Rough Ride

[kselvi]

I have a 75 Blazer with a 4 inch body lift. The truck drives rough, especially at higher speeds. Also, steering is a "little" shaky. I plan to take it to a 4wheel drive/off road shop and have them look at it. My initial thoughts is new shocks and alignment check. Any other thoughts?

[1976K5CHALET]

Actually yes there are a couple things you can check if you have some tools and a floor jack. If the vib is usualy at a certain speed that you can power out of i would check the tires and have them balanced. Have the weights installed on the inside AND outside of the wheels as the taped weights never like to stay put. Sometimes a whell might be bent...sometimes the tires aren't balanced right. And one out of balance tire be it a weight or a cord issue can make bad vibs. Balancing tires is cheap and a good place to start. Plus i'm still old school and recommend rotating your tires and re balancing during the rotation process twice a year...more if you put more miles on her.

Next problem. I'm not a fan of bodylifts at all...but a 1 inch puck to clear say a park brake disc or a doubler transfer case set-up is ok with me. Body lifts seem to cause their own brand of grieve eventually but i can't see it causing a vibration. The next thing to check is your rear driveline angle. You did not mention whether the K5 has a suspension lift also...but when doing so the angles are changed. A single u-joint is designed to run within a 3 degree window...a double carden (two u-joints like your front shaft) are designed to run at 6 degree's. The joint will be happiest right in the middle of the 3 degree's. If not within the range they actually slightly bind due to the running angle and act like a washing machine that is poorly or overloaded. If you have a harbor freight tools near by you can buy an inexpensive angle indicator. I have the electronic version but you don't need to go that fancy to fix the issue. Measure the angle of the tcase yoke itself on a somewhat flat area to get a base of where the tcase is...then measure the driveline angle just after the u-joint and subtract the two to see where you are at. Then do the same with the rear end yoke and driveline. There are other ways to do it and somewhere i have a disc from rockwell where you just plug in the numbers and it calculates it for you as semi's have a few more shafts and angles to deal with. There are a couple ways to dail in the proper angle...and the rear diff i add a new spring pack center bolt and a 1-6 degree shim. At the tcase i allways use the spacers that are in the frame rail that the tcase xmember bolts go thru and put them between the frame and the xmember to drop the tcase just a bit. Usually these two methods will get things back in shape and cure the issue. Something else to do while you are playing with the dline is to chock the wheels and remove the rear shaft and remove a couple u-joint trunion caps and check the condition of the trunions. Most of the time i see one of two issues...brinneling from excessive angle...or lack of lube...in either case you will have to replace the joints....and being anal once again i use genuine spicer joints...period. While the shaft is out one thing to look for that gets overlooked is the yokes themselves. The yokes will have a small tit on either side of the area the joint rides in...if they are worn it allows the joint to move sideways...not good. If this is the case replace the yoke...no amount of peening or other half a-- method is going to permantly fix the issue.

If you want i'll post a small article on how to check your front end and adjust the gear box etc.

DW