vibration

[chatto]

Hi there, I have a swb NJ and it had like a shuder at 110 took it to get a wheel balanc and know it has got like a vibration through the body . has any one had this problem or know what it is. thanks

[hudson44]

Has it been lifted? Mines developed a harmonic vibration between 85 and 100 kmh. Did a ball joint flip the other day and had it up the road to get the castor corrected and got them to balance the tyres while they had it thinking it was just a balance problem. Vibration still there......

I'm thinking it has something to do with the gearbox mount. The small support mount has been broken for as long as i can remember but i think this has caused the main mount to sag. They are a funny setup on the manuals. Instead of sitting on a rubber block they support each side of the cross member with rubber.

I'm going to measure up the support mount and try to find an insert for it and see how it goes. I will let you know. Sorry to hijack, but has anyone found an aftermarket replacement for the small G/box mount on the manual 3lt's?

[-Scott-]

It must be the season!

I had the tyres rotated before I go bush next week, and it came back with a driveline vibration.

The mechanic identified that the rear output shaft has excess play. Reading OL, I discovered that a new bush is required, but it's not available as a spare part - either custom made, or replace the rear housing. They also found the bushes in the rear control arms are loose - they're rotating in the arm!

So, they're going to replace the bushes, and try to find a fix for the loose bush (I had to suggest they call Mitsubishi... )

[crh]

I had this problem a year ago. I had the tailshaft balanced and it is now about 90% right.
The extension housing on the TC is about $300 and is not stocked in OZ. I had the clearance on the bush checked and it was within tolerance apparently. I also changed the uni joint as it was binding at one point in the travel.

I have resorted to doing 90kmh or 120kmh to avoid the vibes.

[NJV6]

Scott, did you find a thread on the splined output and movement? I think I posted a thread on here a while back but didn't find anything out...

Mine doesn't leak but has some good movement

[glenn_c]

Scott
Don't use anything but geniune rear control arm bushes. After market ones will break the first time you do some rear 4wding.
Regards Glenn

[BBP]

crh wrote
"The extension housing on the TC is about $300 and is not stocked in OZ"

I would buy one if it was that cheap!. I priced one just the other day and was quoted $845 retail, and over $600 trade!!. At that price I would try to get one or two machined, probably be cheaper. Apparently a bush from an L300 van fits, though a little shorter in length. Mitsu parts could not even find one listed.

I also have "slop" in the bush, have not taken it off to measure but if feels like a couple of mm. Probably not but feels that way.
I don't get any vibration at speed, only at 1200-1300 rpm in 3rd gear. Well that's when it most noticable. May even be the gearbox yet, $$$.

Robin

[-Scott-]

I don't know what they did to the rear arms - I haven't picked it up yet, I don't even know how much I've paid.

The rear housing was under $300, but it has to come from Sydney and they left it too late to organise - so I'm going bush without it done.

[-Scott-]

Well, they installed Pedders polyurethane bushes. I wonder if they'll make it to the end of this week. I hope I make it home again.

Supply and fit replacement extension housing, they quoted $400. I wonder if they'll be replacing the bushes under warranty at the same time.

[hudson44]

Urethane bushes will be fine. They should (in theory) last longer than the rubber ones. The only downside i can see to urethane over rubber on the rear arm bushes (i'm assuming it's the front bushes of the trailing arm we're talking about) is the lack of flex they may have compared to the rubber. This also depends on what flex and shock length you have in the rear and whether the shock is limiting down travel or the front bushes.

Now to hijack this thread even more......... Does anyone know of an after market complete mount or rubber insert for the small support mount on an NJ manual gearbox?

[-Scott-]

It's the rear bushes, the ones which need to deform as the rear axle articulates. I don't have a rear sway bar, so they'll get a bit of a work out if we find some fun tracks.

[hudson44]

Do the shocks still limit the diff travel with the urethane bushes in? ie Does the shock fully extend?

[J Top]

Have you checked that the tail-shaft is not disengaging from the g/box.
As you lift the vehicle the shaft has less support allowing more movement, I have had spacers made up for the rear of tail-shafts in the past to increase engagement

[hudson44]

Have you checked that the tail-shaft is not disengaging from the g/box.
As you lift the vehicle the shaft has less support allowing more movement, I have had spacers made up for the rear of tail-shafts in the past to increase engagement

I think you're on to something here.......

Unbolted the flange from the diff today and moved the shaft forward (into the box) by about 15-20mm and there was a lot less radial movement. Almost none. I'm going to make up an alloy spacer plate tomorrow and see how that goes.

[NJV6]

Gabe, before you drop it down and go blasting down your favourite track.... might pay to whip the springs out and cycle it through its suspension cycle to make sure it doesn't 'min' out if you get my drift - I'd hate for it to try and push the guts of the transfer case into the flywheel!!!

Just a thought - no idea if its a reasonable one or not.

[hudson44]

Yeah i thought of that. I'm only going to space it about 15mm. Its got patrol H Duty springs which gives it about 4 to 4 1/2" of lift so this should bring it back to about standard. The tailshaft moves into the transfer about 2-3 " before it bottoms out. I will measure the tailshaft at full inward travel then I will flex it up and measure again tho just to check.