TJM 4" Lift Install (1 Viewer)

[DIGLERZ]

Wow - I really need to stay off this site... I've already got a mild case of tire envy, now Christo's post above has me thinking I should buy and new set of radius arms (those look nice).....

 

[bhicks]

Don't the drop bracket solve most of the issues you guys are having. I have the 3" MAF drop brackets with about 4" of total lift and they are great. I was able to use the factory arms with the factory bushings with zero binding and great flex. The only down side is that the control arm mounts are now hanging lower and are vulnerable to getting bashed on the trail. I plan to plate and box in those mounts so I don't have to worry about them.

 

[dontblink]

Here's a photo of the lift overall, other than the non TJM associated part teething problems, I can say that I'm really happy the way the Cruiser handles on the 315's. Firm but not harsh and quite stable. The lift is a little lower in the back I think, (haven't actually measured it yet) but I don't have any weight up front. I have an ARB winch bumper in my shop waiting to go on which will eventually have a winch installed. It should be fairly level once the weight is on the front end, which will be great if it means not adding spacers. Fingers crossed.

That looks awesome!

 

[Rusty]

I'm not sure why people seem to think you need longer arms with a 4" lift.

In stock form the center of the axle is 2" higher than that of where the arms bolt to the frame mount.

Assuming a 4" springs yields 4" of lift then the axle is now 2" lower than the frame mount.

So comparing the axles position vertically they are exactly the same. They are just at the opposing sides of zero.

This was one of the design considerations when engineering my caster plates. I wanted a plate system that would retain the axle's position on the arm. That was achieved by relocating the holes on the axle bracket to only rotate the axle.

Attached are a couple of pics taken just a few minutes ago of a stock truck sitting in my drive way.

It's true, if axle centre on stock suspension is 2 inches above the pivot, or frame bushing, then a 4 inch lift should drop the end of the arm 2 inches below the center of the pivot. You can draw an imaginary line between the two points either side of the pivot that would bisect an equally imaginary horizontal line at 90 degrees, or the "zero" as you mention. Of course that's really over simplification though because caster correction that maintains spring alignment requires rotating the axle while keeping the spring perches in line. You just can't do that with stock arms, in essence you have to extend them to be able to relocate the axle pivot point and you run out of arm to do this.

Perhaps your caster plates achieve axle rotation to correct caster by pivoting the axle further out from where my lousy Ironman plates do. Undeniably this means that you really don't have to buy arms if you are prepared to drill and alter the axle bracket holes. You either alter the radius arm brackets on the axle or you extend the radius arm length.

At this point I'd rather try to source new arms than punch a second set of holes, next to, or nearly on top of the existing ones.

 

[Jake40]

Looks like you're running front bump stop spacers. Remove and problem solved.

 

[Rusty]

Looks like you're running front bump stop spacers. Remove and problem solved.

Removing the bump stop spacers doesn't put the springs back where they belong though.

 

[Jake40]

Alright I'll rephrase then. Contact between the spring and bumpstops is common on lifted 80's running stock control arms and dropped bumpstops. If the axle is square under the truck, the caster is within spec, and lift is uniform in height, then I personally wouldn't worry about the visual difference of the spring from left to right. I would simply remove the bumpstop spacers, as many have done before, and enjoy my truck with far less money invested than the alternative options that have been discussed. Just my opinion. Ignore if you'd like.

 

[Rusty]

Alright I'll rephrase then. Contact between the spring and bumpstops is common on lifted 80's running stock control arms and dropped bumpstops. If the axle is square under the truck, the caster is within spec, and lift is uniform in height, then I personally wouldn't worry about the visual difference of the spring from left to right. I would simply remove the bumpstop spacers, as many have done before, and enjoy my truck with far less money invested than the alternative options that have been discussed. Just my opinion. Ignore if you'd like.

I did think about doing this and from what I can tell there are mounts on the frame for the frame bump stops. I'm guessing that it would just be a matter of using those instead of the ones in the centre of the spring.

My driver's spring is quite bowed though so I'd really like to get things back in line. I'm going to own this Cruiser for some time so I don't mind spending the money to dial it in.

 

[Delancy]

You can draw an imaginary line between the two points either side of the pivot.

Not to perpetuate argumentation, but really, you can't.

It's not two points. Have to draw two imaginary lines, therefore it alters the length of one by rotating.

I'm not the sharpest tool, nor know how to input the radius arm into a calculator, but essentially it's a 4 link with pan hard and by increasing the distance of the vertical plane (lifting) it only makes sense that it shortens one of the link lengths, considering the pivot is the same location on both.

Right?

 

[kidglove13]

Obviously this is documented problem with lifting an 80 4 inches and higher.

But for one of your springs to be that much more off than the other I would really investigate to see if something else is not the problem.

 

[landtank]

It's true, if axle centre on stock suspension is 2 inches above the pivot, or frame bushing, then a 4 inch lift should drop the end of the arm 2 inches below the center of the pivot. You can draw an imaginary line between the two points either side of the pivot that would bisect an equally imaginary horizontal line at 90 degrees, or the "zero" as you mention. Of course that's really over simplification though because caster correction that maintains spring alignment requires rotating the axle while keeping the spring perches in line. You just can't do that with stock arms, in essence you have to extend them to be able to relocate the axle pivot point and you run out of arm to do this.

Perhaps your caster plates achieve axle rotation to correct caster by pivoting the axle further out from where my lousy Ironman plates do. Undeniably this means that you really don't have to buy arms if you are prepared to drill and alter the axle bracket holes. You either alter the radius arm brackets on the axle or you extend the radius arm length.

At this point I'd rather try to source new arms than punch a second set of holes, next to, or nearly on top of the existing ones.

