Rear Hub Wont Fit... Grrrrrrr

[Tspringer]

The nightmare of converting to Alloy bananna arms continues.

Note to those considering this: DON'T DO IT. The weight savings total is less than 15 pounds. It is a MONUMENTAL pain in the butt. NOTHING fits right. I would never do this conversion again.

I have the alloy control arms on the car. I installed the e-brake assemblies (of coarse after buying new ones, original are a different size) and needed to install the hub.

Of coarse installing the hub is a neat trick. Should have had the machine shop press it all on in a jig when they did the wheel bearing but I didnt. I got a threaded rod, a couple of large sockets and some nuts for the rod. I put one socket around the edge of the inner wheel bearing edge and the other socket on the hub with the rod running through both sockets. Then I used nuts to secure one end and bring the other tight. I made sure the sockets were properly seated on the bearing and the hub and the hub was straight with the bearing. I began to thus pull the hub into position.

The instructions in the Haynes manual say to just use the stub axle and castellated nut to pull the hub on, but of coarse this is impossible. the stub axle cannot protrude enough to get the nut threaded until the hub is already partially pressed in place.

In other instructions I found it says to carefully press the hub into place until the stub axle nut can be threaded and then let the nut finish pulling the hub into place. No instructions gave any clue on how to actually start the hub into position.... but my threaded rod trick seemed to work pretty well.

The Hub did line up well and appeared to slide into place when pressure was applied via my new hub install tool. It did not require any massive torque and it went in smoothly. Up to a point. Then it did not want to go any further. So I stopped.

At that point I could install the half shaft and the castellated nut would thread on. So I figured I would use the shaft and nut to finish torqueing the hub into place. So... I got my breaker bar and socket out and tried.

Please note at this point: My car is a 1969 911S that originally had steel control arms. I am still using the original half shafts, stub axles and hubs. Only the control arm itself and the e-brake assemblies were replaced all other control arm related stuff is stock (well... torsion bars, SAW spring plates, mono-balls, smart racing anti-roll bar..... ).

I torqued that CRAP out of that nut. I used a 3 1/3 foot cheater bar and my 1/2 drive MAC tools breaker bar. I got it on to the point where the hold for the cotter pin was visible but the correct size cotter pin would not fit. I figured it needed some more.... but at this point I am applying perhaps 600ftlb of torque to it alreadly (I weight 240lb and I was pushing on that 3+ foot bar with almost all my weight). I figured "Dang.... that must be enough". I planned to just drill out the hole in the half shaft a bit so the cotter pin would fit.

Wont work that way. The caliper wont bolt up. The hub is not on far enough, thus with the rotor on the caliper cannot fit over the rotor and fit in place on the control arm. Foiled again.

So I decide to torque that sucker again. My breaker bar shatters scaring the crap out of me.

What the hell is going on here? I fear I am going to destroy the wheel bearing and require removing the entire control arm again (which of coarse means removing the engine/trans AGAIN).

Is the caliper different? Nothing I have ever read indicates this.... my understanding is the rear "m" caliper is the same through the carrera. Is the stub axle supposed to be different? Do the entire half shafts have to be changed as well? As much as I have torqued that hub now, I fear removing it will probably require destroying the bearing and put me right back where I started.

I've honestly just about had it with this car. IT has fought me on EVERY single task. Not one job on this hotrod project has gone in a normal manner. Im about convinced that when this car finally does see the track... it will drive ITSELF straight into the first concrete wall available.


Terry

[Tspringer]

I measured the bearing depth on the new bearing at 1 5/8. The bearing depth on the old steel arm was 1 7/16. The stub axle length is 2 3/16 from the inner flange to the end of the teeth and 3 17/16 from the inner flange to the end of the stub axle.

I have been reading dozens of posts on converting from steel to alloy control arms. So many people have run into so many different problems while others have no problem at all. It seems its a total roll of the dice and NOBODY actually knows what all the possible combinations are.


Terry

[Randy Webb]

There was an magazine article on how to so this some time ago -- 3-4 yrs.? It discusses what needs to be done for different years. Search on webb & arm and you may be able to pull up the name of the magazine & the issue/year. At a guess it was European Car and was during their upgrading the 911 series.

- You might post what year your alloy arms are - maybe someone can help based on that.

[Tspringer]

Randy,

The article you refer to does not address any stub axle or hub issues. In that instance the aluminum arms were installed with the hub already in place, not attempting to use the original hub. Also, the car in that article had a 915 trans. thus different half shafts and CVs.

I know my alloy arms are '74 to '77 because they have the ball type connector for the anti-roll bar. Other than that I have no idea what year they are nor any way to tell. I will look at them and try to find a part number and will post that.


Terry

[304065]

Hey Terry,

I read your post with great interest as I have all the parts for the conversion myself and am planning on it. I am STILL planning on it, but I agree with you, every situation is different but I guess that's what this board is for.

Anyway, if you look on the arms, somewhere there should be a small casting mark that's got the date in a circle, and then around the outside there are a number of bumps that give you the month of production. In the arms I got for mine (which supposedly came off a '74) I got one '74 casting date and one from an '86 that had been converted. I guess that car had been in a wreck along the way (before the wreck that killed it for good).

