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Need Help For Bad Handling...


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I haven't had the time yet,

back to the office in Milan every damned day and can't get home

before 7pm.

Will check it out this evening,I don't exactly know how much "play" I should feel though...

to throw itself off the road

Yeah...same here,with the nice feeling of a self-destruction process in act.

It feels like the whole creature is about to fall in pieces.

Damn.

:angry:

I'll remove those isolators ASAP.

P.S.

Pigster,just noted your updated signature...tell more about those lovely Silverstone M117!

B)

Pics of the truck are always a pleasure to see

;)

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The pics will come shortly - well next week now.

but the tyres... very nice.. same sorta handling properties as the simex (as in pretty dam bad)

they come in the same sizes roughly... be it 35, 10.50, 16's or 11.50 16's and also come in 15 inch rims as well. I don't know when all these varieties are going to be released to the open world though. er, I have the 35's which are only just about as tall as a simex, if anything the simex and a few mill more to play with. Also the simex are again a little bit wider, but only a cm or so.

The silverstones - cheaper by a long way, brought from bronco, the tread is v v v similar, the only difference is that the lugs are slightly smaller (narrower) and more spaced out (probably only because they are narrower) same with the centre lugs that run down the middle, slightly smaller and spaced out a bit further, which I hope means they will self clean a tad more and grip even better. I think the side wall gripes are better on the silverstones, more of them.

Other than that watch this space, I will be testing them this sunday.

It should be an interesting test, because I used to run Simex 35's but thought I would try something different, infact I still have the simex tyres in my garage, just incase the silverstones are naf.

I think the price for the silverstones were 150 inc Vat (tyre only) whilst simex were 158 plus vat (tyre only)

:)

watch this space.

and for the panhard rod bushes - there should be no play, get a good gripe and just shakes the bar about, and you should tell pretty quick that they are knackered. the other option is get someone to rock the steering wheel back and forth whilst you look for play, which again should be obvious.

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Oh...judging by the diagram I was looking at the steering bar...not the Panhard...er...

emudiagram8.jpg

(re:Silverstone only 8GBP less than Simex?I think they should cost much less...ask Serious IIa in Holland IIRC) :)

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the difference being though . . .the VAT.

for you it may be different...

the silverstones where 150 inclusive of VAT whilst Simex 158 excluding VAt.. so they actually cost about 180 quid.

which doesn't include delivery, or wheels.. still expensive but cheaper, if you get what I mean. Also the King remoulds are again a little more expensive I think they were about 155.

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Well,for those curious...

After all the steering linkages and bushes were found in place (...) and in working order,

I spent 2 hrs to remove the spring isolators I had fitted.

Back on the road...the rattles came back,AND!the bad handling is still there!

:o

Sooo,I'll take some time ASAP and re-fit the original springs;moving rear to the front

and spend some more euros to get 2X 110 springs...and see.

Rats.

:(

But before,I have to bring the truck down at my usual garage for the routine timing belt check,

tomorrow,while there I'll ask them to give a look around,maybe I missed something.

Uffa.

:angry:

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Michele,

before you go and haul the springs off, check the swivel pre-loads. It shouldn't take long to check, certainly less time than changing the springs. If the pre-load is low that will certainly give the symptoms you are describing, especially as the self-centering will have been reduced as a result of the change in the castor angle due to the suspension lift.

Also don't rely on the free lenght of the springs as an indication of the difference in ride height. The longer springs may be a lower (softer) rate which will result in a greater amount of compression for the same weight. The only easy way is to compare the height between the axle and chassis.

Good luck with the hunt for the cause and don't let it get you down too much. Think of it as learning more about your motor :rolleyes:

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Hi Renny,

so far the swivel preload is the only thing to be checked yet.

But I don't have much spare time to do all things...

I'll have a rush at the garage tomorrow and ask if they can check it out...

("sorry,you have to book a visit...next week?")

("UFF!!!")

I drove the 90 to the tires shop last Sat,the guy took "her" for a drive,and got shocked

:(

Springs yes,they're softer,or,better,almost same rate of the oe ones.

Indeed I expected them to sag enough so not to start handling issues,

but-being me,er-I was wrong.

:huh:

I'll let you know if something changes.

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NRC9447 D90 Front passenger side i.e. 14.80"

to this

NRC4304 RR HD Rear 17.71" red/white

17.71-

14.80=

____

2.91?!?!

M

I haven't looked up the spring rating (Lbs) for these 2 springs, but unless the poundages are EXACTLY the same the gain will vary.

Ie if you replace a hard spring with a soft longer one, it is likely that it could sit lower whwen the weight is on it.

Replace a soft spring with a longer harder wone and the lift could easily be graeter then the difference in free length ?

Mucking about with springs, poundages and free lengths and shocks etc is a nightmare !

edited to say :

I have looked up NRC9447 175 lbs, and NRC4304 170, so virtually the same poundage - but the standard poundage for a 90 is around 225 lbs rear from memory, ....have you added any weight to the back end / front end ?

