spring length with a 5â€

[JBE]

My caster is out of spec with 4.5 deg. positive (Nissan manual lists 2.5 deg +- 0.5 deg.) and I’m convinced that this causes the wobbles my truck is has had since day one the lift went in. I am not too sure if this excessive caster is caused by sagged springs or if the caster correction plates were mounted incorrectly in the firs place.

Could someone with a 5â€

[HeathGQ]

yep - the lift will change castor and make the truck handle like a dog. It has been discussed a million times on this forum

see the bible or search my friend......

[turps]

yep - the lift will change castor and make the truck handle like a dog. It has been discussed a million times on this forum

see the bible or search my friend......

Yer but he does have the caster plates to compensate. I would say the wrong caster plates where installed. As there is a set for 4-5" lifts then theres a set for 6" and higher isnt there.
Maybe it has the 6"and higher set in there.

[JemmyBubbles]

There are two sets as turps said...

5.5 degree castor plates and 7 degree castor plates. The idea being that the smaller ones will restore 'near' factory castor for lifts around 4-5 and 7 degree castor plates for lifts of around 6 -7. To tell the difference between the two the 5.5 degree plates will have had a new hole drilled and the 7 degree plates will have bolted straight up to the existing holes.

There is a definate way to install the 5.5 degree plates ie; there are two half cut washers the rest on the outside of the front radius arm diff mounts. This gives you the location with where to drill the holes in the front mounts. If this is out you should be able to notice it.

As I mentioned if you have the 7 degree plates there is no way the install could have gone wrong.

You shouldn't have too many dramas with running to much positive castor, the only ill effect is initiating a corner is a little harder - but the again nissan's are funny little things. I have a buddy who had a 7 inch lifted lwb with 7 degree plates who took the 7 out for a 4 - 5inch lift and it runs fine. He says steering response is less 'touchy'..

Interestingly if you talk to cheezy he will tell you the only way to get your 2.5 degree of positive castor back is by rewelding the mounts, that is if you keep the 3 link radius arm setup.

I do find it funny that nissan probably (or probably not ) spent millions of dollars in R & D for the whole front end geometry of these things and for a couple of $$$ we completely change it..

I have found what causes vibrations in my car is panhard rod bushes worn, panhard rod diff mount slightly loose, badly balanced tyres. Did you get the adjustable panhards with the kit ?? Were the bushes urethane ?? If so get rid of them and put in genuine nissan versions...

In some cases, from what I have hear, you can never entirely get rid of the gq death wobbles... Mine doesn't wobble but it is because of the above panhard rod related fixes...

[JBE]

I have the caster plates which require the hole to be drilled and the half cut washer. As I said, the car has had the wobbles since the day the lift went in.

I don't know if the hole in the bracket on the diff can be positioned wrong (2 deg. over spec). It was all done in a workshop where they sell heaps of these lifts.

Fact is that I can't reduce my caster back 2 deg. with diferent caster plates. I have the 5.5 deg plates in.

I tried 3 deg offset bushes without caster plates, but this gets my caster down to 0 deg. This setup make the steering too direct, but also makes the front shudder disappear completely.

I was thinking of going for the snakeracing 5" drop arms, but was told that it only works for a 'true 5" lift' (meaning with a 5" lift, they would correct the caster to 2 deg.). I was thinking if I could get some measurements of springlength (mounted) in other GQ LWBs, I would be able to establish if I actually had a 5" lift.

The other alternative would be to use 2 deg offset bushes to rotate the diff back to 2.5 deg as per Nissan spec

[JemmyBubbles]

Not offset bushes, stay away from them. YOu want to keep genuine rubber in everything. Urethane = Devil.

If you are looking to get rid of the shake then surely a miscellaneous 4wd fab shop could cut and rotate your radius arm mounts on your front end and restore 2.5 positive castor for cheaper than the $1500 snake racing/3rds productions are asking for there drop arms...

Dumb question.. you haven't got offset bushes in the radius arms in addition to the castor plates ??

[blackmav]

JBE do you have the wobbles or the wanders? If its the wanders its the caster, if you have the wobbles it could be panard bushes etc etc etc
If its the dreaded death wobble you will sure know about it. I've had my caster measured at +1 which is supposed to be within reason but it still tracks a bit.

[Tiny]

I get some exess feedback through the steering ATM but due to worn dampner on the RTC setup.......developed a mojor wobble aftr rolling a tyre of the rim, but the wheel was way out of ballance, and had mud and water in the rim....changed the tyre and cracked open the old one and cleaned her up etc and wobble gonski.

Wobble can be from a number of thing, but the smaller lifts with bushes flog out early and wobble

[JBE]

Not offset bushes, stay away from them. YOu want to keep genuine rubber in everything. Urethane = Devil.

If you are looking to get rid of the shake then surely a miscellaneous 4wd fab shop could cut and rotate your radius arm mounts on your front end and restore 2.5 positive castor for cheaper than the $1500 snake racing/3rds productions are asking for there drop arms...

Dumb question.. you haven't got offset bushes in the radius arms in addition to the castor plates ??

I tried 3 deg offset bushes in arms I borrowed from a friend without caster plates. I don't like them as they seem to transmit the noise from the road surface/wheels into the car body. No, I don't use them together with my caster plate. Apart from that, the steering deteriorated beyond what I consider being acceptable. I was seriously contemplating tying to rotate the diff back with 2 deg offset bushes and see how it drives.

I got all the ususl suspect-bushes replaced (panhard rod, radius arm), got the wheels balanced and checked steering components as well, but I still don't see much of an improvement.

Snakeracing have been really EXTREMELY helpful with answering all my pesky questions, but I don't believe that my springs sagged one inch or more and subsequently caused an excessive caster as it has been a problem from day one.

I thought about rotating the radius arm brackets. My suspicion is that the support hole that positions the caster plate is 2 deg out of where it is supposed to be. To be honest, I don't have too much faith in the mod shops in Sydney and I dont want someone to completely trash my front by rotating the brackets. So, I thought if I can get an out of the box solution like the Snakeracing 5" drop arms, I would go for them if it fixes my problem. I believe that a pos. acster of 2 around 2 deg will fix my wobbles (0 deg certainly does, but steers like sh**).

Snakeracing claim thet their 5" drop arms together with a 'true 5" lift' will achieve a 2 deg pos caster.

The only thing I need to find out is, is car still riding on a 5" lift, or has it sagged below 4". That's why I asked for comparative measurements.

I also managed to trash the radius arm bushes (at the chassis end) on a single 10 days trip to the Vic Alps (done a lot of the hardcoier stuff there).
Replacing them also adds up if you take labeour into account.

So, I'm still trying to figure out how close to a true 5" lift my setup is. Come on guys, someone with a 5' Megailft kit, grab a tape measure and measure the mouted spring length seat to seat.


Cheers
Joachim