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Transmission "clunk" into drive by Rsvl-Rider
Started on: 04-09-2014 11:48 AM
Replies: 19 (466 views)
Last post by: Rsvl-Rider on 04-16-2014 02:12 PM
Rsvl-Rider
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Report this Post04-09-2014 11:48 AM Click Here to See the Profile for Rsvl-RiderSend a Private Message to Rsvl-RiderEdit/Delete MessageReply w/QuoteDirect Link to This Post
I getting a definite "clunk" when shifting into drive. Hardly any when shifting into reverse. Fluid level is fine and looks and smells ok. I can see the engine jerk a bit when watching during the shift. I am considering replacing the engine/tranny mounts and the dog-bone. Not planning on doing the cradle mounts at this time. Looks like a bigger project than I am up for as a novice Fiero guy.

I bought the car a couple of weeks ago. The seller told me the engine was replaced with a 3.4L out of a Camaro. (sounds great by the way!) So I am wondering if the mounts will be the same as the 2.8L OEM mounts? Will the 2.8L mounts be a direct replacement?

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My rides...
1988 GT with a 3.4L V6 automatic
2006 Harley Sportster
'cause I love the twisties on two wheels or four.

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cebix
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Report this Post04-09-2014 12:10 PM Click Here to See the Profile for cebixSend a Private Message to cebixEdit/Delete MessageReply w/QuoteDirect Link to This Post
I don't know if it's the same problem but in my '85 duke I also have a "clunk" or even a "slam" when shifting into D or R. Changes gears very fine though. Changed all the mounts to new ones and the dogbone bushings to poly. No change. However when cold it doesn't slam at all - it goes in very fluid. With that being said the engine still looks like it moves but barely an inch - maybe the cradle bushings are shot?
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gwg1995
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Report this Post04-09-2014 12:12 PM Click Here to See the Profile for gwg1995Click Here to Email gwg1995Send a Private Message to gwg1995Edit/Delete MessageReply w/QuoteDirect Link to This Post
Sounds like the transmission mounts and dog bone. I had the same problem about three months ago and I just replaced the dog bone with a polyurethane dog bone from the Fiero Store as a temporary fix. It gets rid of the clunking and holds everything in place.

[This message has been edited by gwg1995 (edited 04-09-2014).]

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84fiero123
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Report this Post04-09-2014 12:37 PM 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
possible CV joint But only in one direction doesn't sound right. it should clunk in both forward and rev

Steve

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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.

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jaskispyder
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Report this Post04-09-2014 01:04 PM Click Here to See the Profile for jaskispyderSend a Private Message to jaskispyderEdit/Delete MessageReply w/QuoteDirect Link to This Post
What is your idle?

Mounts should be the same as what came in the car.
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Lou6t4gto
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Report this Post04-09-2014 01:23 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
trans mounts, engine mount, Dog Bone, Cv joint , it \could even be the CHAIN( inside the trans) is loose ! (long shot)
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Rsvl-Rider
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Report this Post04-09-2014 03:21 PM Click Here to See the Profile for Rsvl-RiderSend a Private Message to Rsvl-RiderEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by jaskispyder:

What is your idle?

Mounts should be the same as what came in the car.


Just ran out to the parking lot to check...

Cold Idle = 1200-1250
Warm Idle = 850-900

Clunks when warm or cold. In drive much more than reverse but both seem to be getting more pronounced.

BTW. The dog bone has those red inserts so I am guessing they are not original to the car. No idea about the motor / tranny mounts.
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Rsvl-Rider
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Report this Post04-10-2014 02:55 PM Click Here to See the Profile for Rsvl-RiderSend a Private Message to Rsvl-RiderEdit/Delete MessageReply w/QuoteDirect Link to This Post
Went into reverse perfectly when pulling out of the garage this morning (cold engine). Then got the usual moderate clunk shifting into drive. Sometimes it is much more pronounced.

Does a different clunk between drive and reverse reveal anything?

I think the idle speeds listed above were OK, right?
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BrittB
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Report this Post04-10-2014 10:34 PM Click Here to See the Profile for BrittBSend a Private Message to BrittBEdit/Delete MessageReply w/QuoteDirect Link to This Post
Mine never clunked until I installed the red poly inserts into my dog bone, could very well be your problem.
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Rsvl-Rider
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Report this Post04-11-2014 12:46 AM Click Here to See the Profile for Rsvl-RiderSend a Private Message to Rsvl-RiderEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by BrittB:

Mine never clunked until I installed the red poly inserts into my dog bone, could very well be your problem.


Boy I'm confused again...

IF the clunking issue is related to the dogbone then is a harder poly bushing better than a softer (more shock absorbent) bushing?

