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View Full Version : The hydramount,a new theory.....discuss


wuzerk
27th November 2014, 15:13
I have a new theory about the Hydramount. I have two brand new diesel
Hydramounts and the old original which was passing serious vibration back to
the steering wheel and the seats. When fitting the new mount cured the problem I assumed that the old one had softened with use and was allowing too much
engine movement coupled with the fact that the rubber had many splits in it.
This does no tally with the fact that the two new mounts are easier to bend
back and forth than the old replaced one! In other words the rubber is more supple. I have come to the conclusion that the reason we have to change the Hydramount is because the rubber has stiffened with age which means that it cannot allow the normal amount of engine movement without passing
some of it back through its lower mounting on the chassis to the steering wheel and seats. I was able to compare the engine vibration at tickover on my car with my sons diesel which needs a new mount and they feel identical but my car has no wheel or seat vibration now whereas his is quite bad. In other words the new softer mount is better able to isolate the same amount of vibration from the chassis.

EastPete
27th November 2014, 15:45
Interesting theory, which seems to make sense to me. I am thinking of changing the hydramount on my CDTi (I have already changed the lower engine and gearbox mounts) to remove some residual vibrations at certain engine speeds that result in a dashboard vibration and an irritating buzz from the door locking button on the drivers door (right next to my lughole !). I am also suspicious of the poorer refinement on my present car from it running on lower profile tyres on alloys, compared to 15 inch steel wheels with higher profile rubber on my earlier 75, which was much more refined. In fact, yesterday, I ordered a set of 15 inch steel rims from a scrapyard that are breaking a basic spec 75 classic - 4 rims for 60 quid - I plan to put Goodyear Vector 4 seasons tyres on them (60 pound each for the 195/65 R15s from mytyres) - I expect a quieter, smoother ride on these, but I'll keep folks on here updated.

BTW - is the hydramount change difficult ? - a basic 'how to' post would be helpful, although I can probably work it out for myself once I get the spanners out !

Thanks

Pete

first-things-first
27th November 2014, 16:12
Does sound plausible. Considering age of these mounts - most 10+ years. Think of a tyre at that age.

Looked at mine whilst doing thermostat. The rubber is quite crazed and almost cracking. No bad signs of vibration in car though (only annoying little vibration at 1800rpm ish).

And the same as EastPete - dashboard buzz (seems to be come from sunlight sensor area) and both central locking buttons vibrating - but also seem to be dependent upon coarseness of road - have a ZT so 18 inch wheels and budget tyres,

Do you have a picture of the condition of your Hydramount wuzerk? Thanks. Would be good for comparison purposes.

T-Cut
27th November 2014, 18:08
Probably the same reason many prefer the rubber bushed lower tie bars to the new PU versions.

TC

rosephus
27th November 2014, 18:09
Interesting theory, which seems to make sense to me. I am thinking of changing the hydramount on my CDTi (I have already changed the lower engine and gearbox mounts) to remove some residual vibrations at certain engine speeds that result in a dashboard vibration and an irritating buzz from the door locking button on the drivers door (right next to my lughole !). I am also suspicious of the poorer refinement on my present car from it running on lower profile tyres on alloys, compared to 15 inch steel wheels with higher profile rubber on my earlier 75, which was much more refined. In fact, yesterday, I ordered a set of 15 inch steel rims from a scrapyard that are breaking a basic spec 75 classic - 4 rims for 60 quid - I plan to put Goodyear Vector 4 seasons tyres on them (60 pound each for the 195/65 R15s from mytyres) - I expect a quieter, smoother ride on these, but I'll keep folks on here updated.

BTW - is the hydramount change difficult ? - a basic 'how to' post would be helpful, although I can probably work it out for myself once I get the spanners out !

Thanks

Pete


you can solve that door locking buzz by putting some mcdonalds straws over your door locks, cut them down the middle and in half and slide them over. problem solved!

wuzerk
28th November 2014, 06:36
Does sound plausible. Considering age of these mounts - most 10+ years. Think of a tyre at that age.

