Sub-frame Insulators (Isolators)

Machiner 55 · September 29, 2012

Gentlemen,

This one goes out to those of you on the forum here that have personally done the Insulator (Isolator) replacement on the front sub-frame of their Reatta.

In the Reatta FSM for the model years 1988 and 1989 the diagram shows that the Insulators and bolts for all three positions both right and left look exactly the same. As I‘ve dismantled an ’88 and am in the process of replacing the Insulators of my ’89, I can say for certain that the Insulators and bolts etc. are as pictured in the FSM. When placing my order for the parts, I was unable to find the required items listed under 1988 or 1989 Buick Reatta. I was however able to find parts under 1989 Buick Riviera. The diagram is identical to the one for the Reatta one except for the two front insulators and bolts. In addition, I also used as a reference a diagram posted on the forum some time ago showing parts and part numbers for “1989 – 1991 E57 Body Mounting”. This diagram also shows the different Insulator used in position #1.

From what I’ve been able to ascertain, they would fit properly without modification on the Reatta sub-frame. Because I ordered both types of insulators, I can go with the Rivi setup or the original Reatta setup. My question to you is, if you were doing it, which setup would you use? Is there any advantage to using the Rivi insulators over the Reatta?

PS.

Has anyone found a source or has access to the Heavy-duty washer like part #1626368 (cover spacer - 6 required)?

They are the ones that are about 1/8" thick and 2 & 1/2" in diameter with the 1/2" diameter fluted hole in the center which is accompanied by two smaller holes on either side.

John F.

Edited September 29, 2012 by Machiner 55
Added PS. (see edit history)

Machiner 55 · October 3, 2012

PS.
Has anyone found a source or has access to the Heavy-duty washer like part #1626368 (cover spacer - 6 required)?
They are the ones that are about 1/8" thick and 2 & 1/2" in diameter with the 1/2" diameter fluted hole in the center which is accompanied by two smaller holes on either side.
John F.

To all,

OK... who here "special ordered" the last 4 cover spacers PN: 1626368 from Cernak Buick in East Hampton, MA. (The last four spacers on the planet I might add.)

Saturday morning they had 4 in stock but their parts dept. wasn't open on Sat when I called.

I called late Monday morning only to find them gone.

So... what I need to know now is your address and the carrier so that I can intercept the package.

John F.

Edited October 4, 2012 by Machiner 55
add quote. (see edit history)

Machiner 55 · October 4, 2012

To all,

OK, looks like I'm going to have to answer my own question.

After getting all the parts required and getting everything apart and being able to mull over and digest everything, I've decided to use the insulators that were originally installed on the car as it came from the factory. I'll leave trying the "mix and match" method to the more adventurous.

I also want to thank those of you who PM'd me regarding this matter.

John F.

D-a-n-i-e-l · October 4, 2012

To all,
OK, looks like I'm going to have to answer my own question.
After getting all the parts required and getting everything apart and being able to mull over and digest everything, I've decided to use the insulators that were originally installed on the car as it came from the factory. I'll leave trying the "mix and match" method to the more adventurous.
I also want to thank those of you who PM'd me regarding this matter.
John F.

The spacers, washers, and isolators from a fiero will work on all three locations. They are a little wider but fit. Being wider they probbaly hold up just a bit better and the if you can find the stock isolators, they would most likely provide more isolation. The one I will be installing are polyurathane so I expect a bit stiffer response. Also they are available.

Ronnie · October 4, 2012

Do you have part numbers for the Fiero parts? If so I will try to make them available in The Reatta Store.

D-a-n-i-e-l · October 6, 2012

Do you have part numbers for the Fiero parts? If so I will try to make them available in The Reatta Store.

I do not have access to the part numbers for the spacers or the washers. I ordered used ones from a fiero parts place. New washer is here The Fiero Store and the kit for the fiero bushings is here Prothane 7502 Engine Cradle Mount Bushings Motor Mount Inserts | eBay.

It is posible to get just the cradle bushings that fit, but you would have to go through a prothane distibutor. (There is not one in HI) but I am sure it would not save too much on total cost.

Like I said these are available and that is the important thing. If you are restoring for a show car I am not sure if they would doc points for using these, but my current Reatta is not for that purpose and it serves for my current use.

I am sure that we will see alot more of this part substitution in the future as no one is making OEM replacements for much of these cars and I do not see that changing ever.

Ronnie · October 6, 2012

Thanks Daniel. I will see if I can track down something for The Reatta Store.

