small 'shock absorber' engine bay

[Guest F14CRAZY]

I know you guys don't like the idea but I ran my car without it

[KDirk]

FWIW, I had started a thread about this very part about a month or so ago. Never came to any good conclusions, however in that thread I stated that I had found a torque damper strut made by another company for use mainly on import street racers (Mazda's Toyota's and Nissan's). The mounting was different, and it was expen$ive - over $100.

Jeg's sold some of these, and I found a few other places online that had them at the time. Maybe we need to look at this part again (will try to find links for it and post back) and the possibility of modding the mounts for the existing part. I don't particularly like this idea, but what else is there; especially in the longer term?

Or, alternatively is there something that can be done to upgrade the engine mounts so that this part is not needed? I would guess it is there to help reduce stress on the engine and transmission mounts as engine torque causes the power train to "flex" in the cradle.

KDirk

[Ronnie]

If they are important on other models, how does my '88 model survive without one? As far as I know it never had one.

[Roadster90]

Would like to see this thread kept alive untill someone finds a solution for us all....

[charlie1]

Z

Edited August 2, 2009 by CHAS1 (see edit history)

[Roadster90]

Charlie...you have always been and are definitely an asset to the forum. Hope someone can do something with the #'s provided

thanks

[charlie1]

ZZZ

Edited August 2, 2009 by CHAS1 (see edit history)

[Guest imported_blazer1997]

Calling GM the correct name listed as (Driveline Absorber) part # 1646998.

[Guest Squire Tom]

replaced mine today with a part from jim , it was slightly different as far as the threads and 'stop' are located .

seems to work ok though.

[Guest Squire Tom]

spoke too soon - as i was driving back from the mechanic , there was an 'oscillating' thump/vibration in the front end.

i thought it was from the tire rotation done at the same time.

since then i stopped to get the front tires balanced at a goodyear center.

problem still existed.

today , i REMOVED the damper and went for a ride. the oscillation / thump vibration is gone and the car rides as before.

the oil had all leaked from the previous shock that was replaced with a used part. the rod and thread length were different between my original and the used part.

any ideas ??

[Roadster90]

Re post from above: Would like to see this thread kept alive untill someone finds a solution for us all....

_________________________

Has any progress been made on this issue Pleeeeease?

[KDirk]

Nic,

I'm not optimistic, but I have one of my parts guys checking something on this. Hope to hear from him tomorrow maybe. I'm guessing it'll be a strikeout, but you never know.

KDirk

[Roadster90]

Thanks Kevin !!

[Guest Greg Ross]

Tom,

Nobody attempted to answer your question;

You mentioned the length differed, I would think with a difference in length you were bottoming out or stretching to the extent of stroke or travel of the cylinder and hence the thud clunk you were getting.

I bought an 89`front sub-frame from Jim when I was starting into building my SC 5-Spd. setup in Louisiana years ago. It came(obviously) with the strut mounting bracket, I puzzled over it until I did a little research and determined what it was for.

My `88 same as Ronnies` didn`t have one so when I put the new Power Pack together I put in new `88 main mounts, a customized tranny mount using a GM assembly and the DogBone link to the Radiator Bulkhead.

That was about 5 years ago now and the engine has not been thrust thru the hood yet!, Or fallen out the bottom for that matter.

I`ve had the engine tranny package out several times in the past 5 years for clutch and tranny issues and all the mounts are surviving just fine.

I don`t think anyone has determined why this strut was added. Guessing it has something to do with torque thrust in a vertical direction of the front the engine. I`m not having any clash or clatter or vibration or 1é2 shaft problems so.....

As I recall the `89 and later Tranny mount was quite different as well. I would say don`t sweat it.

The engine is not going to self-destruct, nor is this message in the next 5 seconds........

POOF

[Guest Squire Tom]

thanx for the instant experience !

i have it removed at this point in time and will evaluate the ride and any wear issues over the next several months. where i live , i do not do much high speed driving anyway.

on other item if you care to comment .

the 91 had a different gear ratio of 3.3 or so as opposed to the 2.9 or so from previous models. of course the 91 has the electronic controlled tranny. how big a deal is it to drop the ratio for better economy ( currently @22 ) in non freeway driving?

[charlie1]

ZZZ

Edited August 2, 2009 by CHAS1 (see edit history)

[Guest Greg Ross]

Tom,

My manual transmission is a final drive ratio of 3.67 to 1, different again from the automatics. 22 mpg doesn't sound to bad for mixed non-highway mileage. Going to the lower gear ratio found in the pre '91 I doubt would make any real noticeable difference in economy. And not at all practical I don't think to convert the '91 to the non-electrically controlled tranmission.

I seem to recall discussion here on this board that the difference in economy between the '91 and the earlier cars was not that great.

[KDirk]

Nic,

Talked again to my parts guy Thursday PM about the driveline vibration absorber, and came up empty. He had thought he knew of a few new old stock units in a company warehouse but it turned out to be a wild goose chase.

So, we are still stuck and outta luck. I have to say sourcing this part is busting my chops. Hardest thing to find yet for the Reatta. I'll keep twisting arms to try and find some, but I am getting rather discouraged.

KDirk

[Roadster90]

Thanks Kevin...you time and effort is appreciated(A LOT )....From some other posts it seems that these buggers may not be necessary, but I don't care to be honest...if an (GM or other) engineer decided it was necessary - well I would like it on the car and functional....I am wondering if these things can be rebuilt????

thoughts?

[KDirk]

Nic,

Thanks for your feedback. I've not had it off the car yet, but I kind of doubt a rebuild is possible. While it is a relatively simple part, functionally speaking, the way it is assembled, and the individual parts that comprise it would be difficult to replicate.

Clearly, there are rubber parts (diaphragm) internally that are probably shot. Then the outer tube, with seals around both rods. Then the tube itself, which is permanently sealed at the ends with crimps done by a hydraulic press with appropriate dies. This is pretty specialized stuff from a manufacturing standpoint.

IF we could get it open, and somehow source the rubber components (or have them reproduced) and then find some way to manufacture a new cylinder, press the ends shut, and give it a gas charge, we might have something. But, how do we get all that done? About the only part that would be easy to make are the stainless rods, with the threaded ends. Anybody with machining expertise could make those with one arm behind his back.

This is the kind of thing that should be done by the aftermarket, some outfit like Federal-Mogul. Problem is lack of volume (and volume=profit) in selling this part, as it has limited application on cars that are now 15-20 years old. Thus there is no interest or incentive to acquire the tooling and setup to make it.

I think what we should all be looking at is what other similar cars (E-platform, or any early 90's GM FWD 3800) didn't have the driveline vibration absorber, and try to determine what was done to eliminate it's need on those (hypothetical) car models.

Did they have better engine mounts, and if so can we upgrade the Reatta with those same mounts? Was the engine cradle different somehow? Is that something we can replicate on the Reatta cradle by welding on some steel?

I'm just grasping at straws here, so the above ideas may be complete nonsense. Like you, I have to think GM put it there for a reason. If we can run without it great, but at what eventual cost? Do we eat engine mounts every 10,000 miles? Do we risk damaging the engine or transmission where they mate together by omitting this part? Or does it just cause noise, or impact handling or create some other non-critical nuisance symptom?

Too many questions and not enough answers. It's getting late, and I've been up since 4:30am due to the earthquake that roiled those of us in the Midwest today [luckily no damage here], so I think I'm going to call it a night.

KDirk