Assuming the axle perch is sitting flat when in the stock position, once the axle is lifted the spring perch while still vertically centered is actually tilted forward.

Rotating the axle on it's center not only corrects that alignment but returns everything back to it's stock location only 4" lower than before.

A set of arms designed to do this would yield zero gains over drilling new holes in the brackets and might possibly flex less because you would need to accomplish the rotation by repositioning the bushings which I think would introduce more bind.

Good luck with your quest for new arms. I think a company called Snake Arms might have what you are looking for.

 

[Rusty]

Obviously this is documented problem with lifting an 80 4 inches and higher.

But for one of your springs to be that much more off than the other I would really investigate to see if something else is not the problem.

They're both out, one more than the other which is most likely attributed to, as Rick pointed out, the subtle difference between the driver's and passenger's springs. They are handed after all.

I have looked at the suspension closely. The suspension and stock length springs were fine prior to the lift. I thought the panhard rod was binding, it's not, and it's adjusted properly. I loosened the sway bar off at the same time, to check for binding there. It's just fine. Torqued all fasteners to Toyota spec.

I didn't know this was a problem with the Ironman style CC plates otherwise I wouldn't have bought them. I guess the problem was documented, I didn't see this documentation however. Some might think that's anal and move on by breaking out the grinder or some might simply ignore it and live with springs chattering on the bump stop cups. I'd like to get the springs back where they belong, operating more closely in the vertical plane where they were originally designed to be.

 

[Rusty]

Assuming the axle perch is sitting flat when in the stock position, once the axle is lifted the spring perch while still vertically centered is actually tilted forward.

Rotating the axle on it's center not only corrects that alignment but returns everything back to it's stock location only 4" lower than before.

A set of arms designed to do this would yield zero gains over drilling new holes in the brackets and might possibly flex less because you would need to accomplish the rotation by repositioning the bushings which I think would introduce more bind.

Good luck with your quest for new arms. I think a company called Snake Arms might have what you are looking for.

These guys seem to have it worked out...

http://www.superiorengineering.com.au/index.php?pag_id=24

Or maybe not, those things look to improve flex but look like they hang quite low... May as well gone with the Man-a-Fre drop brackets.

I see what you mean about bushing bind now, looks like more reading is required before I make any more moves!

 

[Rusty]

Not to perpetuate argumentation, but really, you can't.

It's not two points. Have to draw two imaginary lines, therefore it alters the length of one by rotating.

I'm not the sharpest tool, nor know how to input the radius arm into a calculator, but essentially it's a 4 link with pan hard and by increasing the distance of the vertical plane (lifting) it only makes sense that it shortens one of the link lengths, considering the pivot is the same location on both.

Right?

That's what I was getting at when I said this in the same post...

...Of course that's really over simplification though because caster correction that maintains spring alignment requires rotating the axle while keeping the spring perches in line. You just can't do that with stock arms, in essence you have to extend them to be able to relocate the axle pivot point and you run out of arm to do this.

Rick is right if his castor plates are set up to rotate the axle at the centreline, either side of zero, or the horizontal plane, an equal distance either side would put the axle in the same vertical location, just horizontally opposite. But to do this you have to drill the caster plates through the axle radius arm brackets to relocate the axle pivot because it's not located along the centreline of the axle from the factory.

It's either that or just bolt on new radius arms that return the axle geometry to stock (aside from the fact that it's 4" lower) utilizing the existing radius arm axle bracket location holes.

This may have a drawback of inducing additional bushing bind though because the axle still isn't rotating about it's center, of course Mr. T purists would be quick to point out that Mr. T didn't set the suspension up on axle centre from the factory, who knows what the reason for that is, so who's to say what the "right" thing really is.

At this point it doesn't matter much to me how spring perch and proper caster is achieved, and I not seeking some sort of uber-flex super sophisticated suspension. I just need something other than Ironman plates to get the springs straight(ish) again.

 

[Rusty]

On another note I'll need a d.c. shaft, the ride to the tire shop was awful due to drive line vibration. It was emitting all kinds of bizarre noise.

The ride home was dramatically quieter, once the 315-75-16 Toyo Open Country M/T's were on board. This must be due to reduced drive line speed. Before the lift and tires I re-geared to 4.88's and drove to the shop on stock 31-10.5's, so things were turning quite a bit faster before the 315's were on. It would be stupid to think that the vibration is actually gone; I'm sure leaving things the way they are will kill the transfer case at some point.

This wasn't a surprise, I thoroughly expected to need a d.c. shaft.

I was surprised at the tires themselves, I had read that modern day M/T's were quieter than M/T's of the past, but didn't really believe it. I had the Cruiser at highway speed on the way home and although they are obviously noisier than a more tame A/T, they were pretty reasonable. There was none of the old school, splitting headache inducing drone or hum that I had come to expect from M/T's of yesteryear. I can say that I'm happy with my tire choice.

 

[Rusty]

Update...

I recently purchased a front double carden drive shaft off Landtank. I installed it last night and took the Cruiser for a run this morning, all my driveline vibes are history now. With the unloaded front end of the Cruiser sitting almost 5 inches higher than stock the dc shaft was definitely necessary. Some claim that they don't need one with this much lift because their driveline vibration isn't that bad, but I know that my Toyo MT's were masking much of my driveline vibration because I had stock tires on intially and the vibration was horrendous. It makes me wonder how many rigs are rolling around without their owners realizing that the driveline is slowly taking out their transfer cases etc.?

Once my ARB bumper, winch, supercharger and dual batteries are installed the front end and will be lower and the driveline angle more slack, but I still think the dc shaft is a good idea.