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> Transaxle issue?, Feels like I'm running over speed bumps
rhodyguy
post Apr 27 2015, 09:28 AM
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stugray
post Apr 27 2015, 09:52 AM
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QUOTE(rtalich @ Apr 27 2015, 09:13 AM) *

Finally had a chance to work on the car this weekend. Thanks for all your help guys! It was the rubber motor mounts. Both of them were sheared in half!!


That is great that you found them!
When I took my engine out the last time I found both of mine broken as well.

However, the broken motor mounts should not cause the behavior that you describe all by themselves (more like a symptom than root cause)
Dont be too surprised if you find that the problem is still there after you replace them.

I would expect broken motor mounts to show thenselves more when starting/stopping or shifting, not driving smoothly over level ground.
Maybe I misunderstood your description of the problem.
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aircooledtechguy
post Apr 27 2015, 02:18 PM
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You may consider solid mounting your motor so this doesn't happen again. You should be pushing north of 350hp with that beast. . . (IMG:style_emoticons/default/blink.gif)
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Dave_Darling
post Apr 27 2015, 07:48 PM
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QUOTE(stugray @ Apr 27 2015, 08:52 AM) *

However, the broken motor mounts should not cause the behavior that you describe all by themselves (more like a symptom than root cause) ...


No, they will cause that behavior. BTDT. The whole drivetrain pivots up and down, slamming the mount brackets against the motor mount bar. WHAM WHAM WHAM WHAM! Most prevalent in 1st gear when the drivetrain is putting the most torque down.

--DD
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messix
post Apr 27 2015, 11:07 PM
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yup btdt too



told ya so !
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stugray
post Apr 27 2015, 11:19 PM
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QUOTE(Dave_Darling @ Apr 27 2015, 07:48 PM) *

No, they will cause that behavior. BTDT. The whole drivetrain pivots up and down, slamming the mount brackets against the motor mount bar. WHAM WHAM WHAM WHAM! Most prevalent in 1st gear when the drivetrain is putting the most torque down.

--DD


So do you think the engine is "hopping" up and down when it does this or twisting/rocking?

I remember driving my fathers TR4 that had a broken motor mount.
The symptom was: when making a right turn, the steering would not self center.
Because the engine was leaning up against the steering shaft - DOH!

Edit - just thought about this.
If both axles are torquing to push the car forward, then the engine is trying to raise upwards in the front.
So with a high HP engine, the front mounts need to hold the engine DOWN.
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messix
post Apr 27 2015, 11:54 PM
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QUOTE(stugray @ Apr 27 2015, 10:19 PM) *

QUOTE(Dave_Darling @ Apr 27 2015, 07:48 PM) *

No, they will cause that behavior. BTDT. The whole drivetrain pivots up and down, slamming the mount brackets against the motor mount bar. WHAM WHAM WHAM WHAM! Most prevalent in 1st gear when the drivetrain is putting the most torque down.

--DD


So do you think the engine is "hopping" up and down when it does this or twisting/rocking?

I remember driving my fathers TR4 that had a broken motor mount.
The symptom was: when making a right turn, the steering would not self center.
Because the engine was leaning up against the steering shaft - DOH!

Edit - just thought about this.
If both axles are torquing to push the car forward, then the engine is trying to raise upwards in the front.
So with a high HP engine, the front mounts need to hold the engine DOWN.

yep, no clutch drop starts or this happens.
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Dave_Darling
post Apr 28 2015, 08:05 PM
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QUOTE(stugray @ Apr 27 2015, 10:19 PM) *

So do you think the engine is "hopping" up and down when it does this or twisting/rocking?


Hopping. The whole thing pivots around the drive axles, lifting the front up. It gets to a certain point and then falls--possibly because the wheels are indeed turning. The motor falls back down onto the mounts. Then the process starts over again. The sound and feel was way too violent for it to just be rocking.

--DD
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sixnotfour
post Apr 28 2015, 09:46 PM
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chain it down like a muscle car...chevy had a kit with a cable so the motor couldn't lift beyond the rubber limit...ya around 1967
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messix
post Apr 28 2015, 09:50 PM
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QUOTE(sixnotfour @ Apr 28 2015, 08:46 PM) *

chain it down like a muscle car...chevy had a kit with a cable so the motor couldn't lift beyond the rubber limit...ya around 1967

btdt
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rtalich
post Apr 28 2015, 09:52 PM
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QUOTE(aircooledtechguy @ Apr 27 2015, 01:18 PM) *

You may consider solid mounting your motor so this doesn't happen again. You should be pushing north of 350hp with that beast. . . (IMG:style_emoticons/default/blink.gif)


Yep!! I don't think these will last long at all! I wasn't sure about using the solid mounts from an engineering standpoint. You take away that 'floating' point and make it static. There might be a failure develop somewhere else. But I may have no choice.
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McMark
post Apr 28 2015, 11:32 PM
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Take off the turbo and pin the throttle to only open 50%. Then your mounts will last. (IMG:style_emoticons/default/av-943.gif)
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rtalich
post Apr 29 2015, 07:13 AM
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QUOTE(McMark @ Apr 28 2015, 10:32 PM) *

Take off the turbo and pin the throttle to only open 50%. Then your mounts will last. (IMG:style_emoticons/default/av-943.gif)


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