Ike

I have pulled the driveshaft, due to vibration above 70 mph, especially while decelerating. Did the test drive with front wheel drive mentioned here: https://www.yotatech.com/forums/show...threadid=11690 and had the same symptoms/results as Jay-Q and nofilter; no more vibration.

The problem is, when I dropped the drive shaft it separated at the splines. I had marked the flanges but the front flange was stuck on the transfer case. After removing that, I tried to line the spline up with the front flange as close as possible. Is this a problem?

Could this vibration have been caused by rear lifting springs? I put on Performance Products springs and Bilsteins about 5K miles ago. The rear is now about an inch higher than the front. (It didn't have any real sag to begin with). So, should I replace the u-joints and/or get the shaft balanced? Will this problem return due to suspension mods? Thanks for any assistance!

jay-q

ike,
my problem was fixed with replacing the u-joints. i think there maybe some relation to the installation of springs/shocks because i too had just recently added pp springs and bilstein shocks. get the u-joints checked out, i'm sure that is your problem. i'm back to driving 80-90mph with no vibration. (well, a little, but thats normal for a 10yr old truck going 90, 95)

incidently i do get "squeak squeak" noises from time to time coming from the rear cargo area while highway cruising, i think it is due to the rear springs/shocks but haven't investigate it further. anyone have this also?

JQ

jay-q

ike,
my problem was fixed with replacing the u-joints. i think there maybe some relation to the installation of springs/shocks because i too had just recently added pp springs and bilstein shocks. get the u-joints checked out, i'm sure that is your problem. i'm back to driving 80-90mph with no vibration. (well, a little, but thats normal for a 10yr old truck going 90, 95)

incidently i do get "squeak squeak" noises from time to time coming from the rear cargo area while highway cruising, i think it is due to the rear springs/shocks but haven't investigate it further. anyone have this also?

JQ

Ike

Hey, thanks for the instant reply!
I'm just wondering if the geometry is all buggered up and this will problem will return. What type of place does u-joints? Machine shop, regular repair shop, drive line shop?

Flygtenstein

I have had stock, 2" lift, 3" lift and now almost 4" of rear lift on my 95 with no issues.

I have hammered the shaft on rocks, gotten in replaced, got some little dingers on the new one and my vibes are from my out of balance tires.

Have the u-joints in phase, that is the yokes lined up, and you should be fine. Keeping them lubed increases longevity.

Ike

Thanks for the replies. Had new u-joints put on at the local machine shop. Put the driveshaft back in & lined up the flanges. Seems like if the flanges are lined up then the splines are either correctly lined up or 180 degrees off.

Anyway, still have a vibration above 70mph and upon deceleration. I've also lubed all the zerk fittings and driveshaft. Had a good alignment (Hunter 9700) about 5K miles ago. No vibrations untill just recently.

Any suggestions?

nofilter

but you didn't have the DS balanced?

also, did you check the transfer case flange nut? it holds the flange on the TC-shaft (i think it's a 30mm). the DS flange bolts to the TC-flange. i think it's supposed to be torqued to 120 ft-lbs (something like that). mine was finger-loose.

Ike

"...but you didn't have the DS balanced?"
No, I was trying the cheapest method first.

The flange nut on my '95 has a "tab" holding the flange nut in a channel on the pinion shaft the flange nut is on. Do you bend this tab and just tighten, or is this different?

My other problem is that the driveshaft came apart at the slip joint. I tried to line everything up as it was. Plus now I'm wondering if the flanges are off due to hard to see marks. Would a balance solve any or all of these problems?

Ike

Any ideas out there?

nofilter

yes, bend the tab, then torque the nut to 120 or 140 (something like that). after i bent the tab, the i could turn the nut by hand (just snugged it a bit), then torqued it, it moved tlike a 1/4".

if when you put the DS back together, but were off by a spline, or even 180 off, i think this will affect the balance. plus, when the u-joints were put in, did they mark the flange to DS and put it back exactly the same as they pulled it apart (assuming you were able to get the DS splines exact, too)?

so backing up... if the DS was perfectly balanced, and you pulled it off and apart (by accident) - put it back EXACTLY, the u-joints were replaced - and the flanges were put back EXACTLY, and put the DS back on the TC EXACTLY and the axle EXACTLY, then you probably wouldn't need a balance.

when i pulled mine, i marked the flanges, but after banging on the u-joints with no success, i brought it into a DS shop. they checked the play in the splines (cuz he said sometimes this is worn out - if you don't regularly lube it), popped in the u-joints and balanced the whole thing. since they welded some new weights on the DS, i figure it was out of balance. when i put it on, no more vibrations. - but then again , the TC flange was probably wobbling, too, since it wasn't on tight!!

good luck, let us know...

Yoda

The splines have to be put together in phase (exactly the was it was before it came apart). The fixed end of the DS (end WO the splines) has the 2 "ears" where the U-joint is. So, the end with the the splines is assembled so the "ears" are exactly in line with the ears on the other end.

If there are an odd number of splines, there is only 1 way to assemble it it phase. If there is an even number, it has 2 ways.

Here is a site called "driveline 101". Great info on your driveshaft, pinion angles (like after a lift), etc

http://4crawler.cruiserpages.com/4x4...l#Measurements

Ike

1st thanks for the help.

I tried to get the flange nut off but the indent wouldn't budge. Compared the nut on the differential, it looks like someone overdid the indent because the differential nut has some clearance to easily unseat that tab.

I tried a little screwdriver and hammer to unseat the tab. But, with no clearance between the indent on the nut and the pinion shaft channel I didn't have any luck.
It was a little loose but now it's got less slop just from trying to pound up the indent with a screwdriver.

I'm wondering how can the nut loosen when it's seated in the pinion shaft?

On a more positive note, I made sure the u-joints were in phase (driveline 101) and put the shaft back in. I'd say the vibration is at least 50% less! Unless I'm risking a pogo stick rollover that's how it's going to stay for while.

Thanks again for all the great input!

Yoda

How much of a rear lift is in it?

Did you measure the angles of the flanges? Sometimes a lift will change the pinion angle, and that may cause a vibration too.

driveline 101 shows how and explains why.

Ike

The rear end is 1" higher the front about 3/8-1/2" after 4 Billstein shocks and Performance products 1" rear lift springs. However, I did this almost a year and 6k miles ago. I didn't measure the angle. I was hoping the flanges were mis-aligned.

After further road testing it is exactly as before u-joints etc.

Ike

Had a new shaft made by unitrax and all is well. Great shop cheap price.