74 + 911 Rear Hubs for 5 Lug Conversion, spacer thickness Options

[jaxdream]

Hi guys, I've been reading some of tyhe posts concerning using the 74 + hub centric eared 911 rear hubs for a 5 lug conversion. Iv'e seen mentioned that one needs to use a 5mm spacer on the hub on the wheel side against the outter inner bearing race . My question is why the 5mm spacer instead of a 6mm spacer ?? 914 and earlier 911 use a 36mm wide bearing the later mentioned 911 used a 42mm wide bearing , what happens with the leftover 1 mm?? Does it stick out to be sqished up against the stub , will it not allow the hub / stub to fully seat ??As i have figured on using the inner races from the aforementioned 74+ hub bearing having them ground down on a surface grinder for squareness sake , just want to be sure of the thickness demention before the grinding to get the right thickness I need.

Jaxdream (IMG:style_emoticons/default/confused24.gif) (IMG:style_emoticons/default/blink.gif) (IMG:style_emoticons/default/unsure.gif)

[SLITS]

I acquired a car with this setup. No spacer on the hub, just washers under the rotors (911 rotors) and calipers (stock /4) to TRY and center the caliper over the rotor. What a pile of shit.

Problems:

1.) rotors would not run true to be able to set venting clearance.

2.) makes getting the calipers off / on a real PITA

I wound up trashing the 911 rotors in favor of /4 redrilled rotors which eliminated the washers under the rotors, but still had to space the calipers inward to center them.

I was also told the 911 axles were too short and a spacer should be put between the transmission flange and inner CV joint to not "overextend" the CV joint.

My solution .... I will be changing the whole shitten mess to /4 stuff. Then I know that everything will line up correctly and function. I also have a set of EARLY 901 hubs and stub axles, but the /4 setup makes it so much easier ... no freakin spacers anywhere.

I know this didn't answer your question, but I had to rant about it. Ok Eric, you can beat me up on this one.

[PRS914-6]

The spacer info you need is in THIS THREAD

[Eric_Shea]

I was also told the 911 axles were too short and a spacer should be put between the transmission flange and inner CV joint to not "overextend" the CV joint.

My solution .... I will be changing the whole shitten mess to /4 stuff. Then I know that everything will line up correctly and function. I also have a set of EARLY 901 hubs and stub axles, but the /4 setup makes it so much easier ... no freakin spacers anywhere.

I know this didn't answer your question, but I had to rant about it. Ok Eric, you can beat me up on this one.

Here comes your whoop'n.

You're kinda right but, you give up too easy (and you're grouchy too). (IMG:style_emoticons/default/biggrin.gif) You just need to pull those hubs and have a proper spacer made for the hubs shaft like Paul done did. I had struggled over getting 911 CV's and a fairly easy five lug solution for a fairly high powered six. The light bulb came on one day while talking to Paul. Luckily, the light bulb came on over his head a while back so I didn't have to strain my noodle. When he mentioned; "Why not just get the right length axles?" I thought well... WHY NOT?

You are correct. The 911 axles are too short. By 28mm I believe. Photographic evidence to ensue:

(this is the part where Slits makes fun of my digital calipers, Ron tries to stop him but Slits prevails)


Ménage à Trois - Sway-A-Way 28 spline Porsche axle, stock 914 axle (with the CV before I sent everything off to Gint the parts whore) and the stock 911 axle:


I'm not the expert on the spacer. Paul is the one who's BTDT so I'd hit that thread for enlightenment. My set up does not use the later hub centric hubs. I'm using1970 stuff. 911 Hubs. 911 Stub Axles. 911 CV's. Sway-a-Way Axles. and 911 Flanges. I had the pics so I thought I'd throw a visual up to the axle issue.

If I can get the right tool to crimp my clamps, I'll post a thread on the entire axle conversion today.

[rhodyguy]

hurry eric. that jon (v-caliper, 911 mid engine caddy conversion) i sent your way will need it. he's all sideways with studs, spacers, etc. but he doesn't know how wide of wheels he's going to use.

