New theory for leaning to the right - Thoughts Welcome

[snowgoose]

Well after changin all leaf springs and shockies, although things have improved somewhat, I am still leaning to the right, a 20mm height difference between left and right.

So hell bent on sorting this out I measured gap between the rubber damper and axle to confirm whether this was a suspension issue or body mount issue. Same result, a 20mm difference between left and right suggesting this is still down to suspension.

However having a close look at the angle of the rear mounting shackles between right and left, showed that the right shackle was a much greater angle than the left. While the left was almost vertical, the right was about 25 degrees towards the rear, hence having the effect of flattening the spring and by extension making it lower to the ground.

So next thing I thought, whats causing this and then it occurred to me that the rear propshaft has some kinda hydraulic shaft in it which is greased up. I remember seeing this shaft move out slightly when I did a grease up some weeks ago. Now I reckon this would have had the tendency to push the axle further to the rear, with a bias on the right side as this is where the diff sits and consequently move the shackle backwards stretching the leaf flat.

I guess the thing to do would be to remove the propshaft and once again measure the differences, does this new fandangled theory make any sense to anyone or am i just kidding myself?

cheers

Snowy

 

[jonb96150]

Interesting. I have around 20mm droop on the right rear as well.
You might need to drag it around in front wheel drive for a bit to work the suspension before measuring.

 

[theyis]

That line of thinking would assume the drive shaft would not be able to move in while compressing. It is designed to slide in and out so if it got stuck in the out, or long, position to move the axle (and shackle) back you would have more problems than just a leaning truck. I'd be more inclined to think the cruiser is heavier on that side or something like that. I can't remember which direction mine leaned but it would be interesting to see if the right hand drive and left hand drive cruisers lean in opposite directions. Of course my comments are assuming I was reading your thought process right...

 

[roscoFJ73]

Hi Gavin . The splines on the driveshaft are just slip joints so the axle can move up and down without tension on the driveshaft.

Your right about the shackle on a lean . If you put a lever in the shackle on the low side and and push down on the shackle ,it should level the cruiser as it causes the spring to arch upwards. Obviously when you let go it will return to its former state.

 

[crushers]

did you torque the shackle bolts or just tightened?
if one side is tighter than the other then the pivot will be more restricted and will take more force to "flatten" the spring.

 

[Farmer_Fred]

my KZJ70 has a slight lean to the right. I had put it down to driving without a passenger, but after changing shocks/springs, there is still that lean. Hmm...

 

[snowgoose]

That line of thinking would assume the drive shaft would not be able to move in while compressing. It is designed to slide in and out so if it got stuck in the out, or long, position to move the axle (and shackle) back you would have more problems than just a leaning truck.

So could we safely assume that if there was to much grease, then it would reach a saturation point of compression and then begin to push the actual dff/axle towards the rear which in turn would move the shackle rearwards, flattening the spring?

Hi Gavin . The splines on the driveshaft are just slip joints so the axle can move up and down without tension on the driveshaft.

Yeh thought this would be the case Rosco, but if say it was overfilled with grease as above, then I guess you'd expect there to be constant pressure on the axle and the tendency to push the axle back, particularly and moreso on the tarmac rather than in off-road terrain

 

[crushers]

not a chance would too much grease cause this.
but
if it did then BOTH springs would be flattened but you would blow the front cap on the driveshaft stub long before this happened...

 

[snowgoose]

not a chance would too much grease cause this.
but
if it did then BOTH springs would be flattened but you would blow the front cap on the driveshaft stub long before this happened...

Thanks Crushers, so whats you're take on whats going on here, whats causin one shackle further to the rear?

 

[crushers]

poor engineering... (no, Dougal, this is not directed at you) or manufacturing.
the spring is too soft to support the weight it is trying to. it is flatter than the other side so the shackel is sitting on more of an angle.
picture a curve with a fixed end on the right and a pivot on the left, if both curves are the same then the pivot is the same.

i have been battling this crap for decades now. OME, DAkar, Belton they all sit wonky... sometimes you get lucky but usually you are out by anywhere from 1/2" to 1 1/2".
i used to pull the packs apart and move leafs from side to side to level it out...a lot of time involved.

OME use to sell a "leveling kit" wich was a plate you stuck between the axle and the spring perch to "level" it out. cheap fix... cheaper than retooling the line.

 

[Greg_B]

OME use to sell a "leveling kit" wich was a plate you stuck between the axle and the spring perch to "level" it out. cheap fix... cheaper than retooling the line.

