87 Carrera strut replacement ?'s

[ianc]

Hi Folks,

First, the disclaimer: I've searched and didn't come up with a lot.

I did the front struts on my SC awhile ago and ran into the issue of determining whether the car had Boges or Bilsteins and how to determine which. Seems like color is a fairly reliable indicator with SC's.

With the Carrera, it seems as though the car also came from the factory with Boges or Bilsteins. Is this correct? How does one tell which one has? Is the color of the strut again a good indicator?

When ordering replacements, I've read that even if you have Boges, there is a replacement Bilstein insert. Correct?

With the SC, you needed to drive out a roll pin to remove the insert, but it seems like the Carrera has a large cap nut on the top securing the insert in the strut. The Bentley says the entire strut must be removed from the car to make the replacement. Is this necessary?

Can enough torque be put on the cap nut with the strut still in the car to break it loose? What tool is recommended to remove this?

Thanks for any help,

ianc

[89911]

Originally posted by ianc
Hi Folks,

First, the disclaimer: I've searched and didn't come up with a lot.

I did the front struts on my SC awhile ago and ran into the issue of determining whether the car had Boges or Bilsteins and how to determine which. Seems like color is a fairly reliable indicator with SC's.

With the Carrera, it seems as though the car also came from the factory with Boges or Bilsteins. Is this correct? How does one tell which one has? Is the color of the strut again a good indicator?

Very few late Carreras came with Bilsteins from the factory. My car had the sport suspension and it was still Boge. The Boge struts have "Boge" on them sumewhere.

When ordering replacements, I've read that even if you have Boges, there is a replacement Bilstein insert. Correct?

Biltstein inserts directly fit into Boge struts. If you Bilstein struts you need a different insert. Specifiy this when ordering.

With the SC, you needed to drive out a roll pin to remove the insert, but it seems like the Carrera has a large cap nut on the top securing the insert in the strut. The Bentley says the entire strut must be removed from the car to make the replacement. Is this necessary?

Yes, I use a big pipe wrench. The easiest way I found to remove this nut is to first take off the top nut (usually requires an air impact wrench), compress the shock and carfully position it outside the fender. Remove the shock cover, compress, and place back into the top mount. Now you can get leverage on the nut without the shock housing floping all over the place. Remove the old one and remove all the remaining oil. The new cartridge is a self contained one that fits inside the Boge strut.

Can enough torque be put on the cap nut with the strut still in the car to break it loose? What tool is recommended to remove this?

The top nut usually requires an impact wrench to counteract the turning of the shock piston.


Thanks for any help,

ianc

[M Scahfer]

My 88 came equipped with BOGE and I replaced with BILSTEIN's HD in the front and SPORTS in the rear. Very worthwhile upgrade. The old BOGE front struts can be removed by compressing the strut and carefully angling in out around the fender lip. There is about ~200cc of oil in the old BOGE strut/housing that needs to be removed since the BILSTEIN's are gas struts. Shox.com by far gave me the best prices and delivered to HI in about 5 days. If you have someone who has done this before it's about a 90 min. job for the front and half that for the rear. The nut on the top of the strut housing can be removed with a pipe wrench since the new BILSTEIN's come with a new top nut and special wrench. Good luck it will transform the car, you will realize this once those BILSTEIN's are in place.

[Icemaster]

Dont' get intimidated, it's actually pretty easy.

Pipe wrench will remove the ring nut holding the insert in place, pump out the old oil (unless they've been replaced already), get underneath the wheel well and compress the insert, tilt the strut straight out the wheel well, but put as little pressure as possible on the brake line or you'll be replacing that also. Slide the insert out, watch your clearance on teh lip of the well.

Install is the reverse, it's easy.

[ianc]

Thanks for the advice guys. I've already done Bilstein HD\Sports on my SC, so I have a good idea of what's required, but I just wondered if enough torque could be generated on the cap nut with the strut still on the car. Thanks again,

ianc

[Wil Ferch]

You can generate enough torque on the nut...and safely too...by "bracing" the steering lever arm with a piece of 2x4 against something like the back fender well.

Wil

[CharlesJones]

My strut cap nuts were so tight they felt like they were welded on, but I still managed to get enough torque on them to get the buggers off. I used a large pipe wrench and got my girlfriend to hold the strut still with both hands while I heaved at the cap with the wrench. After a lot of grunting from us both they finally came free. I think Wil's suggestion sounds a better idea though.

[ianc]

Do I need to worry about this nut then, or does a replacement cap nut come with all Bilstein inserts? And wrench?

ianc

[KTL]

No worries about saving the old nut. A new, different, better nut comes with the new Bilstein inserts. A tool should also come with the inserts. It looks like a flat crowsfoot eyelet. Sorta similar to the ball joint socket pattern with square pins around the perimeter of the tool which go into the notches in the new nut.

[ianc]

Thanks Kev,

ianc

[rnln]

anyone have similar write up for the rear replacement? I found that the rear shock came through the engine bay and stay at the rer most, hinding by a bunch of stuff. How do you guys get your hand and impact gun back there to undo the top nut?
Thanks.

[HarryD]

Originally posted by rnln
anyone have similar write up for the rear replacement? I found that the rear shock came through the engine bay and stay at the rer most, hinding by a bunch of stuff. How do you guys get your hand and impact gun back there to undo the top nut?
Thanks.

