Rubber tends to go soft or hard with age according to its
additives. I wonder if the rubber mounts for the 3.6 engine on
a '89 Daimler become harder with age. I can certainly feel engine
vibration in the cabin. Was there a revised engine mount
introduced aroung 1990?
Any experience?
Regards,
Peter Parsons, Cornwall, UK.–
peter Parsons
–Posted using Jag-lovers JagFORUM [forums.jag-lovers.org]–
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In reply to a message from peter Parsons sent Tue 18 Dec 2012:
Peter,
I don’t see a difference in the LH rubber mount (CBC12916)
between model years but it would seem that under that part
number it is no longer supplied so perhaps they have one
from a later model which can be used although they do not
list it as a superseding part in the JDHT catalogue so you
would need to talk to JDHT.
Rubber tends to go soft or hard with age according to its
additives. I wonder if the rubber mounts for the 3.6 engine on
a '89 Daimler become harder with age. I can certainly feel engine
vibration in the cabin. Was there a revised engine mount
introduced aroung 1990?
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !
In reply to a message from Bryan N sent Tue 18 Dec 2012:
Peter & Bryan,
When I did all the front-end rubber in our car a few months
ago my Jaguar specialist parts supplier checked with Jaguar
directly and was told that they now use the same part number
for both the left and right side engine mounts. In the
archives I found posts from others who had been given the
same information. The answer may be different for a 3.6L
car. See my photo album on engine mount comparison to see
what the old and new mounts looked like, and the adjustment
I made with the fiber washers so that the heights of the new
mount/washer assemblies would match the heights of the
original ones.
Don–
The original message included these comments:
I don’t see a difference in the LH rubber mount (CBC12916)
between model years but it would seem that under that part
number it is no longer supplied so perhaps they have one
from a later model which can be used although they do not
list it as a superseding part in the JDHT catalogue so you
would need to talk to JDHT.
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !
In reply to a message from peter Parsons sent Tue 18 Dec 2012:
When I was researching the archives about engine mounts I did see a
Jag TSB about engine vibration-don’t remember what years it
included- and a revised softer mount to eliminate the problem.So
the engineers were aware of the problem. Of course those are
discontinued so the only choice is aftermarket. The new mounts I
installed give a slight vibration on cold start until the engine
warms up. Don B did say when he installed his there was less
vibration so it may depend on the aftermarket brand that you
pick.And you may want to check the vee mounts to see what condition
they are in. Replacing them made a big inprovement in reducing
vibration also. Cary–
The original message included these comments:
additives. I wonder if the rubber mounts for the 3.6 engine on
a '89 Daimler become harder with age. I can certainly feel engine
vibration in the cabin. Was there a revised engine mount
introduced aroung 1990?
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !
In reply to a message from 72bird sent Tue 18 Dec 2012:
Good point Cary.
I replaced my engine mounts and vee mounts at the same time
and still haven’t noticed any new vibration on cold starts.
I don’t know if changing only the engine mounts might have
contributed to the slight vibration on cold start that you
experienced.
Don–
The original message included these comments:
When I was researching the archives about engine mounts I did see a
Jag TSB about engine vibration-don’t remember what years it
included- and a revised softer mount to eliminate the problem.So
the engineers were aware of the problem. Of course those are
discontinued so the only choice is aftermarket. The new mounts I
installed give a slight vibration on cold start until the engine
warms up. Don B did say when he installed his there was less
vibration so it may depend on the aftermarket brand that you
pick.And you may want to check the vee mounts to see what condition
they are in. Replacing them made a big inprovement in reducing
vibration also. Cary
Visit the Jag Lovers homepage at http://www.jag-lovers.org for exciting services and resources including Photo Albums, Event Diary / Calendar, On Line Books and more !
You said you can certainly feel engine vibration in the cabin.
Remember that the engine AND transmission being bolted together are really one big chunk of metal held in the car at only three places.
The two front engine mounts are very simple and straightforward. Basically if they are not coming apart, they’re good. The transmission mount is a whole different animal. Lots of parts, springs and
bushings. If I was troubleshooting engine vibration that’s where I would look first.
jaguarlandroverclassicparts.com (you’ll have to type it in your search engine. For some reason it won’t hyperlink from here)… select your car model … go to engine … go to engine and gearbox mounting.
Groove this is the mount for transmission…true?..and there are 2 of that mounts for engine…I change all three and I’m ready…there are some good brand for their?
Thanks for all your time…
Yes there were revised softer engine mounts introduced by a TSB sometime around 1991. I had them fitted to my 1990 4.0 XJ6 back in the day but really never noticed any difference.
I think the only way you’ll be able to get the whole transmission mount assembly would be from a donor car.
But unless the “hard” parts have somehow been damaged in an accident you only need to replace the two springs #4 & 12, the foam buffer #7, and the two rubber isolating spring seats #11 & 3 and your assembly will be better than new. All these parts are readily available from online vendors.
then … everything changed! perfect rear suspension … while the transmission mount has a play that is not nice. with the mechanic we changed the 4 parts listed except the spring (12) and reassembled everything exactly as shown in the diagram, but something is wrong. the mechanic immediately noticed while assembling the various parts that the system was not very stable and in fact when I tested the car on the road both in corners, in braking, and taking holes … you hear a noise like rolling dice in a plastic bottle … he has verified and it seems that in the immediate future there are no particular risks and that something could possibly be invented to solve … but what could it depend on? we assume that before the noise did not exist but the spring was not even under tension and everything hung exaggeratedly.
If I understand, your transmission mount has too much play … correct ?
Are you ABSOLUTELY sure your mechanic didn’t use the Haynes manual to put together the transmission mount assembly. The manual is wrong and has parts #7 and #5 incorrectly reversed.
The diagram above that I sent you is correct. Very common mistake because the Haynes manual
is what everyone uses. Years ago I made the same mistake
If you are sure the mount is assembled correctly and you still have the problem, remember the only consumable parts are the two springs (#12 and #4) and the foam isolator (#7), all the other parts are just metal.
… well except for the rubber parts #11 & #3 and they don’t affect anything, they just keep the springs
from rubbing on the housing.
the transmission has no play … the play is inside this block … when you brake you accelerate or make curves something slams inside it … the following diagram is this and in red the changed parts, the spring 12 is intact. it seems that all the parts that are inside the 2 are only resting inside it without stability.
To clear up any confusion the assembly we are talking about in the diagram is called the “Gearbox (or transmission) mount”. I’ve had that assembly apart many times and am vey familiar with it.
Your problem sounds a little like parts #5 and #7 have been reversed. this results in a very bouncy mount allowing the engine/transmission to move up and down too much.
The only other thing I can think of is that there is a metal safety cable that is attached to the mount assembly. It goes on last after the mount is installed and is NOT shown in the diagram. If it is installed incorrectly or misaligned it can touch the assembly and cause all kinds of vibrations and noises. I speak from experience here.
