new vibration

olejunky

olejunky

Well-Known Member
Joined
Oct 11, 2006
Location
knoxville
we just put a front ford dana 60 in the rear of a jeep did not cut the tubes or anything. Ever since installation we have gotten a really bad vibration, would the driveshaft being set at an angle cause this to happen it doesnt't hit anything or bind up just driving down the road it will about rattle your teeth out. Other then that everything works great. possibly considering building a driveshaft with a pillow block or carrier bearing to help with misalignment. Just wanted to hear from some other people with rear steer
 
the driveshaft is round we put it together ourselves like every other one we have ran. length would probably be close to 3.5 to 4 feet. the wheelbase is about 115 not sure about the angle because we didn't recenter the dana 60 it is probably 12 inches out of center
 
Are you using CV or regular 2 joint driveshaft? I am thinking a regular 2 joint would be better with the offset. I don't think CV shafts like running at side angles much. Hell, it doesnt matter an angle is an angle to a ujoint, sideways or vertical so if its a CV shaft thats bad.
 
Bent spindle? When was the last time this Ford 60 rolled? Condition?

I would tend to agree that it's more than likely driveline related. A 36-44" driveshaft isn't terribly long, and if it's got a fair amount of lift, THEN the 6-7" offset, I'd bet that's all of your vibes. You could pull the rear driveshaft and drive it in FWD to confirm.

I would tend to disagree with jdubb though...I think a double cardan CV at the t-case would help and/or eliminate vibes here (if you can make the angles).

Where's your pinion pointed back there? If you are running a CV, you want to aim the pinion right at the back of the t-case. If not, then the pinion is supposed to be parrallel to the t-case output (almost horizontal).
 
jdubb said:
much. Hell, it doesnt matter an angle is an angle to a ujoint,
Click to expand...

true... but not to your yokes! the Ujoint can twist to accommodate to the angle, but the yoke can't.

Hold a pencil between the ends of your thumbs to simulate driveshaft and yokes. and think about how your yokes are going to sit in relation.

Check teh ends of your yokes and driveshaft. Any shiney spots where they been hitting when rotating?

12" offset is quite a bit, especially with lift considered too.
 
novacayne75 said:
2 much offset (compound vibration )the only way to stop it will be cv on both ends
Click to expand...

CrashKnott said:
.I think a double cardan CV at the t-case would help and/or eliminate vibes here (if you can make the angles)..
Click to expand...

Geez..

Repeat after me..

A Double Cardan (CV) will ONLY stop vibrations if your pinion is pointed directly at the t-case output. Otherwise, you need a standard 2-joint shaft, and the pinion shaft and t-case output shaft need to be parallel if you want no vibes.

Not to mention, balancing said driveline can't hurt.
 
I've seen others run with offset rear axles and centered transfercase outputs with success, even in a CJ7 with some lift (enough for 38" tires).

However, if your driveshaft is 4' long with a 12" offset, thats already a 14* angle for your joints, without taking into account a lift. At 3.5' long, thats 16* of angle...

maybe a little too much angle
 
Rich said:
Geez..

Repeat after me..

A Double Cardan (CV) will ONLY stop vibrations if your pinion is pointed directly at the t-case output. Otherwise, you need a standard 2-joint shaft, and the pinion shaft and t-case output shaft need to be parallel if you want no vibes.

Not to mention, balancing said driveline can't hurt.
Click to expand...

Whew...I was reading down through those posts hoping someone would save it...
 
olejunky said:
we just put a front ford dana 60 in the rear of a jeep
Click to expand...

Just wanted to make sure that everyone caught that this is a Rear Steer application...

Whats your caster angle? What are you doing for steering? New parts?

Things to think about along with your d-shaft.
 
wow this thread exploded. the pinion is pointed up at the transfer case yoke, not making for a great caster but as mentioned it is on the rear so we weren't concerned to much about that. It is 4 linked with air shox. Maybe we should try a double cardan setup for the rear shaft that would help with the angles. I didn't think about the compound angles giving us the problem because i have seen regular shafts run straight with much more drop then this has. I will definitely pull the rear shaft and drive it and see if there is a difference before i start cutting just to make sure that is our problem and not something else. Oh and steering is the same set up as in the front we just used a Tractor supply ram and a pto valve instead of an orbital valve to set it up and make sure it works, no problems steers great but when driving straight down the road is when you get the vibes so steering wasn't really something that i thought could give us the problem thanks
 
I would try running it in 4hi and take out the rear ds like you said. That will tell you if it is the DS or something else. Sounds a lot like the problems the cherokees have from 97 on.
 
Hey Ben(ole junky).!!!if rear shaft out dosent help, make sure you havent totally fried the upper pinion bearing from lack of oil by running pinion, ring, and slinger in reverse, coupled with being tilited up. unless youve modified the oiling setup. its high pinion anyway, plus tilted up, sure hope its somthing easier and less$$. is uppper pinion bearing below oil level?
as far as steering goes, im with you on not thinking thats stanleys issue. This is on stanleys rig, right? with the factory recomendations of 5-9 dedrees of positive caster would actually be 5-9 negative on his rig with the axle in the rear- not good. but by tilting the pinion up, hes improved it, may be even 0 degrees or even negative caster( which in his setup would be actully positive caster-good). btw, shoot me some pics of your rig in each stage from full truck to truggy to buggy, as im making a slideshow on each guy in our group and the progression of his rig. thanx
 
actually

CrashKnott said:
Bent spindle? When was the last time this Ford 60 rolled? Condition?

I would tend to agree that it's more than likely driveline related. A 36-44" driveshaft isn't terribly long, and if it's got a fair amount of lift, THEN the 6-7" offset, I'd bet that's all of your vibes. You could pull the rear driveshaft and drive it in FWD to confirm.

I would tend to disagree with jdubb though...I think a double cardan CV at the t-case would help and/or eliminate vibes here (if you can make the angles).

Where's your pinion pointed back there? If you are running a CV, you want to aim the pinion right at the back of the t-case. If not, then the pinion is supposed to be parrallel to the t-case output (almost horizontal).
Click to expand...
Actually I thought a REGULAR non-CV would be better with the offset. Putting a CV at the tcase with that offset would be bad and the side angle would vibrate as bad as or worse than an out-of-whack vertical angle. Now you should be able to tell if its pinion speed vibration or wheel speed vibration. If you stick with this couldnt you put seals in the diff end and overfill to help the pinion bearings. This is assuming everything in the diff were good to start with.
 
Angles play a big part in your d-shaft vibrating, you need a 1 to 4 degree variance between the angle from your pinion to the transfer case.....at least 1 degree but no more than 4 degrees.

When you cut your d-shaft & shortened..lengthed whatever, did you make sure it was straight before you welded it. And if so how did you do that.....eyeball it, lathe, what??

When I balance a shaft, somtimes it takes a weight the size of a quarter to get it in balance, or throw it
off-balance, granted that shaft might be running 3000 rpm at 75mph.
Just saying that d-shafts are critical!
 
i have never balanced a shaft just eyeball it and go, this thing vibrates like this at 15mph. unless i have just gotten lucky all these times i can't imagine that the shaft is that far out of wack. It must be the angle of the shaft with drop and angle it just can't work properly still working on it if i get any new info i'll let you know
 
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