[jaxdream]

Thanks guys , Paul's thread didn't come up in the search that I done , but got me to thinking on my measurements . Paul's thread clered up the question on the spacer thickness , I believe I have the other stuff figuerd out. I will probably be selling my 69-73 hubs and stubs in the near future, I'll have to check , I believe I have 2 sets . Thanks again for the help. Eric you still need 914 rear calipers for rebuild ??Shoot me a PM with your addy and I'll get them out to you. Thanks again.
jaxdream
Jack (IMG:style_emoticons/default/piratenanner.gif) (IMG:style_emoticons/default/driving.gif)

[Eric_Shea]

that jon (v-caliper, 911 mid engine caddy conversion) i sent your way will need it.

I remember him... seems like an interesting project. (IMG:style_emoticons/default/wink.gif) Danke!

E.

[Wilhelm]

Just looking at the different length axles as one option. What is the easiest way to measure these? I would guess I need one length based on the hub in line with the transmission and another with the swingarm in full extension. Does any one know a method to get the right length axle based on a measurement between the transmission flange and the swing arm flange? Thanks

[shoguneagle]

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I have read these great threads and need some clarification for my "old, befuddled brain". Here is what I have:

1. Early 911 stub shafts without concentric lip (69-73).
2. Early 911 transaxle drive flanges
3. Early 911 CV joints
4. Early 911 hubs
5. Sway-A-Way axles (part #2420, 20 and half inches long, 28 splines)
6. Set of early 911 bearings (may be the same as 914 and Boxster to 97)

The items I need your input relate to following:

1. We can use either early 911 69-73 wheel stub axles along with appropriate hubs. These do not have the centering flange or concentric fit that a later model has (74 and later to ????).

2. If the early type are used, can a centering type "puck" be machined to go into the rim, match a shoulder on the hub, and a centering or concentric flange be made to center the rim???? Clear as "mud"?

3. Where is the 5mm spacer located?? Next to the backside of the hub or inboard side of the bearing? Does the inner side(s) have to be canferred??? (beveled edge of the inside of the hub) Who makes or machines these spacers???

4. Sway-A-Way axles part #2420 (please check part number) which has 28 splines and is 20 and a half inches long. I have heard these axles referred to free floating type. Does this mean the CV joints move along the splines and are held in at each end with C-clips??

5. What size are the early CV joints and can later 911 ones be used, or possibly ones belonging to the 930, 944, Carrera, etc.??

6. Early 911 transaxle drive flanges??? or can later types be used???

7. I have not physically looked at the individual parts since they are still assembled in various stages. I have accumulated my parts from reading threads such as this one. I do need your opinion and comments on the above to make sure I am on the right track.

Thanks,
Steve Hurt (IMG:style_emoticons/default/welder.gif) (IMG:style_emoticons/default/welder.gif) (IMG:style_emoticons/default/welder.gif) (IMG:style_emoticons/default/welder.gif) (IMG:style_emoticons/default/welder.gif) (IMG:style_emoticons/default/welder.gif) (IMG:style_emoticons/default/welder.gif)

[J P Stein]

I'm with Slits.....we old farts gotta hang together....with our uncleverness.

70 & early 71 914 hubs give the proper thickness to the hub flange and make the conversion a walk in the park.....just have them redrilled. I've been running 200+ hp with the stock set up for 8 years of serious thrashing and have never had a driveline failure...I prolly ought to knock wood here. (IMG:style_emoticons/default/unsure.gif)

[Eric_Shea]

1. We can use either early 911 69-73 wheel stub axles along with appropriate hubs. These do not have the centering flange or concentric fit that a later model has (74 and later to ????).

Correct. The later "hubs" have that flange, not the stub axles. I personally like the early hub you mentioned as you do not need the spacer. From 1974 on Porsche used a deeper bearing on the 911. To compensate for this, the hub was machined on the backside. Those later hubs can be used but they need to be spaced back out to account for the early 911/914 bearing, as this thread addresses. I've never had an issue with wheel centering on all of the early 911's or 914's I've owned.

