Outer Limits 4x4 Board

just got back from a quick 4wd. and have notied the car is vibration realy bad only in 2nd gear on the way home and only when accelerating. ive cheaked tcase mounts, unis. what eles could it be?

it has alway vibrated in 2nd but never this bad. acceleration was flat to the floor but it still does even at half throttle. downshifting at a normal speed does it too. both gear knobs vibrate like mad!

mabye ist in your gear box

Engine / gearbox / t-case mount?

i will have to cheak all mounts tomrow.
driving the car again i noticed it will do it in 3rd too but at low speed. the speedo jumps around at about 20kmh on the clock (run 32s) but what seems stange to me is it only when accelerating and downshifting

have you also checked your rear pinion / centre
I would be suspect on it being a part of your driveline that is wearing out, it will get worse and you will find it, but the longer you leave it the more damage that can happen to other things that are close to it, like seals and unis that were fine until they kept getting the stuffing shaken out of them.

have you also checked the rear output on you transfer, it doesn't take much to cause a vibe, it you have the time and patients I would take the rear shaft out and check rear diff and transfer output, clean you rear shaft up and have a good look and play with the unis and check they are nice and firm

then pull the shaft out between the gearbox and transfer.

while thay are out, just rebuild them anyway, sounds like you have lift due to the 32's. have you ever replaced them before?
this maybe why they have died, if they did 10 years at stock height they would have worn in to that and then you lift it and they are made to work on a greater angle then ever before and they can become shagged pretty quick.


other wise do you know a good mechanic that will take the time to look at it?

hope that helps
ashley

im putting in a lockright locker in tomrow. i doing it at my uncles (hes a machanic) and hes going to have a look because i get alot of backlash as well. ill tell him about the vibrations.

thanks

pinion bearing! mine did the same kinda thing... dont be scared to tighten the nut on the input flange of the diff... the crush washers take a bit somtimes!

Adam

thanks. i was driving again today. noticed only the tcase knob vibrated realy bad. and again only in 2nd gear 20kmh on the clock not acual speed.

also when acceleration hard in 1st vibrated bad but also herd a banging noice like the same noice that happned when i broke the tcase rubber mounts

though i would put it in here.

anyway at the same time off the vibrations ive noticed when i take off hard in 1st and sometimes 2nded building revs then droping it it makes a big crunch/bang like its broken a tcase mount.you can feel it in the floor of the car when you do it. like a knock. problem is tcase and gearbox mounts are fine.
i am SPOA. i am starting to think axel wrap now because you can feel the car shudder back and forwards like the springs is loading then pushing back loading pushing back ect.it make the noise when the spring is loading

why haven't you fixed it?

I was looking at this post expecting to find the answer to your mistery!

hurry up!

ashley

hopfully fixing it tomrow

ok got my locker in. feels alot different wants to pull to the right when accelerating andd pulls left when you let off. and wants to do burnouts everywhere haha

anyway the vibrations have goten alot worse and likes to do it in 3rd alot more. my uncle (machanic) helped me put my locker in and said that it might be the shaft from the gearbox to the transfer seized up and that it could be causeing it.
i tryed an experiment and drove, got it to vibrate the most then i took off the throttle and the vibrations cut down.

also my tacse shifter is hitting the driveshaft making an annoying sound. it pops out of it seat when vibrating and hits the drive shaft. also the shiter feels like its only being held in by the rubber boot where the shifter shafts goes into the tcase. so my guess the guy befor me has taken the seat out? the tacse has got 2wd lowrange. NO twin sticks

my guess is that you are going to wait until it shits its self and then replace alot more parts all at once. due to the fact that you know its getting worse but keep guessing what is wrong with it!
start fixing before you spend ages chasing vibes, as one vibe will shake the crap out of other parts and they will cause vibes!
ive been there and left that, until it destroyed that!

ashley

but i dont know what it is. going to take the jack shaft out see that

jack shaft is fine. but i spun the front drive shaft as quick as i can you it makes a knock knock knock sound. its not a constand noise it goes with the shaft

The front driveshaft will only cause vibration when the car is in 4WD (hubs locked or unlocked) or in 2WD with the hubs are locked, otherwise the front driveshaft won't be spinning.

