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Rear bearings and bonnet

PostPosted: Sun Nov 11, 2018 3:23 pm
by Emma-Knight
At the moment, I'm fighting with two problems (car related :mrgreen: )
trying to knock out the drive shafts (from the well warmed bearing Housings), the inner bearing moved some mm, so free from the alloy.
The shaft refuses to move in the outer bearing. These were sitting since mid seventies, steel to steel, a bit rusted
Induction heating the race? Other ideas? I'm frightened to crush the alloy

Second one: my garage neighbour pressed down the rear left edge of the bonnet so hefty that it cracked at the clamp recess, completely through the fibre for 5 in towards car center, giving gelcoat cracks almost to the right clamp recess.
Where do I get a well moulded bonnet, original style GFK, preferrably with S2 style bobbins moulded in? (GB or close based)

Anna

Re: Rear bearings and bonnet

PostPosted: Sun Nov 11, 2018 6:34 pm
by nmauduit
if the original bonnet was fitting well and did not have any major issue, I'd repair it : chance are it'll save time, since new ones need some work to get prepped anyway, then fit may become an issue on which you'll have very little grasp depending on what you get (only option will be to try to balance the gaps, with little adjustement options, esp. vertically).

Re: Rear bearings and bonnet

PostPosted: Mon Nov 12, 2018 9:09 am
by nigelrbfurness
You could try soaking the outer bearing - even the whole housing - in 25-75% mix of acetone and diesel for a few days. It's an old trick that always works for me and for the quantities required much cheaper than penetrating fluid. Repeated heating and rapid cooling of the shaft will also help to break the rust seal. I would try to avoid too much heating of the aluminium housing for fear of softening and distorting it, 100C is plenty enough to expand it to remove the bearings. It will eventually come apart, patience and perseverance is the name of the game.

Re: Rear bearings and bonnet

PostPosted: Mon Nov 12, 2018 1:25 pm
by gus
The rear bearings should come out without damage to the housing with moderate force in a hydraulic press

So:
The hub is off?
the inner snap ring is off?
you are pushing on the outer end of the shaft towards what would be the center of the car?

The only thing holding it in is the mild press of the inner bearing on the bearing carrier.

The stub axle and inner bearing come off as a unit.
The outer bearing stays in the housing and is pressed out from inside to outside

If all this is true pics would help


I watched the horrifying wheeler dealer episode where they destroyed a bearing housing, so that is why I spelled it all out

Re: Rear bearings and bonnet

PostPosted: Mon Nov 12, 2018 7:07 pm
by david.g.chapman
I removed some rear wheel bearings just a few days ago. I do not have a press, but if you have access to one, then removing the hub carriers and pressing then out is the safest way to go.

I removed my stub axle with the hub carrier still in the car:

1. First taking off the circlips, and carefully cleaning the inside of the hub carrier when the bearings are to come out. The lip area is weak and can break off is there is any obstruction.
2. Soak the bearings in Plusgas and leave for a day.
3. Tape a small aluminium plate to the threaded end of the stub axle to protect it.
4. I used a 7 pound sledgehammer on the plate - a 12 inch swing or two and the axle was moving inwards. My smaller club hammer was not enough. Needless to say, the car was well supported. Sounds brutal but is has worked for me so far.
5. Drive the outer bearing out from the centre of the car with some thick 35mm dia. steel tubing or something similar.
6. I removed the inner bearing from the axle by cutting slots at an angle in the outer race with a Dremel and a cutting disc, being careful to avoid the washer. I was amazed how easily the disc cut. When nearly through use a cold chisel to break through the race. Then repeat with the inner race - make sure you stop short of the axle bearing surface, then a tap with the chisel and the bearing is off with no force!

Dave Chapman.

Re: Rear bearings and bonnet

PostPosted: Mon Nov 12, 2018 11:24 pm
by nomad
I have considered drilling the hub and fitting a grease zerk to prolong the life of the wheel bearings. Considerable unsprung weight of grease to fill the hub could be reduced perhaps with a closed cell foam sleeve. Anyone done this??? Pro's and Con's????


Bearings that were minus the inner shield would have to be fitted of course or the inner shield perforated when they are fitted.

Kurt
26/3754

Re: Rear bearings and bonnet

PostPosted: Tue Nov 13, 2018 2:02 am
by StressCraxx
I did exactly that 30 years ago. I discovered the oil separated from the thickener and leaked from the bearing housings. All that was left was the thickener from the grease I had packed between the two bearings.

