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Discussion Starter · #1 ·
I have a late model ford 9 inch and it has a 28 spline flange yoke, I have checked the rearend with the car jacked up and each tire turns the same direction when one is turned but when I hold the yoke and keep it from turning the other wheel turns the other way. I believe it is not a posi and was wanting to know how hard and expensive is it to change to a true posi? I donot have a motor or tranny in car yet so I cannot drive to tell if it is a posi or not. The car it is in is a chevy and I have the stock drive shaft and want to use it can I get a yoke to match up to a bastard joint so I can use the chevy driveshaft?
 

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You can have your 3rd member changed over to a posi unit or buy a completely rebuilt 3rd member with the ratio of your choice on ebay for $450-$850 from some very good vendors. I paid $475 to my door a few years ago for my unit which had stock Ford 3.50 gears but it was a 31 spline (axel) 4 pinion posi, all new bearings and clutches etc. In regards to your driveshaft, any good driveline shop can fix you up with the right parts to convert and make a new driveshaft.
 

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High Performance Rear Ends
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You need to pull the chunk out and see what is in it. Every 9 inch Ford that I have ever pulled out that had a Trac Lock in it had worn out chutches in it. It's possible that you have a Trac Lock with worn out clutches and all you need to do is put in new clutches. If you don't have a Trac Lock then you can install a Yukon Trac Lock and have a stronger unit than the Ford Trac Lock. The Ford units are not very strong.

As for the yoke, there are 1310, 1330 and 1350 yokes available for the 9 inch Ford. If you have a '75 or older Chevy drive shaft then you probably have the 1310 u joints in it. If you have a '76 or later Chevy drive shaft then it probably has 3R u joints in it.
 

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Discussion Starter · #4 ·
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I have to take the rearend out of car anyway so I will look inside and see what I have. From turning the wheels I am pretty sure it has 3.50 gears, I was going to go with atleast 4.10 so I will check it out. The driveshaft I have is out of a 70 nova so I guess it has a 1310 yoke. I took the flange yoke off, can I but a 28 spline yoke for a 1310 yoke and use the chevy drveshaft with cutting and welding a new end on it?
 

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Get in, sit down, hang on
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They make conversion (OK ... "bastard" :D ) u-joints for this purpose.

See attached copy of 2011 Neapco catalog pages 350, 351 in PDF format.


You will have to determine "lock-up" type and dimensions (i.e. inside clips or outside clips on the shaft? ... the diff yoke will definitely use the outside lockup dimension)

The next step is to measure the bearing cap dimensions for both the yoke and the shaft.

Edit:
Sorry for the lousy picture quality of the attachments. If you can't make it out, just reply here with your dimensions and I will get you a part number.
 

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High Performance Rear Ends
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He said it has the flange on it, not a u joint yoke, so no adapter u joint is going to fix it. Changing the yoke is no problem when you change the gears because you have to set up the pinion bearings any way. All 9 inch rear ends have a 28 spline pinion except the 35 spline pro gears, which take a special pinion housing.
 

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Get in, sit down, hang on
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...
If you have a '76 or later Chevy drive shaft then it probably has 3R u joints in it.
I am not familiar with the "3R" series designation, so I did a search though the entire catalog for it.

I found it once ... in the u-joint straps section. The catalog says that the corresponding cap diameter is 1.125", so I went looking for a GM ujoint with 1.125" caps.

Neapco #2-3011 which is a "Saginaw 44" ... is that the same as "3R"?

And you are correct. I had missed the "flange" yoke.:embarrass

=============================================
Getting back to the OP's situation:

It looks like ALL Novas from 1962 - 1979 did use a 1310 series UJ
(Neapco 1-0153, Precision 369)

Summit lists a 1310 yoke for a 9" Ford diff, so if he installs that yoke, he should be able to use the "stock" UJ ... correct?
 

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High Performance Rear Ends
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The only problem with using a new yoke is that they are all the short truck type. This usually makes the drive shaft a little too short when doing a Chevy to 9 inch rear end swap. If you find a good used car yoke they are about 1 1/2 inches longer than the truck yoke, which makes the drive shaft about the right length.
 

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I have a late model ford 9 inch and it has a 28 spline flange yoke, I have checked the rearend with the car jacked up and each tire turns the same direction when one is turned but when I hold the yoke and keep it from turning the other wheel turns the other way. I believe it is not a posi and was wanting to know how hard and expensive is it to change to a true posi? I donot have a motor or tranny in car yet so I cannot drive to tell if it is a posi or not. The car it is in is a chevy and I have the stock drive shaft and want to use it can I get a yoke to match up to a bastard joint so I can use the chevy driveshaft?
If you need a flange to bolt to your flange yoke.. I need some info.

Male or Female pilot and size.
Measurement center to center of bolt holes.

I may be able to get ya a part number.
 
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