Front Hydro Subframe

[Spider]

I find when they are like this, one method I'd used to remove them is to spread the tower a bit, then get cut the end off the pin at the step with a reciprocating saw. I use a long bolt and joiner nut for spreading the tower and they spring back after. I've done many like this over the years, all without damage to the arm or the frame.

[Gary Schulz]

A method that I forgot all about (until a forum member pointed it out) is to weld the nut to the engine side of the pin and then put a big bar on it to hopefully break it loose. I think I 'll try that as a first step since it doesn't risk damage to the subframe. If this doesn't work, I will head to the more invasive approaches until I am successful!

[Gary Schulz]

Finally welded the nut on the inside of the pivot shaft (by welded, I mean deeply welded using a TIG at 200A) then took almost two minutes with an impact gun on the radiator side and about 30 seconds on the clutch side to get the pivots to spin so I could withdraw them. Wow, that was brutal but thanks @rich@minispares.com for the suggestion. He was even correct that the radiator side would be hardest!

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[Peter Laidler]

Another example of all that's good about this forum

[Gary Schulz]

Yes, all the suggestions were good and relevant. This forum is a great resource for sure...

[Peter Laidler]

Seeing this and other similar threads, I wonder to myself just how mini restorers manage to restore their cars without being members of the Forum. For example...... How would the average home fitter/enthusiastic amateur non forumer tackle this job without a fair bit of input from the Forum brethren

[Gary Schulz]

As a bit of a postmortem; I was wondering how the upper arms could have been so hard to remove and I guess I see why. The engine side needle rollers on both sides appear to have disintegrated long ago and have worn almost all the way through on one side. The upper control arm hole for the pin is no longer even centered in the arm so everything eventually just fused together. No wonder this was nearly impossible to get apart! Guess the arms are junk too...

EDIT: Looks like the arm is ok. Should be able to reuse this bearing so I can keep the car absolutely original!

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[Peter Laidler]

Jeeeeees...... How bad is that. On the other hand, if hydro upper arms were impossible to get, then I dare say that you could bore out and sleeve the bearing housing. It'd certainly take some setting up on a milling machine....

These are the great pictures to show to practical engineers, to ask them to come up with a solution. Thanks Gary...... I'll be asking a few of my nerdy engineering classic car fiends when we meet up for a couple of beers later this month!

[1071bob]

Mine was like that, had worn through into the arm and damaged the thrust face, could have changed the top arm but all the spare ones had the knuckle pins worn through into the arm. Machined the I.D. and the thrust face and pressed in a 'top hat' sleeve.
The bottom top hat plate was pressed into the arm and bolted to the 'T' slot in the mill, the top plate and bench vice held the arm during machining.

[floormanager]

There are far too many clever people on this forum. Many lifetimes' experiences willing to be shared at the touch of the finger tips. Bloody well done all.

[CooperTune]

My reply while somewhat cave man, was based on my having several hydro sub frames some blasted and powder coated. One front has been in my attic since 1980 with MOWOG stenciled on front cross. Having a collection of Hydro uppers (which I use to increase spring rate on dry cars) and machine oil-lite bronze bushings to replace needle bearings. Having saved every upper arm and rear swing arm shafts over the years none are reusable. The needles wear the shafts and add moisture we see what happens. Oddly, most of the rear hydro arms have worn though the bearing and into the arm itself. It seems std repair for that is push in new bearing then drive finishing nails in around worn side, I have considered a repair as shown on fronts. I have been changing hydro to dry since 1971. My most recent was 72 Inno 1001 odd bird with two bolt per side wet sub with rod change. Somewhere I have a box of the white plastic tubes that protect the front hose as it passes though shell front cross member. My only true Cooper S is a 64 1071 which is dry. Being Almond green and RHD I'm unlikely to restore it. Steve (CTR)

[Peter Laidler]

I am inclined to agree with you regarding the oilite or bronze bushes Steve. On the basis that the upper arms can only travel through approx 30 degrees AT MOST. Needle rollers provide point contact whereas full dia and length oilite.bronze have 360 degree contact area.

Spider Chris has done some work on this too in the past. What about greasing up the shaft and bushes.....? I would suggest that a grease track-way like the rear swinging arm outers would cover all bases.

Alas, as someone said to me a year or so ago '.....it's OK for you blokes but the average mini restorer or home mechanic/enthusiast doesn't have a machine tool workshop handy...' Fair point!

A really good discussion point in a workshop classroom.........

ADDED A FEW DAYS LATER..... Another point to ponder is that in this front and rear suspension application, these needle rollers, as individual needles or as a unit, cannot ever make a full rotation - as they were made and designed to do. Defeating the object. Bushes are a better bet

[CooperTune]

Yes, much like lapping ball joints a few grooves to allow grease to make it's way to thrusts are required. I also replace the inner bearing on rears with bushings. I realize not everyone has access to machine tools. I still find myself making special tools to make life easier. Steve (CTR)
Edit: I now understand how the average Joe feels. From 1975 though 2000 when I retired, I had access to a full-service auto machine shop 24 hours a day. Following that for another 24 years I had access during operational hours. After 99 years this past spring the equipment was sold off and the building cleaned, repainted and sold as well. I live in what is often referred as Seven Cities a huge metro area in land mass. Starting the 25th year since retirement we have lost six auto machine shops during that period. I'm struggling to find a shop that can bore 850,997,998 and 1100s.

[Gary Schulz]

ADDED A FEW DAYS LATER..... Another point to ponder is that in this front and rear suspension application, these needle rollers, as individual needles or as a unit, cannot ever make a full rotation - as they were made and designed to do. Defeating the object. Bushes are a better bet

Absolutely true. The upper pivot pin has a diameter of 0.75" which gives a circumference of 2.35". If the upper arm can move a total of 30 degrees (I think it may even be less), then the individual needle roller needs to have a circumference equal to or less than 1/12 * 2.35" or 0.19" (30 degrees is 1/12 of 360 degrees). As near as I can tell, the individual rollers are about 0.075" diameter which gives a roller circumference of 0.235". Clearly they will not do a full revolution. They do approximately 80% of a full revolution. Of course the suspension spends possibly 0.01 percent of the time at the 30 degree travel limit. The vast majority of the time it is within 5 to 10 degrees which makes the problem even more untenable.

I think there are similar issues in several types of "high performance" rockers that use needles on the rocker shaft. In the case of these upper suspension arms, as long as things are properly lubed they get by ok for a reasonable lifespan but certainly less than ideal.

[Spider]

I have use bushes in Rear Trailing Arms with great success but haven't gotten around to the fronts, though I've found these to be less problematic than the Rears as long as they have the correct bearing fitted and they are greased properly.

One thing I will mention is some of the kits available have soft pins and some are supplied with the wrong bearings, ie Caged types. They must be Full Compliment versions. The other thing to watch here is for poor quality bearings, like those KOR branded types.