Hey guys, I drove my truck on the road for the first time today after the sas and motor swap. What would make the whole truck start shakin and vibratin real bad when i get to 40mph? I'm thinkin it might be my rear driveshaft, cuz i legthened it myself with a torch and my welder. anybody got any different ideas??

 

1. Is it a vibration or is it a wobble?

2. Does it feel different if you let off the gas?

3. Does the steering wheel move a good bit with the movement.

 

well since you did the rear driveshaft yourself, id start there.

 

whole truck starts shakin and wobblin, even if you let off the gas it wont quit until the truck slows down and yes steerin wheel shakes with the truck. im gonna go to junkyard this weekend and get a new driveshaft.(along with tailgate and bumper lol)

 

Its your caster angle.

Set your caster @ 6-8* and set your tow @ 1/16" - 1/8" toe in.

 

Yep, that sounds like "death wobble". Caster angle is most important:
- http://www.4crawler.com/4x4/ForSale/Shims.shtml#FAQ1

 

My toy had a similar problem and I put it up on jacks making sure all 4 wheels were off the ground. I took the wheels off just in case, so that if the jacks would fail then the 4runner wouldn't run into the house LOL! I then had a friend hop in and put it in gear to see what was vibrating or wobbling. Mine was the rear driveshaft u-joint. Replaced it and problem solved. Good luck and hope you find and fix the problem.
DJ

 

thanks guys, im gonna try goose's plan first. then if not that ill take it to the shop and get the front end aligned lol

 

Front end allignment wont help. They can only adjust toe, while that could be your problem, it probably isnt. They cant adjust your caster. Save your self the mortification (its probably a word) of walking into a shop. And just set your toe to 1/16 to 1/8" toe in. you can do it in 5 minutes in a parking lot with a tape measure and a wrench. Then measure your caster with a protractor. Factory it about 1* but that doesnt work for us we need 6-8*. To get that you will need to cut & turn or shim or run less drop on the hanger and more shackle...

 

ok, i wrote those instructions down. this weekend im puttin on my new Holley 600cfm, headers and flow 40's =) im so excited.

 

My instructions sucked....

 

what you mean your instructions sucked?

 

Make sure you measure distance between the front edges of the front rims and measure the distance between the rear edges of the front rims. The difference is your toe.

There I feel better

 

lol that actually helps ALOT thanks 4rnr, you've been a big help to a newb like me

 

I fought with this problem for a few months with my truck. Adjusted caster, replaced tie rod ends, adjusted alignment from 0 to 1/8" to 1/4" in and back and still had it. Ended up being loose shackle blots.

No problems since....knock on wood

 

Forget it, im not gonna fight with it. I'm just gonna go get some fullsize axles and go from there. No sense in doin it later when i can do it now. i'll send my longfeilds back, and sell my yota axles. Rather than fullsize it later, im just gonna redo it all now. A buddy of mine has some old fullsize chevys, ill pull them axles, leaf springs(one of mine is crushed now), and steering.

 

 

I'll be doin some serious boggin and i dont think my yota axles are gonna hang. Not to mention I have to redo the steerin reguardless. I pretty much talked myself into the fullsize thing. ill get some pics of my front end and show you what im talkin bout 4rnr. Plus I love the way fullsize looks under a yota