So I think that the reason that my rear tires are wearing funny is the old, worn-out rubber cones. I know it could be the trailing arms, but everything i read says start with the cones, since they wear out every decade or so, and mine are very much due for replacement.

But...

There are also THESE ITEMS, on Minimania and other places, that replace the rubber cone with modern springs:



These are usable with the stock suspension assembly, or with Hi-Los if I later install them. I read that these springs last much longer than the rubber cones, and perform better (if a bit rougher) since they rebound a bit more aggressively. And, at $195 per pair, they're priced almost the same as the rubber cones (which are $90 apeice from MiniMania, 7Ent and other places).

So... honestly... what am I missing here? Why would I replace the rubber cones when I can get modern tech for about the same money? Tech that, if everything I've read is to be believed, will hold up longer and perform better? Are there reasons why I'd WANT to stick with rubber, all things being even?

Note: I use my 1275cc Mini as a daily driver in the warm moths, and do not track the car or care about keeping "original" parts on her - Fiona's lovely, but she'll never be a Concours or Heritage car.

Thanks as always!!

 

NO.
Proper alignment may be your issue. If the car is not tracking your tires will wear.
That money can be better spent on a camber kit and/or aligning your subframe if it's off.

 

But how can I be sure? When I first raised the tire wear question, I got a variety of answers, from trailing arms to the cones to possibly the rear sub frame (someone asked me if the assembly had ever been off the car - I have no idea).

If I take the car to a suspension place, can they measure the classic with modern tools? Once they determine how much the tracking is off (which it must be since the tires are wearing on the outside edges), will they be able to pinpoint the component that needs adjustment or replacement?

Where do I start? I know the cones need replacing - the car is visibly sagging on the rear, RH corner, and I assumed that this was part of the problem.

 

Cone life is about 5 years. The rubber compresses and hardens. It loses its resiliency. Springs are an improvement and for the price differential, I would go with them.

However, the rear springs do not effect your tracking as the trailing arm pivots at the front end and works the cones via a lever arrangement through the strut. Not like an american car where the spring helps determine the camber angle.( IE weak spring more neg camber.)

You need to have someone knowlegeable in Minis look at your car and find what else is worn or misaligned. You have been given the most likely candidates: misaligned subframe, worn radius arm bushings (very likely), worn subframe mount bushings, bent radius arm or mounting brackets.

Rebuilding the rear suspension is something that can be done by a novice Mini mechanic. You'll only need some machine work (reaming to size) if the radius arm bushings are replaced. If it were mine I'd just rebuild it all, new subframe bushings (rubber or urethane), new springs, new knuckle joint/cups, check the radius arm pin & bushings and install adjustable camber brackets while your at it.

 

The rear cones aren't too hard to get off so maybe you could swap the left for the right and see if the left is now the trouble side.

On a side note I had a hell of a time getting the front cones out of the frame tower even with the frame being off the car. I don't know if I went about it wrong but it seemed that the cones were slightly bigger than the opening in the tower.

 

Did you get the cones out? If they are really old they tend to spread and fill the opening in the front and back, sometimes it just takes a bigger hammer!

 

Let us know if you get these, I have always wondered how they respond. I cant imagine anything stiffer than the rubber cones.

Is both sides wearing the same way? I would have to agree with MiniMad that worn bushings are your culprit.

 

Yeah, the tires are both wearing on the outside edges. The left looks worse but the right is wearing in a similar manner.

I'll go for the springs then - are they hard to install?

I'll need to ponder the rear end rebuild... sounds like it's not THAT hard, but I'll need to watch it done the first time. Plus there's some machining that will be required it sounds like.

Also, what are "adjustable camber brackets"? Are those Hi-Los or something else?

Thanks!

 

Hi-Los are a nice addition if you can afford it. They allow future adjustments if spring/cones sag.

Adj camber brackets are on the outside mount of the radius arm and permit the rear end to be aligned more accurately.

 

These?

http://gbcarparts.com/proddetail.asp?prod=SRRearCamber

Will these be required if I replace the bushings as you indicated, or are they just a "good to have" item? they're not TOO expensive (less than $100), but as always, I'm on a budget.

