Rear Trailing arm NUT size..
 

What size is the rear trailing arm (banana end) Nut # 33 in Bentley Manual says M14 but that is the thread pitch, I just need to know what wrench fits that nut. Is it a 22mm?

Thanks.



(sent from the Sears Parking Lot..)

Bolt diameter.......
 

JT,

M14 is the nominal bolt diameter and this means it is a 14-mm x n (thread pitch number). The size of your wheel lug bolts is 14-mm x 1.5 (thread pitch). The three (3) most common thread pitch in our 911 are 1.0, 1.25, and 1.5. HTH?

Tony

To the Chassis, Torsion Plates or Drop links? If the Last two 19MM

I suspect he's talking about Items 4/6 in the diagram below. These are M14 and should take a 22 mm wrench. Note I haven't personally verified this, but that's what google says. The other two bolts DRACO is referring to are M12 and do in fact take a 19 mm wrench.

http://forums.pelicanparts.com/uploa...1477421840.jpg

22mm
 

My car is an 87 & is (22MM). I had to drill, grind & saw to remove nut & bolt (see pic) because PO had banana arm replaced after accident. Nut had "rounded" Edges & was a PITA to remove. I bought a 22MM socket at Loews (cobalt?) and cut (shortened 1/4") it on my lathe, this helped with clearance issues when reinstalling. Re-installing was much easier! Hope this helps.
Terryhttp://forums.pelicanparts.com/uploa...1477440116.jpg

Thanks.

Wow, this NUT is really stuck - - AND hard to access. I am sure the other side of the car will be just as difficult.
Now I know why people say the rear suspension is harder to tackle than the front. (front is done)

Hangar21.... I think I am going to have to do what you did and cut down / fabricate a shortened socket... there is not a lot of room on the nut side, so the shaved socket sounds like a good plan. Unless anyone else out there has some kind of magic tricks up their sleeve... I am totally stuck ~ the shock tower nut is disconnected, the trailing arm is removed, the axel is 1/2 off so I am REALLY stuck... I can't even roll / move my car at this point, so its not like I can simply bring the car to an 'expert'.
Crap, I am really 'up the creek', the learning curve just got steeper!

HELP!

Since misery loves company, this thread is really good: http://forums.pelicanparts.com/porsche-911-technical-forum/743568-another-trailing-arm-bolt-removal-question.html

and this one : http://forums.pelicanparts.com/porsche-911-technical-forum/262555-trailing-arm-monoball-installation.html


The other thing is working with jack-stands really makes you want a lift, in fact, it justifies owning a lift.
Everyone with a lift you should pat yourselves on the back right now.

Trailing arm nut
 

I'll be able to measure & take pix of my socket (tomorrow). Your welcome to borrow. I had to use a drill & then a Grinder on my dremel tool to remove bolt head (PITA). Then I used a punch to "drive" bolt toward transmission-far enough to expose nut. Now comes the most laborious part! With the nut & bolt exposed, I duct taped one end of new hack saw blade & began the slow process of cutting the nut off. This took a long time! I recommend to saw " slow & steady" & take lots of rest breaks! It will eventually work & with nut removed you can use a screwdriver to push the bolt back into the Banana arm. You can remove the entire Arm. FYI-I had everything removed, shock, brake disc, torsion plate & drive axle. My car was on Jack stands, I would have given anything for a lift! Hope this helps!
Good luck,
Terry
(817) 480-0635
hangar21@me.com

yeah, take a picture of the socket would be interested to see that.

Once you have it in parts there are a couple of ways to help with the problem in the future.

There are two style of Metric Fine Nyloc Nuts- P Type which is 16mm high and uses a 22mm AF spanner

The second is a T Type which is 12mm high and also uses a 22mm AF spanner.

It is relatively easy to find the T Type in a A4-80 Grade Stainless Steel which would normally be used with a Grade 8.8 Bolt and should be strong enough.

With a suitable ceramic grease they should be relatively easy to undo the next time round.

The other nut that works is a K-Nut - prevailing torque type nut.

The M14 x 1.5 versions are 12mm high and use a 16mm AF spanner - very strong with a 23mm dia flange to spread load.

For use on our Rally Cars we make Titanium Bodied Monoball with a 5/8" diameter bore spherical bearing and a spacer to allow us to use a 9/16" diameter AN Bolt.

We use a grip length so that both sides of the mounting clevis engage with the 'grip' of the bolt and then use an Imperial K nut.

http://forums.pelicanparts.com/uploa...1478047930.jpg
Pic of "normal socket (1 1/2") next to my modified socket (1 3/16").
Terry

"We have tools to fix tools"

Thanks Terry, just what I imagined.. determined to get this nut off.

chris_seven, Thanks for the nut-information. Had to look up "prevailing torque type nut" and "Imperial K nut" also known as a Surface-Bearing Lock Nut ( found info here: http://www.fastenerexperts.com/lock-nuts/ )

So, a smaller bolt, eh? with a sleeve... ever had any issues with that? I was thinking about shortening the bolt by cutting it, just to be able to get the socket seated and the wrench in there.

Titanium Bodied Monoball : I think we need to see a picture of that!
Thanks guys..

9/16" diameter is 14.28 so is a little larger than the stock 14mm diameter and why we use a 5/8 NMB Stainless Steel Bearing.

http://i197.photobucket.com/albums/a...psxcmivlxb.jpg

Sorry about the crummy photo.

The housing is 6AL4V Grade 5 Titanium.

The NMB bearing is press fitted against a shoulder with the interference, hence radial compression specified by NMB.

It is retained using a Smalley's Double Spirolox Stainless Steel Retainer (Don't like Snap Rings).

The bearing and the Spirolox are pre-fitted.

The weather seals are Seals-It parts and the misalignments spacers are hard anodised 7075-T6 Aluminium Alloy.

We supply shims to adjust the width of the Misalignment spacers to deal with the variation on width of the torsion bar brackets.

We also retain the Monoball in the arm using a Smalleys' Spirolox Double Retainer instead of a Snap Ring.

And we supply shims to make sure of the correct fit in the arm.

All of the internal and external shims are also stainless steel.


http://i197.photobucket.com/albums/a...psoozls3uh.jpg

Thanks chris_seven,

Larger bolt than stock seems wise. Smalleys' Spirolox Double Retainer : had to look that one up, too.
Nice kit. You had me at Titanium.

The main benefit of the AN bolt is the 'grip' length which you can buy in 1/16" increments.

This means you can arrange the bolt length so the shank fits though both sides of the clevis on the torsion bar tube.

The Porsche bolt us the thread through one side and the shank though the other.

I do understand that providing it is all torqued up tightly this is OK as the clamp force is sufficient but on Gravel Rally cars I just like the extra security.

Is it possible to break that nut with a nut splitter ?

I would say no, it's a BIG nut and maybe its flanged besides there is not a lot of room to access the nut. A ratchet wrench does not even fit in there, even w/o a socket. The '84 and later cars have more room between the bolt and the tranny so you can actually use 'normal' tool to remove it. imagine that! I am thinking with the SC a partial engine drop is the only way, besides cutting.

Rear Trailing arm NUT size..
 

Thread bump on a good topic. I'm at this stage of removal and looking at a good solution for removing the nut from the bolt. The bolt head is 22mm on our car and I will assume it's the same on the nut.

Thinking on a usable solution, has anyone taken two 22mm box wrenches, using the enclosed side and cut the head off and then weld that piece to the other 22mm head? Essentially, creating a double thick enclosed box wrench? Thinner than a socket but still deep enough to get a bite on the bolt.

If you could just confirm that you were still able to get the socket into the confined space between the nut and transmission?

Cheers

...Yeah, well, if there was a way I could talk you out of this I would....this has been a particularly frustrating stumbling block on my rear suspension re-fresh. The amount of space / angle-of-access is different on each side, everything except the size of the nut presents a new problem. On the passenger side I cut-down a socket so it would be lower -profile and fit in there with the wrench attached then I went at it with a leverage pipe attached to socket wrench after liberal spray of Penetrol 24 hrs previous. . It took a could of days (!) to figure it out but when when I finally loosened the nut the sun shone brightly down and a fresh breeze seemed to fill the room. Then I moved on to the drivers-side where there is even a bit less room and it is VERY close to fuel lines (!) accelerator pivot, clutch cable. The only real advice I can give is that this would be way-easier if you dropped the engine transmission, thats what the pro's do, I am sure. This project is NOT in 101 projects book for a reason...it's damn-near impossible!
Ha! ha!!
Let us know how it goes..

Heres a link to (an Instagram post) of how I modified the socket:

https://www.instagram.com/p/BMZbbLDA18h/?hl=en&taken-by=frequently_jt

short film...harsh soundtrack.

I use a standard 7/8 (22mm) O2 sensor socket and turn the bolt side. I usually just hold the nut still with a box end wrench. I'm actually doing this job as we type and it's super easy to get the bolt torqued with the O2 socket.

Pics:

http://forums.pelicanparts.com/uploa...1503262602.jpg
http://forums.pelicanparts.com/uploa...1503262646.jpg
http://forums.pelicanparts.com/uploa...1503262769.jpg

-Steve

Rear Trailing arm NUT size..
 

Thanks! Cool short video too. This is what I have found out thus far. The rear trailing arm "NUT" on our car, a 78SC is 19mm, even though the Porsche docs say 22mm. Day before I put a 22mm socket on the bolt head and with the assistance of a long 36" breaker bar, turned it a couple of turns.

Using a HF special angle 19mm box wrench, I got a bite on the nut and off it came. No drama, excitement or anything. Now onto the passenger side. I had to run an errand today so that gave me an excuse to pick up a flex angle Craftsman ratchet rench set. It was on sale but still spendy. Now into the passenger side nut and as they say......

Second star to the right and straight on til morning.

Oh, just to add a little bit of a challenge to a challenge, I re-installed the transmission support bar from my earlier tunnel fuel line change-out. I figure if I can tackle this with it in place, then anyone can do this with it removed.

Sent from my iPhone using Tapatalk

Rear Trailing arm NUT size..
 

Here is my update:

I honestly do not know why my particular experience was so vastly different for all the others who preceded me on this thread. But alas, here is what happened and my success is removing the nut from the trailing arm bolts.

My platform is a 78 911SC with 260k miles and no suspension updates. Which is the reason I have embarked on this project. The first difference I discovered on the SC data sheets and Bentley manual I have researched, listed the trailing arm bolt is 22 mm and the nut for that bolt as also a 22 mm. The actual nut on our car is 19 mm. With 100% certainty, the suspension has never been removed or updated shown by the condition of the TA pic. Earlier, before starting to remove the trailing arms, I re-installed the transmission support cross member mainly because I needed to remove the jack supporting the transmission while the bracket was off. Re-removing the cross member would have been the prudent thing to do but since I just put the darn thing back on, I was curious if this job would even be possible with it in place. If I was successful, then others might pick up a pointer or two from my experiences.

I should also point out that the car is on jack-stands 18-20" off of the ground, engine and transmission are still in the car, I am doing all of this outside and under a tarp. Kinda a "worst case scenario" for P-Car owners.

I found utilizing these two different wrenches, I was able to reach the nut without too much difficulty.
https://uploads.tapatalk-cdn.com/201...0e56d7cbeb.jpg
This one was used on the nut located on the driver's side where I had the most room.

https://uploads.tapatalk-cdn.com/201...7a4b163fd2.jpg

https://uploads.tapatalk-cdn.com/201...af031fd0e4.jpg
This Craftsman wrench was what I used on the passenger side where room was extremely minimal.

In the end, both nuts have been removed and one of the trailing arms has been removed. As shown in the next pics, the trailing arms have never been removed since the car rolled off the line in December of 77.
https://uploads.tapatalk-cdn.com/201...015db005ac.jpg

https://uploads.tapatalk-cdn.com/201...81b3f28a42.jpg


Sent from my iPhone using Tapatalk

Surprised it is 19mm... I guess they 'beefed it up' in the later SC's? ...Or maybe a P.O. switched it out so it is easier to get at? It certainly makes more room for tools to get in there, so that is an advantage. Congrats on making a quick job of it.



..."outside under a tarp" might be better than the garage mine is in!

Rear Trailing arm NUT size..
 

Thanks, kinda nice to have something go my way for a change. I think the 78's all had the 19 mm so I'm sure they beefed it up in the later years.

I'm glad because my trailing arm look look like crap. I also found it interesting that those that have sailed these waters before me have mentioned that more room on the passenger side of the transmission and minimal on the driver's side. I found just the opposite. Strange the differences. Then again the Bentley is a boiler plate manual and our car was a two year only before Porsche changed up the SC.


Sent from my iPhone using Tapatalk

Just an update on this old thread:

Steve is right, this is what I ended up doing: turning the BOLT side. Just get a wrench solidly on the other side to hold the nut ( finding a wrench which fits on the nut might be the hardest part of the job since you will be doing all this with the transmission and engine in place its a tight fit. Have fun!

I'm planning on using the WEVO EZ pins

https://www.wevo.com/Products/SuspensionProducts/WevoSuspensionProducts-EZPins.htm

Harpo,
Nice, money well spent, especially if one ever wants to remove the trailing arms a lot. Had no idea this was an option, Thanks.
In the end I went to Bel Metric for new nuts which got a bit rounded by the removal struggle.

Thats weird that the earlier SC would have 19mm. I just took off the bolt on my 69' 912 and they were 22mm.

There are many little changes and variations along model years...even within model years probably! The reasons are usually due to engineering development, material improvements or cost savings....

Please enlighten me.
I have probably found all the threads of how to remove the driver side (22mm in my case) bolt if it hits the tranny, but nowhere is it said how to replace the bolt?

Put it in the other way around.

-Steve

If you just want to replace the bolt, don't.. it's not really a 'wear-item' The factory one should be good for many decades.. if you are replacing the bushing you'll need to remove the trailing arm : loosen the nut , if you can. There is not much space to even move a wrench better to hold the nut in place as best as possible and loosen the bolt. The bolt slides out to towards the outside. The nut is on the inside close to the transmission tunnel & bolt slides to the out-side.. towards the wheels. That's how you remove the bolt. and nut.