Wayne, I think that was Toyota, and it was a special service bulletin many years ago. I have the information at home. There is an article which follows the writers process as he and a few shops dealt with this issue on his FJ40. Anyone remember the name of the book the article was in? There were two books published which had all sorts of newspaper articles, writeups, etc all placed together. The article might have been called "Stange case of the leaning Landcruiser" or something similar. The article listed the special service bulletin reference number, and gave the dimensions of the plate.

gb

 

[snowgoose]

poor engineering... (no, Dougal, this is not directed at you) or manufacturing.
the spring is too soft to support the weight it is trying to. it is flatter than the other side so the shackel is sitting on more of an angle.

Cheers Crushers, appreciate your experience and suggestions. I just find it amazing that both springs I changed were exactly the same, brand new, same manufacturer, exactly the same height and size and yet from what I understand, you're saying the RH one is softer, is that right?

I guess one way to dismiss this crazy theory is to remove the propshaft entirely and see what happens..,

 

[crushers]

you could deffinately be right... i thought that OME also sold a similar kit...no?

Wayne, I think that was Toyota, and it was a special service bulletin many years ago. I have the information at home. There is an article which follows the writers process as he and a few shops dealt with this issue on his FJ40. Anyone remember the name of the book the article was in? There were two books published which had all sorts of newspaper articles, writeups, etc all placed together. The article might have been called "Stange case of the leaning Landcruiser" or something similar. The article listed the special service bulletin reference number, and gave the dimensions of the plate.

gb

 

[crushers]

yep, that would answer the debate.

of course that leads to the question...why was there so much grease stuffed in there in the first place?

there is a tin plug at the u/joint end of the stub shaft... when you take the shaft off take a look and you will see what i am talking about. similar to a frost plug in design... used to keep dirt out of the grease for the slip joint.

i thought the rear springs had L and R designations... or is that the fronts?

 

[Greg_B]

you could deffinately be right... i thought that OME also sold a similar kit...no?

Found it...Manual - Book - Land Cruiser

Part of the "LandCruiser Gold Portfolio" books.

Don't know about OME. I thought they addressed it with left and right side spring packs.

gb

 

[crushers]

thanks for the link Greg...
once again you prove to be a walking book of knowledge. <insert grin>

 

[roscoFJ73]

Yeh thought this would be the case Rosco, but if say it was overfilled with grease as above, then I guess you'd expect there to be constant pressure on the axle and the tendency to push the axle back, particularly and moreso on the tarmac rather than in off-road terrain

I tried to reply last night but couldnt get through.
However,I agree pretty much with what Crushers said about 1 spring being softer.
I would try Westralia Springs ,after all they promised you a level ride.
I think they will come to the party if your tactful

Ill come down and show them my 4yo dobinsons that have sat level from day 1

 

[snowgoose]

yep, that would answer the debate.

of course that leads to the question...why was there so much grease stuffed in there in the first place?

Why is there too much grease in there?... prolly overzealous mechanics at some point prior to my purchase

there is a tin plug at the u/joint end of the stub shaft... when you take the shaft off take a look and you will see what i am talking about. similar to a frost plug in design... used to keep dirt out of the grease for the slip joint.

Yeah cheers Crushers will do and see whats goin on here, thanks.

i thought the rear springs had L and R designations... or is that the fronts?

Seems it depends who you talk to, some say no, some say they only have designations to aid the fitter, others say there is a significant difference

...mmmm, now that I think about it more, when I changed the springs I did the left first and then when it came to doin the right I had a hellava time gettin locating pin lined up. I had to use a jack like a porta power to push the spring rearward enuff to line up this pin. I spose for the experienced, alarm bells would hav been goin off at this point, but I just moreless thought I was enduring the normal challenges one faces, it would appear in hindsight that I should have investigated further at that stage.

So am guessing now, that there was (and still is) too much pressure from somewhere pushing on the axle, hence the shackle being pushed further to the rear, does that make sense? I'm guessing such pressure could only come from the propshaft or transfer case and if left like this, I assume one could flatten the spring pretty rapidly, and then one would go thru the whole motion of changing springs again with no effect. So next step is Crushers advice, pull out prop and hava good look.

Oh just one more thing...sorry, once I remove the prop, can I drive it around without doin any damage to anything? Just thought a spin round the block to settle springs back into home position may clarify any changes that have occurred. The trouble is though, if this pressure has already flattened out my new spring, then I won't really know unless I fit another new one...oh it goes on and on

 

[crushers]

first
when i do a lift i remove the grease nipple from the driveshaft stub end. this relieves the pressure and makes the fit MUCH easier.
as long as you remove both parts of the driveshaft then you can drive in 4WD on the front for as long as you want... expect some torque steer to occure.

before you remove the prop, remove the grease nipple, it will make the removal easier, otherwise you will have to try and compress the grease to get past the companion nut on the companion flange...