Replacing right rear hub key?

[lotusroads]

John,
I sent a message to Spyder and have my fingers crossed for a good reply. I appreciate all the great suggestions.
Regards,
Greg

[garyeanderson]

More photos because it tells a lot more to most folks than just a bunch of words. I am not trying to be a jerk but its the truth. Photos tell the story just like watching someone do the job, kind of like Brians father related to him. I am not an expert, I just have the parts available and a free camera, a free hosting service, and some free time on my hands. Oh I did say free a few times but that doesn't make me a cheap whore, but maybe i'm slut?

Hub internal taper with a quicky lapping


Hub seated on shaft with locating pin set at the right height


(2) AN half height nuts (left), Lotus nuts new and old (middle), and (2) AN full height nuts (right)


Another view of the correct reletive heights of the shaft, key and hub.


Pin length is 1 7/16 inch with a diameter of .186 or 3/16 inch. Notice the slight taper on the right, that goes away from the hub nut. If you don''t get the location right, to close to the washer and the key will prevent the washer from seating properly, to close to the inside of the hub and the tapper will not seat. Its a balancing act.



More nuts!


Pre lapping on the left and after lapping on the right.


Another view of the depth of the shaft below the lip of the hub along with the correct washer.

If you don't have any luck with Spyder I have 2 righthand (green marking) and one Lefthand (Red Marking) plus the driveshaft (issue 18 stub axle) for this Plus2.


Gary

[garyeanderson]

I forgot to mention that the washers should be FLAT, if they are cupped they may bottom on the stub shaft before the proper torque is reached that pulls the tapered parts together giving a false reading on the torque wrentch. The reading wont be false but the torque on the tapper will be.

Here is one severly bent washer, I am pressing down on the edge of the washer that is on a flat surface and the other edge of the washer is lifted up 3/16 th of an inch. Not a good photo but you get the idea.

[lotusroads]

Gary,
If a picture is worth a thousand words than a bunch of pictures must be worth like a million! Your visual essay is extremely informative. I will try to post photos of my offending equipment and perhaps you'll know if its suitable to continue doing yeoman work on the right drive wheel.

I checked my hub again last night and it does hold onto the axle with the bolt snug but not fully tightened. The washer is definitely bent like the one in your photo. I'll need to purchase a new washer and hub key (pin) for sure. Do you know where these items can be purchased? Bean doesn't have the hub key. It was mentioned earlier that one could be made from a mild steel dowel, but not sure where to get the stock material. A machine shop perhaps?

If my hub is toast, it would be fantastic if I could purchase one of your rear righties (Spyder has not responded). Let me know what you thin.
Regards,
Greg

[john.p.clegg]

Greg

If you're in the U.K. recently I purchased some stainless 3/16" just for this purpose and you're welcome to a bit...

John

[CBUEB1771]

When it comes to tightening the hub on with the nylon nut, can I go really tight with the nut or will this have negative effects on the bearing?

The nyloc nut only puts the shaft in tension and the hub into compression. No loads are imparted to the rear hub bearings by this nut. Just bring the nut up to the correct torque, 100 to 110 ft-lb per the workshop manual.

[garyeanderson]

Maybe others can chime in here on the dowel, but why wouldn't a 3/16 drill shank work if its only for alignment? As far as parts availability in the U.S. goes, its Dave Bean, Ray at RD Enterprises, or Jeff at JAE. I have not bought anything from JAE but I used to keep the others living rather well a numbr of years back. Anything shipped or mailed from the U.K. will cost you as much as the part unless its under a kilogram. Best to buy it all in one place if you can. I have been cleaning parts this morning as they have been sitting for 8 years or so and have started to form some surface rust, I lapped the plus2 hub to one of the shafts and dropped it down square onto the stub shaft and I had to give it a couple of good hits with a urethane mallot to break the tapper, I could not turn the shaft on the hub to loosen it. Remember its the taper that holds it...

As for the washer goes, you can flatten them with a hammer on a flat plate/anvil or another hammer for that matter. If its not badly bent, flip it around and reuse it. Others may not agree but Thats my opinion.

Gary

[lotusroads]

Here are some photos of the hub and spindle:

Another look at the shaft.

Nasty looking edge on the keyway.

You can see where the broken key did some machining.

Keyway needs some deburring.

[69S4]

Like many others I've had my problems with rear hubs. Either they won't come off when I want them to or they come off when I'm not expecting it (like in the outside lane of the A1) so, while I don't have any problems at the moment, I've been following these posts and filing away the info as I'm sure it won't be long before I need it

A number of people have said that the key is for location purposes only and that the taper, lapped into submission if necessary, is what actually takes the torque. That's as I understood it but perhaps someone could explain why the key is necessary at all. The hub doesn't have to be in any particular position and if the lapping / machining has been done properly it should be sufficient. Any (simple - I'm not an engineer ) explanation appreciated.

