Drive Shaft U Joints (3 Viewers)

[abuck99]

I took advantage of the sale at Mr. T of Decatur AL and bought a new OEM shaft for a deal. Let's see how this goes. Worst case, I have an extra spare now.

Was just about to recommend that- good call.

 

[MongooseGA]

Was just about to recommend that- good call.

Just to follow up on this.

I installed the brand new rear shaft today. The vibration is significantly improved but is still present, and I suspect it will get worse as I run the rear shaft in the truck (just as it did after rebuilding the older rear shaft). Running FWD the last week has been great on the highway, buttery smooth. No noticeable vibes at all in just FWD.

I will revisit my pinion angle, and I'm considering having the 3rd looked at by a shop to measure run out on the flange. Possibly it's been smacked and bent at some point. There is something causing the u-joints to fail very quickly, I need to figure that out. It's not tires, not the shaft, not CVs, not brakes...

 

[abuck99]

Idk - steep angles are the only thing that I can think of wears them out quickly. But you really don’t have that condition going on. The Tom woods drive shaft you previously ran most likely didn’t have Toyota ujoints and those small spicer jeep ujoints wear pretty quick compared to Toyota spiders. I doubt very much your new prop shaft and ujoints will wear out during the remainder of your ownership as long as you grease them often and don’t run them over rocks.

I biffed my rear pinion flange last year at windrock and it produced a pretty noticeable vibe- inspect it for scrapes.

The yokes that hold the spiders get biffed and will cause vibes- but you’ve got all that new now.

Vibes come from all over- and the frame in the 100 series is like a flipping tuning fork- it will resonate a fart.

Check runout on all these things- Tires- wheels-axles-pinion-pinion flange-transfer case-input flange output flange- front diff- axles- rotors ….. …. or surrender- it’s a highly modified truck- that’s wheeled like it was stolen - it’s not going to ride like the Benz

 

[SquareOne]

After reading this, when should you replace the u-joints on the 100? I get when it's lifted you open a can of worms, but is there a time frame/mileage for these?

I have vibration when accelerating to 60+, when I let the gas go it stops. I'm gonna change my tires first since the treads are pretty much gone. I have a diff drop it helped with the lift angles and the vibration lessened a tad.

 

[MongooseGA]

Idk - steep angles are the only thing that I can think of wears them out quickly. But you really don’t have that condition going on. The Tom woods drive shaft you previously ran most likely didn’t have Toyota ujoints and those small spicer jeep ujoints wear pretty quick compared to Toyota spiders. I doubt very much your new prop shaft and ujoints will wear out during the remainder of your ownership as long as you grease them often and don’t run them over rocks.

I biffed my rear pinion flange last year at windrock and it produced a pretty noticeable vibe- inspect it for scrapes.

The yokes that hold the spiders get biffed and will cause vibes- but you’ve got all that new now.

Vibes come from all over- and the frame in the 100 series is like a flipping tuning fork- it will resonate a fart.

Check runout on all these things- Tires- wheels-axles-pinion-pinion flange-transfer case-input flange output flange- front diff- axles- rotors ….. …. or surrender- it’s a highly modified truck- that’s wheeled like it was stolen - it’s not going to ride like the Benz

I will have all of these items checked. Very likely that there's been a good whack on that flange. Less likely on the T-Case side, but certainly not impossible.

Lee had the same advice- get over it. It's a built truck, it's geared, covered in heavy steel, etc. You're both not wrong, but there's definitely still room for improvement here. Despite it being wheeled like a red-headed stepchild (and that's coming to an end, kind of), I do 25-30k miles in this vehicle annually, largely at 75-80MPH. Getting this nailed down is more cost effective than buying an appliance car and keeps miles off that Benz (which looks sweet, BTW).

After reading this, when should you replace the u-joints on the 100? I get when it's lifted you open a can of worms, but is there a time frame/mileage for these?

I have vibration when accelerating to 60+, when I let the gas go it stops. I'm gonna change my tires first since the treads are pretty much gone. I have a diff drop it helped with the lift angles and the vibration lessened a tad.

I don't know of any specific mileage interval. It just depends on how they've been maintained. If the truck has no real vibrations (U-joints can be pretty obvious) then no need to mess with them.

 

[abuck99]

I will have all of these items checked. Very likely that there's been a good whack on that flange. Less likely on the T-Case side, but certainly not impossible.

Lee had the same advice- get over it. It's a built truck, it's geared, covered in heavy steel, etc. You're both not wrong, but there's definitely still room for improvement here. Despite it being wheeled like a red-headed stepchild (and that's coming to an end, kind of), I do 25-30k miles in this vehicle annually, largely at 75-80MPH. Getting this nailed down is more cost effective than buying an appliance car and keeps miles off that Benz (which looks sweet, BTW).



I don't know of any specific mileage interval. It just depends on how they've been maintained. If the truck has no real vibrations (U-joints can be pretty obvious) then no need to mess with them.

On the T-case wasn't referring to flange but internal bearings- input/output shaft axial play. this can also induce some driveline vibes. Its tedious or costly to check run out on all that stuff-maybe buy a kit and try check as much as you can DIY.

 

[JLink]

What year is your 100? I'm not in the office yet this morning but we stock Matsuba (OE Japanese) joints for the 25-100 shafts, I'm 95% sure we have the 100 options (2 different rear as I recall) in stock. $37.50 each so not quite Spicer cheap but then you have a known high-quality Japanese option. We use Spicer in our power-steeering conversions, nice stuff and I don't worry about quality so much as application.

Thanks for posting this, just ordered 4 from you for the price of 2 OEM.

 

[FamilyCamper]

Don't get drivework advanced auto parts ones....used them as a filler until I got the OEM ones from partsauq.