Changing Wheel Studs
04-22-2003, 02:32 PM
#1
Advanced
Thread Starter
Join Date: Oct 2001
Location: London
Posts: 50
Likes: 0
Received 0 Likes
on
0 Posts
Changing Wheel Studs
OK, label me officially "challenged" in the wrenching department. Over the Easter Weekend I did a little exploratory surgery and tried to fit some longer wheel studs to the rear of my 1989 Carrera. I successfully got to the stage of removing the rear brake disc and even removing one OE size stud. I couldn't get the longer 72mm replacement in (even after pulling handbrake assembly to bits to gain a little room) so I reinserted the OE stud and put it all back together again.
What is the trick? Do I have to remove the big old nut in the centre of the hub? If so, what size socket is required?
Perhaps there is a tech article somewhere (I couldn't find one) that someone may refer me to.
I am also looking to replace the front studs but I was told that this is a bigger job. Any pointers on that would also be appreciated.
Many thanks,
Richard <img border="0" alt="[bigbye]" title="" src="graemlins/xyxwave.gif" />
What is the trick? Do I have to remove the big old nut in the centre of the hub? If so, what size socket is required?
Perhaps there is a tech article somewhere (I couldn't find one) that someone may refer me to.
I am also looking to replace the front studs but I was told that this is a bigger job. Any pointers on that would also be appreciated.
Many thanks,
Richard <img border="0" alt="[bigbye]" title="" src="graemlins/xyxwave.gif" />
04-24-2003, 11:28 AM
#3
Technical Specialist
Rennlist
Lifetime Member
Rennlist
Lifetime Member
If you don't get an answer here, go to <a href="https://rennlist.com" target="_blank">www.rennlist.com</a> and pose the question on the general 911 email list.
04-24-2003, 01:16 PM
#4
Three Wheelin'
Join Date: Jun 2001
Location: SF Bay Area
Posts: 1,276
Likes: 0
Received 0 Likes
on
0 Posts
I recently changed the front wheel studs on my 87. First you need to disconnect the brake calipers from the strut and pull them off the rotors. You can leave the brake fluid lines connected by carefully moving the calipers out of the way and hanging them from the fender wells using a coat hanger.
You then need to pull the grease cap (a search on this forum will give you tips on that process) and remove the front hub. You will basically disassemble the front hub from the rotors, so if you want to do any brake work (rotors, calipers) now is the time. This is also a good time to replace suspension connections (tied rod ends, ball joints) if they are old and tired.
In any case, once you have the grease cap off you will see the retaining nut on the end of the strut shaft. This is a clamp type nut and you need to loosen it with an allen wrench. You can then spin if off the shaft and pull the hub and rotor assembly. When you do this it is likely the outer wheel bearing will fall out. No big deal as they just pop back in. You should get some Swepco wheel bearing grease for this project as well. On the back of the hub is the inner wheel bearing grease seal. If you do a search on a place like Pelican Parts you can find diagrams of most of this stuff. If your wheel bearings have not been repacked in some time (or ever in most cases), I suggest popping off the back grease seal with a large screwdriver and cleaning and repacking the the inner wheel bearings. You will need to have new grease caps (about $5 per)if you do this. Do a search on packing wheel bearings for more info.
You then need to remove the hub from the rotor. There are five bolts that you will need to remove. At thispoint you will have the rotor by itself with the 5 wheel studs poking through. To remove these you should put the hub, studs facing up, on blocks of wood, or some other suuport system where you can leave a gap to pound out one stud at a time. Use a heavy hammer or mallet to pound the studs out. You can also find a machine shop with a press that can press the old studs out and the new studs in. Once all the old studs are out you then reverse the process. I used a punch to seat each stud. It literaly took about 60-100 good hits per stud to seat them all the way. Make sure you line up the splines before punching the studs in place. Then you reassemble everything.
I looked in my Bentley manual for the rear wheel assembly, and it appears that you do need to remove the lagre retaining nut that holds the hub in place. You would then pull the outer hub and pound out the studs. You should not need to get into any grease packing issues though.
If it sounds like a lot of work - it is. I have had the front end apart before and this still took me several hours for just the front.
