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  #1  
Old 11-04-2001, 11:56 AM
Joe J-Truck Joe J-Truck is offline
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Hey porkchop Your x-case setup in your 67 wag sounds badass dude! How'd you do it? How's it perform? Pics?
What's the deal with the twin stick stuff, what did they come in?

[ December 03, 2001: Message edited by: Sitting Bull ]
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  #2  
Old 11-07-2001, 02:50 PM
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porkchop porkchop is offline
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I just saw this! It is late so I will write everything tomorrow.
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Old 11-07-2001, 03:06 PM
Joe J-Truck Joe J-Truck is offline
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I have yet to choose an x-case, and that sounds badass!! Please enlighten us!
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  #4  
Old 11-08-2001, 07:48 AM
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Ok let me start. I had originally had the D20 in my wag when I bought it. It came behind a T-85 three speed. I wanted to swap back to this after I had to change the chain in my QT and I hated buying the QT fluid.

After doing much research and many group discussions I decided to go with a D18 instead of the D20 because of the offset axles and the twin stick which will allow me to have 2 hi, 2lo, N, 4hi, and 4lo. After looking for a case for some time I found one up in phoenix from a fellow board member, thanks Ralph! I picked up the case and got it home and found out a few things.

First is that it had the weaker 1 1/8 inch intermediate shaft not the stronger 1 1/4 inch and had the three inch diameter input hole. I could not use this case with the factory adapter.

I was in the garage one night staring at the cases and saw that they were pretty much the same case except for the D18 was right/right drop. I then did some more research and found out what that it is possible to swap the gears.

I took the gears out of the D18 and found that the inside diameter of the intermediate gear was the same as the D20. So I used the 18 gears, 20 case, and the 20's intermediate shaft and roller bearings.

After getting it together it looked great. Then more problems came up. The new hybrid case fit on the adapter but the main gear would not work. the D20 has two different gear cut angles. The 20 degree cut gear came with the manual trannys and the 17.5 came with the autos. And of course the D18 never came behind an auto so it had the 20 degree cut and the adapter I had came with the 17.5 cut. I looked at this chart from Novak adapters, Chart, and it let me know which gear I needed. After an extensive three week search I found an original gear.

After I had all the pieces, I swapped the rear tail shaft in the TH400, thanks Mike, and put it all together. So far I am very happy with the swap. It got rid of the driveline backlash. The only other problem with this swap is that the front driveshaft has clearance problems. You cannot use a CV shaft. One is not needed since it is a part time case anyway. I have one on the way and as soon as I get it I will let you know about the clearance issue.

Did I miss anything?
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  #5  
Old 11-08-2001, 11:05 AM
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Retro93 Retro93 is offline
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Hi porkchop,

I have a couple of questions regarding your T/C. I assume that you are using the stock Jeep TH400 adaptor and sleeve. The sleeve should have a 15 spline count for use with the T/C input gear, but what is the spline count on the transmission side. In other words, what is the spline count on the transmission output shaft? Is this shaft the same as what would be found in a GM passenger car TH400?

Did you use the shift housing from the D18 to give you the twin stick capability?

I really enjoyed checking out your website. Your driveway looks very similar to mine. [img]smile.gif[/img]

Thanks,

Kim
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  #6  
Old 11-08-2001, 12:52 PM
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Yes, the tranny shaft is from a GM passenger car with the short shaft. I cannot recall the spline count, sorry, but I believe it is 32 or close to it. Yes I did use the D18 housing to give me the twin stick .

Thanks for the compliments on the site. I am redoing it as we speak.
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  #7  
Old 11-08-2001, 01:45 PM
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Lindel Lindel is offline
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PC, what's the gear ratio of the t/c, since the swap to the different gears?
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  #8  
Old 11-08-2001, 02:23 PM
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Porkchop, I've heard tell that there can be slight differences in the th400 tailshaft between the chevy and jeep. What I've heard is that the seal surface on the tailshaft itself is in a different spot on the chevy versus the jeep. The splines, etc were all the same but the lengthways location on that seal was different. Any truth to that?
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  #9  
Old 11-08-2001, 02:52 PM
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The gear ratio of the 2 case is 2.46:1. This is upgrade to from the 2.03:1 of the D20, but it is a downgrade of the 2.62:1 of the QT. This is not enough of a difference to really make a difference to me. The .16 can be made up else where. Plus I have a gear driven case with twin sticks that takes regular gear oil .

I have never seen one from a jeep. The one I have is from a caddy TH400. It fits great with no problems. So I do not know if there is a difference. Sorry.
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  #10  
Old 11-08-2001, 02:59 PM
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Porkchop, I really don't mean this sarcastically because I plan on doing the same swap on my J20 but let me know if you lose any tranny fluid into the tcase. I hope you don't, it's just I had a guy really pound it into my head that there was a difference and the seal didn't match up.
J20
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  #11  
Old 11-08-2001, 11:53 PM
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I just pulled my t-case last night to change a few seals and gaskets, it is leaking on me, and it was fine. No tranny fluid. I will let you know if there is a problem though. I have a picture of the very shaft that I used. If you want it let me know.
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  #12  
Old 11-09-2001, 01:26 AM
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Excellent, I'm glad it's a non issue. Let me recap what you did and tell me if I'm right then. You simply took the gears out of the D18 and switched them and the front yoke/shifter cover over onto the D20 case. Did you have to do any of the internal grinding that Teralow talks about? You also had to use the automatic input gear?
J20
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  #13  
Old 11-09-2001, 02:02 AM
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That about sums it up . I also had to use the 1 1/4 inch intermediate shaft and roller bearings from the D20. I didn't have to do any grinding. I would have to if I used the 4:1 low gears.
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  #14  
Old 11-09-2001, 09:17 AM
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Retro93 Retro93 is offline
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Hey porkchop,

I'd like that picture ot the output shaft if you don't mind. I'm going to the parts house..errr...junkyard in a couple of days to see if I can find one. Might be nice to know what I'm looking for.

My email addy is: klwilson01@earthlink.net

Regards,

Kim
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  #15  
Old 11-09-2001, 07:56 PM
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Got the pic porkchop...now off to find one. Thanks...Kim
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