[GrUmPyBoDgEr]

Like many others I've had my problems with rear hubs. Either they won't come off when I want them to or they come off when I'm not expecting it (like in the outside lane of the A1) so, while I don't have any problems at the moment, I've been following these posts and filing away the info as I'm sure it won't be long before I need it

A number of people have said that the key is for location purposes only and that the taper, lapped into submission if necessary, is what actually takes the torque. That's as I understood it but perhaps someone could explain why the key is necessary at all. The hub doesn't have to be in any particular position and if the lapping / machining has been done properly it should be sufficient. Any (simple - I'm not an engineer ) explanation appreciated.

Well I think there are a couple of possible explanations for the Key being a part of the Design:-

1. As has been mentioned previously, as a location so that the Hub may be prevented from rotating during the initial Nut tightening process.
IMHO of great use!

2. Maybe some "dyed in the Wool" Person at Lotus said "But we've always done it that way"
That's a phrase that's been repeated in Design Offices all over the World millions of times I would think.

I think option 1. is the most likely as it would has eased & speeded up the assembly process at Lotus, which may have offset the cost of machining the necessary Slots & the Key.

I believe that some tougher "Competition" shafts may be ordered without the Slot.

The previous Photos showing distorted the Washers is worrying!
I think they may have been made of inferior Material because the Load spreading washer is dimensioned so that the clamping load of the tightened Nut is fed into the Hub & should not be expended in distorting the Washer.
A Washer that distorts may end up seating on the Shaft Shoulder & would also falsify the effective Torque loading, which would be defeating the object.

John

[garyeanderson]

Hi All

I have pulled apart 10 or probably more sets of hubs over the years of both Bolt on and Knock on types. NONE of them have just fallen apart. Most were a bitch to disassemble. My guess is none had been disassembled before as the dead Elan's I purchased (never bought a runner) failed for some other reason. I can't remember where every part comes from, most times I take the best of what I have and it goes into the Elan that I am working on. The washer that was bent badly has been around for a while, might have been from my original S2 Elan that I bought 34 years ago or could be off of 45/7334 as that Elan was as used up as I have seen. Someone in Buffalo was still driving 45/7334 with 3 out of 4 corners of the chassis rotted away and just the fiberglass holding the suspension in place. Anyway after I took the photo I went out and placed it on a flat surface and gave it some well placed hits with a 24 oz. hammer. After each hit I compared it to the other in the photo, back to back then flipping it so that each surface was compaired with another, 4 surfaces in all after each hit. After a couple minutes it looks ok, other than the rust pits. I guess I may use it someday, its been in the spairs for most likely 15 plus years, it may stay there till i'm dead. If I use it, I'll torque up the nut to the spec and then remove the nut and inspect the washer if it looks fine (still flat), re-install and re-torque back to spec. Then i'll drive it. As I said in the earlier post, its the torque of the nut appied to the hub (through the washer) that sets the hub on the taper. I think most of us agree about tapers...

Gary

[lotusroads]

John/Gary,
Did you have a look at the photos I posted of the spindle and hub? The spindle looks completely shot (that keyway groove took a beating), but do you think the hub may be useable? It won't be set up for racing, however it does need to be reliable. The photos show the inner surface and it doesn't look perfect, but there isn't any major damage in there either. I guess it all depends upon how it mates to the new shaft. Let me know what you think.
Thanks,
Greg

[GrUmPyBoDgEr]

John/Gary,
Did you have a look at the photos I posted of the spindle and hub? The spindle looks completely shot (that keyway groove took a beating), but do you think the hub may be useable? It won't be set up for racing, however it does need to be reliable. The photos show the inner surface and it doesn't look perfect, but there isn't any major damage in there either. I guess it all depends upon how it mates to the new shaft. Let me know what you think.
Thanks,
Greg

From your Photos I'd say yes that Shaft is "Shot", buy another & have fun replacing it, getting the Bearings out can be a sod of a job
I let a specialist do mine because I couldn't shift the things.
It's a "Strut off the Car job & a Press would be useful.
Probably better giving that job to someone who already has some Press Adapters for that job.
New Bearings aren't expensive
You'll need to "pair" the new Shaft (lapping) to a/the Hub so why not give the existing one a go.
On the other hand I believe someone's offered you another Hub which will be the most direct route.

[rgh0]

Recovering a damaged hub (and shaft) is possible but generally not worth the effort except as a temporary repair. I have done it by cleaning up the damage with emery cloth and then extensive lapping when I spun a shaft at a race meeting. The hub moves inwards as you lap it in and it will probably hit the alloy bearing carrier when bolted up. i had to also file off a part of the hub rear to create more clearance.

I replaced the hub and shaft straight after the meeting.

Incidently the hub loosened on the taper because the hub itself was flexing under racing loads and the hub distorted into a horn mouth shape rather than a straight taper. I replaced the original iron Lotus bolt on hubs with higher strength steel units.

regards
Rohan

[garyeanderson]

Greg found another used shaft someplace local and I sent him the spare RH Hub Friday that I had so that he can get his Plus2 back up and running. The hub ought to be there today or tomorrow so he should have what he needs except for the key and nut and those don't sound like they will be show stoppers.

Gary