Premature U-joint Failures...
Thread Starter
|
Cross-Country
Joined: Jul 2004
Posts: 57
Likes: 4
From: Spokane
Premature U-joint Failures...
This seems to be a common problem - my rear driveshaft u-joints often failing after only a few hundred miles - I've heard many theories, but are there any definitive answers? My truck is a 76 F-150 4x4 with the 390 engine.
Junior User
Joined: May 2004
Posts: 70
Likes: 0
From: American Falls, Idaho
There are alot of conditions which will effect u-joint life. Is your truck stock or lifted? Are other parts worn (pinion bearings, cardan joint if you have one)? Have a lead foot? Had the truck through water?
Just a few thoughts.
Just a few thoughts.
Senior User
Joined: Jul 2004
Posts: 407
Likes: 0
From: ct.
Take the driveshaft out and take it somewhere that they will balance it and professionally install new u-joints. This corrected the problem for me on a plow truck I was having problems with. It may be expensive but it should come back as good as new. They should also supply you with a warranty on there work.
Senior User
Joined: Jun 2004
Posts: 103
Likes: 0
Hi:
I have a '78 Ford Custom (300-inline, 4 sp. OD) and recently I am hearing some sort of clunking noises at very low speeds (almost stopping) and particularly when I engage the clutch. The noises appear to be coming from the driveshaft but I do not feel any vibrations in the cab. I do not hear any noises or vibrations at speed or when cruising (even if I engage the clutch). I suspect the U-joints are shot, am I right? Should I take the driveshaft to be balanced and new U-joints installed? If I only needed joints, could I do this at home (regular hand and power tools) or do I need any specialized tools?
Thanks, Raul
I have a '78 Ford Custom (300-inline, 4 sp. OD) and recently I am hearing some sort of clunking noises at very low speeds (almost stopping) and particularly when I engage the clutch. The noises appear to be coming from the driveshaft but I do not feel any vibrations in the cab. I do not hear any noises or vibrations at speed or when cruising (even if I engage the clutch). I suspect the U-joints are shot, am I right? Should I take the driveshaft to be balanced and new U-joints installed? If I only needed joints, could I do this at home (regular hand and power tools) or do I need any specialized tools?
Thanks, Raul
Junior User
Joined: May 2004
Posts: 70
Likes: 0
From: American Falls, Idaho
Probably is a u-joint or two. Climb underneath and grab the driveshaft and try to move it and twist it. There shouldn't be any movement in any direction or when you try to twist it.
Clunking could also be brakes, or a worn differential (I managed to break the ring gear carrier on mine - go figure).
I wouldn't automatically take it to a driveline shop unless you have some reason to think it needs it - vibration, etc. U-joints can be replaced with a BFH and some sockets, but a press makes things alot easier.
Clunking could also be brakes, or a worn differential (I managed to break the ring gear carrier on mine - go figure).
I wouldn't automatically take it to a driveline shop unless you have some reason to think it needs it - vibration, etc. U-joints can be replaced with a BFH and some sockets, but a press makes things alot easier.
New User
Joined: Sep 2004
Posts: 23
Likes: 0
You can do it superbepro.
If you have a bench vise or a big C clamp you chould be able to change your u-joints yourself, as long as there are no other problems (driveshaft balance, bad bearings in output shaft etc...).
A good trick (after you pull the shaft) is to use two sockets, one small and one large. Use the small socket to push the u-joint out into the large one in your vice. You can drive them out with a hammer, but you risk collateral damage. It is also best to use the vise to install the new joints.
Now a question for you. Is your truck a short bed or long bed? 2wd or 4wd? Is the slip joint in the back of the transmission or in the driveshaft? I am putting a 4speed in my 2wd 1979 F150, but am having a hard time finding the right drive shaft. Would be most helpfull to me if you would pass on the specifics.
A good trick (after you pull the shaft) is to use two sockets, one small and one large. Use the small socket to push the u-joint out into the large one in your vice. You can drive them out with a hammer, but you risk collateral damage. It is also best to use the vise to install the new joints.
Now a question for you. Is your truck a short bed or long bed? 2wd or 4wd? Is the slip joint in the back of the transmission or in the driveshaft? I am putting a 4speed in my 2wd 1979 F150, but am having a hard time finding the right drive shaft. Would be most helpfull to me if you would pass on the specifics.
