Bump stop issue

[Acronymous]

My 79 twin cab has been raised, 3" [I was told by the previous owner though I'd like to check that measurement].

Aside from that I've noticed that on the RH side the bump stop cone, inside the spring, is slightly misaligned and at max compression comes into contact with the spring and presumably doesn't insert into the concave cavity on the lower spring mount point.

I'm guessing this means I'll have to pull the assembly apart and have the conical steel section at the top of the bump stop assembly straightened, though I can't be sure where the problem lies and I can't see a bend at any particular point although the lower end of the bump stop is way too close to the spring at a point where it's clearly been making contact .

I can't see any obvious way this might have happened in the first place other than a) it was assembled out of alignment or b) the tip of the "cone" has missed the cup at some point, slipped to one side and bent the assembly.

Has anyone had experience with this event, are there any suggested remedies and could it have connection to the 3" of suspension lift?

Suggestions welcome.

Jules

 

[Acronymous]

Hmm, looking at the pic, it seems as though the whole bump stop assembly might be positioned too far outwards at the top mount and could actually be straight. Is that possible? How is the top of the bump stop located in the top mount for the spring? Is it possible it just hasn't been settled down properly in the spring mount?

Looks like a job for Workshop Manual!!! I see it's now not ok for ordinary people in this country [Australia] to own or look at a workshop manual because they might be tempted to do work on their car that only a qualified expert should do, pah!

Jules

 

[Shayne]

Whats the other side like ?

I'm wondering if you need to extend the panhard rod to centre the axle after the lift ?

 

[Acronymous]

I've been wondering about that. The Panhard rods appears to be the original ones so yhey could be an issue. The other side spring/bump stop is fine though, being centered. There might be an overall suspension misalignment problem. The tyre on the LHS looks to be f eathering slightly on the outer edge. Viewed from the front , the wheels have a fair bit of +ve camber and I don't know if that's "normal" or not. For someone who likes a bit of negative camber it's a little disturbing.

 

[Shayne]

How was caster correction done ?

 

[Acronymous]

I have no idea and I can't find out from the former owner. I've got an alignment booked in so that might bring some clarity. There's no oddities in the handling.

 

[Acronymous]

Thanks for the suggestions Shayne. Could you recommend a source for a workshop manual? I think I'll have to settle for digital but some sites can be a bit dodgy for manuals and I want a genuine version.

Jules

 

[Acronymous]

Is there any way I can tell if caster correction bushes have been fitted to the radius arms?

 

[Shayne]

I would think you can tell visually by the bolts not being central

While i don't know the 70 series at all it is generally accepted that a 2" lift doesn't need caster correction but 3" and more does .

Springs look quite knew as well , and perhaps they are over rated for a winch bumper that was never fitted making a 3" lift look more like 4 ?

 

[Acronymous]

Thanks Shayne. The radius arms at the point where they connect to the bushes pretty much shroud them, so it's not easy to judge if they're off-set or not. I managed to contact the previous owner to ask him a few questions and he reckons he's fitted caster correction bushes plus the lift is 2", which is ok with me. There's no sign of shimmying on the highway so I think I can stop worrying about caster.

The panhard rod is original, non-adjustable but I understand that should be ok with 2" of lift.

Two things need doing 1) The wheel alignment is out, by quite a bit I estimate but 2) the wheel bearings either need adjustment or replacement before I can do 1).

A problem with feathering on the outside of the RH front wheel looks most likely to have been caused by the wheel alignment, so I'll see how things look after fixing that.

The spring/bumpstop misalignment might have to go to someone who has the gear to deal with compressing the spring to sort it out.

Thanks for the help. I've worked on various cars before but this set-up is quite new to me.

Jules

 

[Acronymous]

Latest theory. In the pic below you can see that the bottom land for the spring is shaped so that the end of the spring has a particular place to sit:

It looks to me as though the spring should be rotated about 180 degrees so that the end of the spring sits in that stepped depression on the foot mount. I reckon that because the spring is being supported at the wrong place it's deformed the middle of the spring inwards, hence it's making contact with the bump stop cone.

Possible?

Jules

 

[Tractionman]

I've been following this thread with interest, and I think you have hit the nail on the head, and that looks exactly what's happened. Previous owner hasnt assembled correctly, although why he missed it is a mystery.

 

[Shayne]

All around the houses to find the obvious answer .

 

[Acronymous]

Spring rotated, problem sorted, thanks for the answers. I can't see how anyone could have put it together so carelessly but there's signs of a few things having been done like that on my car ... good ideas and parts, poorly implemented.

I'm contemplating caster correction. At 2" of lift opinion seems to be that it's unnecessary but would it make any difference?

Jules

 

[Tractionman]

Well done mate, such a simple job on installation.
Check out other areas as and when, previous owner has no idea, if that's his idea of job done.

 

[Shayne]

At 2" offset bushes are your only option which is counterproductive i would think as by their very nature they can't be as good as genuine original .

 

[Acronymous]

Well done mate, such a simple job on installation.
Check out other areas as and when, previous owner has no idea, if that's his idea of job done.

Thanks, wheel alignment is fairly badly out and the wheel bearings needed adjustment but I haven't found any serious issues and the oil changes were frequent, which is always good to know. I discovered breather tubes fitted to the diffs and gearbox ... some rather casual fixing of parts with zip ties but that's easy to sort out.

At 2" offset bushes are your only option which is counterproductive i would think as by their very nature they can't be as good as genuine original .

Aaagh yes, it's frustrating to have to pull apart assemblies like that when bushes fail prematurely. I'd better start a thread on the various bits and pieces I'm doing with this car.

Jules

 

[Tractionman]

Ahh, the good old zip ties, used them many times, a great quick or temporary type of solution, unfortunately in some situations, they turn into a permanent bodgers friend.

 

[Acronymous]

In relation to the 2" lift and changes to caster, I've just had the wheels aligned and the caster for both front wheels is around the 2 degree mark. The specified limits are 3 degrees 20 minutes to 5 degrees 20 minutes, so there's quite a difference. According to the recommended alignment specs this could cause tyre wear, handling and safety problems ... hmm, handling feels fine and given the accepted wisdom is that it's ok to stay with std. bushes I think I can use the money elsewhere. I will be keeping a close eye on toe-in though.

Jules