Looked at mine whilst doing thermostat. The rubber is quite crazed and almost cracking. No bad signs of vibration in car though (only annoying little vibration at 1800rpm ish).

And the same as EastPete - dashboard buzz (seems to be come from sunlight sensor area) and both central locking buttons vibrating - but also seem to be dependent upon coarseness of road - have a ZT so 18 inch wheels and budget tyres,

Do you have a picture of the condition of your Hydramount wuzerk? Thanks. Would be good for comparison purposes.
Here the pic of my diesel Hydramount which was allowing serious vibrations
to reach the steering wheel and seats

Note the splits in the rubber which I now believe are because it has hardened over time losing its ability to absorb the engine vibration without passing it through the car.
http://imageshack.com/a/img829/9616/px5v.jpg

wuzerk
28th November 2014, 07:08
Interesting theory, which seems to make sense to me. I am thinking of changing the hydramount on my CDTi (I have already changed the lower engine and gearbox mounts) to remove some residual vibrations at certain engine speeds that result in a dashboard vibration and an irritating buzz from the door locking button on the drivers door (right next to my lughole !). I am also suspicious of the poorer refinement on my present car from it running on lower profile tyres on alloys, compared to 15 inch steel wheels with higher profile rubber on my earlier 75, which was much more refined. In fact, yesterday, I ordered a set of 15 inch steel rims from a scrapyard that are breaking a basic spec 75 classic - 4 rims for 60 quid - I plan to put Goodyear Vector 4 seasons tyres on them (60 pound each for the 195/65 R15s from mytyres) - I expect a quieter, smoother ride on these, but I'll keep folks on here updated.

BTW - is the hydramount change difficult ? - a basic 'how to' post would be helpful, although I can probably work it out for myself once I get the spanners out !

Thanks

Pete
The 15" wheels, steel or alloy, will obviously give a softer, quieter ride with a decrease in cornering ability.
The Hydramount is easy to change unless the mount itself proves difficult to unscrew from its mounting. It has a metal band around it with cutouts in
it which a special tool fits to unscrew it. You can use a drift on these flats. If it proves difficult then, on the diesels, it is easy to pour some releasing fluid into the bottom cup in which the Hydramount sits and leave to soak in. Mine released after five minutes. The petrol models do not have the bottom cup fitted. You must drop the engine undertray, remove one of the 15mm bolts from the lower engine mount and loosen the other one so that the lower mount can hang free and not cause the engine to be
prevented from being swung, at the top, into the correct position to undo the rather large casting which sits on top of the Hydramount. To remove this casting you need to jack up the engine slightly,remove the engine cover, the power steering reservoir bracket (easy), the nut on top of the Hydramount, and four long 15mm bolts holding the casting to the engine.
Then, with the two 15mm bolts connecting the top link to the secondary engine mount (bolted to the O/S inner wing by three 15mm bolts) removed the whole casting complete with the linkage will lift off.
I will try to add some pics next.
This pic shows the two 15mm bolts which need to be removed on the link (the two with a black line across them). Apart from removing the top nut from the Hydramount, and the upright bracket holding the power steering pipe that is all in this area. In the bottom R/H corner of the pic you can see one of the long 15mm bolts holding the top casting to the engine. More pics to follow.
http://imageshack.com/a/img537/7122/4473ab.jpg

wuzerk
28th November 2014, 11:18
i have posted a how to for the hydramount change.

first-things-first
28th November 2014, 11:27
Thanks wuzerk for the image.

Yours looks like a 8/9 (out of 10) for damage - mine is more like the lighter crazing below the top ridge of the hydramount. So I would estimate more a 2/3 at the moment.

Will keep an eye on it.

whippet
29th December 2014, 14:07
After changing my lower engine mount to a mondeo mount, the vibration through the body is still there when accelerating, my next move will be to change the Hydramount, i cannot see any cracks/perishing of the rubber body, after reading many posts on this subject,looks like this could be the culprit.

rosephus
29th December 2014, 14:36
After changing my lower engine mount to a mondeo mount, the vibration through the body is still there when accelerating, my next move will be to change the Hydramount, i cannot see any cracks/perishing of the rubber body, after reading many posts on this subject,looks like this could be the culprit.

me too :xmas-smiley-007:

Anthony & Maricel
29th December 2014, 14:43
After changing my lower engine mount to a mondeo mount, the vibration through the body is still there when accelerating, my next move will be to change the Hydramount, i cannot see any cracks/perishing of the rubber body, after reading many posts on this subject,looks like this could be the culprit.

