Outer Limits 4x4 Board

Hi Guys

This is my first post here so ill just introduce myself…. Or perhaps the car!

I have an `89 Feroza which is rooted, which about sums it up! I raised the poor thing about a year ago, which made a big improvement to the ride but totally stuffed up my tailshaft, which has brought on things like intermittent vibrations around 2,500rpm in 5th, harsh grinding/clattering when decelerating in any gear and many other vibrations here and there.

I pretty much knew it was the lift so I had the tailshaft lengthened, a leaf removed from the spring pack, and put in caster spaces to lift up the diff angle a bit. I have managed to improve things a bit but it still carries on like a pork chop sometimes. I was keen to get the uni’s replaced because they have never being done but I have been told it could make it worse.

Is it that risky changing the uni’s or should I go ahead and do it?

I hit the uni’s (to move them into a different position) and put the shaft back on the vehicle and it was really smooth for a few days but has been slowly going downhill. The vibrations happen intermediately which tell me that it can’t be the angle of the shaft because the vehicle height doesn’t change from day to day.

PS. I have even tuned the engine, got a NEWER GEARBOX, bought a second hand tailsaft which turned out to be stuffed for testing and check absolutely everything I can think of.

Should I do the unis?

Yes, change the uni's, but first, was the tailshaft put back on correctly. Do the uni yokes at each end of the tailshaft line up correctly. If they are out of sync, then the tailshaft balance will be up the duff.

You MAY have to lower the rear of your gearbox to regain correct alignment. This MAY help with your vibrations.

Driveline vibrations can be a real PITA to find.

Good Luck.

Mine has a slight increase in vibes when decelerating (at lower revs)- apart from that can't notice any difference.

What sort of lift have you got (height wise?)

yeah I never got any vibe issues with mine..... strange....

BUt I would definately look at uni's

The other day I was under mine and noticed that one the rubber things that support the exhaust in the middle was gone. It didn't seem to make it hang down too much but I got some wire and did a quick fix up on it to hold it up and ever since then I have been getting vibrations while accelerating. I haven't had a chance to get back under and undo it to see if it stops the vibrations but maybe I did it too tight? I dunno but that might be worth looking at...

Anyone else had this?

Cheers
Ben

Try getting a proper rubber isolation mount and the vibes will most likely disappear.

ha ha so simple...I cant believe I didnt think of that!

Anyone got a spare one? I'll contact the wreckers.

Cheers
Ben

just go to your local exhaust shop and ask for one... can't be anymore than $10

Ohh, I forgot to mention that I have also spaced the back of the gearbox down but I couldn't go very far because the engine began to vibrate on the body. It didn't help much anyway.

It was lifted by about 50mm but when we got one of the leaves taken out it went down by about 15mm.

The shaft I have on it now was a second hand one that has never been modified and works great if you give the unis a bit of a tap, but its beginning to go crap again.

The markings as mentioned in the manual mentions are long gone if there were any and of course there is no way of knowing how it was attached on the original vehicle.

I can't go back to my modified one because its has even more problems.

I have checked anything that could vibrate on the body, however it really seems to be something driveline related.

Yeah it sounds like the tailshaft.
I use to get a slight vibe on 5th gear when letting go of the gas.

Ended up just living with it. It never got any worse.
Just grease your uni's often.

Tailshafts can be balanced too; but the uni's first would probably be the best thing.