You then need to pull the grease cap (a search on this forum will give you tips on that process) and remove the front hub. You will basically disassemble the front hub from the rotors, so if you want to do any brake work (rotors, calipers) now is the time. This is also a good time to replace suspension connections (tied rod ends, ball joints) if they are old and tired.
In any case, once you have the grease cap off you will see the retaining nut on the end of the strut shaft. This is a clamp type nut and you need to loosen it with an allen wrench. You can then spin if off the shaft and pull the hub and rotor assembly. When you do this it is likely the outer wheel bearing will fall out. No big deal as they just pop back in. You should get some Swepco wheel bearing grease for this project as well. On the back of the hub is the inner wheel bearing grease seal. If you do a search on a place like Pelican Parts you can find diagrams of most of this stuff. If your wheel bearings have not been repacked in some time (or ever in most cases), I suggest popping off the back grease seal with a large screwdriver and cleaning and repacking the the inner wheel bearings. You will need to have new grease caps (about $5 per)if you do this. Do a search on packing wheel bearings for more info.
You then need to remove the hub from the rotor. There are five bolts that you will need to remove. At thispoint you will have the rotor by itself with the 5 wheel studs poking through. To remove these you should put the hub, studs facing up, on blocks of wood, or some other suuport system where you can leave a gap to pound out one stud at a time. Use a heavy hammer or mallet to pound the studs out. You can also find a machine shop with a press that can press the old studs out and the new studs in. Once all the old studs are out you then reverse the process. I used a punch to seat each stud. It literaly took about 60-100 good hits per stud to seat them all the way. Make sure you line up the splines before punching the studs in place. Then you reassemble everything.
I looked in my Bentley manual for the rear wheel assembly, and it appears that you do need to remove the lagre retaining nut that holds the hub in place. You would then pull the outer hub and pound out the studs. You should not need to get into any grease packing issues though.
If it sounds like a lot of work - it is. I have had the front end apart before and this still took me several hours for just the front.
04-24-2003, 03:44 PM
#5
Three Wheelin'
Join Date: Jun 2001
Location: SF Bay Area
Posts: 1,276
Likes: 0
Received 0 Likes
on
0 Posts
One last tip - when reinstalling the front hub you need to get the wheel bearing play correct. The shop manual says to tighten the locking nut just enough so that the washer under the nut is snug but can still be moved back and forth with a screw driver.
04-24-2003, 05:34 PM
#6
Technical Specialist
Rennlist
Lifetime Member
Rennlist
Lifetime Member
</font><blockquote><font size="1" face="Verdana,Tahoma,Helvetica">quote:</font><hr /><font size="2" face="Verdana,Tahoma,Helvetica"><strong>tighten the locking nut just enough so that the washer under the nut is snug but can still be moved back and forth with a screw driver.</strong></font><hr /></blockquote><font size="2" face="Verdana,Tahoma,Helvetica">Also, don't lever the screwdriver against anything when you test it. Just put the edge of the screwdriver on the edge of the washer and push it with your hand.
And reset your torque wrench to zero when you're done putting your wheels back on.
And reset your torque wrench to zero when you're done putting your wheels back on.
04-25-2003, 09:34 AM
#7
AutoX
Join Date: Jan 2003
Location: SLC, Utah
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
Richard,
I just changed all of the studs on my car to longer ones. However, they were only 7mm longer. I was able to sneak them by the e-brake parts and trailing arm pieces without removing the hub.
Basically you have a dilemma now. You need to remove the hub from the trailing arm, change the studs and then replace the hub back into the trailing arm. Removing the large castle nut is the first step. It will disconnect the axle shaft from the hub. The problem is that you will then need to pull the hub out of the bearing (it is 'light' press into the inside races of the bearing). The problem here is that conventional wisdom states that those bearings are damaged when disassembled. It is a double row ball bearing with a split inner race. The outboard half of the inner race will come out with the hub. You will then need to remove all of the bearing pieces (the inner race from the hub and the remaining sections from the trailing arm). This is a big PITA. First remove the emergency brake backing plate because it acts as a retainer to the bearing. You will need some special tools and probably will have to pull the axle shaft out of the car to gain clearance on the inside of the trailing arm. The bearing should be pressed out of the arm in a press, but it can be done with a tool that uses a large threaded rod and some specially sized collars and disks pull the bearing out of the arm. I have used the tool on VW front wheel bearings (same style).