2. If the early type are used, can a centering type "puck" be machined to go into the rim, match a shoulder on the hub, and a centering or concentric flange be made to center the rim???? Clear as "mud"?

Not very clear at all; sorry. The early type hubs do not have a centering type puck. Just like a 914 hub that might be re-drilled. Again, I've never had an issue with centering but I know for a fact others like them. The later centering hubs should work with all 5-lug Fuchs. I have a feeling you're confusing "hubs" which your rotors hang on and your wheels bolt to, with "stub axles" which attach to the end of your axle and thread/slide through the hub.

3. Where is the 5mm spacer located?? Next to the backside of the hub or inboard side of the bearing? Does the inner side(s) have to be canferred??? (beveled edge of the inside of the hub) Who makes or machines these spacers???

Patrick Motorsport has them but they are hard to find in the catalog. These slip over the shaft on the hub. Paul made some as well but I don't think he wants to make them unless it's a bulk type thing. Not sure, never hurts to ask. Not sure why you're asking because, from your post, it looks like you have all the right parts needed.

4. Sway-A-Way axles part #2420 (please check part number) which has 28 splines and is 20 and a half inches long. I have heard these axles referred to free floating type. Does this mean the CV joints move along the splines and are held in at each end with C-clips??

Should be correct. The length is 20.25" just like a 914. These are referred to as "full-floating" by the off-road crowd. Big plus from what I understand, although I generally don't second guess Porsche engineers. They are held at each end by the clips into the CV's which are, obviously, bolted to the stub axles and the flanges. "My understanding" is the full-float allows the CV's to find a more natural center and allows them to handle the torque better.

5. What size are the early CV joints and can later 911 ones be used, or possibly ones belonging to the 930, 944, Carrera, etc.??

Your limiting factor here will be the flange that attaches to the 914 version of the 901 transmission. The 911 used the 901 so, any of those flanges and CV's from the early 911 will work. Even the early 915's had a flange that would work. These flanges need to be coarse splined to fit into a 901/914 tranny. That's it. Later the spline count changed and they will not work with the 914/901. Simple rule of thumb is matching the entire system. 915 flanges work "through" 1976 "I believe". Look at the problem one of our members is currently having finding a 6 bolt 100mm flange. Get an entire system from a same year car and you should be fine. If you do go later than 1973, get spacers for the hub shaft. 108mm can be used but they will be tight with about 3.5mm on either side when in the control arm. Any 100mm CV should be able to handle the power you feed it but, again, others like the bigger stuff. I believe Paul is using 108's with his 3.6.

6. Early 911 transaxle drive flanges??? or can later types be used???

Explained above but, for further edification: 1969-1976 coarse spline should do the trick. (others weigh in if there's a year discrepancy)

7. I have not physically looked at the individual parts since they are still assembled in various stages. I have accumulated my parts from reading threads such as this one. I do need your opinion and comments on the above to make sure I am on the right track.

If it's the list you posted, you have everything you need with the exception of the axles. Talk to Chuck at Elephant Racing, he's a good guy and he can supply the axles. Once you get your axles, plan on not much elbow grease but plenty of grease on the elbows.

See this thread for the BTDT side of things:

http://www.914world.com/bbs2/index.php?showtopic=91963

Running 914 CV's with 200+ hp in an autocross environment is a "when" not "if" situation.

[PeeGreen 914]

Since this is on par with everything Eric has been posting if anyone is looking to do some axle/ CV stuff here is a good start:

http://forums.pelicanparts.com/showthread.php?t=453379

[charliew]

Wilhelm I'm not the answer man on the axle length but I've been thinking about it and it seems that the full extended position with the surface of the flanges would be the dimension a axle supplier would want to know. Where the axle is still fully inside the cv at the extended position. I'm not sure about room for the clips though if they are used, surely the axles don't just float between the flanges inner pocket. I would think that the distance from the flange surface to the depth of the flange pocket would be the room for the axle in the straight position.
I am watching for a smart guy's answer also.