I have a '73 and when I did my rear shocks, I found you need to be a bit of a contourisist (sp) to get those nuts. You may need to push aside some parts to get access.

[livi]

Hey ianc,

Look at it this way.

Even I managed to swap shocks front and rear myself. Boge to Bilstein.

And, as you know, that says A LOT !

BTW, my biggest dilemma was getting enough angle on the front shocks to pull it clear of the fender lip. The brake hose was the limit. I pulled of the little clip to the inner fender wall and pulled the metal part of the hose threw the fastener and managed to get a few more inches, which was enough.

But you probably new that, right.

[Nine9six]

Originally posted by rnln
anyone have similar write up for the rear replacement? I found that the rear shock came through the engine bay and stay at the rer most, hinding by a bunch of stuff. How do you guys get your hand and impact gun back there to undo the top nut?
Thanks.

The front replacement is easy, and the rear replacement is even easier.
Remove the parts that hinder your access (5 mins)
Top nut and bottom bolt and out comes the shock. Insert the new one, and button it up.

[KTL]

Originally posted by rnln
anyone have similar write up for the rear replacement? I found that the rear shock came through the engine bay and stay at the rer most, hinding by a bunch of stuff. How do you guys get your hand and impact gun back there to undo the top nut?
Thanks.

You can use a pair of pliers/vise grips on the shock shaft and then use a wrench to take off the nut. The top nut is typically not that tight. But you never know. If they've been previously replaced, the previous replacer could have gorilla tightened the nut for no good reason.

I'd be careful using an impact on the bottom bolt. The trailing arm is alloy and you can easily strip out the threads if the bolt is stuck in there. Best to use a long breaker bar to start the bolt coming out. Once it's loose and feels like it's coming out cleanly, you can speed it out with the impact.

Be careful using an impact to reinstall. The alloy threads are easy to cross thread, even when you think you've properly started the bolt by hand. Make sure you have plenty of thread engagement by using your hand, hand ratchet or wrench before putting an air tool on this bolt. The important thing is to use a floor jack to raise the trailing arm to the same elevation as the drooping end of the shock absorber so you can align the shock and trailing arm to prevent the bolt going in cockeyed. Then torque it to 125 Nm/92 ft-lb (torque value is for alloy trailing arm- I don't know what size nut and bolt is used on the early steel arms)

[NO LIFT]

I found this thread very helpful, but I could use a little clarification for my feeble mind and lack of self confidence in my mechanical abilities...

My car is an '88 Carrera and has already has green bilstein struts. I believe the inserts may have already been replaced because the PO has upgraded the t-bars and sway bars.

In reading Wayne's book, it sounds like I remove the roll pin from the bottom, remove the large nut on the top of the strut, compress the shaft, and swing it out from under the fender and pull it out?

Is it easier to loosen the large nut on top with the weight of the car on the suspension first?

Any hints for the roll pin? Tap out, or drill out?

Installation of the new is the reverse?

Since the upper strut bearings and strut mounts to the hub is not removed, do I need to check alignment?

Thanks in advance for input.

[KTL]

4 days and no reply.......... Surprised no one else answered your questions.

That's right. You remove the roll pin at the bottom and the nut atop the shock shaft at the strut mount inside the trunk/luggage compartment. You do NOT have to remove the piece around the top of the strut tube itself. The Bilsteins are not like other struts (Boge, for instance) that have a collar/gland nut on the strut tube to hold the shock insert in place. On the Bilstein struts, this piece is a scraper seal & bushing to clean/lubricate and support the shock. However, it does not require removal to get the shock insert out of the strut

It is indeed easier to loosen the top nut when the shock is loaded by the weight of the car. This nut is not that tight, so an impact wrench should easily zip it off. DON'T zip it back on with a lot of torque. 60 ft-lb is the torque spec I recall off the top of my head, but double check that number in the Bentley manual or Wayne's 101 book to be certain.


The roll pin just taps out with a suitable punch or bolt of the necessary diameter. Take note of the roll pin when you get it out. If it drives out really easy, you should replace it. The roll pin is split and provides a press fit by being slightly larger in diameter than its receiving hole, but allows for compression due to the split or springing effect. Note that it has a flat end and a tapered end. You want to insert the tapered end first when you reinstall to aid in smooth insertion. If you were to insert the square end, it'll typically not go in and gouge the hole.

No alignment check needed, but you might find your front end rides a little higher with new shocks and you have to lower the front end. Once you start messing with the height, you should get it aligned. Height affects camber and toe. On the street its not a big deal. However at higher cornering speeds it does have a substantial effect. I messed with my front height on my racecar this past weekend and my car handled like crapola....

[mtb001]

and when you start hearing clunking noise from front end, the strut cap has come loose, allowing the insert to move slightly and beat against the bottom of housing. Use thread lock on nut and really tighten well.

[NO LIFT]

Thanks KTL!

I spend a bit of time this AM reading as many old threads as I could.

Thought I'd pull a front wheel off so I could locate the roll pin.


D*mn, thought I had Bilstein struts! I saw the green cover, I guess I'm glad I checked before ordering.

But, this leads to another question...Bilstein inserts are held in a BOGE housing by what? There is no roll pin, is there a threaded collar on the top?

Input greatly appreciated!

[HarryD]

Under the dust cover is a threaded retainer. Bilstein offers a special too for R&Rl or you can use a big pair of channel locks or pipe wrench to remove. If you use the alternative tool, cover the jaws with duct tape to avoid marring the retainer.