U joint question
 

So it looks like its time to replace the U joints, and it looks like I have three connections.

one at the transmission,

one past the middle support that connects to another drive shaft (it seems)

and one connecting the differential.

As I look to purchase the U joints, I see there is one for the front (transmission) and one for the back (differential) but the stores don't say anything or hint about the middle one.

Is that a special size/uniqiue U joint that I need to find or can I just use one of the front or back sizes?

any tips on taking the two seperate dirve shafts out?

anything I need to know about this process with an 84 ford f150?

thanks so much!

Two piece driveshaft has a center support and 3 u-joints. One at the front, one at the center near the support, one at the rear.

See 4635 in pic:


https://cimg1.ibsrv.net/gimg/www.for...74668f578d.jpg

great!

the question remains...

can I just use one of the front or the rear u-joint for the middle one?

If I'm reading the diagram right, all three have the same part number.

You are not reading it right. Only basic part numbers are shown in illustrations.

The text section of the parts catalog is required to get the complete part number by adding the apropos prefix and suffix.

Every u-joint for every FoMoCo vehicle since the 1930's has a basic part number of 4635, so obviously they're not all the same.

The 3 u-joints used with the two piece driveshaft: Two are the same, the other is different, but the OP didn't give enough info.

So I'm not going to post the part numbers, because there are several different possibilities.

I need to know the type of rear axle and transmission, if it's a Regular or Super Cab, 2WD or 4WD .. The OP only said it's a 1984 F150.

Is this the same or similar to the engine casting numbers with the date at the front and the revision at the end?

I don't know what the rear axel is, but
it's and AOD trans with 2WD, 84 ford f150 XL, regular cab, 302 5.0l

If you can post a picture of the certificate label on the left door post or post the numbers on it.
That will tell us what it left the factory with.
Dave - - - -

It's either the 8.8" integral that has an inspection cover, or it's the Ford 9" that doesn't have a cover.

https://cimg9.ibsrv.net/gimg/www.for...ed69343668.jpg
https://cimg1.ibsrv.net/gimg/www.for...259e8435f3.jpg
https://cimg4.ibsrv.net/gimg/www.for...54509b5028.jpg

With out looking up the cert code, Certification Label - Gary's Garagemahal (the Bullnose bible) , that looks like a 8.8 rear axle as it has a cover that bolts on like ND posted.
Dave ----

AXLE code 19: 8.8" with 3.55-1 ratio.

Worth mentioning: Be very aware of the grease fitting placement. A U-joint with the grease fitting rotated 90° or pointing the wrong way (forward vs rearward) can be very difficult or impossible to access. Place them in the same orientation as they are now, provided they are all currently accessible. Check the carrier bearing for smooth operation. I have replaced mine twice, about every 50,000 miles. The spline at the center joint should slide in and out freely. They have a grease fitting but seldom get greased.

That truck is very clean underneath! It has not gone unnoticed by others here.

now that we know what axle it is,

which two u joints are the same and which u joint is the different one within the drive shaft?

and how do I get the different one? so far all the stores that I looked say the have front and the rear u joint, but no one says anything about the middle one for my particular situation.

is there a place to get the middle one that someone can point me to?

or do i just look for that particular one in the already made/different size u joints in the market?

The front is different from the rear, but I don't have the part number for the center.

The hipopart.com C/D is missing 'coupling shaft' section 48.3 where the part number is located.

Usually I'd just use my original catalog on microfiche, but the viewer bulb has burned out, so I have to find another, this bulb ain't cheap...25 bucks.