Rear Engine Mount - Bolt, Rubbers, Spacers, etc. Stuck

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vbro

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Hi,

Doing a frame up resto on a 69 and got stopped trying to remove the rear engine mount. Mount bolt will spin freely, but won't slide at all. Had to cut the bolt to remove the mount from the frame, and now still can't get the bolt to move. Tried getting penetrating oil in as far as I could, no improvement. Have not wanted to use heat, as the rubber will melt, might create more headache than help.



Suggestions?

Thx.
 
vbro said:
Hi,

Doing a frame up resto on a 69 and got stopped trying to remove the rear engine mount. Mount bolt will spin freely, but won't slide at all. Had to cut the bolt to remove the mount from the frame, and now still can't get the bolt to move. Tried getting penetrating oil in as far as I could, no improvement. Have not wanted to use heat, as the rubber will melt, might create more headache than help.



Suggestions?

Thx.
Click to expand...

I suppose you could take the cradle assembly to a press and have what is left inside pressed out but if you are doing a frame up restoration I would replace the rubbers anyway. Even a press may damage the rubbers; not sure what would come loose first, the spindle inside the rubbers or the rubbers inside the housing.
 
The bolt is rusted on the inside and will not pass through the bushings.

I might take a hole saw of the right size, like for cutting door handle holes, and simply cut out the center on both side and pull it all out. Abviously there is little to save.

You could also take a 1/4" drill or so and start punching hole around the parimeter of the bushings into the old rotted rubber.

I would not worry about hurting anything, even if you scratch the inside of the tube it's no big deal.
 
Dances and Pviss,

Thx, going to go ahead with drilling out the rubber, see what happens.

Cheers.
 
As Dances said, it is advisable to replace the rubbers anyway if doing a frame up rebuild. The old rubbers have to be pushed out by whatever means does the trick, my old ones were rather perished and came out fairly easily. You have already cut the bolt, so from here on you have nothing else to lose.
The inside of the tube was a bit rusty. I cleaned it up and painted it with rust guard paint. This will help the new rubbers slide in. They are a tight fit. I found the rear ones easier to push in than the fronts.
Cheers
Martin
 
In addition to painting the inside of the ISO tubes, upon reassembly, I would look for a long term durable water proof lubricant. There are some silicone lubricants that may do the trick. Slather it on thick on the rubbers, inside the iso housing, inside the steel tube integral with the rubbers and the spindle or bolt that goes through the rubbers. Still no gaurantee. Even if there were a stainless steel through bolt (which I do not recommend) the steel tube on the rubbers can rust up.

Really a challenge when you think about this. Norton provides the rubber/plastic gaitors to seal the isolastics from the elements but we all know this is not water tight. Maybe in addition to the above suggesting the gaitors get slatehered in water resistant grease and get inspections and regrease on a regular basis.
 
Just to add, these old rubber aren't pressed in there anymore. They are stuck and fused to the inside wall of the tube. If you press them out they will rip apart to some extent and either way you will need to scrape and cut the remnants away. As said before, you can't hurt anything, it just a stupid tube. :lol:
 
Ah, I have dealt with the stuck main iso stud a number of times

As others have said, it is galled into place and will not slide out of the rubber donut bushings

What I have done that worked well was to remove the big nuts on either side and just start tapping firmly on one side of the stud then over to the other side, tap tap, in time it will start to move a little, then more and more as you are breaking free the galled stickshun in there, back and forth driving it harder getting it to move a half inch, then more
until eventually using a long metal punch to drive it the rest of the way out

JB penetrating spray shot in there through holes drilled in the rubbers helps also
 
Thanks for all the input,

got the bolt out by carving out the spindles of the rubbers, and indeed, there was a single long spacer between the two rubbers, corroded to the bolt and preventing it from sliding. Now gotta clean out the mount tube, there's a bunch of rubber left from the donut (see pic), anyone got tricks?

Also, is there a metal ring on the outside of the rubber donut that has to come out? Or is the rubber just jammed into the tube? If there is a metal ring, any suggestions on moving that?

Thx.



Rear Engine Mount - Bolt, Rubbers, Spacers, etc. Stuck
 
A bunch of cuts with a long sawzall blade, then long radius chisel and mallet.? Maybe get close with a round file.
 
vbro said:
Also, is there a metal ring on the outside of the rubber donut that has to come out? Or is the rubber just jammed into the tube? If there is a metal ring, any suggestions on moving that?
Click to expand...

1969 model.

I don't remember it being mentioned before but the early workshop manual drawing shows the front and rear Iso rubbers fitted inside thin spacer tubes.

Item marked 'T'
Rear Engine Mount - Bolt, Rubbers, Spacers, etc. Stuck


The 69 parts book also shows a 'Spacer tube' (5) as part of the rear Iso. assembly.

Item 5
Rear Engine Mount - Bolt, Rubbers, Spacers, etc. Stuck
 
Snortin, will try a radius chisel, great thought, thx

LAB, thanks for the drawing, that makes sense to me. Going to try ringing a parts guy near me tomorrow, see if I can get clarity on any inner tube.

Cheers everyone.
 
Looks like you drew the short straw. They deleted that outer sheath around the rubbers on later models for that very reason; they weld themselves to the cradle. That got a mention in my workshop manual. I don't envy you. The only suggestion I can offer is, when things are very hard to remove, heat often helps (along with a lot of banging, gouging, grunting and swearing).
Cheers
Martin

P.S. Maybe if you could get a longitudinal cut through the sheath to break its back so to speak, it might be possible to drive it out with round bar or pipe.
 
my FB has the same setup, i was told that you can get that sleeve out by hacksawing it into several pieces but that the right way to do it is have it pressed out.
 
I remember comparing my iso setup with the book and I didn't have that spacer in mine, luckily. I wondered if they really existed. If you don't mind, what is your serial number vbro? Mine's 132031, Apr 69.

Dave
69S
 
Just throwing out ideas here but maybe gentle heat on the cradle and some light oil with dry ice on the inside to shrink it a bit. Liquid Nitrogen would work on the a treat on the inside if handy.
 
DogT said:
I remember comparing my iso setup with the book and I didn't have that spacer in mine, luckily. I wondered if they really existed. If you don't mind, what is your serial number vbro? Mine's 132031, Apr 69.

Dave
69S
Click to expand...

Hi Dave, sorry to have missed this, she's a mutt so not sure if the numbers will help you or not. But I have confirmation from a wise old owl that the 69s did indeed have metal ringed rubbers and a spacer tube, as the drawings and others suggested above. He suggested torch cutting the ring (longitudinally) and then working it out in pieces.

Haven't been on this bike for a while, but back at er now. More questions to come I'm sure.

Thanks for your help.
 
I used a flapper disc in a battery drill with extenstion to clean in side the tube
Regards Mike
 
vbro said:
He suggested torch cutting the ring (longitudinally) and then working it out in pieces.
Click to expand...

I know I'm repeating myself here, that's because I only put my brain into gear properly AFTER my previous post. It should be fairly easy to make one, two, three or more longitudinal cuts through the tube with a hacksaw to make it easier to remove. Even if you nick the main tube slightly it's no big deal, as long as the offending piece is cut fully through.
I don't know how you could torch cut the unwanted piece without also cutting into the main tube, but then I'm a novice when it comes to that sort of thing.
As I said before, my next step would be to find a piece of bar or pipe just the right diameter to use as a drift, in conjunction with a press or a f*!#%ng big hammer.
Cheers
Martin
 
I think I've seen several tranny cradles on offer. might be easier to start over.
 
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