NP435 4 1/4 ext. vs 12 1/4 ext. - What does that mean

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jamesrtw
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NP435 4 1/4 ext. vs 12 1/4 ext. - What does that mean

Post by jamesrtw »

Ok I've been looking at a lot of online junkyard NP435 transmissions. Call me stupid but I keep seeing this code 4 1/4 ext or 12 1/4 ext. What does that mean? :hmm: I thought all of the NP435's in a ford pickup from 1967 to 1996 were basically the same. Check out the screenshots below:
Here is the 4 1/4 ext
Image

Here is the 12 1/4

Image

Thanks ahead of time for info you guys have :help:
"Yard Built" 72 F100 LWB Custom - Currently: 360V8, C6
Future plans: T18 trans, Detroit Truetrac in rear differential
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Re: NP435 4 1/4 ext. vs 12 1/4 ext. - What does that mean

Post by 71PA_Highboy »

Length of the output shaft?
Got Ford?
2 EarlyBroncos (68,69)
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Re: NP435 4 1/4 ext. vs 12 1/4 ext. - What does that mean

Post by mmerlinn »

Means that some tail housings are 8" longer than other tail housings.
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Re: NP435 4 1/4 ext. vs 12 1/4 ext. - What does that mean

Post by jamesrtw »

mmerlinn wrote:Means that some tail housings are 8" longer than other tail housings.
That makes sense. Thank you :) Now I have another question; on our bumpsides which tail housing length would have been the standard length for a 1/2 ton LWB pickup? I would like to be able to find a front driveshaft that would fit correctly (I may be dreaming on that, and may have to have a front one made) :pout:

As usual, Thanks again for the help! :D
"Yard Built" 72 F100 LWB Custom - Currently: 360V8, C6
Future plans: T18 trans, Detroit Truetrac in rear differential
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Re: NP435 4 1/4 ext. vs 12 1/4 ext. - What does that mean

Post by 71PA_Highboy »

is this a 4x4 or 4x2?
Got Ford?
2 EarlyBroncos (68,69)
2 Classic Mustangs (69,70)
1 F250 4x4 (71) - OB - 360, NP435, D24, HPD60 4.10, D60,
1 94 Ranger, 2.3, 5spd
1 Lincoln Mark VIII
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Re: NP435 4 1/4 ext. vs 12 1/4 ext. - What does that mean

Post by jamesrtw »

71PA_Highboy wrote:is this a 4x4 or 4x2?
It's for a 4x2
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Future plans: T18 trans, Detroit Truetrac in rear differential
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Re: NP435 4 1/4 ext. vs 12 1/4 ext. - What does that mean

Post by mmerlinn »

jamesrtw wrote: That makes sense. Thank you :) Now I have another question; on our bumpsides which tail housing length would have been the standard length for a 1/2 ton LWB pickup? I would like to be able to find a front driveshaft that would fit correctly (I may be dreaming on that, and may have to have a front one made) :pout:

As usual, Thanks again for the help! :D
71PA_Highboy wrote:is this a 4x4 or 4x2?
Reading challenged?
mmerlinn (http://mmerlinn.com/catalog/makeridx.htm)

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Re: NP435 4 1/4 ext. vs 12 1/4 ext. - What does that mean

Post by jamesrtw »

mmerlinn wrote:
jamesrtw wrote: That makes sense. Thank you :) Now I have another question; on our bumpsides which tail housing length would have been the standard length for a 1/2 ton LWB pickup? I would like to be able to find a front driveshaft that would fit correctly (I may be dreaming on that, and may have to have a front one made) :pout:

As usual, Thanks again for the help! :D
71PA_Highboy wrote:is this a 4x4 or 4x2?
Reading challenged?
Maybe I wasn't clear. It's a 2 wheel drive. It's a long bed. It has a TWO piece driveshaft. I was wanting to make sure I get correct housing length on the tranny so I could maybe find/use the stock driveshaft off another manual tranny truck. (I'm only switching out the front portion of the TWO piece driveshaft.

Is that clear?
"Yard Built" 72 F100 LWB Custom - Currently: 360V8, C6
Future plans: T18 trans, Detroit Truetrac in rear differential
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Re: NP435 4 1/4 ext. vs 12 1/4 ext. - What does that mean

Post by mmerlinn »

Ah, now it is clear to everyone. Thank you.