You will then need to replace the bearing (they are about $50 each), change your studs and re-assemble. Heat on the aluminum arm and freezing the bearing can make reassembly of the bearing into the arm much easier. Be careful to not destroy the new bearing by pressing the hub in without retaining the inboard half of the inner race. The tool should be able to press the hub back in. Also, the large nut that you first removed should be torques to somewhere around 400 lb-ft of torque. This is a big PITA in itself, because you have to be able to hold the axle from spinning. Basically re-assemble the brakes and have someone stand on the brakes while tightening.
You'll be happy to know that fronts are much easier Not easier than what you first attempted, but much easier than the procedure I outlined above for the rears. Just pretend like you are changing front rotors, but change the studs once you get the rotors off. You probably should change rotors too while you are in there and repack the front wheel bearings.
Given that procedure, perhaps you should just use bolt on spacers. I use a set for a particular odd set of wheels I have. You can get them up to a couple of inches wide.
If this is really confusing, I can elaborate more. Just e-mail me.
-Aaron
I just changed all of the studs on my car to longer ones. However, they were only 7mm longer. I was able to sneak them by the e-brake parts and trailing arm pieces without removing the hub.
Basically you have a dilemma now. You need to remove the hub from the trailing arm, change the studs and then replace the hub back into the trailing arm. Removing the large castle nut is the first step. It will disconnect the axle shaft from the hub. The problem is that you will then need to pull the hub out of the bearing (it is 'light' press into the inside races of the bearing). The problem here is that conventional wisdom states that those bearings are damaged when disassembled. It is a double row ball bearing with a split inner race. The outboard half of the inner race will come out with the hub. You will then need to remove all of the bearing pieces (the inner race from the hub and the remaining sections from the trailing arm). This is a big PITA. First remove the emergency brake backing plate because it acts as a retainer to the bearing. You will need some special tools and probably will have to pull the axle shaft out of the car to gain clearance on the inside of the trailing arm. The bearing should be pressed out of the arm in a press, but it can be done with a tool that uses a large threaded rod and some specially sized collars and disks pull the bearing out of the arm. I have used the tool on VW front wheel bearings (same style).
You will then need to replace the bearing (they are about $50 each), change your studs and re-assemble. Heat on the aluminum arm and freezing the bearing can make reassembly of the bearing into the arm much easier. Be careful to not destroy the new bearing by pressing the hub in without retaining the inboard half of the inner race. The tool should be able to press the hub back in. Also, the large nut that you first removed should be torques to somewhere around 400 lb-ft of torque. This is a big PITA in itself, because you have to be able to hold the axle from spinning. Basically re-assemble the brakes and have someone stand on the brakes while tightening.
You'll be happy to know that fronts are much easier Not easier than what you first attempted, but much easier than the procedure I outlined above for the rears. Just pretend like you are changing front rotors, but change the studs once you get the rotors off. You probably should change rotors too while you are in there and repack the front wheel bearings.
Given that procedure, perhaps you should just use bolt on spacers. I use a set for a particular odd set of wheels I have. You can get them up to a couple of inches wide.
If this is really confusing, I can elaborate more. Just e-mail me.
-Aaron
Trending Topics
04-25-2003, 12:58 PM
#8
Three Wheelin'
Join Date: Jun 2001
Location: SF Bay Area
Posts: 1,276
Likes: 0
Received 0 Likes
on
0 Posts
Wow Aaron - thanks for the great write up on the rears. Sounds like a royal PITA. I really wouldn't recommend someone even doing the fronts on their own without a decent tech manual that has assembly diagrams and tech specs (such as torque values).
Richard - you can generally fit 1/4 inch (6-7 mm) spacers using the stock studs and still have enough thread for the wheels. If you use Aaron's suggestion above to squeeze in studs that are 7 mm longer, that would give 13 - 14 mm more clearance. How much do you need?
Richard - you can generally fit 1/4 inch (6-7 mm) spacers using the stock studs and still have enough thread for the wheels. If you use Aaron's suggestion above to squeeze in studs that are 7 mm longer, that would give 13 - 14 mm more clearance. How much do you need?
