U Joint Questions

[Already Gone]

The steady bearing on my 72 C10 long box is worn and its time for a new one. It has already been recommended that I get one with the polyurethane bushing which I plan to do. While I'm at it i want to change out my 3 U-joints as well. First question is are the u-joints all the same size? Second I am leaning toward Moog replacement U-joints but am open to suggestions. Lastly Moog has regular and greasable u-joints and I would like to know which would be better for a cruiser truck with a stock 350/350 set up the the greasable or non-greaseable ones.

[Xeen]

I would recommend Spicer greasable for the U-joints.
As far as their size you will need to measure them with a caliper after you pull them because you can't assume everything is stock and the pickup has never had any driveshaft work.

[KY_GMC]

Find a drive line shop and let them handle it. I had my 72 GMC LWB done. Replaced the carrier bearing and all universals, balanced and painted for $200.

They used all NEAPCO parts.

Was the best money spent on my project so far. It was done in a day!

[Already Gone]

Originally Posted by Xeen

I would recommend Spicer greasable for the U-joints.
As far as their size you will need to measure them with a caliper after you pull them because you can't assume everything is stock and the pickup has never had any driveshaft work.

Why greaseable? I'm thinking if they really needed grease wouldn't that be the only way to buy them.

[Already Gone]

Originally Posted by KY_GMC

Find a drive line shop and let them handle it. I had my 72 GMC LWB done. Replaced the carrier bearing and all universals, balanced and painted for $200.

They used all NEAPCO parts.

Was the best money spent on my project so far. It was done in a day!

It will be done by a shop when I get it done, just trying to figure out the best parts to get.

[Stocker]

Originally Posted by Already Gone

Why greaseable? I'm thinking if they really needed grease wouldn't that be the only way to buy them.

IMO, the difference is how long you expect the part to last. All u-joints require grease, and the ones without fittings are already greased. It will last until the grease eventually dries out. No telling how long that will be, could be several years. A greaseable u-joint will potentially last much longer -- IF you remember to give it a shot of grease regularly.

[Already Gone]

Originally Posted by Stocker

IMO, the difference is how long you expect the part to last. All u-joints require grease, and the ones without fittings are already greased. It will last until the grease eventually dries out. No telling how long that will be, could be several years. A greaseable u-joint will potentially last much longer -- IF you remember to give it a shot of grease regularly.

Thank you, makes sense. I guess i will go with the greaseable ones.

[Mr Handy]

I would definitely go greaseable, and make sure the shop uses greaseable joints with the zerk fitting in the body and not a needle fitting in the cap...

[jeffahart]

All U joints with needle bearings need grease. Only question is do you have a zerk to grease or do you need to pull the joint to grease. A joint with a solid cross has extra strength, and cannot accept a zerk anyway. The spicers were using Japanese steel a few years back, so I was told, not sure about that anymore though. Could be 100% Chinese now.

[mike16]

u joints, come with needle berings and grease fittings, needle bearings and no fittings, and no bearings and no grease fittings


u joints needle bearings and grease fittings, weakest in terms of strength but that is relevant, in normal use and proper servicing they can easily last the life of the vehicle. in terms of strength they are very stong and rearly fail, usually in off road aplications with extream angles of drive shaft and hi power hi torque.

u joints needle bearings no grease fitting. the holes drilled through the centers of a u joint are drilled there to transfer grease to each set of needle bearings, those hole, when dilled are percieved as weakening the u joint. These u joints dont have grease fittings and those holes are not drilled. They are used in hi torque drag / racing aplications. after a race they are disassembled , inspected and repacked with fresh grease. so servicing them under those conditions , is not problem. the added strength is important but only under very adverse conditions, they must be serviced like normal needle bearing u joints, they just dont have the convient grease fitting.

u joint no bearings nor grease fittings, yep they are out there, rather than a needle bearing they have maybe a bushing, sometimes the bearing surfaces ride directly upon the oposong bearing serface. requires grease between races and carful servicing, extream duty and short lived.

use the best grease approved, grease on a periodic basis and before extream use and after extreame use. worn u joints cause vibrtions that can damage transmission bearings and transfercase bearings(if you have a t221 rockwell transfercase this is important) If you pressure wash tour drive train, grease it up first, wash it then grease it up again.

greasable u joints and mobile 1 grease, ...for ever. if your u joints are failing and you are servicing them properly then ther may be an alignment/ vibration problem somewhere else in the train. if not that then extream angles of the drive shafts. ya gotta fix this otherwise you'll be doing u joints and eventually drive shafts alot and out on the road and triail.