My dodgy front driveshaft vibrates badly in 4H at speed or with the hubs locked, but I have no problem in 2WD on the road.

Steve.

have you taken your rear drive shaft off the transfer and checked that the rear output of your transfer is nice and tight, ie not wriggling around, it may be flogged out. I've had this happen, it was from running a drive shaft that wasn't ballanced, the shaft stayed together but being off ballance it flogged the bearing that the rear output run on.
the same thing can happen if you drive on a flogged out drive shaft for too long!

you also haven't said that you have checked your unis yet. ans you are spoa aren't you?

I know its a bit of a pain but take the time to take your shafts out, you can't just put your hand on your shaft and give it a wiggle and expect a result.
it doesn't take much to cause a vibe, it does sound like it is coming from around you transfer as it is shacking all over the place.

when my rear output was flogged I had the same problem the transfer lever shook all over the place when accelerating and it would hit the floor sometimes.
it may not be you rear output as the front and input can cause the same.
I haven't had a drama with an input, but I did have a front output get so bad that I couldn't use 4 low because the front wheels would not spin when under load ie trying to drive up over rocks and ledges as the gear were not meshing properly and it would slip, making a bloody awfull noise. this was because I had a front shaft that was like a banana for a very long time and thought it would be ok. now I would get proper shafts made and balanced, but you live and learn.

hope that helps
ashley

My money is on axle wrap. I had the same thing in my SWB especially up hills in second, say after a corner or from the lights i.e when the drive line is most loaded and has most torque.

i dont think it is axel wrap because it does it with slight acceleration. i will be taking the diff center off tomrow ill cheak the output of the Tcase.
also i need to extend my front shaft do you think an extended Slip yoke would be alright or just get the shaft extened?

brendan_h wrote:i dont think it is axel wrap because it does it with slight acceleration. i will be taking the diff center off tomrow ill cheak the output of the Tcase.
also i need to extend my front shaft do you think an extended Slip yoke would be alright or just get the shaft extened?

Do you need the extra slip, or just the extra length. If you only need a short bit of length, just fit a drive shaft spacer, it will be the cheapest option. If your SPOA with RUF and flat springs an inch spacer should keep your slip joint happy.

Have you acutally pulled your shafts to check the uni's properly, as well as check your pinion and output flange nut tension? If you only have a soft set of springs and no trac bar you will be supprised how much axle wrap you do suffer from.


Layto....

i think ill probaby need about an inch of spacer.

diff center is going to a drivetrain place on weds so ill ask them to cheak it all out

oooooo $$$$$$

ok vibrations are still there on acceleration and decelleration in 2nd.
i am now, after a an hour of research and thinking it the drive shaft angle. its at about 20* at ride height. alot i know but it has only just started doing it.

Have you checked the unis yet by pulling the shafts out first?? I see you said you checked your jackshaft, so were the unis all smooth is all directions? Did you regrease them? Still sounds like your problem is around that area. Unless you bent a rear drive shaft somehow.

Heres a few checks:

Put Tcase in neutral and then put in in gear and see how much vibrations you will get. These vibrations will be mainly from the jackshaft. If thats acceptable crawl under the car and pull the rear shaft out. Put transfer in 4H and go for a drive (dont drive it like a race car it will handle totally differently take it easy) this will eliminate the rear shaft. You should find the problem somehow through this.

Dan

the unis are fine but i have noticed the rear shaft feels worn out in the splines. theres a bit of movment

diud what you said jrzook went for a drive in FWD. yup vibrations still there. posibly its worce.

i am now thinking just to rebuild the Tcase replace all bearings, pilot bearings ect and then go from there.

So how were the vibrations from the jackshaft when the tcase was in neutral?

there was very very minimal most likely coming from the engine vibrating

Do you have a driveshaft spacer installed?

no i dont.
i change the jackshaft uni because i felt the smallest bit of movment. it did help but the vibrations are still very bad. going to rebuild tcase