driveline vibes still...

Boonie Buster · Feb 23, 2009

So, I have replaced the two rear output bearings in my ford np205, and aligned my pinioin properly for a CV driveshaft. And I am still getting a pretty bad vibration at about 50mph

What else could it possibly be?!!?! Even with the bearings replaced I can still move the pinion up and down slightly on the output of the t-case. I know there are some large needle bearings that connect the two shafts together on it's way through the t-case, could those have gone bad? Is my actuall casing bad around where the bearings ride?!?! I am just kinda lost, I am possibly going to take it into a shop soon if I can't figure this out soon.... It's driving me mad, and i don't want something to grenade on me while going down the road...

Could it be my driveline was not properly balanced and is "jump-roping" slightly? Do i need to replace bearings further in my t-case? Do I need to roll it off a cliff and buy a pre-built toyota or jeep? I just don't know, anyone have any other ideas that i haven't exhausted???

bigiron · Feb 23, 2009

Maybe the slip joint in your driveline is out of phase? or driveline twisted?

Boonie Buster · Feb 23, 2009

bigiron said:
Maybe the slip joint in your driveline is out of phase? or driveline twisted?

i dont think so/hope not, it's pretty new, and never been taken out of the slip, i will recheck though.:eeek: I doubt it's twisted, but ya never know, i'll check all that stuff, later this week. :awesomework: Now, my dad has the same t-case in his '79 ford pickup, he said that he had his looked and and there were shims/washers that the shop or someone had to put in to adjust some tension to get rid of some wobble.....i don't know.... I have never heard of this before and i think the shop didn't know what they were talking about either or were talking about the axle pinion....:eeek:

Fordzuki · Feb 23, 2009

Just curious as to why you didn't replace ALL the bearings while you had the case open? It sure sounds like the ujoints are out of phase. :eeek:

Boonie Buster · Feb 23, 2009

Fordzuki said:
Just curious as to why you didn't replace ALL the bearings while you had the case open? It sure sounds like the ujoints are out of phase. :eeek:

Because i took someone's word that is was entirely rebuilt, and never thought to do it since it was "already rebuilt" whether it was or not, i dont know, the bearings look and felt pretty new, but had i know i was going to go through all this trouble, of course i would have replaced them all...

I only replaced the two that were easily accesable from the outside while it was still in the truck, I never had it apart enough to warrant a full rebuild.:booo:

I will check the phase sometime this week i think, i gotta head home to retrieve a tire anyways...:corn:

It almost had a rythmic humm to it the other day, i just hope it's as easy as an out of phase driveline...:corn:

1982cj7 · Feb 23, 2009

If you have play in the output shaft of the t-case that could cause some vibration. I am not familiar with 205's but if it has tapered roller bearings on the output then there has to be preload on them, that is usually done with shims between the bearings.

Boonie Buster · Feb 23, 2009

Another thing i just thought of...Maybe I am running the driveline too fast... I have 5.13s and 36's, would that be putting the driveline into a bad RPM range maybe? :eeek:

Edit: According to my calculation on my phone, my driveshaft is running at 2875 RPM's .... Is that maybe too high? I just can't see it being worse than the toyota running 5.29s and 35's...:eeek:

Boonie Buster · Feb 23, 2009

1982cj7 said:
If you have play in the output shaft of the t-case that could cause some vibration. I am not familiar with 205's but if it has tapered roller bearings on the output then there has to be preload on them, that is usually done with shims between the bearings.

no tapered bearings, they're caged type bearings, might be different on my dad's truck but i highly doubt it. I am just wondering if the case itself might be bad....

nowires · Feb 23, 2009

Have you had the driveline checked
Is it timed right
if so 180 the slip and see if it makes a differance
Tube could be bent

Boonie Buster · Feb 24, 2009

nowires said:
Have you had the driveline checked
Is it timed right
if so 180 the slip and see if it makes a differance
Tube could be bent

The driveline was built by precision driveline in kirkland maybe 3 months ago, it has maybe 5 MILD runs on it. I don't think i've pulled the slip apart since i got it.... but i wlll def. double check. I am just thinking it's in the t-case...:eeek:

86badboy · Feb 24, 2009

take the rear driveshaft off and run it down the street in fwd. then you will know if its the case. HTH

nevada · Feb 24, 2009

are u sure its in the drivetrain, and not the tires?

USUALLY a DL vibe will come on alot sooner than 50mph.

Boonie Buster · Feb 24, 2009

nevada said:
are u sure its in the drivetrain, and not the tires?

USUALLY a DL vibe will come on alot sooner than 50mph.

ya, i thought so too, like around 35mph-40mph.... The tires are balanced with BB's...

I think if i tried running it with just the front driveshaft it might sound worse! lol, the u-joints up front are kinda loose... but i could always replace them and give it a go.

Grommit327 · Feb 24, 2009

Boonie Buster said:
ya, i thought so too, like around 35mph-40mph.... The tires are balanced with BB's...

I think if i tried running it with just the front driveshaft it might sound worse! lol, the u-joints up front are kinda loose... but i could always replace them and give it a go.

I would check the tires too. I get vibes in my truck too around 30 and then 50 and it comes from the wheels/tires. Running 37 pibulls with airsoft BB's but it doesnt seem to balance them worth ****

nevada · Feb 24, 2009

Boonie Buster said:
ya, i thought so too, like around 35mph-40mph.... The tires are balanced with BB's...

I think if i tried running it with just the front driveshaft it might sound worse! lol, the u-joints up front are kinda loose... but i could always replace them and give it a go.

maybe there's not enough BB's...or maybe too many.
thats not a great way to balance tires....

do u have another set u can throw on, see if the vibe changes?

86badboy · Feb 24, 2009

i ran bbs (12oz in each) in my tires for a while but with every little bump you could hear the bbs crashing around and the death shake would kick in. but on smooth flat surface they worked great.

in my experience i would ditch them. my .02

Boonie Buster · Feb 24, 2009

Ya, it could be the tires, but would it be causing the t-case shifters to shake? I have a more rigid mounting system than stock, but it shouldn't be having difficulties driving down the road.... I am gonna leav the airsofts alone for now, i've been using them for a number of years now even before this remake and ran them at 70mph no prob....

CHOP SHOP · Feb 24, 2009

Boonie Buster said:
Ya, it could be the tires, but would it be causing the t-case shifters to shake? I have a more rigid mounting system than stock, but it shouldn't be having difficulties driving down the road.... I am gonna leav the airsofts alone for now, i've been using them for a number of years now even before this remake and ran them at 70mph no prob....

You coulda built a toyota for what youve spent on drivelines in the past few years.:beatdeadhorse:

CHOP SHOP · Feb 24, 2009

Its a truck and its going to shake.

TRY SOME STOCK TYPE TIRES ON IT. That will tell you if your trying to make irocs drive like a caddy or if you have a real problem.

Boonie Buster · Feb 24, 2009

DUDE! I got all my money back from AZ Drivelines months ago!:awesomework: I didnt' pay a ton for these to be built. I just really think it's an internal thing in the t-case, I just don't know what.

Could it be the input bearing is bad, or the intermediate needle bearings on the shaft are shot?!?! Those are my two guess right now, or that the case itself is bad...:eeek: