Which standard height springs?

Hello all

After having no luck at all with a vibration issue at 55mph on the addition of a 2 inch suspension lift, I am going back to standard springs. The expensive double carden front prop did not fix the problem and I went through two transfer boxes, a set of new UJ's, and two output bearings. Some 90's never have an issue with this lift, and some do I guess.

For the lift I had four yellow Britpart Super Gaz dampers and 4 yellow 50mm springs.

Am I right in thinking that I can keep the dampers and simply change the springs back to standard height? I am told that there is a 'black and red' spring that might be a good choice. Can anyone offer some advice with this alteration?

Thanks!

Jamesyboy said:

Hello all

After having no luck at all with a vibration issue at 55mph on the addition of a 2 inch suspension lift, I am going back to standard springs. The expensive double carden front prop did not fix the problem and I went through two transfer boxes, a set of new UJ's, and two output bearings. Some 90's never have an issue with this lift, and some do I guess.

For the lift I had four yellow Britpart Super Gaz dampers and 4 yellow 50mm springs.

Am I right in thinking that I can keep the dampers and simply change the springs back to standard height? I am told that there is a 'black and red' spring that might be a good choice. Can anyone offer some advice with this alteration?

Thanks!

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are you sure the vibration was down to the lift?

you say it only vibrates at a certain speed,daft as it sounds have you checked your wheel balancing?

or wheel bearing?

Hi Wilts

I got the lift at the same time that I got an engine transplant - a Disco 300tdi. I also had a disco t box and r380 fitted - the latter two are new - the t box is a new one after the old disco one was wrecked by the lift.

I had an independent mechanic check all the geometry and measurements for the new fittings and he confirmed they were correct.

The R380 box used the original lt77 mounts - that is the only thing that worried me as the the R380 mounts look alot firmer and are square (I guess to fit a welded on mount) rubber blocks, not the old round rubber dampers.

I had castor correction bushes fitted afterwards and they made the problem way, way, way worse - you could actually hear t box grinding as the Landy moved up and down on it's springs on a country road.

Before I had any of the work done, I never had a problem. The new suspension also feels alot harder. The double carden had made a bit of a difference - more so than a wide angled front prop that I tried.

Interestingly, my vibration at 55 mph is in 5th gear - shifting down to fourth whilst maintaining that speed seems to remove the vibration. I know regardless, the prop is moving at the same speed.

Remove the front prop, lock centre diff and go for a drive. That will soon tell you if it is prp shaft related for not

When I jack the REAR wheels up, they can be wobbled very slightly on a vertical axis, not horizontal though - makes a sort of clicking sound as if a couple of the wheel nusts were slightly loose (but are not). When driving there is no rumbling from the wheel bearings.

I ahve alternated between both props off and on - I get varying vibration on both. I guess I just don't want to do another set of UJ's or a t box output bearing again - it's very frustrating having to replace them when I've done it already :-(

do they spin smoothly when jacked up. my disco had to have noo rear wheel bearing for it's MOT, Never heard any rumbling whilst driving.

Not sure how they fitted the disco gearbox as it's not designed to fit in a 90. I assume the gear levers are too far back. Could be that they've screwed up the gearbox mounts??

They spin fine - but as it is a drum brake on the rear axle, they don't free wheel completely. The R380 is a Defender box - the engine had new mounts welded on to take the Disco engine but not effect the Defender gearbox positioning. It's the original mounts but the gearbox is using the original dampers which are bolted onto the chassis - the round ones normally used for the 77 box. Whatever is happening - it's the t-box that is getting the abuse. I had a mechanic check the diffs and he said they were ok and nothing was sticking. Maybe by going back to normal springs I can find out once and for all.
One thing I do note - the older 90's like mine (1988) do seem to have the most marked problems with a lift in terms of vibration. Perhaps it's the fact they have the old 12 spline diffs, which in some way cannot cope with adjustment as well as higher spline versions?