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C4 conversion

jerrybromley

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I am in the process of converting my 67 from a 6 cylinder manual to a V8 and a C4 transmission. I don't have everything in place yet. Does anyone know whether the original driveshafts will work with the C4?
 

honeycoon_

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Jul 18, 2017
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Not sure about how or if the 6 cylinder to 8 cylinder swap factors in, but when we converted our 69 from manual to a C4 we used the same driveshafts.

Someone else may have a more sophisticated answer though!
 

Viperwolf1

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I am in the process of converting my 67 from a 6 cylinder manual to a V8 and a C4 transmission. I don't have everything in place yet. Does anyone know whether the original driveshafts will work with the C4?

Yes. The D20 should stay in exactly the same place. Just got to get the new motor towers in the correct V8 location.
 

garberz

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The rear crossmember is the same, and stays in the same place on the frame. So yes, same drive shafts. I did the same swap on a V8 as well.

Mark
 

Broncobowsher

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One of the things you can do is use the transmission crossmember to locate the engine. Welding in the frame horns there is potential for being off a little bit. But since you know the transmission crossmember is in the correct location. Drop in the drivetrain, make sure the adjustments around the transfer case are centered, and the engine will place the engine towers in exactly the right place. None of this fighting it when a little bump in the frame says the bottom of the tower is in the right place but the top is a half inch off.
 
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jerrybromley

jerrybromley

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It appears you have fought this battle before Broncobowsher . ;) Unfortunately , in my zeal to get sh*t done, I have already welded the motor mounts in when I had the body off . I guess in the next week or so when I put the motor and tranny in I will find out if I screwed up or not.
But ,hey, at least I know how to fix it now. Cutting and welding on a newly painted frame is a bummer, but what will be will be
 

rydog1130

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The rear crossmember is the same, and stays in the same place on the frame. So yes, same drive shafts. I did the same swap on a V8 as well.

Mark


I thought the yokes were different? My 68 had borg warner and after that they went to spicer? I had to change mine on my output shafts in order for it to work, if I recall correctly. I ended up putting a new drive shaft in because my original was shot, so I may have these yokes if you need one jerry. Actually if you have your original transfer case still you can pull the yokes from that and put them on your C4 t case


post #128

https://classicbroncos.com/forums/showthread.php?t=249119&page=9
 

garberz

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I thought the yokes were different? My 68 had borg warner and after that they went to spicer? I had to change mine on my output shafts in order for it to work, if I recall correctly. I ended up putting a new drive shaft in because my original was shot, so I may have these yokes if you need one jerry. Actually if you have your original transfer case still you can pull the yokes from that and put them on your C4 t case


post #128

https://classicbroncos.com/forums/showthread.php?t=249119&page=9

rydog you’re correct. I forgot about the earlier Borg-Warner style drive shafts.

Mark
 

rydog1130

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Ok, well I know I have one spare for sure, I havn't replaced my front shaft as its fine. Let me know if you need the yoke jerry
 
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jerrybromley

jerrybromley

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Thanks Rydog and Garberz ..Just when I thought it would be simple, I find out it's not ;D

I will try some test fits this week but I have a feeling I will have to make some changes
 
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jerrybromley

jerrybromley

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Just a thought ...I still have the original 67 6 cylinder transfer case . Are they the same size? Can I pull the yokes off the early transfer case and install them on the newer one ?
 

Rustytruck

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depending what transfer case you are using. could be issues with Spicer and Borg Warner u-joints. Using the older transfer case you keep the same driveshafts. using the newer transfercase you will have yolk issues to deal with.
 
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jerrybromley

jerrybromley

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I will be pulling the yokes off soon . Is it just the nut holding the yoke on ..or ..will I need a puller to make it happen ?
 

Jdgephar

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Just take of the nut. Should come off relatively easy, no puller required. Be sure to seal behind the nut when you reinstall so the splines don't leak.

Sent from my SM-G981U using Tapatalk
 

rydog1130

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Just take of the nut. Should come off relatively easy, no puller required. Be sure to seal behind the nut when you reinstall so the splines don't leak.

Sent from my SM-G981U using Tapatalk

I theres a seal thats about $10... worth replacing IMO if your pulling everything apart.
 
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jerrybromley

jerrybromley

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Right as always Rydog :) I filled my transfer case with oil this week and low and behold I have a serious leak coming from the front yoke area . I have the new seals on their way .
I also noted that I have Borg Warner yoke on my front drive shaft and Spicer on the rear. Fortunately it looks as though both yokes take the same seal
 
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