J Spring question... (1 Viewer)

This site may earn a commission from merchant affiliate
links, including eBay, Amazon, Skimlinks, and others.

Clutchee

I'm fun sized!
Joined
Apr 19, 2004
Threads
214
Messages
4,363
Location
Hotel M-F, home weekends!
I got done installing J springs & shocks on wifes truck. Now taking off at low speeds get a vibration, also at about 45 get it also but not as bad. The initial take off vibration is the worst, is the where the double cardon drive shaft comes into play?

SETUP-J-springs/Mr.gasket spacers on front/Castor plates installed/315's /126K

I feel as though its due to the J-spring height but wanted to confirm other have had same issue or is there something else.
Thanks to all who reply.
 
Last edited:
I have the same setup without the plates and no vibration. Pull the driveshafts 1 at a time and drive around with the CDL engaged to see which one is the problem. If I knew the mileage on the vehicle I might also suggest U-Joints as when they get older they don't like to run at new angles.
 
fj60guy said:
I feel as though its due to the J-spring height but wanted to confirm other have had same issue or is there something else.

I just installed j-springs on the front with 285s, have no vibration and I have not yet even addressed caster. With your caster plates, you should have removed the driveline angle that would result in vibration brought about by the lift. I'll let others comment but you may have a bad u-joint that just showed up. Does the pinion-to-driveshaft line look fairly straight?
 
OK, removed front drive shaft & drove-no vibration. Flexed the front drive shaft u-joints & no excess movement???
-so do I put u-joints in & hope for the best or...
-do i buy the double cardon....
-any of this making sence to anyone?
*IS it ok to let the wife drive the truck without the front drive shaft in...do I need to push the center diff lock button on or off???
 
fj60guy said:
OK, removed front drive shaft & drove-no vibration. Flexed the front drive shaft u-joints & no excess movement???
-so do I put u-joints in & hope for the best or...
-do i buy the double cardon....
-any of this making sence to anyone?
*IS it ok to let the wife drive the truck without the front drive shaft in...do I need to push the center diff lock button on or off???

Can you look at the pinion angle and see if it is still well above the driveline angle?
 
Looked at driveline angle before pulling front shaft & looked strait.
 
fj60guy said:
Looked at driveline angle before pulling front shaft & looked strait.

Well if the driveline looks relatively straight and you see no other issues then I am with landtank....the u-joints aren't liking the new angle of the driveline. A "good" driveline specialty shop can mount that driveshaft and tell you right away what's wrong with it, if anything. They can also talk to you about a double cardan. Be sure and keep up with your marks so you can reinstall it in the same phase from which it was removed.
 
Being Sunday evening have not talked to a drivetrain shop yet, will see tomarrow.
By the way THANKS...after the install I was hoping for a clean install but I guess something has to go wrong once & a while.
 
Caster and correct drive line angles (for normal shafts) are mutually exclusive on the 80 series front end with +4" of lift. You can get one or the other, but typically not both. The 80 series front diff flange and tx case flange is postioned like this \------/ Angles are the same, but flanges are not parallel. So when you drop the diff, there is a point where the situation is ideal for a double cardan shaft. The pinion points straight at the transfer case. That will explain why there is no vibrations with the same setup, when the caster is not corrected.
 
fj60guy said:
Being Sunday evening have not talked to a drivetrain shop yet, will see tomarrow.
By the way THANKS...after the install I was hoping for a clean install but I guess something has to go wrong once & a while.

I think too many guys have gotten into the notion that you can slap a set of OME coils and springs on and be done. In reality, there are numerous other things that need to be done to make it reliable, safe and performing to its maximum ability. Look at it this way: You've done everything else so you might as well have the DS in tip-top shape. It's better in the long run.
 
Christo-thanks for that explaination.
WIFE SAYS THANKS-she said that made total sense!
I will call first thing for a front drive shaft-Double Cardon!
(guess I just got a spare front shaft)

UPDATE: installed front double cardon shaft- take off vibration gone.
-all in all great product & Christo & Robbie came through in the clutch!!
THANKS SLEE!!!
 
Last edited:

Users who are viewing this thread

Back
Top Bottom