I just went and drove my 40 since we turned the caster shims the correct way:mad: and dayum what a difference, I guess -10 degree caster is a bad thing.

She feels great on the road except for a teeth rattling vibration between 40 and 50 MPH.

I had assumed I'de need to shim the rear 2 degrees so that the d-shaft wasn't pointing directly at the t-case. I called TPI and talked to them and they said it sounded more like u-joints to them. I already replaced the front u-joints but have not touched the rear.

YOUR opinion???

Jack the truck up, put it in neutral and play with the driveshaft. Is there any movement???
(side to side)

If not then it probably is not your U Joints :)

With a CV you shoud have the axle pointing directly at the tcase.
with a non CV (which you have) the pinion and the tcase should have the same degree to the axle.

However, I run a non CV pointed directly at the tcase and have not had any vibrations.
Swampers might make a difference there though ;)

I can tell you positivly,with out a doubt what it is! :D

The yoks of your DL must be alliigned so that they have the same orientation. From the pic, I see you have them mis alligned. This will cause a FUC*ED up vibration. Easy fix,...Drop your DL,....pull the slip yoke off the t-case end,...turn it so it lines up with the axle end,.. put it back on. have a :beer:

I did check the rear driveline the other day but not as you described.

The rear u-joints are only 25 years old:rasta: and TPI thought the "NEW" driveline angles were making the old joints show their age. I suppose I could go ahead with the new joints and then shim if necessary.

The shop commented again on how well the KM's balanced. Wal-Mart was terrified when I picked them up because they didn't want to try and balance 35" mud tires...................wusses:flipoff2:

Im tellin ya DSC , its the yokes :D

ya think???? :confused:

I didn't have the vibration before the lift?

I was afraid to change the orientation of the rear driveshaft because I thought it would be out of phase and cause more problems:(

if i'm 1 spline off on my yoke alignment won't it be worse???

FC's right you got to have those yokes lined up.

Your angles look about thee same as mine and I had the same thing happen once, I was about two splines off and the vibration was a bitch.

BTW my u-joints are complete garbage, should have been replaced years ago :D

DSC, Listen to FC as I think he is dead on the mark. It is eay to get your d shaft off a spline or two and not notice it, but the vib will tell. Also check the shaft as it shoud have alignment marks on it. If that doesn't fix the problem then check the pinion angle and the rear of the t-case with an angle gauge to make sure they match our you are asking for trouble.

I'll agree with fc187... your driveshaft is about 60 degrees out of phase.

It is progressively more noticale as the angle grows, so you may not have noticed it with little lift, but now with more lift the thing would vibrate bad!

You need to pull one end of the d/s and get the inner yokes to line up.

-Brett

did I mention that these shafts were modified by the PO when he did the V8 conversion:confused: I wonder if he balanced them.

o.k.

I'm going to go ahead with the u-joints and align the yokes and see if it goes away. Soooooooooooooooooo close:( I really want to drive her this weekend:bounce2: thanks guys! I'll report back tomorrow and give an update & maybe some pics:p

I read the above, but the pic tells it all.

Your u-joints are not in phase....the slip yoke has been pulled apart and the splines are one, maybe two splines off. Only need to pull the axle end to correct.

It also looks as tho you may have the pumpkin tipped up a bit much, but the real reason is the phase issue.

I've been getting my parts (u-joints) from Jay Marks Toyota in Texas, they can get me stuff faster and cheaper than my local dealership:flipoff2: (the 25% TLCA discount kicks ass).

so tomorrow, new u's and align the Yokes and Maaaaybe I can do some field testing this weekend;)

If it is not a phasing problem (it does look out of phase) then it may also be an angle mismatch because the angles look different too.

NEAPCO Ujoints are junk because the caps are too small in diameter and do not fit the bores in the yokes.

Oh man, everyone here is dead on - those yokes are waaaaay out of alignment. Don't wait for the u-joints, just go out and align the yokes! It'll take you 15 minutes tops.

Also, the it looks like the PO lengthened the shaft by cutting and sleeving over another tube... Most likely not balanced.

I've got a similar angle right now (not good) due to flipped springs and 6 degree shims and I get a slight vibration between 55 and 60, but my driveshaft isn't balanced.

Originally posted by fj40bill


Also, the it looks like the PO lengthened the shaft by cutting and sleeving over another tube... Most likely not balanced.



Yikes! :eek:

I didn't notice that, but if the PO didn't mark the shaft before cutting it and line it back up before welding it, there may be no way to get in phased properly and it may really be farked.

:eek: looking closer it has got a bit of bootie fab, but he should have still done it so it lines up

hell, i even made my square driveline so it phased in properly!! :D

First thing I saw before I scrolled down was that your shaft was not in phase with the yoke, as said fifty times above, fix that and you'll be fine. You pinion angle looks fine. If you wanna change your U-joints thats fine, but once you align that shaft you'll be vib free.

ok...just to clarify (for me)...the cap on the ujoints at the tcase and the pinion need to be lined up to have the shaft in phase? Mine has been apart and back together a few times and I haven't seen a mark, or had any horrible vibrations.
Thanks

Originally posted by fj40john
ok...just to clarify (for me)...the cap on the ujoints at the tcase and the pinion need to be lined up to have the shaft in phase? Mine has been apart and back together a few times and I haven't seen a mark, or had any horrible vibrations.
Thanks

You got lucky :D

DSC, those ujoints could last another 25 years! Hell, I have never broken a well lubed Cruiser Ujoint! Ever! Nor have I had to replace one.....

Damn fine units and strong and durable as hell.

You may want to give some thought to making that shaft a spare seeing that it could be a bootie fab job by the PO.

Is it shorter or longer than a stock FJ-40 shaft?

Easiest thing to do is find a used '60 shaft and have it cut down if it is longer than stock....

Nolen, the shaft is about 4" longer in the rear and 4" shorter on the front. I checked my over e-mails with the P.O. and one of his buddies did the welding on the shaft and he didn't know if it was balanced, so it probably wasn't.

I'll go step by step, today I will align the Yokes and replace the u-joints, if that doesnt do it I'll start looking at options to balance the shaft, cut one down, or order one from Jess @ high angle driveline;)

Didn't see this mentioned so I thought I would...

Pull the driveline and take it to a driveline shop (assuming your close to one). They can not only phase it correctly for you but they can balance it as well. I have even seen hacked up DIY drivelines at driveline shops getting balanced with some degree of accuracy. Plus its cheap when you consider ruining new u-joints and drivetrain wear with all that vibration... I think it only costs like $20 to have them balance it (around here anyways)

Some one stated that they have never broke a cruiser u-joint or had to replace a broken one...this is so true... you hardly ever see broken ones, worn out ones yes but rately a broken one...even behind huge v8's and 38's.

I think I can count all of the broken cruiser u-joints I hae seen on one hand easily...and a few of those were probably maintainance issues that turned into breakage...

Good Luck:D

In most cases you need a c/v too- but he's right about the slip yoke and how it lines up- its 90 degree's of there- Jess:D

Originally posted by Deep South Cruisers


YOUR opinion???

No, YOUR pinion!! ;) :D