Weak Link In Power Upgrades?

[THoltz]

After gauges, better exhaust, better fuel pump, better transmission, and any number of devices on the market today that are designed to help the engine produce more HP & torque, what should be upgraded next? How does the stock drive shaft and U-joints hold up? I am trying to anticipate what will fail that we never talk about and inspect or replace before failure. I hate breakdowns.

 

[p-Bar]

Haven't heard any major issues with the driveline other than some out of balance situations and premature u joint failure. I think the biggest issue is the trans that you have already addressed.

 

[R C Cola]

Weak Links

I have had some U- joint problems but am now convinced that I went too long between lubrication intervals (months instead of miles) Now lube at mile intervals with no more problems. Learned the hard way that the rear axle will roll forward and break the u-joint if I drop two gears on a downshift trying to restart after the engine died. Learned that too much twisting force is not a good thing and... our trucks do not die without a reason that needs to be cared for (that time I had run out of fuel) Worth noting " the u-joint itself did not break under all that stress ( I was fully loaded) it was the strap that has the 2 bolts that holds the joint in place that let go. Also learned that the Dana 70 rear axle was probably a little weak for my application. It gave up at 150k of loaded miles. Now use a Dana 80 from a 95 dually with no problems. Recently decided that pilot bushing will wear out (can't lube it without removing the transmission) and will pull transmission and replace along with throwout bearing at 100k regardless, along with rear seal while in there. Also injectiion pump will pull and go thru at 500k since at 600k we found I had a broken spring (fatigue) All the lubrication in the world will not stop fatigue. I like you do not like to break down (inconvenient plus the $1400 loaded tow bill. Maintenance is I beleive the solution.

 

[RLHannink]

Make sure the little bolts that hold the straps for the u-joints are there and tight... Threw the front driveshaft and had it swing under the control arm and stop the truck. Ouch.

 

[THoltz]

How is the U-joint lubricated?

 

[R C Cola]

Lubricated

Factory u-joints cannot be lubricated, most all of the new joints have zerks or are ready for them to be put in.

 

[Hammer]

Driveline upgrades for power are an area that alot of owners do overlook at time I feel. One area I had zero luck with was greasable u-joints. The factory original joints lasted for over 100k and the newer greasable joints only lasted half of that. I used a good synthetic grease and they were serviced every 6k at oil change time. I went back to the 1410 Spicers which are non-greasable and hope the premature failures stop. Also,you may want to change the u-joint hold down straps to ensure proper fit and remove any chance of vibration. I had mine changed at 100k when we redid the driveshaft.



My front drive shaft was just redone and I removed the CV joint due to it being worn and sloppy. The cost of a new deal from Ma Mopar made me seek out other ideas and I had a custom front drive shaft built using the same 1410 joints as the rear drive shaft uses. No more cheap CV joint to wear out and create vibrations.



Gear lubes should be considered also due to the extra torque associated with more HP. I ran Amsoil for years and have very good success with it and only recently switched to Schaeffer Oil's synthetic lube. It doesn't matter what brand you use anything is an upgrade over a dino based lube. Hope that helps you some... . Andy