tanderson2002us

I had a 5" suspension lift over the summer and since have always had a bit of "wobble" in the driveline when taking off. When, first excelerating, there is a bit of wobble which dissapears pretty quick.......it is most noticable under a heavy foot. The shop who did the lift told me that there is a bearing or seal that has to be modified to eliminate this........has anyone had a similar problem? Is this due to the angle of the drive shaft now?

Thanks,
Tom

Hottrodjim

Tom,

Check to see if the lift company put any shims under the driveshaft support block. If there are not then that is most likely your problem. You can either make or purchase the shims if you need to. I can't recall the formula for the shims. I think it was 1/4" shim for every inch of rear lift. I will see if i can find the formula tonight.

KATOOM

First think I would do is call the company that made the lift kit. They should know everything about your lift and what your truck should have. If there is something missing or something is not done right then go back to the shop and make them fix it. Just because a "shop" did the job doesnt mean it was done right. If I ever have to leave my stuff in the hands of others (only if I havent the right tools) I will be looking over their sholders to make sure things go right.

DF5152

what do u mean by wobble? does the truck move left to right and u accelerate and goes away only because the frequency gets so fast u cant feel it. Is it a vibration in the seat of ur pants????

Hottrodjim

Tom,

The 1/4" shim per inch of lift is correct. If the shop that did the lift won't make it right then you can add the shims yourself. This is a very common problem when our trucks are lifted. The above spec is just a starting point. You may have to add or subtract shims until you get it correct.

phox_mulder

Front or rear driveshaft?

When I got my lift done, they put an angled spacer under the rear blocks, turning the differential up a wee bit, kinda pointing the pinion at the end of the transmission, so no wobble or vibration there.
(short bed, no carrier bearing)

Front driveshaft on the other hand.

Angling the differential isn't an option, as it would throw out the alignment (also create wierd torque action on the springs).
Some kits come with a transfer case reindexing ring, which as I understand it, turns the transfer case a bit so it is facing down more, instead of right alongside the transmission.
The Skyjacker 4.5" kit doesn't include this, but the 7" does.
I guess 4.5 isn't enough to create a problem.(on most trucks)
I gained 5 inches though, and have a nice vibration in my front DS. (I removed it for a week to confirm).
Day to day driving only sees a vibe at highway speed, over 50mph-ish.
Offroad results in binding while turning with 4x4 engaged.

Options are:
Grinding the CV joint where it binds (hopefully keeping everying balanced) ($$)
New high angle driveshaft. ($$$)
Lowering the angle by adding some weight to the front end.
(Hoping this works, planning on a Warn 12K winch being just enough to fix the problem).($$$$$)
Converting the front axle to lockable hubs (for the highway vibe anyway) ($$$$$) and wouldn't do a thing for the offroad binding.

Living with it for now till I have fundage to start with option 1 or get my winch.


phox

tanderson2002us

Thanks for the replies......think I will do "all of the above:.....call the manufacturer, look into the shim and go by Les Schwab who installed the lift and wheels/tires....I noticed a nice chunk of tread missing from a rear tire, looks like the siping weakened it and maybe some rock tore it off...."new tire please".

cmckinney

I noticed that you have a 02' truck. I had the same issue with the front driveshaft when going over 70 mph. It was a nice shake so I took of my D25 Skyjacker coils and it all went away. It is the angle of the front drive shaft that is causing your vibrations. Sounds like you need to drop your Xfer-case and Transmission to solve the problem you described.

-CM

KATOOM

Sorry I didnt say this earlier but I didnt notice that you had a '02. I think there is a thread on this already but, DC went and changed the front end in '02. Why? Dont know, but they pushed the front axle forward and tilted the housing downward. Causing the vibration that guys are talking about on the '02's aroung 65+ mph. There is a fix but I dont know how involved it is. I would assume you would need to rotate the pumpkin upward for starters but that will change the caster. Sorry that I cant remember where I read all this stuff either. Now this pertains only to your truck if you dont have the front axle disconnect. If you do then your front drive shaft isnt spinning all the time, so no vibration from there.

LE

I had the same issue which seems to be prevalent on the 2002s. This is due to the lack of front end disconnect that used to sit on top of the axle tube pre 2002. My front driveline was "toast" after 15,000 miles because of the lift. My understanding is that the stock non lifted trucks will eventually have the same problem, but the lift just accelerates the problem. There are a couple of fixes to this problem. The fix I recommend is call LS and have them call Tuff Country and ask for the modified trailing arms. They are 1/4" longer and will replace the current upper arms you have now. This will cause the pinion to rotate toward the t-case and correct the vibration. If the problem has been present for an extended period of time or miles (5K), I recommend you get your front driveline repaired. When the shop does your driveline, have them make your upper joint "bulletproof". This will cost around $180.00 and will last forever. If you do not have a TC lift, call whoever made it and ask them for the same fix. If you need help with the parts, let me know and I will see what I can do. Good luck................................LE

Cowhand

I had this same problem on my '96. The vibration comes from a bind in the forward universal. There are two "nubs" on top of the driveline yokes (on top of the U joints) that bind on the inside radius of the other section. Get under the truck, rotate the driveline by hand, and watch the U joint. You'll see what I mean. Drop the driveline, break apart the U-joint, and grind off the nubs. Put it back together and run it, if the vibration is gone, it's all good. If not, check to see that it's not binding, and if not, send it to a shop to get it balanced. Cheap.

Be wary of the extended upper arms. This changes the front axle caster, and can lead to all sorts of nasty problems like accelerated tire wear or the dreaded "Death Wobble".