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What are the symptoms of engine/transmission mount/mounts that need replacing? by a gem
Started on: 08-15-2013 04:09 PM
Replies: 11 (2605 views)
Last post by: AL87 on 03-16-2014 11:36 PM
a gem
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Report this Post08-15-2013 04:09 PM Click Here to See the Profile for a gemSend a Private Message to a gemEdit/Delete MessageReply w/QuoteDirect Link to This Post
I believe there are many symptoms that might be noticed and been diagnosed as some other problem. I'm sure that this has happened to someone?
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Corvus
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Report this Post08-15-2013 04:13 PM Click Here to See the Profile for CorvusClick Here to Email CorvusSend a Private Message to CorvusEdit/Delete MessageReply w/QuoteDirect Link to This Post
In my experience the main engine mount went out first. I could hear the engine rattling and when I crawled underneath I could see that it was dry rotted. If you go to Rock Auto you should be able to find some baseline ones pretty cheap. You can also get some pretty high performance ones from Rodney Dickman. While you're replacing the engine mount, you should probably place the dog bone and both transmission mounts.

[This message has been edited by Corvus (edited 08-15-2013).]

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a gem
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Report this Post08-15-2013 04:44 PM Click Here to See the Profile for a gemSend a Private Message to a gemEdit/Delete MessageReply w/QuoteDirect Link to This Post
okay that's one symptom, thanks for answering. On my first fiero, when I came to a stop something kept banging into me from the engine compartment. I thought maybe the battery. The engine had just been put back in after the lower mount bracket broke on the only other owner of the car. It turns out that the upper mount was messed up causing the problem in the fist place. I ordered the poly mount and when it came it was the wrong shape so I used my old grinder and reshaped it to fit the dog bone. Works great and the engine is solid. I'm asking for any/all symptoms that did or could happen to anyone?
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Lou6t4gto
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Report this Post08-16-2013 03:37 PM Click Here to See the Profile for Lou6t4gtoClick Here to Email Lou6t4gtoSend a Private Message to Lou6t4gtoEdit/Delete MessageReply w/QuoteDirect Link to This Post
IF it's an automatic, start it, have someone else sit in the car with the brakes On, have them shift from drive to reverse and back while You watch the engine. the engine should not move much. if you have a broken mount or dogbone, the engine will move from front to rear when it is changing gears.
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David Hambleton
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Report this Post08-16-2013 08:57 PM Click Here to See the Profile for David HambletonClick Here to Email David HambletonSend a Private Message to David HambletonEdit/Delete MessageReply w/QuoteDirect Link to This Post
I became aware of an unusual vibration after 27 years & 350,000 km in my '84 SE. The mounts were worn out.
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DaytonTD
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Report this Post08-17-2013 01:22 AM Click Here to See the Profile for DaytonTDClick Here to Email DaytonTDSend a Private Message to DaytonTDEdit/Delete MessageReply w/QuoteDirect Link to This Post
I broke the rear transmission mount once. When I accelerated it vibrated bad. Vibration increased as I put more load on the engine.
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Saint_Ferret
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Report this Post03-13-2014 02:15 AM Click Here to See the Profile for Saint_FerretClick Here to Email Saint_FerretSend a Private Message to Saint_FerretEdit/Delete MessageReply w/QuoteDirect Link to This Post
1985 Iron Duke Isuzu combo.
Thought that I might have thrown something on the clutch. Unusual shuttering during acceleration in all gears. Problems with stable rpm growth, but sm00th revs in neutral. The car would barely roll in first gear and smelt 'hot' after a while shuttering around in second and third. After complete tear down this weekend to do a clutch job we find that the plate is mostly intact, hardly glazed. bell housing and throw rod are a little gritty but shined up really quick. They only charged me $20 at the local clutch place to turn the flywheel so I guess it wasn't super merked up.
BUT!
Both trans mounts have nearly disintegrated, and the engine mount is on the way to the grave.
I will be replacing the clutch any way (and a few other things while she is bolt-less). But is it a real possibility that my rpm concerns and acceleration issues were nothing more than broken $10 rubber?
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Csjag
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Report this Post03-13-2014 06:37 AM Click Here to See the Profile for CsjagClick Here to Email CsjagSend a Private Message to CsjagEdit/Delete MessageReply w/QuoteDirect Link to This Post
On my 85 duke 5 speed that I resurrected the engine was thumping when changing gears. I replaced the dog bone, lower engine mount and both tranny mounts, now she's nice and solid.
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Formula88
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Report this Post03-13-2014 11:14 AM Click Here to See the Profile for Formula88Send a Private Message to Formula88Edit/Delete MessageReply w/QuoteDirect Link to This Post
A couple recommendations.

When you replace 1 mount, replace them all. Chances are they're all worn and if one has failed the others are likely close behind. A worn mount will allow more flex that will cause the new mount to wear prematurely.

Never mix poly and rubber mounts. Same reason as new & old - they flex differently. If one flexes more than the other, it puts extra stress and wear on the mount. Swap them all at the same time and use the same type (OEM, poly, etc.) all the way around. Dogbone included.

I'm sure some will say you don't "have to." That's right, you don't. I think it's a good idea, though.
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Gall757
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Report this Post03-13-2014 07:53 PM Click Here to See the Profile for Gall757Send a Private Message to Gall757Edit/Delete MessageReply w/QuoteDirect Link to This Post
The engine can shift (a few inches) and clunk when you accelerate, and then when you decelerate, it clunks back to the original position.
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84fiero123
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Report this Post03-14-2014 07:15 AM Click Here to See the Profile for 84fiero123Click Here to Email 84fiero123Send a Private Message to 84fiero123Edit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Gall757:

The engine can shift (a few inches) and clunk when you accelerate, and then when you decelerate, it clunks back to the original position.


It can, when they are old, they shouldn't and don't when they are new, old school trick was already posted above to check them.

 
quote
Originally posted by Lou6t4gto:

IF it's an automatic, start it, have someone else sit in the car with the brakes On, have them shift from drive to reverse and back while You watch the engine. the engine should not move much. if you have a broken mount or dogbone, the engine will move from front to rear when it is changing gears.


You can do the same thing with a standard by setting the e Brake and slipping the clutch to the point of almost stalling the engine. in neither case should the engine move more than a fraction of an inch.

Steve

------------------
Technology is great when it works,
and one big pain in the ass when it doesn't



Detroit iron rules all the rest are just toys.

[This message has been edited by 84fiero123 (edited 03-14-2014).]

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AL87
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Report this Post03-16-2014 11:36 PM Click Here to See the Profile for AL87Click Here to Email AL87Send a Private Message to AL87Edit/Delete MessageReply w/QuoteDirect Link to This Post
on transmissions, the rear transmission mount goes all the time. ESPECIALLY the aftermarket ones. they aren't made/designed like the OE.

I had one go out a week after changing it, and then another one a week and some days later. its just vulcanized rubber on the back of a plate, with a "finger" to catch in case of failure...

id just go with some Rodney dickman mounts... experience points me to the use of his products on a quality replacement parts basis.

I remember him saying he's developing some better quality rubber mounts because aftermarket ones are poo.
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