On your control arm I went outside and looked at some 83-84 aluminum arm assemblies and the cv cavity is very shallow on them and also a bigger diameter, they might be 944 arms as I bought them for a dune buggy awhile back and don't remember the particulars. They do have the angle emer. brake expanders though. I got to looking at them and they maybe could be cut up and from the swing plate to the hub used and bolted to a modified or fabbed 914 arm. You might could even make it adjustable in ride heigth. They are very similiar to irs vw but will hold the 11 inch x 18 wheels I have. I don't think the cv's would interfear with those arms as the hole is real shallow.

[Eric_Shea]

Since this is on par with everything Eric has been posting if anyone is looking to do some axle/ CV stuff here is a good start:

http://forums.pelicanparts.com/showthread.php?t=453379

Whew... damn good price too. Think about it; that's $25.00 per CV! (IMG:style_emoticons/default/ohmy.gif)

[Eric_Shea]

it seems that the full extended position with the surface of the flanges would be the dimension a axle supplier would want to know

I'm not sure if it's a custom application but I do know a standard 914 axles is 20.25". I would simply measure the difference from stock to what you've created and add this to the 914 length.

[Wilhelm]

it seems that the full extended position with the surface of the flanges would be the dimension a axle supplier would want to know

I'm not sure if it's a custom application but I do know a standard 914 axles is 20.25". I would simply measure the difference from stock to what you've created and add this to the 914 length.

Problem is:
930 tranny with sportomatic flanges and custom trailing arms. Just looking for a simple method to measure for axles without having to mess about with all the greasy cv joints while doing a mockup.

[shoguneagle]

(IMG:style_emoticons/default/bye1.gif) Thanks everyone, especially Eric, for the information. It cleared up a lot of things.l This thread is one for the books and needed if one is doing the conversion.

Next project 911 brakes and e-brakes. get ready, Eric!!

Thanks,
Steve

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[Eric_Shea]

Problem is:
930 tranny with sportomatic flanges and custom trailing arms. Just looking for a simple method to measure for axles without having to mess about with all the greasy cv joints while doing a mockup.

I would get out the calculator again.

20.25" - (1/2 Difference in Width of the 930 w/Flanges over the 914/901 w/Flanges + The Difference in your new 928 spaced out hubs) = Your New Axle Length. This is assuming the 930 is wider.

You have specifics and only one variable... your new control arm.

914 Axle = 20.25"
901 Flange to Flange = X
930 Flange to Flange = Y
Difference in new control arm from stock = Z?

20.25"-(X-Y/2)+Z=New Axle Length

(IMG:style_emoticons/default/confused24.gif)

I know what you're getting at but I don't have a "tape measure" answer. If the 914 CV's sit relaxed vs. hyper or hypo extended then I would imagine the 20.25" number is a good baseline.

Thanks everyone, especially Eric, for the information.

Happy to help. (IMG:style_emoticons/default/wink.gif)

[J P Stein]

Running 914 CV's with 200+ hp in an autocross environment is a "when" not "if" situation.

Do you have any empirical data to back that up or are you just vomiting up your version of conventional wisdom?

I have all the records for my 914 from day one. These lead me to believe the original CVs are still on the car. In 8 seasons of AX on very rough venues with your 200+ hp and more tire than most, I have never broken a drive line part. I have seen other car's suspensions collapse on theses venues....including a Porsche.

Sure, everything wears out but given proper maintainence our CVs are pretty damn tough. Most failures I read of are from those that didn't keep an eye on the CV joints to include grease, proper washers under the bolts, and proper torque. I have found loose bolts but got to them before any damage was done....that's part of the racin' game.

I did have the steering rack come loose 10ish years after fooling with it. I'll add that to my list of things to be looked after.

I am a firm believer in KISS and I ain't sellin' anything.

[PeeGreen 914]

I have seen 914 CVs go at an AX and Greg Fordahl likes to call them fuses so even though you have not had it happen I would guess they have been an issue. Most of the guys I know that have had it happen are people who do take great care of thier car and inspect it often.