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new engine mounts rubber to hard
Posted: Tue Sep 23, 2014 8:05 am
by martin418
hi has anyone found a good source of engine mounting rubbers where the rubber is soft enough to allow movement , the ones on my car had fell apart so i had to change them and the replacements are so hard they have no give , it had less vibration with split mounts !

i have tried all the usual things like making sure the mounts are sitting square etc , i removed the stabilizer rod and it's the same and with the rod off ,there is not movement in the mounts , i took one rubber off clamped it in the vice and i can hardly flex the rubber at all , any ideas
Re: new engine mounts rubber to hard
Posted: Tue Sep 23, 2014 8:26 am
by bmcecosse
Send them back for a refund! You could drill a number of holes through the rubber - but I'm not sure it would help.
Re: new engine mounts rubber to hard
Posted: Tue Sep 23, 2014 10:39 am
by M25VAN
If it's black and engine mount rubber shaped it must be ok.
I wonder if these could be made out of polyurethane like all the suspension bushes?
Re: new engine mounts rubber to hard
Posted: Tue Sep 23, 2014 12:12 pm
by 54woody
Having a similar issue. Recently rebuilt engine in my car is sitting on new motor mounts purchased from Moss (USA). There is an awful lot more vibration and rattles noticeable in the car since the swap. I've been wondering about how to cure it. Unfortunately I don't have the old motor mounts to go back to.
Re: new engine mounts rubber to hard
Posted: Tue Sep 23, 2014 10:20 pm
by MikeNash
I've got the same problem! I bought new mounts from Bull Motif long ago -too long to reasonably complain - and found a lot more vibration particularly around 30-35 in top when pulling hard than I had with my old collapsed 1963 originals. Do we have a "rubberoligist" in the house? I expect we're into Shore Hardness and all that sort of thing.
Regards, MikeN.
Re: new engine mounts rubber to hard
Posted: Wed Sep 24, 2014 9:58 am
by bmcecosse
As above Mike - drill some holes through the rubber...
Re: new engine mounts rubber to hard
Posted: Wed Sep 24, 2014 12:16 pm
by 54woody
bmcecosse wrote:As above Mike - drill some holes through the rubber...
That's an interesting idea. Has anyone actually tried that and had success? Would be worth having a go if it works.
Re: new engine mounts rubber to hard
Posted: Wed Sep 24, 2014 3:41 pm
by martin418
the drill holes idea is worth a try , i have found one original useable mount in a box of odds so i might try drilling a new one and see what happens it cannot be worse
Re: new engine mounts rubber to hard
Posted: Wed Sep 24, 2014 5:13 pm
by bmcecosse
If you are stuck with them - no hope of return - then it's worth a go.
Re: new engine mounts rubber to hard
Posted: Thu Sep 25, 2014 3:12 am
by 54woody
Martin, please report back if you do try drilling holes in one of the new mounts. I'm very interested to see photos and hear results.
Re: new engine mounts rubber to hard
Posted: Thu Sep 25, 2014 9:22 am
by alexmcguffie
Could it be that you have become used to your original mounts softening over the years and changing to new ones has highlighted the difference?
Re: new engine mounts rubber to hard
Posted: Thu Sep 25, 2014 12:03 pm
by 54woody
I can't speak for Martin, but in my case the amount of vibration in the car now is VERY noticeable and bordering on unpleasant. I'm sure the car wouldn't have been like that when new.
Re: new engine mounts rubber to hard
Posted: Fri Sep 26, 2014 8:43 am
by MarkyB
Both the engine steady bar and the wire that retains the gearbox should be neutral, no tension on either.
It's possible that fitting the new engine mounts has moved the engine enough that they need to be checked.
Re: new engine mounts rubber to hard
Posted: Fri Sep 26, 2014 8:55 am
by MikeNash
Ah yes! Thanks, will check, MikeN.
Re: new engine mounts rubber to hard
Posted: Fri Sep 26, 2014 12:07 pm
by 54woody
MarkyB wrote:Both the engine steady bar and the wire that retains the gearbox should be neutral, no tension on either.
It's possible that fitting the new engine mounts has moved the engine enough that they need to be checked.
Neither of those parts exist on my '54 series II.
Re: new engine mounts rubber to hard
Posted: Sat Sep 27, 2014 12:52 pm
by Longdog
The rubber used in the new mounts is way too hard. The way I solved the problem was to source some NOS ones. The difference was stratospheric so it's not just a case of your old ones being too soft. Interesting idea to drill them though. Poly would be the ultimate but I suspect the volume would not justify a production run.
Re: new engine mounts rubber to hard
Posted: Sun Oct 12, 2014 9:13 pm
by 54woody
Thought I'd post a follow up on this thread. I managed to source a pair of NOS motor mounts. Just installed them on my car and the difference is like night and day. All that unpleasant vibration and resonating inside the car has gone. Back to how it used to be. On comparing the engine mounts, the 'rubber' in the new replacement pair is hard as a rock whereas the rubber in the NOS mounts can be depressed slightly with your thumb nail.
Re: new engine mounts rubber to hard
Posted: Sun Oct 12, 2014 10:52 pm
by bmcecosse
Thanks for the update, Where on earth did you find nos Minor engine mounts - in Canada ??
Re: new engine mounts rubber to hard
Posted: Mon Oct 13, 2014 3:57 am
by 54woody
The same engine mounts were used on the early MG Midget / AH Sprite. Plenty of Midget parts listed on eBay here and in the USA. I got lucky and found a pair on eBay.
Re: new engine mounts rubber to hard
Posted: Mon Oct 13, 2014 9:29 am
by bmcecosse
I thought that would be the answer! Just wondered if you had found a supplier of good 'nos' mounts.