January 13, 2013

Has anyone determined whether the Fiero kit will work? Or the Dorman kit from RockAuto (#924004 and 924005)? I would like to order the Dorman kit, and I need to do it so I can get the parts installed next weekend.

January 18, 2013

So nobody has any info as to whether the Dorman bushing kit will work? And since our isolators are the same in all 6 locations, why do you need two different kits? It's just a lot less expensive than the Fiero kit, and has the bolts and spacers.

Ronnie · January 18, 2013

Kieth,

Dorman's website shows the Dorman kit #924004 or #924005 will not fit a Buick Reatta. I can't say if the Fiero kit will fit or not.

Hope this helps.

Machiner 55 · January 18, 2013

Keith,

You may have to be the guinea pig on this one. As you mentioned, the same isolators (insulators,as per parts list) are used at all six positions. Perhaps you should buy a set of six Dorman's, install them, and report back how it went. Then we'd all learn something.

John F.

Machiner 55 · January 18, 2013

Keith,

I also have a bunch of pics taken during my sub-frame project if you need them.

John F.

D-a-n-i-e-l · January 18, 2013

So nobody has any info as to whether the Dorman bushing kit will work? And since our isolators are the same in all 6 locations, why do you need two different kits? It's just a lot less expensive than the Fiero kit, and has the bolts and spacers.

The fiero ones will work. I have done every thing but bolt them in. They are bigger but have the same double d shape. If anyone needs more one them they will have to wait until I complete my swap after returning.

January 21, 2013

Keith,
You may have to be the guinea pig on this one. As you mentioned, the same isolators (insulators,as per parts list) are used at all six positions. Perhaps you should buy a set of six Dorman's, install them, and report back how it went. Then we'd all learn something.
John F.

Thanks, I may just do that. But, aside from the fiero option, specifically what are you folks using for this repair? If there was just get a straight-forward post that said "Buy this, this and this (insulator, bolt and spacer part numbers) from this vendor", life would be so much simpler. Or am I the only one that's had to do this since the stock parts were discontinued?

D-a-n-i-e-l · January 21, 2013

Thanks, I may just do that. But, aside from the fiero option, specifically what are you folks using for this repair? If there was just get a straight-forward post that said "Buy this, this and this (insulator, bolt and spacer part numbers) from this vendor", life would be so much simpler. Or am I the only one that's had to do this since the stock parts were discontinued?

There is not one. No one has found a reliable source, hense all of us looking for them.

Machiner 55 · January 22, 2013

Originally Posted by Keith_Milford View Post

Thanks, I may just do that. But, aside from the fiero option, specifically what are you folks using for this repair? If there was just get a straight-forward post that said "Buy this, this and this (insulator, bolt and spacer part numbers) from this vendor", life would be so much simpler. Or am I the only one that's had to do this since the stock parts were discontinued?

Keith,

As time goes on, more and more part for these cars are being discontinued. As for where to get the Insulators (Isolators) you can go to your local Buick/GMC dealer parts counterman as I did. Their computerized inventory system can search/locate these items nationwide.

When I did mine last summer, I was told that the insulators and the bolts were still available in the Chicago warehouse. The Cover Spacers (washers) can't be had to save your life. You may be able to reuse the ones that come off your car but it's extremely doubtful.

The part numbers for the items required are as follows:

PN - 1627359 Insulator $24.08 (6 required).

PN - 11517635 Bolt $3.58 (6 required).

PN - 1626368 Cover Spacer (washer) $7.77 (6 required) Unavailable. (Certainly won't hurt to ask for them though)

PN - MFN7132 Metric Flange Nuts (M6x1 thread) $0.11 (18 required) These can be purchase locally or let me know. I can get them.

Anything else? Feel free to axe me.

John F.

Edited January 22, 2013 by Machiner 55 (see edit history)

January 29, 2013

The part numbers for the items required are as follows:
PN - 1627359 Insulator $24.08 (6 required).
PN - 11517635 Bolt $3.58 (6 required).
PN - 1626368 Cover Spacer (washer) $7.77 (6 required) Unavailable. (Certainly won't hurt to ask for them though)
PN - MFN7132 Metric Flange Nuts (M6x1 thread) $0.11 (18 required) These can be purchase locally or let me know. I can get them.
Anything else? Feel free to axe me.
John F.

Thanks, John. I have now acquired the correct insulators and bolts. I think I'm going to order the spacer/washer from the Fiero site; from the picture it looks like their "Rear Cradle Bolt Washer" will serve the purpose.

