Ol' Green

Just lifted my 98 cherokee 3.5" inches and now I'm getting some drive line vibes. I'm aware its because the drive line is at a more slanted angle, but how would I go about fixing this? I'm a student in high school with not a whole lot of money, so some cheap solutions would be appreciated. Maybe a t case drop kit?

hippydippy

I know a slip yoke eliminator is the best solution and you can get one for like 150$ the rugged ridge on Amazon is the cheapest. I have 3 inch also and have vibes only at 55 like if I go faster it goes away. I'm also curious if the she would fix that

hankthetank

Or in the mean time, measure your pinion angles and adjust as needed.

CanXJ

Prior to installing a SYE I installed a TC drop and shimmed rear axle. Wasn't perfect but helped.

Demonoid369

Both adjusting(like tank said) and t-case drop/sye can help. Use a t-case drop as only a temp fix till you can either do a hack-n-tap or buy an actual sye. And you don't even need to buy a t-case drop if you have some tools and skill. Just get some 1" square tubing and longer bolts. Or even just longer bolts and a few nuts to space it out(tubing is preferred)

Ol' Green

I like the home-made tc drop idea better than spending money on something i can do myself.

CanXJ

Ol Green, PM your address I will send you the TC drop that I took out of my XJ, no charge and I will pay the postage.

freegdr

Did ya get front alignment yet hhere a good start if not....http://go.jeep-xj.info/HowtoAlignment.htm

Ol' Green

Got an alignment earlier today actually

RubberSideUp

Call local driveline shops and ask them if they will perform a free diagnosis of your driveline vibrations. Some shops will do it free and may even fix the problem for free. Depends on the shop and how good of mood they are in or how simple the fix is. LOL

Some possibilities if you can't or don't want to take it to a shop for free diagnosis.

In no particular order. There really are so many possibilities but here are some things that can help. Begin by checking tire balance. Cheap way to address this is to use balancing beads (airsoft pellets, etc) and also check tires for uneven wear and rotate if necessary. Check your transmission and motor mounts for wear (can cause u-joint vibes).

Pull the front driveshaft and drive it and see if the vibes are gone. If so, the front driveshaft or t-case is the problem. If not, pull the rear and put the vehicle in 4WD and drive it and see if the vibes are gone. This way you can single out which driveshaft or part of the transfer case is the culprit.

Check u-joints. First grab the shaft and try to wiggle it and spin it by hand. It should have no slop. Be sure you chock the wheels and have the trans in Park with motor off. To truly inspect u-joints it requires removal. (hammer them out and make sure they are lubricated and not missing any needle bearings, also make sure the seals on them are in good shape. If not, replace them for cheap). Here's a video on how to replace them:


Measure your pinion angle and output shaft angles. Use a magnetic angle finder ($10 or less at DIY Home Improvement Stores). Here's a few videos of how to do that and they also explain how vibes occur and how to adjust driveline angles:

Pinion angle measurement and adjustment basics:

Driveline vibration basics:

In-depth way to measure and calculate driveline angles:

4) Transfer case vibrations. Here's an overview of the NP231 teardown and rebuild process (pretty much step by step):

(Part 1-6 of teardown and rebuild of NP231)

Using these NP231 rebuild videos, you can get an idea of what can cause vibrations in the case and how to fix them. Most common problem is transfer case chain stetched, shift fork pads worn or damaged, broken teeth, shift linkage not properly adjusted, etc.

Assuming your pinion and output shaft angles are correct and u-joints are in good shape and your front shaft is not the culprit: Driveshaft re-balancing and rebuilding slip joint. Some times the driveshaft wears out or gets dented or throws weights. This requires taking it to a driveline shop and having them rebalance the shaft and possibly rebuild the slip joint if it's worn out or wallowed out. This is usually the last thing I recommend doing since most people can't do it themselves.

Last but not least...Assuming your pinion or output shaft angles are incorrect: Shimming axle and possibly shimming transfer case (crossmember bolts with washers or transfer case drop). This requires using the measurements you made earlier from the pinion angle and transfer case output shaft to purchase or make degree shims, new centering pins, and new u-bolts (never reuse centering pins or u-bolts IMHO). You may need to flip the shims around depending on which direction the pinion is rotated (up or down). With the factory driveshaft, you need to get the output shaft and pinion angles parallel. With a SYE you need the pinion to point at the output shaft or 1-2 degrees below pointing directly at the output shaft on the transfer case.

Some ideas and things you can try. I hate to say just throw a SYE and new shaft at it for 3.5" lift. As this doesn't always solve the problem and can actually make the problems worse if people don't understand why driveline vibrations can occur. This should give you an education on driveline vibrations and make you a better Jeep owner. You never know, you may become a driveline shop owner one day.

Ol' Green

thanks for taking the time to write this up! I'll deffinately check out the videos.