170 is a low poundgae for a 90 HT, yes its ok, but more siuted to softtop / truck cab, it will easily bottom out and hit bump stops......and really soft springs on a lifted 4x4 can make for interesting handling !

Nige

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I can only reinforce what the others have said.

The panhard rod sees heavy loads. When you check for play in the bushes, you could easily think that there is very little play, but they can still be the problem.

Swivel preload is also a common cause of the death wobbles.

The change in the caster from the extra lift will make the underlying problem worse. You mentioned getting caster correction radius arms in your earlier post - the best way (IMHO the only good way) to correct caster is to rotate the swivel balls.

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Nige,front sports now 8274 steel cable charged (in a desperate try to force the springs sagging-but not!) on my modified winch bumper (you'll get preview pics soon).

Loadbay almost empty as usual.

Perfectly levelled!

Steering shakes only few times every now and then,regardless the speed,but when it does it's horrible.

On the motorway back home yesterday it went fine but once or twice,

by eye it feels certain corrugations or irregularities.

Tried on some mountain roads,holes patches and ruined tarmac a go-go,nothing!

It handled well.

Is it somehow cursed?

:angry:

It's only springs now...

:(

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(...)When you check for play in the bushes, you could easily think that there is very little play, but they can still be the problem.

Swivel preload is also a common cause of the death wobbles.

(...)the best way (IMHO the only good way) to correct caster is to rotate the swivel balls.

G'day John

:)

I may be wrong with the panrod bushes play,

I'll have it checked tomorrow by someone more skilled,better...

:rolleyes:

As to the swivel balls,you mean re-drilling the mounting holes?

It falls in those minefield which is Italian regulations about vehicles,

basically even changing springs could be considered illegal...

<_<

(hush!!!)

:ph34r:

(OT)P.S.

There's a chance I'll meet an Aussie of yours (Isuzurover) for the big German gathering in Oct...

;)

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...As to the swivel balls,you mean re-drilling the mounting holes?

It falls in those minefield which is Italian regulations about vehicles...

Slot the mounting holes in the flange of the swivel ball.

With a spring lift, the radius arms rotate down and cause the axle housing to rotate and reduce the castor angle.

The radius arms can be cranked or caster correction bushes can be fitted to rotate the axle housing back so that the castor angel is returned to stock.

The problem with both of these methods is that they make the angle of diff pinion wrong for the driveshaft. Also the castor correction bushes reduce axle articulation off road.

So the only way to have both the pinion angle and castor angle correct, is to rotate the swivel balls.

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Hiya!

It's back!

(the LRA forum!)

OK,1st I'm glad to say that the trouble was solved yesterday.

Panhard rod bolts! were both loosen!

I rocked the st. wheel while the mechanic gave a look under.

Fixed in 2 mins.

Now it handles as before!

:D

YEEEEEEEEE-HAW!!!!!!

Er,including the slightly compressed arm bushes and the screwed up caster angle

and the rumbling driveshaft due to the wrong working angle...

:rolleyes:

But I can live with it until I have the chances to tune the truck as needed.

BTW:Tomcat corrected swivels

FRONT AXLE CASTORED

150£ +26.3VAT =176.3£ total

:(

I'm interested in the process though.

Any DIY link?

I'll try a search on OE44.

Thanks all!

:)

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Before you rotate the swivels, you need to determine how much rotation is needed.

Stock rovers have about 64mm (2-1/2") travel between the axle and the bump stop and approximately 3 deg caster angle.

A good rule of thumb for estimating approximate caster angle is, for every 25mm (1") of lift above this, the caster angle reduces by 2 deg.

So if the travel between the axle and the bump stop is 114mm (4-1/2"), the lift is approx 50mm (2") and the caster will be about minus 1 degree. Then the holes in the swivel ball need to be slotted to allow 4 to 5 degrees of rotation, to permit the caster angle to be restored to the stock 3 degrees.

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BTW:Tomcat corrected swivels

FRONT AXLE CASTORED

150£ +26.3VAT =176.3£ total

:(

I'm interested in the process though.

The process for the castor corrected axle involves cutting the axle ends off (where the swivels bolt on) then rotating these mounts by the required angle to return the castor to standard, or what ever you desire. Tomcat are apparently using a jig to ensure accuracy and sophisticated welding to ensure good quality.

They used to supply castor corrected swivels that used OEM swivels with the holes drilled in the correct places to correct the problem. They may have been discontinued, but it could be worth giving Paul a phone or dropping him an e-mail.

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Hello Renny.

Thanks you too,I gave Tomcat MS site a look,

it's just a matter of $$$

:(

2XQt arms @ 180GBP+VAT (330Euros)

Tomcat bits @ 176.3 X 2 (GULP)

Something to do in a future...

:rolleyes:

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Michele,

if I understand it correctly (which I may not) by using a caster correct axle or swivels you will not require castoer corrected arms or a double carden prop. Might actually be the cheapest option in the long run.

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