mjwalfredo

Hi,
I am still trying to figure out my vibration problems. I talked with someone who is very knowledgable about rear ends and he said that with the rear driveshaft off, I should not be able to feel any vibration coming from the differential. Must be somewhere else in my driveline.

I originally thought it could not be the front driveshaft because it does not turn when in 2wd. But, the other day I was reading on this board that it does turn some when in 2wd. I cannot find the post that I read that in though. Can someone confirm if the front drive shaft spins at all when in 2wd on an ADD setup? Thanks.

mt_goat

I doubt it and if it does at all it's probably not spinning fast enough to cause a vibration. Isn't that the whole propose of ADD, assuming it is working right? Tape a piece of string to the drive shaft and go for a drive. If the string is wrapped around it then yes it was spinning.

wjwerdna

i was wondering the same, great idea

Glenn

While there shouldn't be a physical connection between the driveshaft and the axles, there can be a viscous connection similar to an automatic transmission's torque converter. The lubricating oil (if thick and cold enough) can cause the driveshaft to turn slowly, but not usually anywhere near the speed it would normally be travel were it in 4wd. And it should stop turning once the lubricating oil is warmed up and flowing in the differential more.

02SE

I think the string would become wrapped around the driveshaft, from air turbulence alone, even if the driveshaft wasn't spinning.

mjwalfredo

But even the transfer case should not turn the driveshaft, especially when the fluid warms up? I am getting ready to give up on this vibration and get rid of the truck if I can't solve it soon.

JHupp

the front drive should definately not spin with ADD. ADD only relases the driver side axle fron the center diff, and back on again, check out this F A Q, if the front drive shafting was spiining, and the ADD was not engaged, you would power to your passenger wheel up front. )unless it is spinning due to natural causes, and very slowly, as suggested above). In short, your drive shaft out of the centerdiff/transfer case should NOT spin under the engine's power while in 2wd with ADD.

Gerdo

Are you sure that the vibration isn't form unballanced tires? Toyota aluminum wheels are a pain to get the ballance just right.

JHupp

A common problem I have found also, I think Alberqueque Jim had also was that the UJoints needed to be lubed on the drive shafts. There is an awesome writeup on here, and I ran into the same problem, had 3 alignments done, and the wheels balanced several times. There can be many issues, but that is one that sems like it is common, worked for me! One thing I noticed too was that when putting the truck into gear(on an auto) the end would make like a stress noise(not sure how to explain it) like a wind blowing against a house, like a creaking sort of, and that was synomous with the u-joints needing to be lubed.

mjwalfredo

I am going crazy. I have taken off both the front and drive shafts and changed out my CV axles and the howling is still there. The shop I bought my tires from used the Hunter GSP 9700 machine to balance my tires. They may have done a bad job though because I noticed when I got my truck back, the tires were aired to 50 psi cold!! If that says anything about there workmanship I need to tell them to double check their work and then possibly go to the dealer as a last resort. Question, if a Hunter 9700 is used, do I need to make sure the technitian also uses the Haweka adapter or is it an either or thing with the adapter and 9700? Thanks a bunch guys!

hupptoy

The Haweka adapter is reguired to balance our lug-centric wheels. The Hunter 9700 is an added bonus, but not absolutely necesary.

I have no tire shops by me that have the Hunter or the Haweka. After 3 shops tried to balance my tires, finally had to go to the dealer (30 miles away)...

hupptoy

vegaskurt

Correct me if I am wrong, but isnt the t-case on the limited a full time 4wd even when you are in 2wd? I think this is one of the reasons why sonoran steel wont do SAS swaps on limiteds.

mjwalfredo

I just spoke to a tech that seemed very knowledgable at a different location of the place I got mine balanced. He said the place I went to originally has a Hunter machine but it is about 6-7 yrs old and it was not a roadforce balancer. I am going to try with the roadforce tomorrow. He also said that the Haweka adapter is not necessary with the roadforce balance. We'll see what happens.


Vegas, my Limited Runner is not full time 4wd. Are you refering to the newer 3rd Gens that have the Center differential?

4RUNN!N

I think he's referring to the 99-00 Limited and 01-02 4WD 4Runners which have a selectable full-time 4WD

JHupp

probably could use another thread on this discussion, but taken from the yer to year changes found on other sites,
"2001 Toyota 4Runner: 4Runner lost its base 4-cylinder models and manual transmission for 2001, but all models now had full-time 4-wheel-drive and an antiskid/traction-control system. All models also got a revised grille and taillamps, and the Limited added standard heated front seats, Homelink remote door opener, and an optional in-dash CD changer."
I still don't completely understand this full time 4wd system. I do not know what the point is of pushing the 4wd button on my shifter to put it into part time 4wd if that is what this system allready is doing normally. I have never got a good answer on this.

vegaskurt

My bad, got my years messed up. The limited 97's front drive shaft does not move when you are in 2wd. Just had my co-worker back it out/pull it into a spot while I crawled next to it and watched.

brick privy

did you buy the truck new? maybe a LSD was installed in the front. this would make the drive shaft turn all the time.

BajaRunner

Just to let you know, the front driveshaft does NOT turn in 2wd even with ADD.

I know this because for a few days I had the front driveshaft laying against the crossmember before I could cut it for clearance after my drop bracket lift install.

mjwalfredo

THanks SCd, I now realize this after dropping it did not fix vibration

02SE

What that quote from another site should say, is that 4X4 '01-'02 4Runners have full-time 4WD capability, with vehicle stability control, and traction control.

Just driving along, you are in 2WD, when you push the button on the tansfer case shifter, this shifts the truck into full-time 4WD, which can be used anywhere, anytime.

If you then also push the center difflock button on the dash, this connects the front and rear driveshfts together with no differentiation. This is what's known as part-time 4WD. You only want to use this mode on slippery surfaces, otherwise you can get binding in the driveline, which can break parts.