Boge front struts problem - difficulty removing shock absorber insert

CharlesJones · 08-26-2005, 06:42 AM

Hi,

I need to replace both shock absorber inserts from my front struts of my '84 3.2, but I'm having major difficulties getting the insert out of the strut. The struts are Boge, and so I presume the inserts are also Boge.

In Wayne's rather excellent book it says you just need to undo the strut top nut (in luggage bay), remove the dust cover from the strut, then simply slide the insert out of the strut. Unfortunately it doesn't seem to be quite so easy for Boge struts though, since there is a retaining collar/nut which holds the insert in the strut which I just can't get off.

I've scoured previous threads in the forums looking for advice, and can find lots of threads on the topic but unfortunately there often seems to be some confusion about what is being discussed - whether the strut top nut is being referred to or the retaining collar nut etc. Just to make things clear for this querie I've attached a diagram below - its item number 4 which I'm having difficulty removing.

Is there a special tool which I need to remove this nut, or can I make do with something else? I've been trying various wrenches from my shed, but I can't get the thing to budge. If there is a special tool, do you any of you chaps know where I can buy it (I'm in the UK, so it would need to be online/by mail order).

Also, after reading previous threads I'm expecting the strut to be full of oil when I eventually get this retaining collar nut off. Is it okay for me to leave this oil in when I put the new inserts in, or should I remove it or replace it?

And one final question - do any of you guys know what I should re-torque the nut in luggage bay up to (item number 11 on the diagram) when I eventually put the strut back in place again?

Many thanks for your help. This forum has been an absolute life-line for me during my top-end rebuild which I had to do after bending all my exhaust valves after a mis-shift. Now all I need to do is replace the front shocks in order to get the MOT test certificate which is needed here in the UK before a car is allowed to be put on the road. Once its back on the road I will post pictures on the forum just to show you all what your advice and support has helped me achieve!

Thanks again,
charles.

Jeff · 08-26-2005, 06:49 AM

Charles, you can use a big pipe wrench to get the top nut off (#4 in your picture). After that pull the strut housing away from the car and pull out the cartrige. If you get it started before you pull on the strut housing it will be an easier exit as you have to pull quite hard on the housing to counter act the torsion bar. Also may want to put some tape on the fender so you don't accidentally scratch the paint.

Jeff · 08-26-2005, 06:55 AM

Just re-read your post. Use a rag to soak up the oil left in the strut housing before you install the new ones.

Torque on top nut should be 80 Nm or 58 ft-lb.

CharlesJones · 08-26-2005, 07:08 AM

Thanks for your reply Jeff - that's very much appreciated.

I don't want to sound like a retard, but is a pipe wrench one of these things:

Also, after I've removed the oil from the strut is it necessary to put in new oil before slipping in the new insert? I've just received my new inserts today, but I don't know how much space there will be in the strut when the insert is in place (since I haven't got that damned collar off yet!).

Thanks again,
Charles.

john walker's workshop · 07:17 AM

i use big channel-locks to get the nut off. the original insert is not a one piece unit. when the nut is off, use a pick to remove the black o-ring that was under the nut, them the rest pulls out easily. have a pan nearby to set the drooling guts into, then suck out the remaining fluid with a sump gun.
before you angle the strut out of the wheel well, remove the brake line horseshoe clip that holds the flex hose to the fender well to avoid stretching the hose.
don't drop both sides together or you will fight the swaybar tension on reassembly. finish one side then do the other.

Jeff · 08-26-2005, 07:18 AM

Charles, Yes that is the wrench. No need to put any oil in.

And as always, What John said.

CharlesJones · 08-26-2005, 08:19 AM

Thanks very much guys - this is incredibly valuable advice and I really aprreciate it. Thanks John - I didn't know the original insert wasn't one peice. I guess that's why Jeff says I won't need to put any oil in it when I put the new one in? Presumably the strut being full of oil was to enable the earlier system to work?

UK Carrera · 08-26-2005, 08:30 AM

Personally I would put a small quantity of oil in, say gearbox oil. There should not be any movement of the insert in the strut housing but the oil will damp out any that occurs.

Had a devil of a problem with a non-Porsche many years ago after replacing some front strut inserts. Chased it around for ages until I re-did the job but this time putting a small quantity of oil in the housing before putting the new inserts in. Basically I could feel vibration through the front of the car.

