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Lynx
02-03-2008, 10:34 AM
Hey I got a cherokee with 350/th350 combo. I get vibrations all the time while accelerating. Not too bad, but worst accelerating at around 50 km/h. Cruising no vibes and varies with throttle.

Apparently their were no vibes when the previous owner had it, it's been sitting for awhile. It has some type of high angle drive shaft, and is set up weird. Has a tcase slip yoke but it set up like. (it has no double cardan)
http://www.4x4wire.com/toyota/tech/driveline/05.gif

Other question, might be a related problem. Does anybody know what the end of the dipstick is supposed to look like? Mine has piece broken off the end somehow. Looks a straighbar with a 1/16th notch cut back a 1/4 inch. Isn't it sapposed to be a hoop at the bottom? No fluid touching the stipstick but im scared dump anymore fluid in.

dirka dave
02-03-2008, 10:49 AM
Zero degrees on a u-joint is the worse angle possible. The u-joint is designed to run at a minimal 1 degree angle otherwise the roller bearings in the cups will not rotate hence no lube. A vibration around that speeed could be a tire balance problem or a drive shaft out of round. Hope this helps.:)

Lynx
02-03-2008, 01:11 PM
I dont see how a vibe problem related to power could be a balance issue.

ManDown
02-03-2008, 01:20 PM
zero degrees is NOT optimal unless the side at the T-case is 0 zero. the ujoints being like that will cause everything to speed up and slow down as it goes around its really hard on the whole driveline

Lynx
02-03-2008, 06:28 PM
Yea I realize 0 degrees isnt the greatest but I'm just trying to figure out this vibration problem right now.

and I really wanna try getting the right amount of transmission fluid in the tranny without draining it all or overfilling it.

Lynx
02-06-2008, 05:52 AM
So I got a new dipstick and tube in.

Figured I probably need a SYE for the np241 ($350) and a CV shaft modified from my current 1 piece ($500-$600).

Fuck, looks like I wont be driving it for awhile. Think it would make much difference if I lowered the transfercase an inch?

Leithmc
02-06-2008, 08:05 AM
Lowering the T-case in an XJ is a bit of a bitch if you're using the original mounting location for the cross member. The have studs sticking out of the frame so if you want to try it just as a test, I'd suggest you rig up some kind of long nut or something like that to put between the frame and cross member. Thread it onto the stud and thread another bolt into it to hold the cross member in place. That way if it doesn't help, it'll only take a minute to switch it back and keep your clearance.


Leith

arjan
02-06-2008, 09:49 AM
Could axle wrap be the issue?
When you hit the throttle the axle tilts backwards a bit, changing the angle on the u joint slightly.
A bad u joint might get more noticeable because of that.

Kinslayer
02-06-2008, 10:30 AM
you get vibes BECAUSE your pinion is zero. The angle at the case is supposed to be exactly opposite of the angle at the pinion, IE 2 degrees down, two degrees up. It has to make a perfect z shape (stretched out). The vibration created on the pinion is then exactly opposite and equal to the vibration caused at the t-case, and thus cancel each other out. Think of how a sub box would perform if the subs are hooked up backwards - one would pump up while the other pumps down creating NO bass.

The other way of doing it is to create a reverse z (S?), the pinion points way up and the tcase points down..but you don't see that too often as that would require a LOT of lift..

Kinslayer
02-06-2008, 10:40 AM
73349

arjan
02-06-2008, 01:12 PM
That's only true if you have 2 u joints Kinslayer. Above pictures show a double cardan, it doesn't have the wobble a u joint has.
Then your rear u joint should be near straight, else you'll get a wobble again.
My 4Runner had the double cardan setup from the factory.
The torsion bar ifs systems from Toyota have them on the front driveshafts.

Kinslayer
02-06-2008, 05:48 PM
That's only true if you have 2 u joints Kinslayer. Above pictures show a double cardan, it doesn't have the wobble a u joint has.
Then your rear u joint should be near straight, else you'll get a wobble again.
My 4Runner had the double cardan setup from the factory.
The torsion bar ifs systems from Toyota have them on the front driveshafts.



So to Chevy's and Jeeps. With the double cardon you effectively have TWO ujoints at the one end..which means you have to have double the tcase angle than the pinion angle. IE, if you have a DC joint as in pic you'd want to have 2 degrees at the pinion and four at the DC..the purpose of a DC is to be able to run a flatter pinion on a shorter driveshaft with acceptable angles.

The reason you don't want a zero degree pinion angle is simple: what is double zero? that's right, zero. Which means you have to have a zero degree t-case angle to 'cancel' any vibes, but unfortunately that theory just doesn't work with a zero degree angle, you just end up cancelling nothing and having all the vibes anyway..as well as the lack of lubrication issues stated above