Now I have a question for you. What website did you use to get your cut and paste images from in your first post?
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Re: NP435 4 1/4 ext. vs 12 1/4 ext. - What does that mean

Post by 71PA_Highboy »

mmerlinn wrote:
jamesrtw wrote: That makes sense. Thank you :) Now I have another question; on our bumpsides which tail housing length would have been the standard length for a 1/2 ton LWB pickup? I would like to be able to find a front driveshaft that would fit correctly (I may be dreaming on that, and may have to have a front one made) :pout:

As usual, Thanks again for the help! :D
71PA_Highboy wrote:is this a 4x4 or 4x2?
Reading challenged?

Not at all. See your signature file.
Got Ford?
2 EarlyBroncos (68,69)
2 Classic Mustangs (69,70)
1 F250 4x4 (71) - OB - 360, NP435, D24, HPD60 4.10, D60,
1 94 Ranger, 2.3, 5spd
1 Lincoln Mark VIII
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Re: NP435 4 1/4 ext. vs 12 1/4 ext. - What does that mean

Post by jamesrtw »

mmerlinn wrote: What website did you use to get your cut and paste images from in your first post?
hhttp://www.ebay.com/itm/230653756366
http://www.ebay.com/itm/280624783555

There are a bunch of them out there on eBay. Scroll down to the bottom and you will see where I clipped out the dimensions.
"Yard Built" 72 F100 LWB Custom - Currently: 360V8, C6
Future plans: T18 trans, Detroit Truetrac in rear differential
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Re: NP435 4 1/4 ext. vs 12 1/4 ext. - What does that mean

Post by mmerlinn »

jamesrtw wrote:
mmerlinn wrote: What website did you use to get your cut and paste images from in your first post?
hhttp://www.ebay.com/itm/230653756366
http://www.ebay.com/itm/280624783555

There are a bunch of them out there on eBay. Scroll down to the bottom and you will see where I clipped out the dimensions.
Thanks for the links. However, I was looking for the source of that information which you obviously do not have.
mmerlinn (http://mmerlinn.com/catalog/makeridx.htm)

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Re: NP435 4 1/4 ext. vs 12 1/4 ext. - What does that mean

Post by jamesrtw »

Thanks for the links. However, I was looking for the source of that information which you obviously do not have.
I wasn't even worried about the tail shaft length until I ran across those darn eBay parts. So it gave me another element to watch for. Up until now I had base my search on the information provided by this Novak Conversion website, which looks like very detailed info on the NP435 transmissions. http://www.novak-adapt.com/knowledge/np435.htm
It talks about everything except tail shaft lengths. However it reminds me about that there are the 2wd drive versions & the Divorced 4x4 versions that have the same bolt pattern. Maybe that is what the difference in tail shafts comes into play. I suppose bottom line is, I'll have to take my chances on getting the correct tail shaft length and if it is wrong I will need to make a custom driveshaft. Does anybody out there have a stock bumpside with a NP435 that wouldn't mind measuring it for me? I apologize ahead of time for ya if you have to lay in rocks or a greasy floor to get the measurement. :oops:

Thanks folks for the info so far. :D
"Yard Built" 72 F100 LWB Custom - Currently: 360V8, C6
Future plans: T18 trans, Detroit Truetrac in rear differential
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Re: NP435 4 1/4 ext. vs 12 1/4 ext. - What does that mean

Post by fireguywtc »

Sorry I never did measure the tail housing lenght but I know for sure that a np-435 for a divorced 4x4 is the same tail shaft length as a 2wd np-435. At least in the F250's I am not for sure on F100's but I don't think they are any different. I recently took an old 2wd trans with a 4wd divorced and made one good trans from the two. The tail shafts are identical, only the tail shaft housing is different to allow for mounting of the transfer case shfiter and lack of speedo-hole in the 4wd. Things may be different for the F100 4x4's with a married transfer case or newer np-435's that you listed above. I only know about bump side stuff for sure.

Here is a link to my trans project if you want to check it out. http://www.fordification.com/forum/view ... lit=+np435
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