hi I purchased a 9" ford/ Currie rear end complete which was supposed to be a bolt in rear. I am having a situation which bothers me the conversion ujoint does not sit square in the yoke. The yoke appears to be egg shaped with the ujoint only making contact by the tab which locates the ujoint only making contact in the center of the yoke, when the strap is tight the ujoint is contacted by the strap and right by the locating tab and if you hold a light on the side of the yoke you can see a gap between the yoke and ujoint. Does this seem right?
Get bigger caps. Lots of caps interchange on the same cross. Measure your opening and get the right size cap for that.
You need a U-joint with bigger diameter cups. I'll bet the distance over the cups is way less than the tabs on the yoke. That will allow the universal joint to move laterally as the driveshaft rotates.
If that is the small side of the conversion joint you possibly didn't need a conversion joint. You should be able to either check the build sheet on the rear or call them with the ticket number and they can tell you what yoke they used and what U joint cups it is intended If I did my homework right the caps you need should be 1-1/8 diameter aka 1.125.
Just adding info, in case you did not know: Ford did build cars with a rear U-joint with bigger caps on one side of the cross. I just went through that a few months ago when I swapped a 65 Mustang V8 8-inch into an antique car. I never had the Mustang driveshaft, so I went to an old-time junkyard and after measuring some driveshafts, the owner said he never saw a Ford shaft with 4 caps like the yoke I measured on the rear end. He suggested a antique parts place in town, and sure enough, their books showed the original Mustang joint had two sizes of caps. Sorry, I did not write down the sizes.
There are all sorts of joints that have differing cup sizes, and cross sizes between the sides. 1310 and 1330 on the same joint, 1310 and 1350 on the same joint, 1310 and 3R on the same joint, etc. NAPA has a lot of these. The rest can be had online. If you are using your existing driveshaft, you should be able to figure out what that side is. As has been mentioned, you should be able to look at the build sheet, or call the supplier, to find out what size the yoke is. Once you know both of those sizes, finding the correct joint is easy. I just set up a customer's truck with a 1310 to 3R combination joint on his pinion yoke. Cheap and easy! Just by eye, and WAG, that is a 1310 u-joint in the picture, and you need a 1330. Don't take that as gospel. I just want to see if I am right.
Just a thought, As a "conversion" U joint has two different sizes on the cup od you do have the one with two sizes in that spot? The brand and part number of the U joint you used and the drive shaft you used might help one of us clear things up a bit. In other words what driveshaft are you trying to use with the nine inch?
the conversion is from a 1310 which is the chevy driveshaft size the ford size is supposed to be a 1330 but it doesnt seem to fit
If you don't have a vernier caliper for accurate measures, just try to get a decent measure as possible: Cup diameter and width between the yoke "nubs". Cup "diameter" of the non-existing cup is measured across the face of the yoke, with that joint removed out of the way. .
So they sent a new joint and straps but in my stupidity it sures seems like a crappy fit since the stock ujoint into the original rear has no space for the cardboard to fit
That is not right. Is there anybody you can borrow a vernier caliper or a machinist ruler. Measure across the U valley to get the OD of the cup size. If you can get measurements, someone here can give you the correct part number. .
That still is not right. Common dimensions: 1310 Cap: 1.0625" Cross: 3.219" 1330 Caps: 1.0625" Cross: 3.622" 1350 Caps: 1.188" Cross: 3.622" You will note that the first two have the same cap size, but different cross size, and the second two have a different cap sizes, but the same cross size. Does that joint fit snugly between the tabs on the pinion yoke? In other words, is the cross size correct? If that yoke is billed as a 1330, and the cross size is correct for a 1330, then it is also correct for a 1350, which has caps that would take up about that much extra gap. The 1350 cap is 0.1255" inches larger, or 0.06275" on each side. Maybe you actually have a 1350 yoke. A 1310 to 1350 conversion joint should be easy enough to get.
Or: http://www.driveshaftspecialist.com/HTML Measure/UJ ID Guide.html "This photo (click it) illustrates the difference in Ford Pinion yokes (both are quite similar). The pinion yoke on the left is a standard cap at 1 1/16 and has the correct U-Joint cap. The yoke on the right is a BC (Big Cap) and requires a 1.125 cap. A standard 1 1/16 cap is in it and it fits loose. A paper clip is inserted in one edge to illustrate the amount of play. Check this carefully. We have other ways to check. Please call. If you see any play in the UJ cap and the pinion yoke. IT IS TO MUCH! If there is play there are 2 possibilities. One is the pinion yoke is worn or 2. (more likely) is the wrong UJ cap is on the driveshaft. If you have the wrong U-Joint in the pinion yoke it will typically have a hi-speed vibration, this would be speeds from 50 on up. In addition you will see shiny rub marks inside the pinion yoke. There should never be any shiny rub marks. In defense of Ford I can see a (possible) reason the Big Cap was used. All of these yokes use a U-Bolt to hold the U-Joint in place. With a U-Bolt you can apply enough force to distort the U-Joint cap slightly. Then the needle bearings do not rotate and you will ruin a U-Joint in less than a 1000 miles. Torque load is 15-18 lb.ft. With the thicker cap it was harder to distort the cap. You can not get a torque wrench to the nuts. So pull it snug and a bit more. STOP. Do not tighten as tight as tight as possible. For security use a little Blue Lock-Tite on the threads."
I'm sorry for your dilemma, but I'm learning new thangs, so thanks for posting. Also, thanks to everyone who is tossing out the u-joint info. This is why I hang around this place.
The part number for the Ford-specific joint at the pinion is: DANA SPICER 5-7439X NAPA: TWD 57439X. Should be under $20. I checked stock at all three of your local NAPA stores. It is a second-tier item, and will need to come from the warehouse. That should be next-day. This has the bigger 1-1/8" cap that goes in the yoke. It is a standard 1310 yoke on the driveshaft side.
I don't recall the 1350 u-joint being an OEM item on a 9". I could be, as I often am, wrong. I am more inclined to believe, given what I have uncovered, that this needs a "large cap" 1330.
I'm guessing you need a "ford big cap" u joint. Gimpy put up the picture with the paper clip for reference I was going to go find.
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