D-a-n-i-e-l · January 29, 2013

Thanks, John. I have now acquired the correct insulators and bolts. I think I'm going to order the spacer/washer from the Fiero site; from the picture it looks like their "Rear Cradle Bolt Washer" will serve the purpose.

The fiero washers are much larger in diameter than the reatta washers.

January 29, 2013

The fiero washers are much larger in diameter than the reatta washers.

So won't work? Or will have just a large overhang?

Machiner 55 · January 30, 2013

Keith,

This is one of the six original Cover Spacers from my '89 Reatta. They are, I believe, made from "unobtainium". Don't know the dimentions of the Fiero Spacers.

John F.

D-a-n-i-e-l · January 30, 2013

So won't work? Or will have just a large overhang?

If you use the fiero isolators, you will have to use the complete assembly in each location you want to use them in. Other wise they will not fit properly.

January 30, 2013

Daniel,

As shown above by John, the original spacer is 2.5" dia. Any idea of the dia of the Fiero spacer? It appears the fiero spacer also doesn't have the interior flange. Could be a problem. Just have to hope I can reuse my originals, I guess.

D-a-n-i-e-l · January 30, 2013

Daniel,
As shown above by John, the original spacer is 2.5" dia. Any idea of the dia of the Fiero spacer? It appears the fiero spacer also doesn't have the interior flange. Could be a problem. Just have to hope I can reuse my originals, I guess.

They are not identicle but the bushings have the same double D as the original. I can not think of any reason for the interior flange. There are many cars made by GM that do not use it. All I know is that if we need a replacement this looks to me to be a good solution and should not cause any issues, except being a little stiffer than stock.

D-a-n-i-e-l · January 30, 2013

Oh... did I mention they are readily available?

January 31, 2013

Oh... did I mention they are readily available?

Yes, I believe you have mentioned that once or twice. And since they are available, and you apparently have some, can you tell me the diameter of the washer/spacer?

D-a-n-i-e-l · January 31, 2013

Yes, I believe you have mentioned that once or twice. And since they are available, and you apparently have some, can you tell me the diameter of the washer/spacer?

The flat "washer" is roughly 3.5" and the "spacer" is roughly 4". these were done by my daughter, so I am sure they are not exact. The measurements should be fairly close, as she know more about mechanics ect than most men I know these days.

Ronnie · January 31, 2013

Daniel is it possible you could get me all the part numbers for the Fiero parts so I can put all this stuff in the Reatta Store? I think it would help everyone if it was all available in one place and easy to find.

D-a-n-i-e-l · January 31, 2013

I do not have access to them. I am kind of in an area where GM delerships are few and far between, but I will see what I can do.

January 31, 2013

Thanks Daniel. Now, as for the install, ASSUMING I have the proper parts and that disassembly goes smoothly (I understand the problems with rusted bolts),off the top of my head, I'm suggesting this is the (over-simplified) procedure. Let me know where I'm wrong. BTW I have no lift.

1. Set parking brake, raise front of car, stabilize on jack stands (behind the subframe), use block of wood on floor jack to slightly raise transmission (to relieve pressure on bushings).

2. Dealing with one side at a time, whack bushing bolts a couple of times with a ball peen hammer to (hopefully) break loose threads. Use PB-Blaster also.

3. Work the bolts back and forth and remove. Remove the three small flange nuts on each mount.

4. Lower the trans jack enough to remove the three mounts on that side.

5. Install the new mounts, raise the trans jack and tighten the hardware.

6. Repeat on other side.

So, this is all total speculation, not having tried any of this before. Please tell me how far off I am.

Machiner 55 · January 31, 2013

Keith,

You are close.

Check your PM inbox.

John F.

Ronnie · January 31, 2013

I do not have access to them. I am kind of in an area where GM delerships are few and far between, but I will see what I can do.

I had forgotten about that. When it is convenient for you to get them will be fine. No hurry. Thanks for all you do for our country.

D-a-n-i-e-l · February 1, 2013

I had forgotten about that. When it is convenient for you to get them will be fine. No hurry. Thanks for all you do for our country.

Quite alright. My mission here has slowed a bit, for the time being, so I should not have too much of an issue finding the time to track down the PNs.

Machiner 55 · February 1, 2013

I am kind of in an area where GM delerships are few and far between, but I will see what I can do.

Sounds like a phenomenal business opportunity! Little to no competition.