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Rsvl-Rider
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Report this Post04-12-2014 04:43 PM Click Here to See the Profile for Rsvl-RiderSend a Private Message to Rsvl-RiderEdit/Delete MessageReply w/QuoteDirect Link to This Post
Bumping this post to try to get answers to a couple of related questions...

Does the fact that the "clunk" from Park to Drive is much more pronounced than from Park to Reverse mean anything in terms of understanding / diagnosing the problem?

What is the point of the hard poly red bushings in the dogbone verses the standard rubber bushings? One member reported that they quieted the clunk while another reported the clunking started when they were installed.
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Report this Post04-13-2014 08:54 AM Click Here to See the Profile for cebixSend a Private Message to cebixEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Rsvl-Rider:

Bumping this post to try to get answers to a couple of related questions...

Does the fact that the "clunk" from Park to Drive is much more pronounced than from Park to Reverse mean anything in terms of understanding / diagnosing the problem?

What is the point of the hard poly red bushings in the dogbone verses the standard rubber bushings? One member reported that they quieted the clunk while another reported the clunking started when they were installed.


Probably because when just the dogbone bushings were changed all the other mounts weren't.
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84fiero123
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Report this Post04-13-2014 12:45 PM 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 Rsvl-Rider:

Bumping this post to try to get answers to a couple of related questions...

Does the fact that the "clunk" from Park to Drive is much more pronounced than from Park to Reverse mean anything in terms of understanding / diagnosing the problem?

What is the point of the hard poly red bushings in the dogbone verses the standard rubber bushings? One member reported that they quieted the clunk while another reported the clunking started when they were installed.


if its the CV joint get the car in the air and twist the tire back and forth, you should be able to fell it, if it is the CV joint.
the poly joint you did, stiffened up the engine and it could be another mount but I really don't think so.
it could also be a wheel bearing is lose, but I have never heard of them making a clunking noise.

Steve

[This message has been edited by 84fiero123 (edited 04-13-2014).]

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Lou6t4gto
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Report this Post04-13-2014 07:07 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
Have someone else be in the car with their foot on the brake and shifting back and forth from drive to reverse, you watch what the engine/trans DO. the dogbone has an "Adjustment SLOT", so you can fine tune it. My money is on a Trans Mount.
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BrittB
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Report this Post04-13-2014 07:37 PM Click Here to See the Profile for BrittBSend a Private Message to BrittBEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by Lou6t4gto:

Have someone else be in the car with their foot on the brake and shifting back and forth from drive to reverse, you watch what the engine/trans DO. the dogbone has an "Adjustment SLOT", so you can fine tune it. My money is on a Trans Mount.


An adjustment slot, where?
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Lou6t4gto
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Report this Post04-14-2014 01:20 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
the bracket where the dog bone bolt "goes through",( 1 of the brackets has an "enlongated hole, not round) you move the bolt from one end to the other (when the engine is "torqueing" (In drive, foot on brake, nudge gas a little), the engine will "twist" a little, tighten bolt at that time.
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PaulJK
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Report this Post04-15-2014 05:21 AM Click Here to See the Profile for PaulJKSend a Private Message to PaulJKEdit/Delete MessageReply w/QuoteDirect Link to This Post
Have you checked the engine "shock absorber" ?
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Rsvl-Rider
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Report this Post04-15-2014 09:02 PM Click Here to See the Profile for Rsvl-RiderSend a Private Message to Rsvl-RiderEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by PaulJK:

Have you checked the engine "shock absorber" ?


Umm... Where would I find that? Are you talking about the torque strut "dogbone" or some other part?
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PaulJK
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Report this Post04-16-2014 06:35 AM Click Here to See the Profile for PaulJKSend a Private Message to PaulJKEdit/Delete MessageReply w/QuoteDirect Link to This Post
Nope, not the dogbone. The drive line absorber connects the engine to the frame to dampen movement of the engine. If I remember correctly, it's under the car below the rear of the passenger compartment. Maybe someone has a pic or diagram they can post. Here's a little discussion i found in the archives.

http://www.fiero.nl/forum/A...120111-2-109951.html

[This message has been edited by PaulJK (edited 04-16-2014).]

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Rsvl-Rider
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Report this Post04-16-2014 02:12 PM Click Here to See the Profile for Rsvl-RiderSend a Private Message to Rsvl-RiderEdit/Delete MessageReply w/QuoteDirect Link to This Post
 
quote
Originally posted by PaulJK:

Nope, not the dogbone. The drive line absorber connects the engine to the frame to dampen movement of the engine. If I remember correctly, it's under the car below the rear of the passenger compartment. Maybe someone has a pic or diagram they can post. Here's a little discussion i found in the archives.

http://www.fiero.nl/forum/A...120111-2-109951.html




Thanks PaulJK. I'll take a look in the service manual.

A pic would be a big help if someone could post one...
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