[brad_man_72]

Don't buy the poly/billit mount! Unless you want to add a slip and stub to the rear shaft.

Non greasable ujoints such as spicer life last more that 100,000 miles and don't sling grease everywhere. Id only recomend greasable joints for a truck that gets submerged in mud.

Just speaking from personal experience building thousands of driveshafts.

Like said before take it to a driveshaft shop. Those 2 piece shafts have to be balanced perfect.

[jayoldschool]

Don't be afraid to do this job yourself. It's not difficult. I rebuilt the driveshaft in my 65 LWB myself. I used an inexpensive joint press, but you can do it with a big vise and sockets.

[Gromit]

I agree; you can do this yourself; but like others have said in other posts, make sure you mark the position of the drive shaft relative to the rear yoke before disassembly. It was kind of embarrassing but I bought a jar of yellow nail polish for this purpose one day at the local drugstore - the young cashier gal looked at me kind of funny but that was all.

If you decide to tackle it, make sure you orient the u-joints so that the grease zerks are in compression rather than tension as the driveshaft spins in forward gear.

I used a $70 Harbor Freight ball joint press to R&R the U-joints and it works fine for both assembly and disassembly

Mostly the two piece drive shafts only go together one way; (though it is hard to see why on first inspection - if you look closely there is just a slight curve to two of the splines and that pair of splines mates to the wider space of all the grooves of the corresponding yoke)..

Also on my THM350; the trans yoke also only goes together one way, due to a similar kind of spline arrangement.

Though I have to admit; if you could get all this done for $200 and a day; that sounds awful tempting.

But there is also something nice about knowing exactly how everything goes together; and after all you will care a lot more and take a lot more effort than most shops can afford to expend on a job like this - but of course they are miles better at it too than a first time DIY'er like me.

My area doesn't have a dedicated driveline shop - when I called the closest thing we have to that to ask about driveshaft balancing; the owner said balancing wasn't necessary even if all three U-Joints had been replaced so long as I marked the shaft and put it back the same orientation. Not sure I believe him about that though - the three u-joints I took out were all from different manufacturers; one Japanese, One Chinese; One USA (sounds like a joke is coming but sorry its not)...

Here are photos:

[Already Gone]

Originally Posted by brad_man_72

Don't buy the poly/billit mount! Unless you want to add a slip and stub to the rear shaft.

Non greasable ujoints such as spicer life last more that 100,000 miles and don't sling grease everywhere. Id only recomend greasable joints for a truck that gets submerged in mud.

Just speaking from personal experience building thousands of driveshafts.

Like said before take it to a driveshaft shop. Those 2 piece shafts have to be balanced perfect.

Thanks everyone for your input. My truck does and will have an easy life. I'm way past racing or burning rubber but like to put the best parts on my truck even if they are somewhat overkill. Could you your comment about the poly steady bearing and adding a slip and stub to the rear shaft.

[Fitz]

Originally Posted by Already Gone

The steady bearing on my 72 C10 long box is worn and its time for a new one. It has already been recommended that I get one with the polyurethane bushing which I plan to do. While I'm at it i want to change out my 3 U-joints as well. First question is are the u-joints all the same size? Second I am leaning toward Moog replacement U-joints but am open to suggestions. Lastly Moog has regular and greasable u-joints and I would like to know which would be better for a cruiser truck with a stock 350/350 set up the the greasable or non-greaseable ones.

All U-joints are not the same. 1310, 1330, 1350 are the common sizes for our trucks and I wouldn't use anything but a Spicer u-joint!

[Gromit]

Fitz's post reminds me; I didn't answer your question - I agree about Spicer - also their site has lots of manuals and tech info about their products.

Probably you would have to remove all three U-joints and measure them before you will really be certain exactly what sizes to order. On mine they were all the same - 1310 Spicers

Spicer has a Youtube video that shows the grease flowing through the zerk and joint - that video helped me to decide which type (greasable vs non) to buy.