OK, so new E-brake assemblies are required, I'll be sure to get those.

[Jim Sims]

First of all remember these efforts are supposed to be a hobby; when things get frustrating I would advise taking a break doing something else for a while.

I looked up some part numbers and I believe the root of your difficulty is the hubs and bearings are different between '69 and '74-'77.

'69:
stub axle part no.: 901.332.232.00
hub part no.: 901.331.065.33
bearing part no.: 999.053.021.00 superceded to 999.053.035.00

'74-'77:
stub axle part no.: 901.332.232.00
hub part no.: 911.331.065.33
bearing part no.: 999.053.020.00 superceded to 999.053.020.01

I will conjecture that the '69 hub has a longer projection (by the difference of the bearing thicknesses) than the '74-'77 hub. By projection I mean the portion that points inward towards the bearing. When this hub is used with the newer bearing (999.053.020.01) which is thicker the result is the the problems you have experienced: (1) the hub won't seat in on the stub axle sufficiently to line up the slots in the castellated nut with the cross drilled cotter pin hole in the stub axle and (2) the hub sticks out too far for the brake system to mount. I haven't done this conversion but I will predict you must either obtain the '74-'77 hubs or use the older ('69) thinner style bearings. I would go the newer hub route as the thinner style bearing may require the addition of a custom made spacer between the bearing retainer plate and the outer race of the bearing due to the fact that the bearing bore is deeper. This is not what you want to read as this means the arm assembly has to come apart again. Given the load you applied trying to seat the hub I am concerned that you may have "brinelled" the races of the bearings and flattened the balls so you perhaps would want to replace the bearings anyway. If it would help, I can post an exploded diagram of the a '74 to '77 rear axle assembly and a '73 rear axle assembly (which is the same as '69). My son and I compeltely rebuilt a set of '73 rear axles and to do it properly we had to have a bearing pusher part made (to load only the outer race), used a hydraulic shop press and also heated and cooled parts to gain extra clearance from the thermal expansion and contraction. There was no "banging" required which I know you haven't done but is sometimes mistakenly done to assemble the hubs/stub axles. Cheers, Jim

[Randy Webb]

One more tidbit -- the CV joints from a '68 or so will _not_ fit on the halfshafts for the newer cars (1973-on) -- ask me how I know ... I am having similar trouble right now trying to get a 901 tranny to work in my 1973 car (I like the shift pattern). Also, you cannot interchange the trans. drive flanges between a 901 and a 915 trans -- the internal splines are completely different.


BTW - you might post the magazine & issue (or even scan the article) for those who will go thru this in the future.

[Tspringer]

John,

Some great points.

I worked on this some more today. I removed the castellated nut and then removed the half shaft assembly completely.

When I look at how the hub was seated in the bearing, I expected to see the hub protrude out past the inner portion of the bearing as you describe would be the case if the '69 hub protrusion is longer than the later models and thus too long to use with the alloy arm. The problem is.... the hub was not protruding past the end of the bearing. In fact, the hub was not about 1/8 inch shy of even reaching the bearing end.

So, I took the other stock '60 hub that is not installed and measured the protruding end. It is about 1 7/16, which matches the early steel arm bearing depth exactly (of coarse as it should). Given that the bearing depth on the later model bearing in the alloy control arm is 1 5/8 the '69 hub clearly will not go all the way in.

So, it appears the problem is the hub is just completely wrong. So, I went to remove the hub and check the bearing. Bad news. The hub did not want to budge. When it did come off, it brought the outermost outer bearing race with it. That race will not come off the hub. So.... the bearing is trash.

This give me yet another fun choice. I can either pull the engine/trans again and remove the entire alloy control arm to take it back to the machine shop and have a new bearing pressed in.... or I can pop for $250 for the bearing and hub install tool. Im sure thats what I will do.

So.... I need 2 new hubs, but I still dont have any idea exactly what new hubs I need.

I looked at the control arms and got these part numbers off them:

Left: 911331513OR
Right: 911331514OR

I am pretty sure these are from '74 - '77 because of the ball type anti-roll bar mounting, but not sure exactly which year and given my luck there were probably 47 different types of hub used in that period


Terry
'69 911S hotrod, the neverending project
'69 Ferrari 365GTB/4 Daytona

[RoninLB]

Originally posted by Tspringer
I looked at the control arms and got these part numbers off them:

Left: 911331513OR
Right: 911331514OR

I am pretty sure these are from '74 - '77 because of the ball type anti-roll bar mounting, but not sure exactly which year and given my luck there were probably 47 different types of hub used in that period

911---- '74-'89 911.331.065.33
911 turbo---- '76-'89 930.331.065.03

[RoninLB]

Hub & Stub Axle

[Tspringer]

Thanks for the part numbers, big Help!

The question now is do I need to replace the hub and the stub axle, or will the later model hub work fine with the '69 stub axle and half shaft.

Isnt the '74 model stub axle different re. the CV joint? It would seem that if the later model stub axle is required, I will need to replace the entire drive shaft, both CV joints and the transmission output shaft.

So.... anyone know what all will be required?


Terry

[Jim Sims]

See your other thread; which why it's best to stick to one thread per topic. Jim

[Tspringer]

Yup... got it, will buy some hubs and get this ***** on the road. Thanks