Rapid U joint wear

[junkyardjeff]

In less then 4000 miles my now 2wd bronco has went through 2 u joints,I first thought the rear end caused the first joint but now its sloppy again. The original driveshaft had a dual U joint system on the rear joint and thinking it might need it again due to the short driveshaft.

[Arnold]

Changing driveshaft angles can do in u joints quick.
Did those Broncos come with both 1 and 2 piece driveshafts?(in the same overall transmission length) I know that 73 to 78 GM 1/2 ton pickups came with both 1 and 2 piece driveshats with the rest of the trucks being identical.
Did you change the housing?
Did the driveshaft get bent?
Are those u joints removeable with clips? Is the housing still "square" and not too tight?
Play in either the pinion or tailshaft bushing?
Mounts broken or gone bad?
Is there a slip yoke? Play in it or stiff?

[junkyardjeff]

Now that its 2wd the driveshaft is a little longer then the original and did not change the pinion angle,the original driveshaft had a built in slip yoke since it bolted to the transfer case and now it has a driveshaft like a normal 2wd since it has a normal 2wd trans.

[wayne petty]

jeff...

just curious.. this is the shaft you assembled a few months ago..

in compatible grease... used by the u joint factory and what you used to fill the cups allowing you to press them in without them falling over or when you greased it...  kinda like mixing orange and green coolant..

i am hoping that you did not use the transparent RED grease that is floating around the market now..   i have had cars come back that the wheel bearings were as clean as the day i washed them in solvent.. but without ANY grease.. it vanished.. so i stopped using the red stuff..


~~~~~~~~~~~~~

now... something off the wall...   can you run the voltage drop test???  it only takes 2 minutes with the engine running and the headlights on..

why... because i have found bad ground connections between the engine and the body...  i found one truck with 8.5 volts of difference between the engine and body...
lets go over it..

engine running.. headlights ON...

digital volt meter to 20 volt DC scale..

1.  battery negative post to battery Positive POST.. 14.1 to 14.8 volts..

2.  battery Negative Post to the engine block... 0.04 volts.

3.  battery negative post to the body...  0.02 volts.

4. engine block to the body... 0.02 volts..

if you get 0.00 on test 2, 3, 4 change the meter to 2 volts DC and retest..  
post your results by number..

1.______

2.______

3.______

4.______

like i said.. this test is really quick.. finds invisible problems that you might not know even exist.. i do this test on almost every car that i touch...


the loss of the engine to body ground may result in higher voltage difference between the engine and the body.. the electrons are going to try to get through somehow.. so they go through the transmission and drive shaft ... to the rear end and up the parking brake cable casings..

in front wheel drive cars.. it causes the wheel bearings to fail....  depending on how the strut is insulated from the body at the mount..

the alternator puts out all the current on the negative side..
and they want to take the shortest direction to where its going to get used..

most fords have a TAB part way down the negative battery cable.. that gets left off sometimes ... or the bolt falls out. .


lastly... if you can slip a transmission rubber seal or big o ring on the yoke..   see how far the yoke pushes into the transmission with the rear unbolted...    mark that with a sharpie.. or measure it...   hook up the shaft.. push the oring forward against the rear seal...  take it for a spin.. bottom it out in a dip.... climb under and see how far  back the ring is pushed..    that your slightly longer shaft is not going into bind and crushing the needle bearings in the joint cups... or brinniling them.. leaving ridges in the races or flats on the rollers as if you hit them with a hammer..

[junkyardjeff]

I will get the volt meter out and check it out and I think I have 1 to 1 1/4 before the yoke is all the way in the trans.

[junkyardjeff]

14.53 volts  negative post to block .003  negative post to to body .061 and block to body .065

[wayne petty]

1.   14.53 volts  good...
2.   negative post to block .003   good.. 0.04 max
3.   negative post to to body .061 too HIGH.. 0.02 max
4.   block to body .065  too HIGH.. 0.02 max

please.... clean and inspect your negative battery cable to the Body connections..

please... Clean and inspect or replace your engine block to body connection...

then RETEST...

either grab a braided ground strap off another car..

or visit a local parts store..  drop one of these from the back of the head after wire brushing or scraping to get to bare metal.. you can use grease to stop corrosion..  and the other end to the firewall...

Help/15 in. Universal Ground Strap   $6 bucks..
Part Number: 60213
Alternate Part Number: 644-125
this has a 3/8" and a 5/16 ring terminal on each end

http://contentinfo.autozone.com/znetcs/product-info/en/US/drm/60213/image/4/


take a look at how GM grounds their mid 80s trucks..

there is an additional ground connection between the engine and the frame or the cap and the frame... as some of the electrical devices are Grounded to the FRAME not the body..

[wayne petty]

if you think that your ford truck has ground issues..

look at this C4 corvette..

i put green marks around the ground connections that all have to be cleaned and verified..



there are different items attached to EACH ground wire.. they are NOT redundant..


one has to understand.. that electrons flow from NEGATIVE to positive...

so.. if the ground connections are all properly installed and sized...   there will be enough electrons when a circuit is activated...  the electron flow on the negative side will also be through the ground cables.. not the long way around.. through the drive or Cv shafts... through the throttle linkage...   i have found many 70s dodge vans that actually burned off the throttle linkage balls as the ground was bad.. you could see  the arcing happening when the throttle was operated..

[wayne petty]

this is for the rest of the forum members also..

lastly... what is a Voltage drop test..


copper wire has resistance when current is flowing through it..

you can measure the resistance with an OHM meter.. but the easier way is to make sure the engine is running.. the charging system is working.. 14.1 to 14.8 .. and at least the headlights are on..  

when you use the digital volt meter between the different components on an active circuit...  

you can measure the slight drop in voltage between the 2 points ..  

if there is NO current flowing through the circuit.. you will get a Reading of 0.000...

why reset from 20 volts to 2 volt scale...

i have run into vehicles that had 8.5 volts between the engine and the body..  that needs a 20 volt scale... and not all digital volt meters will read the millivolts in 20 volt scale.. so 20 volt scale first.. then 2 volt scale for the last 3 tests...

its just dead easy to do.. but only lightly touched on in auto shop.. usually one of the first things discussed...


this is a jpg image of the complete test i post a lot all over the web...

one might want to print it and stick it to the wall of the shop...  and be sure to show friends when they come over..

pick up your volt meter and walk them through the test..



test #1 and #2 can be used while cranking... to verify the wiring to the starter is working properly...  test 2 can also be used positive post to the starter post while cranking..
you will get more voltage while cranking.. usually under 0.25 volts  if your battery cables are big.. it will have less drop.. if they are too small.. it will have slightly higher ..

for rear mounted batteries...  use ONE side of at jUMPER cable laid beside the car from the Negative side.. so you can attach to the digital volt meter up near the motor to get accurate readings for 2, 3, ...

guess what.. this also works for ground circuits on lighting..

[junkyardjeff]

I am going to make up some new ground cables at work tomorrow.

[junkyardjeff]

The motor to body gound was dirty so I cleaned them but going to make a body to battery cable.