Driveline vibration damper questions

[KDirk]

Ok,

I am at a loss here. The Reatta has what is referred to as a "driveline vibration absorber" in the FSM, as I am sure most here are aware. Thing looks like a miniature strut that mounts to the frame/cradle and an upper reinforcement between the passenger side wheel well and the water pump. My questions are:

How can it be determined if this part is worn out? Age alone (17 years) probably means it has lost it's juice, and I am thinking it needs replacement. This leads me to question 2.

Where can a new one be purchased? Is there an aftermarket replacement for this? I spent 45 minutes at the dealer with the parts guy looking at diagrams and finally found the part #, only to discover it is obsolete/NLA from GM. Same with the equivalent Riviera part #, so no good trying to substitute that one.

Anyone had experience with this and willing to share? I'm hoping maybe Moog or someone makes a suitable part, but a google search yielded nothing so far.

KDirk

[D-a-n-i-e-l]

The dampener is a gas strut, it should hold in one position and return to that possition if compressed or expanded. If it does not or does but very slowly then it is most likely wore out. I have not found were to buy a new one yet, but I am thinking a new one might only be available from GM.

[jonlabree]

Did you read????

Where can a new one be purchased? Is there an aftermarket replacement for this? I spent 45 minutes at the dealer with the parts guy looking at diagrams and finally found the part #, only to discover it is obsolete/NLA from GM. Same with the equivalent Riviera part #, so no good trying to substitute that one.

[D-a-n-i-e-l]

Thanks Jon I missed that, I was kind of in a hurry

[Richard S]

As I recall, we discussed this little strut and it role before. The one on my 90 with 190k offered no resistance at all. I think I got one from Jim Finn that worked, though the number of these things out there that might still be working is probably growing smaller by the day. Unless we can adapt one of the other damper systems used on other 3.8 motors, sooner or later most of us will be running our cars without any effective driveline damping.

[D-a-n-i-e-l]

Is the strut on the 91's? If not I may have a solution that I already did on my car.

[D-a-n-i-e-l]

OK answered my own question. So on to the next question. Does the 91 have a cylyndrical build up on the pasenger side CV shaft? According to partsamerica the 91 passenger drive line is diffrent from the 88-90. Also the 91 passenger side is the same as the 91 Eldarado an others.

I am using one from a 91 Eldarado, which has the build up on it. I have an 89'. Every one that I have spoke with about the build-up says it is most likely a "vibration dampener". So if the 91' Reatta does not have the dampener on the CV joint, this may be a viable solution if a strut can not be found.

One last thing. The Eldarodo does not have a strut assembly.

[KDirk]

Richard S-

Point well made. I share this concern, as I am wondering if the damper being bad is contributing to the mystery noises I am getting from under the car.

nx-

Thanks for that info. The 91 does have the mini-strut damper as other years. I assume by "cylindrical build up" you mean that there is an area on the CV axle that has a larger diameter than the rest when you describe this. If I am misunderstanding you, please clarify. A pic, or parts catalog link to a CV axle like you are talking about would be helpful.

FWIW, the 91 driveline may be different because of the tranny change (4T60E) not sure what else connected to it may have been changed as well (CV axles, joints, bearings etc). Still learning a lot about this car as I've only had it two weeks, so please bear with me if I sound like a neophyte.

Further, a search of the Federal Mogul online catalog revealed no suitable after market replacement strut for this. Same with Jeg's - no dice. I did find an outfit called Ingalls that makes some rather expensive engine torque dampers which essentially look like a small gas charged strut for what I believe is this type of use.

First problem is, most of their parts are for imports (Honda, Acura, etc) being modded for street racing. They do have a so called "universal" fit listed in JC Whitney's catalog (yeah, I know - universal and JC Whitney = questionable quality) but it is a bit spendy - $170.00 to be exact. Heck, a pair of front or rear struts doesn't cost that much.

Second problem - the mounting is done with horizontal through-hole bushings rather than a verticallly oriented threaded shaft at the top/bottom, so the mounting brackets would have to be changed/modified. I don't care for this plan at all. So, I am open to suggestions.

KDirk

[Roadster90]

This may be even more of a problem with roadsters....

good thread...need a resolution

[D-a-n-i-e-l]

KDirk

Yes, on the CV shatft between the joint is what I am talking about. The 91 manual does not show this that is why I am wondering if it is on the 91 Reatta. Also it may be because of the tranny being change to the E version. Like I said I am using the one from a Eldarado and have not had any negative results as of yet, but bear in mind that I am running a series one SC motor which is not fully tuned as of yet. That will be finished once I leave the DC area in a couple months.

I will continue to work on the strut issue also, 180 seems a bit steep. May be I can find an odd ball military part that would meet the use.