 transfer cases for years, but to lower the ratios. You'd have to make sure the tcase was lubricated. The pump may not work backwards, but it might be easy to mod it.

The main concern for me would be additional drag. Even in 1:1 it will add some drag, lowering your mileage. If that is not a concern, then it might be worth trying.

Sent from my Galaxy Nexus using Tapatalk 2
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
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Phoenix Az
Have you looked at maybe trying this with a np203 first?

just FYI, the gears inside are not syncroed, so when you go to shift to low (or high in this case), there will be all kinds of nasty noises comin from it
 

barnett performance

New member
Jan 22, 2013
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i would think a divorced overdrive would be a better answer, trying to get everything to spin in harmony at 70+ mph when shifting Tcase almost sounds imposible as the driveshafts will still be spinning even though the transmission is in neutral but hey if you happen to be right get the rights to it and sell it to the big companys for a whole lot of $$$
 

8lug

Escalade HD
Oct 16, 2009
175
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Canada
Also, not sure where you got those gear ratios 1-6 from but I'm sure 5 is an OD and 6 is a greater OD like .71 and .61 or some such...could be wrong.
 

Kspen90

<<<got turbos?
Jul 14, 2011
1,433
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Burleson, Tx
Have you looked at maybe trying this with a np203 first?

just FYI, the gears inside are not syncroed, so when you go to shift to low (or high in this case), there will be all kinds of nasty noises comin from it
Excuse my ignorance, but what is np203? And are dmax t-cases not shift on the fly like the dodges are?
 

Kspen90

<<<got turbos?
Jul 14, 2011
1,433
0
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Burleson, Tx
i would think a divorced overdrive would be a better answer, trying to get everything to spin in harmony at 70+ mph when shifting Tcase almost sounds imposible as the driveshafts will still be spinning even though the transmission is in neutral but hey if you happen to be right get the rights to it and sell it to the big companys for a whole lot of $$$
This is my worry as well. What is a divorced overdrive?
 

Kspen90

<<<got turbos?
Jul 14, 2011
1,433
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Burleson, Tx
Also, not sure where you got those gear ratios 1-6 from but I'm sure 5 is an OD and 6 is a greater OD like .71 and .61 or some such...could be wrong.
Here http://www.dieselhub.com/trans/ZF-S6-650.html
And are you stock turbo?? My 72mm does not love low RPMs!
yes i am still stock turbo, but from my calculations when shifting out of 6th at 3200 rpm, which could easily be revved higher, it would put it coming into "7th" right at 2100 rpm which is the same as all the other gears.
 

Chevy1925

don't know sh!t about IFS
Staff member
Oct 21, 2009
21,694
5,851
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Phoenix Az
i would think a divorced overdrive would be a better answer, trying to get everything to spin in harmony at 70+ mph when shifting Tcase almost sounds imposible as the driveshafts will still be spinning even though the transmission is in neutral but hey if you happen to be right get the rights to it and sell it to the big companys for a whole lot of $$$

What are you going to gain by adding a d-shaft in there a normal t-case doesnt have?





Excuse my ignorance, but what is np203? And are dmax t-cases not shift on the fly like the dodges are?

Np203 is a full time 4wd t-case gm put in early and late 70s pickups and blazers. The plaentary reduction can be easily removed and people make adaptors to make them be able to add on to the np205 so its like you have two low ranges.

Yes its shift on the fly but not into low range. Only going to 4hi is shiftable at speed. Not stopping and trying to shift to low will kill a t-case quick
 

Kspen90

<<<got turbos?
Jul 14, 2011
1,433
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Burleson, Tx
What are you going to gain by adding a d-shaft in there a normal t-case doesnt have?







Np203 is a full time 4wd t-case gm put in early and late 70s pickups and blazers. The plaentary reduction can be easily removed and people make adaptors to make them be able to add on to the np205 so its like you have two low ranges.

Yes its shift on the fly but not into low range. Only going to 4hi is shiftable at speed. Not stopping and trying to shift to low will kill a t-case quick
But low now is now high since the t case has been reversed so has the gear set I would think :confused:
 

Kspen90

<<<got turbos?
Jul 14, 2011
1,433
0
36
Burleson, Tx
I've got an idea! Everybody just send me $5 and ill put it all together and see how bad it tears my shit up! :roflmao: