Things to know when adding wheels spacers
 

I'm planning to install new rotors (disc brakes) in all 4 wheels (Zimmermann)
and I also got some small spacers (7mm and 14mm for the rear) that come with new bolts

changing the discs seems straightforward based on this
https://www.pelicanparts.com/techarticles/101_Projects_Porsche_911/47-Brake_Disc_Repl/47-Brake_Disc_Repl.htm

and

https://www.pelicanparts.com/techarticles/Porsche_911/BRAKES-Front_Brake_Rotor_Replacement/BRAKES-Front_Brake_Rotor_Replacement.htm

but what about the spacers?

I read someone was able to use the existing bolts for the front, given the spacer is only 7mm

but for the rear, I need to use the new bolts.

what do I need to know to change them?

anything else I should know before starting the job?


thanks

Discs are easy to replace, other than corrosion issues. I just had mine off as the recommendation for spacers from Fuchsfelge was backwards and had to be switched.

I just think of the wheels being the last point of safety with me in the car, so I do not take any chances. I used Elephant and I believe H&M spacers and followed their recommendation to the letter.

My front 21 mm spacers required longer studs (66mm) and the rear 32mm were the double bolt variety where the spacer bolts to the hub using the standard studs and the spacer then has new studs that the wheel bolts to. All TuV approved of course.

You want to have spacers that retain the centring capability so it has the flange that the title hole in the centre of the wheel gets something it can get concentric to.....

Check out Elephant, they can steer you straight as to whether your set up is going to be good enough.

D.

I mentioned that already have spacer H&M Track+ 7mm and 14mm and I already have Zimmermann new rotors.

my question is more about if I do need special tools or special instructions...tips and tricks so I'm not unprepared in case of hiccups

so far I found an advice of using a DIY press to remove the old studs without hammering

oops, my bad.

I hammered mine out...but I was very careful to support them with an appropriate socket/hunk of metal. I was a little concerned with the latest swap as I could take off the front hubs and hammer on the bench, but the rears required me to hammer the axle stub on the car. I also had to partially disassemble the parking brake to make room for the longer studs (take them out in my case), but that is not a big deal once you realize you can use a heavy screwdriver to lever open the parking brake shoe to fit the adjuster back in....easy peasy.

I sacrificed a steel lug nut for hammering to save the studs...hammered on the nut and not the end of the stud.

it was no problem....a few sharp blows and it was done.

Getting the new ones on, I sacrificed another steel nut, put in a sleeve, couple of heavy washers, lubed it all up with some light grease and then just used a combination of impact wrench and hand wrench to tighten the studs so they were firm on the hubs.

I did find out that you can get the stubs back on almost easier with a 1/2 inch rachet than using the impact. I ended up just using the impact (electric) for the first half or so just as it was light and went fast but then finished by hand with the rachet.

The rachet lets you feel when the stud is fully seated far better....so that is what I did.

To be fair, once the car has a few miles on it I will probably retighten everything just to make sure, but I am pretty comfortable my method got the job done.

Hope this helps and sorry for the misfire on my part...

D.

thanks that sounds good.

i also just find on amazon a cheap tool to install new studs so I don't need to use a nut
https://www.amazon.com/gp/product/B0BNL1S1WM/

and I was looking for a C-press to remove the rear without banging
something like this
https://www.amazon.com/dp/B0B64NFT56/

Both those tools look fine, only concern with the removal tool is that on the front the studs go into a well in the hub and that device at best could go on the top of the well....and it is quite thick so may not work.

http://forums.pelicanparts.com/uploa...1716929460.jpg

I was worried about cracking the aluminium front hub right where the hub retained the stud, hence I used a socket just slightly larger than the stud head so all the force would be supported.


On the rear, again with the removal tool, it would likely work there but the back of the hub has some raised islands supporting the studs and it may not seat well....but likely would.

Other issue is that for me this was a one time job and I had the two sacrificial steel nuts on hand - just cheaper and easier for a one shot deal.

Sounds good too....for me it was an all day job, what with removing the front hubs and resetting the front wheel bearings and in the back of course the e-brake. Not a biggie....but I am old...

Good luck,

D.

sounds good. i may also split the job in two days, one for the front and one for the rear rotors... I'm not in rush all in all ;)

I think for my front wheels I may not even need to replace the studs, my spacer is only 7mm and I read someone else was able to keep the studs..

either way the tool/c-press was meant only for the rear. i understood for the front I can take the parts to my work table and light hammering them

so when I got my H&R 14mm spacers, the new studs included are 66mm (or 71mm measuring the full bolt) like yours... but I feel the long 71mm (aka 66mm) is too long to be installed without removing the entire hub... how did you install yours?

I wonder, given my spacers are only 14mm, if it;s enough to have around 56-59mm thread bolt... it may help fit without removing the brake hardware

btw
in the meantime, as a test, I placed the 7mm (also H&R) on my rear wheels without changing the studs (I think the stock is 45mm and everything seemed ok. I haven't counted the number of turns (some ay 7 some say 9)

I wonder if I should buy adapters instead of spacer to make it easier?

by "adapter" are you referring to a device that bolts onto the hub and has its own studs? If so, since it's impossible to confirm the tighness/integrity of the bolts holding the adaptor onto the hub without removing the wheel from the adaptor, it not (imo) as safe/"good" of an option as traditional spacers that still allow the wheel to be bolted directly onto the hub bolts.

yes, they are H&R Track + 23mm DRM (DRM stands for the spacer with integrated bolts. I wish I had known earlier I would have wasted time and money returning the one I got)

if they weren't safe they would not sell them.

HI,

I used 66mm (+21mm) for my 21mm rear spacers and managed to install with the hubs in the car using the same method as cloggie. Lost of people safely use adapters instead of spacers, but for peace of mind I like the ability to check the nut torque directly on the stud. I used 2mm spacers at the front to mitigate some inner fender rubbing - I don't think I'd want to go +7mm with stock studs, but if I did would use an open nut to at at least verify enough engagement.

John

I took my front hubs off and did them on the bench. the 66 mm stud is perfect for the 21 mm spacers as I said....and doing a little math, my spacers are 7 mm thicker than yours and my bolts are also 7 mm longer, so a 56-69mm stud ought to be fine....ifi they come in that size of course?

My test would be whether I had full engagement of the nut plus a mm or so, easy to check with a steel nut if you have one lying around...and not that hard with a bit of measuring on the standard nuts. I never used the "turn" measurement on nuts but on bolts I use engagement to blind threads being at least 1 diameter engagement.

D.

...hence my insistence on a TuV approved adapter and being neurotic about checking tightness every time the wheel is off....with a torque wrench.

D.

do you have pics of your car?
so, I ordered the new H&R 23mm for the rear with integrated bolts

but I'm indecisive for the front which spacer to keep. maybe 7mm is too short? will the 14mm be enough?
If I keep the 14mm and I replace the sutds (which seems easier to hammer them on a table) will the 66mm be to long or is just perfect (I have the stock closed but)

also considering: what if I add the 7mm+14mm spacers together?

One thing to look at in rear are your wheels.....my Fuchsfelge wheels have pockets between the stud holes - I think for lightness reasons - but it allows the studs that hold on your adapter to protrude a little into the wheel centre boss. I have no problem with my 32 mm spacers and the retaining nuts/studs for the adapter are fairly close to flush with the wheel mating surface. Methinks your retaining studs my stick out a little

In terms of your front, I just measured my front stud engagement with the 21 mm spacer and 66 mm studs. The stud protrudes 19 mm from the Fuchs mating point so that is the thread engagement I have and very truthfully speaking, I like full engagement especially with the aluminium stock nuts I use.

I also measured how deep the threads are on the stock Porsche wheel nuts and it looks to be about 28 mm before the stud bottoms out in the nut.

So your stud can be (based on my experience) - 9 mm longer than my 66 mm's and still work.

If you went to minimums, with 21 mm spacers and using my practice of one full diameter of engagement - so that would be 13.5 mm or 5.5 mm shorter than mine, which implies the shortest stud you can use - with Fuchs wheels - is 61 mm or so.

If you use 14 mm spacers - 7 mm thinner than mine - then your studs could be as short as 54 mm and still have one diameter of thread engagement.

Like I said, I don't like minimums, but my stock studs measured 46 mm shank length (not including the head) which makes them too short for 14 mm spacers and even a little short for 7 mm ones.

Personally, I would say switch out your studs, feel and be safer.

D.

PS - here is a gratuitous picture of my project which is still on the building stand. Just doing upholstery and then engine build and then on the road. Probably does not help you as the car is not sitting on its wheel. s

thanks for checking, my 14mm spacers came already with those 66mm bolts in the box, so now Im feel safer using them, replacing the old ones..

Francesco -- FWIW, some folks that go with 16x7 wheels up front have issues with the outer edge of their front tires rubbing against (and frequently bending out) the inner lips of their front fenders. Relatively easy to address/resolve by bending in (or shaving off) the front fender lips. Doubt you'd have any issue with 7mm spacers, but 14mm up front might be a bit tight and 21mm up front would likely cause rubbing/etc.

? my wheels are 16x6 in the front. I'm not planning to change them