Spicer Part Number

[Robert E.]

Hi All, Will be replacing my ujoints this spring on my '71 smallblock-4spd and was looking for recommended Spicer part numbers.

I checked the archives, but posts are years old and most make reference to older part numbers.

I've contacted a couple of Spicer distributors and have been given a few choices. One fellow recommended 5-625x for my driveshaft and 5-627x for my half shafts.

Another dealer suggested choices of 5-785X or 5-790X for the driveshaft and 5-799X for the halfshafts.

I made it clear to both distributors that I wanted solid non-greasable ujoints and was for a 4spd application.

Can anyone suggest the correct Spicer ujoint numbers for my application?

Thanks in advance

[Gary R.]

Re: Spicer Part Number

I use them all the time very good part. Be careful of the black rings they often crack, I keep them on hand just in case.
1310 DS is 785
1330 is 790
1/2 shafts 799

[Robert E.]

Re: Spicer Part Number

Gary,
Thanks for your quick reply. What is the difference between the 5-785x and 5-790x?

Also, do you know why I was quoted 5-625x and 5-627x? What are these applicable for?

Robert

I use them all the time very good part. Be careful of the black rings they often crack, I keep them on hand just in case.
1310 DS is 785
1330 is 790
1/2 shafts 799

[Gary R.]

Re: Spicer Part Number

785 is a 1310 joint, 790 is a 1330. about a .500" longer.
The 600 numbers were the old numbers for the same part.

[Joe L.]

Re: Spicer Part Number

Gary,
Thanks for your quick reply. What is the difference between the 5-785x and 5-790x?

Also, do you know why I was quoted 5-625x and 5-627x? What are these applicable for?

Robert

Robert------


You won't need a 5-785X (1310 series) u-joint for any 71-72 Corvette application. All used 1330 u-joints for the driveshaft.

Also, keep in mind that the 5-790X and 5-799X are not configured like original u-joints. These u-joints are forged powder metal (FPM). I don't think that Spicer currently manufactures a non-grease fitting type u-joint for Corvette applications in a traditional forged steel style. Gary would know better, though.

On the other hand, while not configured as-original, the FPM u-joints are FAR stronger and, consequently, far superior to the original style.

[Robert E.]

Re: Spicer Part Number

Thanks Joe and Gary,

I will call my local Spicer dealer and order two 5-790x for my driveshaft and four 5-799x for my half shafts.

I'm more interested in a superior performing ujoint rather than the appearance of a correctly configured ujoint, unless someone can suggest a ujoint that marries both performance and configuration.

Robert

Robert------


You won't need a 5-785X (1310 series) u-joint for any 71-72 Corvette application. All used 1330 u-joints for the driveshaft.

Also, keep in mind that the 5-790X and 5-799X are not configured like original u-joints. These u-joints are forged powder metal (FPM). I don't think that Spicer currently manufactures a non-grease fitting type u-joint for Corvette applications in a traditional forged steel style. Gary would know better, though.

On the other hand, while not configured as-original, the FPM u-joints are FAR stronger and, consequently, far superior to the original style.

[Robert E.]

Re: Spicer Part Number

Joe,

Not to disagree with your part choices, but when I checked the Spicer website ( http://www2.dana.com/expertforms/dek350.aspx) and input my make, model and year, it quotes;

5-785X - Exc. Turbo-Hydramatic 350 Trans. (Driveshaft)
5-799X - Exc. Turbo-Hydramatic 350 Trans. (Halfshaft)
5-790X - w/Turbo-Hydramatic 350 Trans. (Driveshaft)

I'm confused to which driveshaft ujoint to use now.

Robert

Robert------


You won't need a 5-785X (1310 series) u-joint for any 71-72 Corvette application. All used 1330 u-joints for the driveshaft.

Also, keep in mind that the 5-790X and 5-799X are not configured like original u-joints. These u-joints are forged powder metal (FPM). I don't think that Spicer currently manufactures a non-grease fitting type u-joint for Corvette applications in a traditional forged steel style. Gary would know better, though.

On the other hand, while not configured as-original, the FPM u-joints are FAR stronger and, consequently, far superior to the original style.

[Gary R.]

Re: Spicer Part Number

Robert the early car used the 1310 joint, Joe will know the break off years. If in doubt, as I've found plenty of swapped shafts, just measure the cap to cap length. 3.250 is a 1310 and 3.625 is a 1330.
The 799's are pretty strong, we blew apart a 373 diff after 8k very abusive miles and the Spicer 799's installed at the same time were untouched. I just replaced them in fact when we shipped the diff and shafts up to Canada. You may have to put a little radius in the yoke on one side to fit the cross. Again see if you can get some extra black rings you may need a couple.
You can read over my thread on this job on DC, it may help you.

http://www.digitalcorvettes.com/forums/showthread.php?t=76752

[Joe L.]

Re: Spicer Part Number

Joe,

Not to disagree with your part choices, but when I checked the Spicer website ( http://www2.dana.com/expertforms/dek350.aspx) and input my make, model and year, it quotes;

5-785X - Exc. Turbo-Hydramatic 350 Trans. (Driveshaft)
5-799X - Exc. Turbo-Hydramatic 350 Trans. (Halfshaft)
5-790X - w/Turbo-Hydramatic 350 Trans. (Driveshaft)

I'm confused to which driveshaft ujoint to use now.

Robert

Robert------

The Spicer web-site information is incorrect, although it's a common "incorrection" that's present in other manufacturer's parts catalogs, too. It sort of represents an incorrect "amalgamation" of issues applicable to 68-70 Corvettes and 75-81 Corvettes.

First of all, no THM 350 transmission was ever used for any 1971 Corvette. So, that reference is "automatically" incorrect.

Second, the 5-799X is applicable to ALL 1963-79 Corvette half shafts. That application has absolutely no exceptions or exclusions during the 63-79 period.

Third, as Gary mentioned, the 5-785X is a 1310 series u-joint. As far as I know, absolutely no 1971 Corvettes ever used a 1310 (old 1280) series u-joint. I have heard that some early 1971's did, but I've never seen anything to substantiate that and I've never seen such an installation in a known-original car. Want to confirm, for sure, what you need in the easiest possible manner? Look at the extension housing on your transmission. If the embossed casting number on the side of it is 3978764, then you require the 1330 series u-joint, Spicer 5-790X. If the number is 3857584, then you require the 1310 series u-joint, Spicer 5-785X. I'll bet the casting number will be 3978764. If it's anything else, I'd likely question whether the set-up is original to the car.

[Robert E.]

Re: Spicer Part Number

Thanks guys, once I get my car out of storage, I'll do exactly as you gentlemen recommend.

Robert