John F.

February 4, 2013

Through a combination of info received you good people (special thanks to John F.), a review of info in the FSM, and some trial and error of my own, I tackled this job over the weekend, and it went a lot more smoothly than I anticipated. For anyone who's interested, here's how I did it.

Parts:

PN - 1627359 Insulator (6 required).

PN - 11517635 18mm Bolt (6 required).

PN - 1626368 Cover Spacer (washer) (6 required) Unavailable.

PN - MFN7132 10mm Metric Flange Nuts (M6x1 thread) $0.11 (18 required).

I ordered the insulators and bolts from gmpartsdepartment.com. I picked up the 18 10mm automotive (10-9 grade) flange nuts at the local hardware store. I reused my cover spacers as they were in good shape. Also, because of time limitations, I did not replace the two front insulators. They were in good condition (not crushed and crumbled like the rears); I don't think the fronts are subjected to the stresses that the rears endure.

1. Set parking brake, raise front of car with floor jack under front subframe crossmember, place jack stands at jack-point/pinch-weld just behind wheel well, lower car onto jack stands (leave floor jack in place for extra stability).

2. Remove front wheels.

3. Starting on passenger side, place another jack (floor, bottle, whatever) under subframe just inside the inner insulator position to help raise and lower subframe as needed.

4. At some point, you need to have drilled a small hole in the wheel well so as to be able to get to the captive nut on top of the outer insulator (the inner one is accessible through a hole in the frame, behind a mudflap). I would start with a small hole just large enough to get the PB tube through to soak the captive nut/end of bolt. If you discover later that the captive nut has broken loose, i.e. is turning with the bolt, you will need to enlarge this hole enough to get a vise-grip on the nut.

5. Whack bushing bolts a couple of times with a hammer to (hopefully) break loose threads. Use PB-Blaster also.

6. Work the bolts (18mm) back and forth on both inner and outer insulator, and back the bolts out about an inch. Lower the jack so that the frame and subframe have that one inch space between them. This will give you room to work on removing the three small flange nuts (10mm) on each mount. TIP: Make sure to remove the three small flange nuts BEFORE completely removing the center bolt. I failed to do this on the first one, and the studs that the nuts attach to were broken off of the insulator. The insulator came out, leaving the small nuts and studs attached to the frame. It was a ***** getting a grip on the end of the stud to remove the nut. Removing all of these nuts was the worst part of this job for me. If you're lucky, as I was a few times, some of them will just break off when you put some torque to em.

7. After removing the flange nuts, remove the center bolt and pull the insulator down to remove (may have to pry it out if the top is crushed). There should also be enough room to remove the cover spacer for inspection or replacement.

8. Put the cover spacer back in place on top of the subframe, put the new insulator up through the hole in the subframe (only fits one way), and install and tighten the three flange bolts.

9. Make sure the cover spacer is sitting correctly in the top of the insulator (turn it until seats in two small holes), jack the subframe back up against the frame, install the center bolt, and tighten to 103 nM.

10. Repeat on other side.

I think I got lucky in that all of my captive nuts held like they should.

Hope this helps some of you. It was really much easier than I expected, and if I decide to do the fronts, I don't think it would take more than an hour.

juddev · June 27, 2013

Has anyone determined if the Dorman 924-004 will work for our Reatta's?

Thanks

July 21, 2013

Just to be clear: are we talking about these?

July 21, 2013

I would take the car and a dozen doughnuts to a "frame shop". The car will be fixed in less time than it takes to read this thread and eat the doughnuts. They have the tools, parts and know how. This is not a cost effective DIY project

Ronnie · July 21, 2013

Just to be clear: are we talking about these?
[ATTACH=CONFIG]204179[/ATTACH]

Yes. They are commonly referred to as the cradle bushings. Those look to be in poor condition to me. The photos below show how mine, which are in good condition look and what the end result of ignoring bad ones can be.

July 21, 2013

Everyone can see mine need replacing. I need to gather up the parts for the mechanic I go to who pointed them out to me on Thursday.

Can someone confirm that Keith_Milford's post from February 4th is accurate?

Also, he lists " PN - 1626368 Cover Spacer (washer) (6 required) Unavailable.".

Is that the same as GM Performance 1626368 SPACER?

Edited July 21, 2013 by VTRex (see edit history)

July 21, 2013

I'd like to get the parts from someone who specializes in Reatta parts. Anyone out there?

Sub-frame Insulators (Isolators)

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