Most
Common Symptoms and Solutions
All
solutions assume that you have first checked wheels balancing and third
member.
A. Stock Vehicle
These are the more simple to find drive shaft
problems since there hasn’t been any changes to the frame or
suspension.
We make any stock drive shaft for any vehicle. Usually, these drive
shafts can be diagnosed by visual inspection and balancing. Many times, we
find that the end yokes bolted to the transmission and/or the end yoke
bolted to the differential are worn or loose and it is not the drive
shaft. Worn end yokes allow the u-joints to have lateral movement that
is not allowed in a good drive shaft. Rebuild the drive shaft and
balance it.
B.
After Lifting a Vehicle
Some
problems are induced into the performance of the vehicles due to the
lift, change of engines, transmission, and/or transfer cases,
differentials, etc . They are normally symptoms that our customers
communicate to us and we learn
the solutions by analysis or trial and error depending on the
difficulty. Also, the theory of operation teaches
us what to expect.
Click on bullet (black dot) to unfold or collapse the
list
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SYMPTOM:
Vibrations at low speed or high speed. U-joint vibrations are felt
after 5 degrees and the higher the angle the more pronounce the
vibration. The most common symptom after
a suspension lift.
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Solution
(s):
a) drive shaft may now be too short. B) Due to the lift the
angles have increased causing vibrations. To Reduce the angles,
a double cardan CV is used. The CV divides the angles in half
and the angle at the rear u-joint must zero within three degrees
by shimming the pinion with wedges or by adjustable torsion
bars. So now the u-joints do not have a large angle to
traverse, vibrations are gone and as a bonus, the u-joint life
is extended. The knuckle with two u-joints in it is a
performance unit used to lower the angle per u-joint thus
reducing vibrations to very barable levels.
Products: See the Wrangler
kits, Blazer drive shaft, Tahoe CV front, SYEs. Look at these
products and what they can do for you.
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SYMPTOM:
Drive shaft falls out when going over a hole where
the wheels flex downward.
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Solution
(s):
a) drive shaft is now too short and needs to be lengthened. B)
The drive shaft needs longer travel (long yoke, extreme travel
splines) so that it does not come apart when the suspension
extends. See long yokes and long splines sections.
Products: Look at our
long spline drive shafts and or parts categories..
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SYMPTOM:
Drive shaft bolts up but the standard CV binds. A high angle CV
performs the CV function plus allows you to operate at higher angles.
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Solution
(s):
When a vehicle is lifted the angles increase at the transfer
cases as well as at the pinion yoke. High angle CVs are
used to accommodate these higher angles. The pinion must be
shimmed to be a straight line with the drive shaft within 3
degrees. Zero degrees at the pinion and half the angle at the
transfer case and guess what! the angles have been reduced
without reducing your lift. This is wonderful and vibrations are
reduced to give you a smooth ride.
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Don't
forget the laws of diminishing returns, as the angle
increases beyond the limits of the CV vibrations increase
as a function of the angle. The higher the angle the bigger the
CV used should be because the higher the angle the lower the
torque rating. What we have to do is start with a higher torque
rating CV to make up for the torque loss at a higher angle. And
so that is why we make big CVs to handle the higher angle. We
have done high angle CVs for 15 years and we have build some of
our own and you can through anything at us and we probably have
a solution.
Products: See the 5 different types of high angle CVs.
Click here for the big ones.
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SYMPTOM:
You have created a monster and no drive shafts fits it due to the
high angles created by the lift. These are usually vehicles
suspension lifted from 8 to 30 inches. Most vehicle lifted 8 and
above inches usually required very custom drive shafts.
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SYMPTOM:
You hear a clicking noise coming from a from under the vehicle or
from the CV.
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SYMPTOM:
The output of the transfer case does not line up with the
differential pinion input.
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Solution(s):
1.Compound angle drive shaft with two CVs drive shaft.
However, the lateral angle must be greater than 3-5 degree to
have any effect at highway speeds. So drive it first then
decide. 2. Change the
third member or the transfer case to align and only have a
vertical angle on the drive shaft.
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SYMPTOM:
The truck can’t keep a u-joint at the transfer case or at the
pinion.
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Solution(s): 1.
You are probably using “u” bolts and are over tightening
them. 1310 20 ft-lbs, 1350 25 ft-lbs. maximum. Over tightening
u-bolts will crush pin needles in the bearing and the u-joints
burns up quickly. 2. the angles are too severe for proper
u-joint operation. Extreme motor torque is required to turn a u-joint
when a u-joint is lying down 15 degrees or so, as opposed to 5
degrees. So the u-joints and the parts that hold them wear a lot
faster than usual. You need a CV in this case so that two
u-joints to the job of one and a smooth transition through the
angle occurs..
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SYMPTOM:
I have adjusted the angle at the top u-joint and the bottom u-joint
to be within 1-2 degrees of each other and I still get vibrations.
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Solution(s):
Theoretically, 5 degrees is the maximum on a single u-joint
before it creates noticeable vibrations at high speed. Angles
higher than that require a CV for good performance at high
speeds. Don't for get the laws of diminishing returns. If you
put two people in you garden you may get a fair crop picked. But
as you increase the number of people in your garden the harvest
begins to diminish as the more and more people arrive and
begin to step or you crop instead of picking it.
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SYMPTOM:
drive shaft wobbles when it turns.
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Solution(s):
a) check u-joints for excessive movement, B) check all u-joint
clips that they are in their grooves, C) check for signs foreign
object that may have hit the drive shaft and look for dents, E)
have it straighten and balanced. In rare occasions, the output
and input shafts of the TC or the Differential may be off center
and cause a wobble.
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SYMPTOM:
the CV “H” yoke or the stud on the ball stud yoke has broken
more than once.
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Solution(s):
A). the drive shaft is bottoming out causing the CV to break
when pushed back. B) Shorten the tube to give the drive shaft
more compression without bottoming out. B) The angle is too
excessive for the CV and is over flexing. C) The angle of the CV
is excessive and the high power on the vehicle is created a jump
rope effect on the ball stud yoke causing the stud to break. And
just once in a while, you have u-bolts holding the pinion
u-joint and they are being over tightened crushing the pin
needles to the journal. The will mess up
the CV. 20 ft-lbs 1310 and 25 ft-lbs 1350.
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SYMPTOM:
The vehicle is used strictly for heavy duty rock crawling and I
break a lot of CVs and u-joints and bent tubes.
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Solution(s):
a CV is the weak link to a rock crawling drive shaft. Get rid of
the CVs; if you can’t get enough angle, use larger yokes and
u-joints at the transfer case that give you 35 degrees. However,
sometimes you need a CV to make the angle, in which case get
bigger and stronger CVs that can take more abuse. We make
minimum breakage drive shafts with super tubes that won’t
bend. See our drive shafts and end yoke upgrade kits.
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SYMPTOM:
I need long splines in the rear drive shaft and yet I need to travel
at high speeds on the freeway. The extreme travel long splines are
too loose of a fit for minimum vibrations at hi-way speeds.
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SYMPTOM:
When I break at a light or stop sign, and when I let go of the
break, I hear a clunk. It’s like something stuck when breaking and
let’s go when I let the foot off the break.
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Solution(s):
1. Temporary fix is that grease be added to the spline so
that the yoke doesn’t stick. The yoke is sticking. 2. The
drive shaft may be to short creating slop on the yoke and
allowing it to stick when pushed.
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On
two piece drive shafts, moisture might have gotten in the
mid-ship yoke and spline and it is sticking. That happened on my
02 Super Duty. Take it apart and grease it and make sure the
clamps are tight to not let the moisture in.
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