Lotus Elan and Lotus Elan Plus 2 Forums

I'm replacing rear axle bearings and cannot separate one of the hubs from the axle. I have researched the subject here as well as having read Dave Bean's manual. The first hub came off using the RD Enterprises tool and applying heat from a small propane torch. I can't imagine a better tool to use? It's really heavy duty. My question is how much heat can I apply. Dave Bean says 400 F degrees max. I think cast iron can withstand more than that and what do I have to lose if the next step is destructive removal of the hub? Ideas appreciated.

I feel your pain. The hub is actually cast steel. I have used PB blaster penetrating oil behind the hub into the shaft and let it set for a day, then applied the puller and the heat. The important thing when heating is to heat it quickly so the heat transfers as little as possible to the shaft taper. Then hit behind the hub with a hammer while turning.

for this specific job I always strongly advise to get (or at least make) a proper tool to take out rear hubs: they are notorious for getting distorted when one hits them, and not resisting the temptation will have a cost... likewise the use of 2-3 pronged hub extractors will most probably damage the hub.

When one only applies force concentrically from the threades tube to the shaft risks of damage are greatly reduced : the cheapest version I've heard of (but not tried myself) would be to use a spare wheel nut to capture a hardened steel ball or equivalent self-centering pressure piece (find a way to keep it there while the wheel nut is put back on, glued or otherwise), screw it real tight then some more (note: one needs a lot of preload here, so depending on the material used the contact area and volume under pressure needs to be matched or some squishing will occur), heat up the hub where the contact cone is while rotating the hub so as to apply heat homogeneously to the hub (one needs to find the proper amount of heat so that the shaft is still not expanded too much, I do 2-3 min with a propane torch straight up from underneath), then a strong blow dead on the nut with a heavy hammer should do the trick if heat has not already (note: if the shaft nut has been completely removed the hubs assembly may fly some upon getting free - it should be backed several mm at least to give room, depending on what is used to apply pressure below the spare/sacrificial wheel nut).

There are of course dedicated tools for that task, buying of borrowing them is well worth the effort I believe.

In the present case, the tool should do the trick with strong preload (make sure you use a high tensile central hex bolt torqued to the max, not a plain steel bolt since it would distort under the blow rather than transmitting the energy of the hammer) and heat, as the pressure is properly applied concentrically and centered by construction : the hit needs to be sharp, heavy, and bang on the hex bolt head as soon as you've finished heating the hub... if it does not work the first time, let it cool off while soaked with WD40 and go at it the next day (since it's off the car you may even cool it in the fridge overnight to get a larger heat/shrink amplitude).

It'll work. good luck.

Not what you wanted to hear I’m sure but that tool should do the trick. You just may have to use a few more tricks.

As a mechanic on rusty crap in the Northeast US the number one lesson is that you have four tools to get stuff to come apart: heat, vibration, lubrication, and impact. When I did my hubs last year they refused to come off without heat. Once heated they were still stubborn but enough tightening of the bolt and eventually they popped. However if they didn’t I would have tried the following, in this order, seeing if it pops after each step (these steps are cumulative too, i.e. do/have done step 1 if trying step 2)

0. Heat the hub with a propane or oxy acetylene torch
1. Once the hub has cooled spray a penetrating oil down the taper from both sides and let it sit overnight (PB blaster is good, aero kroil is better but very expensive)
1a. If it still refuses to pop don’t apply more, since it’ll just keep burning off each time you heat the hub
2. Invest in a cheap 1/2” drive impact wrench - Earthquake XT from Harbor Freight, Hart from Walmart, etc. If you like good tools and money is not an object get the Milwaukee M18 2767. You are looking for something that is BIG and will put out hard impact blows to really crank down on that bolt. With this step you do start to run the risk of marring up the end of the axle shaft though so be careful
3. After applying heavy preload to the bolt with the impact, if it still refuses to come off even with heat applied, give the end of the bolt a few whacks with a heavy hammer. Then tighten more with the impact. Then hammer again. Repeat this step until suitably frustrated and/or the bolt head mushrooms over and then cut the axle shaft with a hacksaw or gas axe and buy new billet shafts and hubs from TTR.

There are more steps after 3 but I’m omitting them here as they most likely won’t be helpful to the “home gamer” and may start destroying things - such as using an air hammer to rattle the backside of the hub. Personally I’d bet they’ll pop for at least 95% of people on or before step 2.

-Ben

I have this job in my near future. I have the tool from sjs that goes under the spinner. I am planning to try separate the hubs before removing the uprights, so they are fixed in position and have access to the brakes to stop things spinning.

My plan is to apply penetrating fluid, use the tool to apply some tension to split them, then heat the hubs with torch. I am expecting a few cycles of this to be successful.

If that doesn't work then I plan on adding some freeze type spray* to the mix. So heat the hub up hot and use spray on the shaft, hopefully the hot hub and cold shaft will be enough for it to pop off.

* https://www.amazon.com/CRC-05002-Freeze ... B000TFTH00

If all else fails find a shop with a press or hydraulic puller and large bearing splitter that can be fitted behind the hub to support it in the press. The press or puller combined with a bit of heat on the hub and it will come apart.

cheers
Rohan

Thanks Ben, Stress Craxx, Mmauduit and Rohan
I have tried most of these suggestions short of the penetrating oil. I figured if the taper fit was tight no way would it penetrate. However I will give it a try with PB Blaster tonight and keep trying. I have a large Dewalt 1/2" drive impact gun using a 12 point socket but I just ordered a 6 point impact socket as I noticed the bolt head starting to round off a bit. Should all else fail I'll consider the use of a press and bearing splitter. I still wonder how likely it is to damage the hub with too much heat.

Mbell
I would read Dave Bean's paragraphs on the subject. Very helpful and he recommends removing the upright for easier access on the bench. I had no issue with things spinning which would require the use of brakes. I do like your idea of cooling the axle shaft..

Chris

Good luck Chris. Will check Dave beans wisdom on this.

My tool uses the spinner to apply pressure to the drive shaft. I figure I am less likely to damage the drive shaft with it still on the car than trying to clamp it in a vice. Time will tell thou...

Hi, Chris. Having removed over a dozen or more hubs, I can send you a picture of the very large USA puller I use, if you wish. No idea how to post the picture on the forum, but if you send send me an email directly, can do.

Sometimes, patience will work, a bit of impact is helpful, heat directly from my acy/oxy torch has been needed and penetrating oil of choice, too.

If you are coming to the SF Bay Area, bring it over.

Cheers. Mike.

I was finally able to get the hub off the shaft this evening. I guess just the right amount of heat and force. When I went to remove the circlip on the inner bearing the end broke off. I'm soaking it in PT Blaster and will revisit tomorrow. The fun never ends.

I'm going through this exercise at the moment too - hubs have not been apart since new. Penetrating oil overnight, heat using an electromagnetic heater on the hub, and impact wrench failed to move the hub at all. Off to a machine shop with a press.

The Lotus manual is not very helpful either. I presume that the rear hub drive pin between the hub and shaft does not need to be drilled out or punched through before attempting removal. No mention of the pin at all in the manual.

Hi Guy

You really need to heat with a torch from outside, as electromagnetic heater will heat the shaft also and not loosen the hub. You really only use electro heaters for fitting bearings not for removing.

The pin is just there for decoration IMHO not need to worry about it when removing the hub

cheers
Rohan

I'd forgotten what a pig these can be until recently.

Ultimately an 8 tonne hydraulic puller was required with some heat on the back of the hub flange - eventually it gave way with a bang. It's nerve wracking!