Getting both changed at the same time, makes a big difference. My hydro mount started leaking in October, and my lower engine mount went in November. So I had a lot of vibration to deal with, my last journey home from lates600 8 days ago was a totally different one; to the one going. It was both vibration and clunk free, considering the parts on my car are 16 years old. Leighton was quite impressed it was the original lower engine mount, and so was I to be honest. :icon_lol: And I had oem parts fitted, and the parts were not as expensive as some people have been posting on here.

Anthony & Maricel
29th December 2014, 14:49
Here the pic of my diesel Hydramount which was allowing serious vibrations
to reach the steering wheel and seats

Note the splits in the rubber which I now believe are because it has hardened over time losing its ability to absorb the engine vibration without passing it through the car.
http://imageshack.com/a/img829/9616/px5v.jpg

The rubber on that has perished, so if you have one remotely looking like that I would get it changed.

Anthony & Maricel
29th December 2014, 15:01
Probably the same reason many prefer the rubber bushed lower tie bars to the new PU versions.

TC

I agree, pub's alter the ride comfort, makes it more harsher than the original rubber ones.

Jules
1st September 2016, 08:48
I have a new theory about the Hydramount. I have two brand new diesel
Hydramounts and the old original which was passing serious vibration back to
the steering wheel and the seats. When fitting the new mount cured the problem I assumed that the old one had softened with use and was allowing too much
engine movement coupled with the fact that the rubber had many splits in it.
This does no tally with the fact that the two new mounts are easier to bend
back and forth than the old replaced one! In other words the rubber is more supple. I have come to the conclusion that the reason we have to change the Hydramount is because the rubber has stiffened with age which means that it cannot allow the normal amount of engine movement without passing
some of it back through its lower mounting on the chassis to the steering wheel and seats. I was able to compare the engine vibration at tickover on my car with my sons diesel which needs a new mount and they feel identical but my car has no wheel or seat vibration now whereas his is quite bad. In other words the new softer mount is better able to isolate the same amount of vibration from the chassis.



Thread revival (need more of them!)

Having changed a few now with transforming results the same theory goes for the lower torsional pulley.

The new pulleys (only genuine Corteco though) have very supple rubber.

Cheaper aftermarket pulleys have hard rubber which just doesn't last nor does it have the damping qualities even from day 1.


Same goes for the lower Teardrop mount.


So if your pride and joy is feeling like a bone shaking noisy Black Cab or an LDV, treat it to one or all 3 of the above and it will feel like new again.

I say again though avoid after market stuff.
It's all what I call fake (landfill stuff) from China and will last as long as your cheese butty!

hogweed
1st September 2016, 09:10
you can solve that door locking buzz by putting some mcdonalds straws over your door locks, cut them down the middle and in half and slide them over. problem solved!

I just wrapped a single turn of black insulating tape round mine :D

But I tell you another thing – my vibration’s gone away. It PLAGUED me, so I got the bottom mount replaced first maybe 3 years ago – that seemed to work for a week or two – then the top one, same, maybe a few days then it all came back… so I gave up.

But I’ve just noticed recently that the nasty buzz through the steering wheel hasn’t been there for AGES now.

God knows where it’s gone :shrug:

Jules
1st September 2016, 09:16
Problem there is I never go to those Mc places ever !!

iandux
1st September 2016, 10:56
Quote: Looked at mine whilst doing thermostat. The rubber is quite crazed and almost cracking. No bad signs of vibration in car though (only annoying little vibration at 1800rpm ish).

Hi - I had the same vibration at 1800rpm - changed the lower (dogbone) engine mount and it disappeared. Took local garage 15 minutes, and most of that was putting it on the ramp and gaining access!