Trending Topics
Thread Starter
|
Cross-Country
Joined: Jul 2004
Posts: 57
Likes: 4
From: Spokane
My truck has no lift kit, etc., but I am running 16 inch wheels and tires; however, this should not affect any driveshaft angles. Also, the driveshaft has been balanced by a reputable shop and I do not have any vibration throughout the entire speed spectrum...any other ideas??
FTE Stories
Ford Trucks for Ford Truck Enthusiasts
10 Things Every Truck Owner NEEDS (2026 Edition)
Michael S. Palmer
Rezvani's Latest Post-Apocalytic Monster Is a Ford F-150 Raptor Underneath
Verdad Gallardo
Top 10 Most Expensive Ford Trucks Ever Sold on Bring a Trailer
Joe Kucinski
2027 Ford Super Duty Buyer's Guide (Every Model, Engine, & Package)
Brett Foote
Top 10 Ford Truck Tragedies
Joe Kucinski
AEV FXL Super Duty - the Super Duty Raptor Ford Doesn't Make
Brett Foote
Lobo Vs Lobo: Proof the F-150 Lobo Should Be Even Lower!
Michael S. Palmer
Ford's 2001 Explorer Sportsman Concept Looks For a New Home
Verdad Gallardo
10 Best Ford Truck Engines We Miss the Most!
Joe Kucinski
Senior User
Joined: Sep 2004
Posts: 196
Likes: 0
From: pennsylvania
Does yor truck have a carrier bearing? ( Pillow block type bearing mounted just behind the T case). If it does, someone may have installed it out of align w/ the rearend. Take accurate measurements from various angles to points like your leaf spring mouting pads, font axle, etc & establish a parallel center. By the way, do your yokes line up EXACTLY? if your slip joint slides into your drive shaft and you're off a spline or 2 your joints won't accept their maximum angular offset. Are you using Spicers, or some $8 U-joint from Asia? Also pick up a set of low cost dial calipers and make sure your yokes are true, faces parallel and bores in align. also your bearing cups should press in to the yokes, not slip in, not one tight-one loose, ifr they are loose you can try using loctite # 603 retaining compound. one last note is try switching from grease-able to non, or visa-versa. Your torque converter is stock stall speed, right? And functioning properly? There's no chance that yor drive shaft is bent is there? Ever fall out? Check with dial indicator. Let us know what you find.
Posting Legend
Joined: Sep 2001
Posts: 30,255
Likes: 37
Any three piece driveshaft with a carrier bearing should be balanced by a driveline shop. Check my FTE web page links section for a driveline angle site. Lots of info there. I have seen way too many misaligned drivetrains. Some were on show trucks and professionally built trucks that were supposedly right. All I could do was shake my head and walk away.
Thread Starter
|
Cross-Country
Joined: Jul 2004
Posts: 57
Likes: 4
From: Spokane
Hmmm, no carrier bearing set-up, just a one-piece rear driveshaft, and no dropped or bend driveshaft either; however, I will check the yoke alignment. The u-joints are $13 lifetime warranty GMBs made in China, meaning it doesn't cost me anything to keep replacing them, but it is annoying...
Senior User
Joined: Sep 2004
Posts: 196
Likes: 0
From: pennsylvania
make sure to check the yokes themselves, too. If say a cup's rollers fell out, & that joint was clanking..that means everytime you hit the gas a hammering effect was taking place inside the bore of the yoke. It may be distorted out-of-round now.
Senior User
Joined: Dec 2002
Posts: 177
Likes: 0
From: Escondido Ca.
I agree with Patrick_PDX, check your springs. My truck used to go through u joints like crazy, and finally a good mechanic figured out that my rear leaf spring on the left side was all out of wack. The weld holding the mounting plate to the axle was broken, therefore allowing the rear axle to twist when I took off. It eventually messed up the angle of the driveshaft, but it was only a subtle change that no one really noticed, and the truck had gone to many many local shops and a bunch of driveline places and they couldnt figure it out. Now, the problem is fixed 
So check your rear suspension 
So check your rear suspension