04-25-2003, 01:21 PM
#9
AutoX
Join Date: Jan 2003
Location: SLC, Utah
Posts: 13
Likes: 0
Received 0 Likes
on
0 Posts
Richard and Bill,
Here is a link to some spacers like I have for my Boxster wheels. I found them in all sort of sizes, but AJ only seems to show them in 1" and 2". It is a simple solution and easily reversible.
<a href="http://www.ajusa.com/cgi-bin/inventory/view_product?prod_id=0000000241&part_number=AJR%20502%20701" target="_blank">http://www.ajusa.com/cgi-bin/inventory/view_product?prod_id=0000000241&part_number=AJR%20502%20701</a>
Aaron
'73 911S
Here is a link to some spacers like I have for my Boxster wheels. I found them in all sort of sizes, but AJ only seems to show them in 1" and 2". It is a simple solution and easily reversible.
<a href="http://www.ajusa.com/cgi-bin/inventory/view_product?prod_id=0000000241&part_number=AJR%20502%20701" target="_blank">http://www.ajusa.com/cgi-bin/inventory/view_product?prod_id=0000000241&part_number=AJR%20502%20701</a>
Aaron
'73 911S
04-28-2003, 10:47 AM
#10
Advanced
Thread Starter
Join Date: Oct 2001
Location: London
Posts: 50
Likes: 0
Received 0 Likes
on
0 Posts
Thanks for your advice everyone.
Just to clarify, the reason for needing longer studs relates to the track wheels I have just purchased. The new wheels are 7/8x15 3 piece Compomotive wheels. Compomotive are a well respected UK wheel maker supplying mainly racing teams. These are replica Fuchs centred wheels and because they are replicas, the thickness of the centres is greater than a regular Fuchs. They were made for an SC and so with the slightly larger Carrera discs and calipers it is necessary to run a small spacer - otherwise they *just* touch the caliper. There just isn't enough stud for the thicker centre together with the 6mm spacer - even with steel wheel nuts. I am used to running the 6mm spacers with my 7/9x16 Fuchs, so this was the first thing I thought of.
I have received some advice from the Rennlist email list (from Walt Frick and others) that suggests that I can get the 72mm studs in (somehow!). One suggestion is to remove the handbrake cable and go in thru that hole. I have also ordered a set of 68mm studs that I think may just go in where the handbrake adjuster can be removed - I nearly got the 72mm studs in that way so this gives me another option.
If I have to start pulling rear bearings etc I think I will give up (or pay someone!). Realistically, I will probably get some 3mm spacers and keep the OE studs, but I would rather have the longer studs as I can then space the wheels about 12-15mm without clearance problems - and that would look tough!
I think I am up for doing the front studs as I have got some pretty good advice on that front.
So, next clear weekend I'm into it.
Again, many thanks.
Richard <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />
Just to clarify, the reason for needing longer studs relates to the track wheels I have just purchased. The new wheels are 7/8x15 3 piece Compomotive wheels. Compomotive are a well respected UK wheel maker supplying mainly racing teams. These are replica Fuchs centred wheels and because they are replicas, the thickness of the centres is greater than a regular Fuchs. They were made for an SC and so with the slightly larger Carrera discs and calipers it is necessary to run a small spacer - otherwise they *just* touch the caliper. There just isn't enough stud for the thicker centre together with the 6mm spacer - even with steel wheel nuts. I am used to running the 6mm spacers with my 7/9x16 Fuchs, so this was the first thing I thought of.
I have received some advice from the Rennlist email list (from Walt Frick and others) that suggests that I can get the 72mm studs in (somehow!). One suggestion is to remove the handbrake cable and go in thru that hole. I have also ordered a set of 68mm studs that I think may just go in where the handbrake adjuster can be removed - I nearly got the 72mm studs in that way so this gives me another option.
If I have to start pulling rear bearings etc I think I will give up (or pay someone!). Realistically, I will probably get some 3mm spacers and keep the OE studs, but I would rather have the longer studs as I can then space the wheels about 12-15mm without clearance problems - and that would look tough!
I think I am up for doing the front studs as I have got some pretty good advice on that front.
So, next clear weekend I'm into it.
Again, many thanks.
Richard <img border="0" alt="[cheers]" title="" src="graemlins/beerchug.gif" />