Also, what other bushings (if any) will I need besides these? This is "all 6 bushings" for the rear as per GBCarparts...

http://gbcarparts.com/proddetail.asp?prod=DeflexRearSub

Here's a rear knuckle joint/cup - I assume these will work with the rear spring kit linked at the top? I'm a bit hampered by the fact that I've never seen the rear joints apart and I don't have my Hayne's book where I am ATM. Thanks!

http://gbcarparts.com/proddetail.asp?prod=KnuckleJoint

 

I run Yokohama 008 on mine which are wide to start with and have spacers in the back and they wear fine, I think if you rebuild the rear end you wont need the camber adjustments, and the answer to getting the rubber cones out it is pretty easy, take the shock loose let the arm drop and pull the trumpet out first the ball will follow. It is actually very easy to do. I am not sure what machining needs to be done unless the arms are no good and require something that is oversize to fix. it has been quite a long time since I have had my rear arms off and I may be missing something but it shoudl all fit back together nicely with new parts. Maybe MiniMad knows something about the bushes, like they make them one size and if you have one type of arm over another is it needs reamed out, I dont know. But the rear is pretty easy to deal with. The front on the other hand takes more work and requires either compressing the old cone with a special took so you can get the trumpet out or you need to take the upper control arm out to get it all apart.

 

The front's wearing great and I just had the ball sockets apart to replace the CV boots, so I was planning on just doing the rears for now (cost issues).

I'm not sure about the "reaming" either, but maybe someone with direct experience can chime in? If it's as simple as taking everything apart and replacing all the worn bushings and the cones with springs I assume the Hayne's book is detailed enough to guide me. Silly, perhaps, I know but...

 

I just took my rear suspension apart a few weeks ago to blast the frame. I can take pics if this interests you.

 

do what's cheapest first.
1. Inspect trailing arms for wear Rebuild kit is cheap.
2. MInis came with positive camber from the factory.....an adjustable camber kit should fix that.

 

Yes please!!

Is the "rebuild kit" the bushing set I linked to above, or something else? The one I found advertises "all bushings for the rear". I'll do the knuckles as well if they work with the springs I want to use (alignment issues aside, I'm sagging so I need to replace them) - they're only $20 for the set and I'd rather just put them in when I have everything apart. Right?

 

Your list of parts is correct.

The camber brackets are "nice to have" but not necessary.

This is a radius arm rebuild kit. you need one kit per side. Note one needle bearing assembly - presses into place. The bushing also presses into place, but when you do so, it decreases the internal diameter. You must ream the bushing out to match the external diameter + clearance of the new shaft. removing old bushings is a PITA. You may want to just take it to a machine shop & pay them if you don't have experience & tools (& patience).

There is no sense in taking the arms off and not replacing all wearable parts. Do it once, correctly.


The trunion bushings (subframe bushings) can be done anytime separate from the radius arm rebuild or spring replacement.

 

not to add more confusion to your thoughts, but sagging can be corrected with Hi/Los unless the cone has fully collapsed and/or you feel the ride is just too harsh.
One more thing you may want to inspect is wear on the bearings......not fun to find out they are bad at freeway speeds.

 

One of the greatest innovations in the design of the Mini was its rubber cone suspension. The compact design & lasting quality of the rubber cone helped make the Mini what it is today. Designed in the late '50s it was ahead of its time - the only problem is that many of us are still driving around on cones that could have been built in the early '60's. The design is good, but not everlasting! The rubber not only get very hard but it also sags and loses its ability to hold the car upright. It is not uncommon to have a cone sag so badly that it lowers the car 2 or 3 inches and it handles terribly! These should be replaced every 5-7 years depending on use and climate. Measured at the wheel, the spring rates at the static load position are 118 lb/in at the front and 98 lb/in at the rear. With three passengers and 50 lb of luggage, the loads per wheel at the same position are respectively 468 lb and 355 lb. These loads rise to 1,050 lb and 670 lb at full bump and fall to 240 lb and 100 lb when the rebound check is in operation. Early cones were SAE (UNF 1/2x20), all current cones now have metric threads (14mmX2)
http://www.minimania.com/web/Item/FAM3968/InvDetail.cfm

 

I don't know if this helps or not.

http://s412.photobucket.com/albums/pp201/pournarast/