Jeroen · 08-26-2005, 08:41 AM

IIRC you fill the strut up to a third or quarter
anti-freeze fluid has also been used instead of oil

Bulldog9 · 01-24-2014, 04:53 AM

Sorry to pull this up from the dead,

In the middle of this project right now, got the cap/nut off no problem, but the struts dont want to come out? These are the original oil filled cartridges. The cartridge spins easily in the strut housing, but it will not pull out. What am I missing?

Thanks!

KFC911 · 05:16 AM

Quote:

Originally Posted by Steve Pratel

Sorry to pull this up from the dead,

In the middle of this project right now, got the cap/nut off no problem, but the struts dont want to come out? These are the original oil filled cartridges. The cartridge spins easily in the strut housing, but it will not pull out. What am I missing?

Thanks!

'Bout ten years ago, I had a similar issue removing a new Bilstein insert that I had put in about 6 months earlier. Spun freely, but just wouldn't slip out like they are supposed to. I was a novice (still am

), so I took it to a local import shop. They'd never seen anything like it either. Never did figure out why it wouldn't budge (wasn't bent, suction, etc.). Solution...put a nut back on the top to give you something to strike against and use a chisel (up against the nut) and a BFH (that's what the guy used)...took several solid whacks. Hope this helps...

ps: I was in the process of a suspension refresh...strut was off of the car.

UK Carrera · 01-24-2014, 05:52 AM

Is there any oil in the strut housing?

Long shot (hair brained musings of a delusional sometime engineer) - if you're pulling against some oil in the strut housing (i.e. around the insert) would there be sufficient suction force to cause this? Would spin as you've noted but difficult to pull out.

88911coupe · 01-24-2014, 06:30 AM

I'll be tackling this project as well and was wondering if someone could shed some light on the purpose of oil/no oil? Is this something that comes with new shocks or is it used on a case by case basis? I'm just trying to be prepared when I do this on my '88 which has 195k miles on the original shocks! They seem solid when I do the normal "bounce" test but they have to be shot...right?

theiceman · 01-24-2014, 07:12 AM

you cant get it out because the oring is till in there i am betting .. get a pick or something and get the oring out .. i think it is a decent thickness o ring.. once you get that it will slide out ..

The old shock is hydraulic with all that oil .. the new insert is a gas shock fully self contained .. get all the old oil out or it will come out on its own with force when you drop the new insert in ..

and dont forget to tape the fender .. painters mask on the paint ( easily removeable ) then cover that with dut tape , that is really protecting your paint if you catch it ..

aj88cab · aj88cab's Garage

When you try to pull the old insert out, suction is holding the old strut piston & rod in the shock tube. Wrap a rag around the top and push the rod down into the tube and everything will pop out. Trust me, you really want that rag around the top, otherwise hydraulic fluid will shower you.

Reiver · 01-24-2014, 12:32 PM

and wrap your brakes/disc and caliper in a plastic bag and tape it shut so you don't contaminate the pads with oil....it'll shoot out of there.

Flojo · Flojo's Garage

as this thread is recently up, may i ask if there is a pictured docu?
its to get some clear ideas when seeing the dismantled parts.
thanks!

zippy_gg · zippy_gg's Garage

I recently pulled mine out...

Here is what the Boge plunger assembly looks like

... compared to a Bilstein insert for Boge strut

I had to put the strut in a shop vise and use a pipe wrench to remove the collar while my very strong stepson was holding the assembly steady (my bench was moving under my effort

).

john walker's workshop · 01-24-2014, 03:25 PM

slip the big cupped washer back on the shaft and attach the nut. now you have something to knock on to get it moving. i use an airhammer , lightly. the original boge should come right out after removing the internal o-ring. it's the one piece replacement inserts that can give you trouble.

Bulldog9 · 01-24-2014, 04:24 PM

This was the issue. Once I pulled the o ring out with a small pick, the inner unit slipped right out. The struts (and entire front suspension) is out of the car for a total refresh, clean, paint, etc.... Ditching the rubber suspension bushings and going with the Rebel Racing units, upgrade to turbo tie rods, monoball uppers. whoo hoo!

Thanks for the input!

Quote:

Originally Posted by theiceman

you cant get it out because the oring is till in there i am betting .. get a pick or something and get the oring out .. i think it is a decent thickness o ring.. once you get that it will slide out ..

The old shock is hydraulic with all that oil .. the new insert is a gas shock fully self contained .. get all the old oil out or it will come out on its own with force when you drop the new insert in ..

and dont forget to tape the fender .. painters mask on the paint ( easily removeable ) then cover that with dut tape , that is really protecting your paint if you catch it ..