On the Spicers I bought from that hot rod place in Nevada the crosses were made in China (not a problem - hey China was doing cast iron when we westerners were still swinging from the trees over in Europe)

And all the other parts of the Spicer U-Joints are USA made

[mike16]

yea always buy the best, greasable and servicable, dont really need to drop 2 bills to have someone else do it. better to do it and learn for yourself. its called expertise.

another point i forgot to mention was ther carrier bearing i think it gets mentioned as a steady bearing in posts above. I ve used rubber and polly materials in the support. in the warm southwest I ve never had a problem and the both have worked well for ages summer and winter. I opperatted these trucks up in Minnasot(EH?) and had one rubber and two polly mounts fail. not the bearing, and not the metal mounting structure buth the rubber itself and the polly. IN winter, in Minnisota, they failed. That is they became too stiff to flex and came physically out of the mount. began to spin outside the drive shaft. Dont know what to say about this. If cold weater opps is a possibility shop with that consideration in mind.

if i dont want grease slung all over the underside of my truck i incorporate an intermediate step in the installation process, I clean up my mess..

pumping grease into a zerk fitting is not a reliable way to remove dirt and contamination from a u joint.its relied upon too much with that expectation in mind but its not reliable means of removing the contamination that can damage a u joint.

[brad_man_72]

Originally Posted by Already Gone

Thanks everyone for your input. My truck does and will have an easy life. I'm way past racing or burning rubber but like to put the best parts on my truck even if they are somewhat overkill. Could you your comment about the poly steady bearing and adding a slip and stub to the rear shaft.

The billet poly mount doesn't allow for any foreward or reward movement of the shaft like the very soft orignal bearing mount. Somethings gotta give when the rear suspension moves up and down the driveshaft needs to get longer and shorter before a solid atachment to the frame. In a one piece shaft the trans yoke is usually where it slips. On every other kind of multiple piece driveshaft on every non IRS has the slip in the rear shaft due to them having a more solid carrier mount.

I have built thousands of driveshafts and have a well equipped shop, this isn't a job I would do at home..... really. Its very easy to swap parts on a driveshaft, doing it properly takes a bit of skill, a little bit of knowledge, a hammer pare of dikes and a 9/16s socket and oh yeah a $50,000 driveshaft balancer.
This particular design of carrier is super sensitive to out of balance situations. Even if you mark everything and put the exact same parts back in the balance will change. Anybody who says anything different has never spent any time behind a driveshaft balancer.

Something that a shop will do that can take them 30 min is check to make sure your shaft is straight within .010" and the carrier stub is within .002" and straighten it if its not.

[Already Gone]

Originally Posted by brad_man_72

The billet poly mount doesn't allow for any foreward or reward movement of the shaft like the very soft orignal bearing mount. Somethings gotta give when the rear suspension moves up and down the driveshaft needs to get longer and shorter before a solid atachment to the frame. In a one piece shaft the trans yoke is usually where it slips. On every other kind of multiple piece driveshaft on every non IRS has the slip in the rear shaft due to them having a more solid carrier mount.

I have built thousands of driveshafts and have a well equipped shop, this isn't a job I would do at home..... really. Its very easy to swap parts on a driveshaft, doing it properly takes a bit of skill, a little bit of knowledge, a hammer pare of dikes and a 9/16s socket and oh yeah a $50,000 driveshaft balancer.
This particular design of carrier is super sensitive to out of balance situations. Even if you mark everything and put the exact same parts back in the balance will change. Anybody who says anything different has never spent any time behind a driveshaft balancer.

Something that a shop will do that can take them 30 min is check to make sure your shaft is straight within .010" and the carrier stub is within .002" and straighten it if its not.

Thanks for your advice. I have no vibrations in the driveline now just a whine at certain speeds. I had it checked and was told my steady bearing was loose and that was causing the whine. I did have the differential serviced thinking that was the problem but after a thorough check and service of the differential the whine persisted. So your advice is to use an original type steady bearing and get the driveshaft checked and balanced by a shop. This may sound like a dumb question but if I bring my driveshaft to a shop, have it balanced and new u joints installed along with a new steady bearing on the truck when it all goes back together it will it be balanced and good to go?

[brad_man_72]

yup she will will be ready to use from the shop.

I've taken a balanced shaft out of the balancer, changed the carrier then put the shaft back in the balancer about 50 times. The balance changed every time.

It doesn't sound like you currently have a vibraton problem, you don't want one.

I had a guy crack 3 transfer cases due to an unbalanced driveshaft, he never felt a vibration. Just because your but dyno says something is okay doesn't mean you don't have a problem.