Just my opinion, I think sealed bearings with the suffix 2RS would be best. Rubber seals both sides seal in the prefilled lubricant. The bearings should last a long time and driving the car keeps the oil in the grease from separating from the thickener. YMMV

Re: Rear bearings and bonnet

PostPosted: Tue Nov 13, 2018 7:46 am
by alan.barker
Emma-Knight wrote:At the moment, I'm fighting with two problems (car related :mrgreen: )
trying to knock out the drive shafts (from the well warmed bearing Housings), the inner bearing moved some mm, so free from the alloy.
The shaft refuses to move in the outer bearing. These were sitting since mid seventies, steel to steel, a bit rusted
Induction heating the race? Other ideas? I'm frightened to crush the alloy

Second one: my garage neighbour pressed down the rear left edge of the bonnet so hefty that it cracked at the clamp recess, completely through the fibre for 5 in towards car center, giving gelcoat cracks almost to the right clamp recess.
Where do I get a well moulded bonnet, original style GFK, preferrably with S2 style bobbins moulded in? (GB or close based)

Anna

Are you sure the Bonnet is not touching the Rad Cap :shock:
Alan

Re: Rear bearings and bonnet

PostPosted: Tue Nov 13, 2018 10:27 pm
by Emma-Knight
I normaly leave the bonnet open, resting on the clamps, so I can easily turn the Fan weekly. This time, when I took the cover off, left Side was pressed deep into the clamp, leaving the bonnet twisted at its rear end. First days, there was a couple of spider cracks, 6 # wide. Two Weeks later, almost full rear Return flange wide.

Some new Bearing housing photo,
inner c- ring is out, area clean and inner bearing moved ( at preheated 100 deg. Celsius.

Anna

Re: Rear bearings and bonnet

PostPosted: Wed Nov 14, 2018 8:40 am
by rgh0
If the inner bearing is moving in the bearing carrier and you still cant drive the shaft out then its the outer bearing that has seized on the shaft. Looking at the rust in the outer bearing that is not surprising. You need to clean up the outer shaft outside the bearing and try to get your favorite penetrant oil between the bearing inner race and shaft.

I would try to heat the bearing inner race with a hot air gun and then cool the shaft next to the bearing with loctite "freeze and release" spray. Support the rear of the bearing carrier evenly and then drive or press the shaft out.

cheers
Rohan

Re: Rear bearings and bonnet

PostPosted: Wed Nov 14, 2018 8:44 am
by alan.barker
+1 Rohan spot on
Alan

Re: Rear bearings and bonnet

PostPosted: Wed Nov 14, 2018 2:19 pm
by nomad
StressCraxx wrote:I did exactly that 30 years ago. I discovered the oil separated from the thickener and leaked from the bearing housings. All that was left was the thickener from the grease I had packed between the two bearings.

Just my opinion, I think sealed bearings with the suffix 2RS would be best. Rubber seals both sides seal in the prefilled lubricant. The bearings should last a long time and driving the car keeps the oil in the grease from separating from the thickener. YMMV


I imagine the grease separation would be a problem and agree that double lip sealed bearings would be better. Least that is what I imagine 2RS means. Been many years since I had a Fafnir catalog.

Kurt

Re: Rear bearings and bonnet

PostPosted: Wed Nov 14, 2018 2:35 pm
by alan.barker
For me the Bearing has always been "2RS".
The only thing that changed from early Cars was the width of the Inner Bearing
Alan

Re: Rear bearings and bonnet

PostPosted: Wed Nov 14, 2018 6:17 pm
by knockoffnut
Hi Emma, I recently tried swapping bonnets between S1, S2, S3 cars and I found significant variations between the cars I had available to test. This leads me to believe that sourcing and fitting a new bonnet to an S2 shell may be more difficult than, for example an S3 or S4 car. If it was me I would repair the existing bonnet, as I expect it would be less work, and also provide a better end result. Grinding out the cracks and filling with glassfiber filled "fiberglass panel adhesive", which is sold by bodyshops for repair of Corvettes, for example, is a good way to fill cracks. High quality epoxy primer helps reduce the risk of cracks re-appearing in area of the repair.

Re: Rear bearings and bonnet

PostPosted: Fri Nov 16, 2018 8:51 am
by Emma-Knight
So I will follow the heat / could / oil route for the bearings and try to fix the bonnet.
The bonnet thing is so annoying - someone broke it and does'nt stand to it. Lost one car by fire this year, caused by someone who refuses to tell the claim to his insurance. So I have to consult a lawyer :twisted:
People keep me busy...
Thanks for the help, Lotus Folks
:D
Anna