Write-Up: Subframe/Cradle Mount Insulators & Bushings

EDIT

BMD wrote:

What is holding the motor and trans up at this point?

This whole operation is done already. I'm just slowly catching up on the write-up stuff.
If you're talking about those last few pictures, the hoist is still supporting everything from the top; you just can't see the hoist in the pictures which is kinda freaky.

Ahhh Ok, thanks man. Very good write-up so far, thanks for documenting.

So far some good info in this thread. I'm getting ready to replace all my cradle mounts. A few questions:

Can I do one or two cradle bolts at a time, without needing to support the engine?

How do the zzp spacers work? Where do they install exactly?

I visited my GM parts counter today. They recommend the following:

qty (3) spacer #25654083 (is this qty right? Will I even need to replace these?)

qty (2) insulator # 2575173
qty (2) insulator #25757174

qty (2) insulator # 25674564
qty (2) insulator # 25674565

qty (2) insulator # 25643387

qty (2) retainer #25609143 (2 packs of 5)

qty (6) nut #11609712
qty (1) retainer #25636517 (pack of 10)

Here are prices from GMpartsdirect (spacers not included):



Thanks in advance for help. PS - Ed Morad does not have these parts for sale; they say the used ones they see aren't worth reusing.

Okay, did some research on this and found the cradle mounting hardware varies slightly year to year:



Parts (listed by year):

1995:
01 - N/A
02 - 11609712 RETAINER (NUT), 6 Required (1995-1999)
03 - 25654083 SPACER, 6 Required (1995-1999)
04 - 25757175 INSULATOR, 4 Required (1995-1996, use for #08*** assumed, please check)
05 - 25643389 INSULATOR, 2 Required (1995-1996)
06 - 25609143 RETAINER, 6 Required (1995-1999)
07 - 11588419 BOLT, 6 Required (1995-1998) Spec: FRM(SILVER)(M14X2X105,10.9,38THD)(REDUCED BODY)(08.900)
08 - N/A (1995-1996, use #04*** assumed, please check)
09 - 25674564 INSULATOR, 2 Required (1995-1999)
10 - N/A (1995 use 25757173 INSULATOR, 2 Required*** assumed, please check)
11 - 25643387 INSULATOR, 2 Required (1995-1999)
12 - 25636517 RETAINER, 6 Required (1995-1999)

1996:
01 - N/A
02 - 11609712 RETAINER (NUT), 6 Required (1995-1999)
03 - 25654083 SPACER, 6 Required (1995-1999)
04 - 25757175 INSULATOR, 4 Required (1995-1996, use for #08*** assumed, please check)
05 - 25643389 INSULATOR, 2 Required (1995-1996)
06 - 25609143 RETAINER, 6 Required (1995-1999)
07 - 11588419 BOLT, 6 Required (1995-1998) Spec: FRM(SILVER)(M14X2X105,10.9,38THD)(REDUCED BODY)(08.900)
08 - N/A (1995-1996, use #04*** assumed, please check)
09 - 25674564 INSULATOR, 2 Required (1995-1999)
10 - 25757173 INSULATOR, 2 Required (1996-1999)
11 - 25643387 INSULATOR, 2 Required (1995-1999)
12 - 25636517 RETAINER, 6 Required (1995-1999)

1997:
01 - N/A
02 - 11609712 RETAINER (NUT), 6 Required (1995-1999)
03 - 25654083 SPACER, 6 Required (1995-1999)
04 - 25757174 INSULATOR, 2 Required (1997-1999, same as #08)
05 - 25674565 INSULATOR, 2 Required (1997-1999)
06 - 25609143 RETAINER, 6 Required (1995-1999)
07 - 11588419 BOLT, 6 Required (1995-1998) Spec: FRM(SILVER)(M14X2X105,10.9,38THD)(REDUCED BODY)(08.900)
08 - 25757174 INSULATOR, 2 Required (1997-1999, same as #04)
09 - 25674564 INSULATOR, 2 Required (1995-1999)
10 - 25757173 INSULATOR, 2 Required (1996-1999)
11 - 25643387 INSULATOR, 2 Required (1995-1999)
12 - 25636517 RETAINER, 6 Required (1995-1999)

1998:
01 - N/A
02 - 11609712 RETAINER (NUT), 6 Required (1995-1999)
03 - 25654083 SPACER, 6 Required (1995-1999)
04 - 25757174 INSULATOR, 2 Required (1997-1999, same as #08)
05 - 25674565 INSULATOR, 2 Required (1997-1999)
06 - 25609143 RETAINER, 6 Required (1995-1999)
07 - 11588419 BOLT, 6 Required (1995-1998) Spec: FRM(SILVER)(M14X2X105,10.9,38THD)(REDUCED BODY)(08.900)
08 - 25757174 INSULATOR, 2 Required (1997-1999, same as #04)
09 - 25674564 INSULATOR, 2 Required (1995-1999)
10 - 25757173 INSULATOR, 2 Required (1996-1999)
11 - 25643387 INSULATOR, 2 Required (1995-1999)
12 - 25636517 RETAINER, 6 Required (1995-1999)

1999:
01 - 25766845 FRAME, 1 Required (1999)
02 - 11609712 RETAINER (NUT), 6 Required (1995-1999)
03 - 25654083 SPACER, 6 Required (1995-1999)
04 - 25757174 INSULATOR, 2 Required (1997-1999, same as #08)
05 - 25674565 INSULATOR, 2 Required (1997-1999)
06 - 25609143 RETAINER, 6 Required (1995-1999)
07 - 11517701 BOLT, 6 Required (1999)
08 - 25757174 INSULATOR, 2 Required (1997-1999, same as #04)
09 - 25674564 INSULATOR, 2 Required (1995-1999)
10 - 25757173 INSULATOR, 2 Required (1996-1999)
11 - 25643387 INSULATOR, 2 Required (1995-1999)
12 - 25636517 RETAINER, 6 Required (1995-1999)

source: http://parts.nalleygmc.com/showAssembly.aspx?ukey_product=0&ukey_assembly=381137&ukey_make=1022&modelYear=1998

Using GMparts direct to replace all the cradle hardware on my '98 would be $285.99. I've decided to try reusing the spacers, nuts and bolts, so total will be $147.68. I still feel this is a lot for 12 pieces of rubber and some metal clips, but I don't see any other option right now.

If needed, McMaster-Carr sells compatible bolts and nuts for lower prices. I ordered a pack of 5 bolts and 10 nuts for about $20:

Bolts: http://www.mcmaster.com/#91310A796

Nuts: http://www.mcmaster.com/#92497A550

Thanks for this info Aaron. I think its time for most of us to get on this!

AA, those part numbers do match up to what I got for my '97.

For the nuts, I see no reason to buy more than 2. There is absolutely no access to the other 4 for replacement.

Just to clarify what these pieces actually are since the dealer's terms are pretty generic---
6 11588419 BOLT - obviously the bolts
6 25654083 SPACER - large cups that retain the bigger upper insulator with the bolt extensions that go down through the whole mount assembly
6 25609143 RETAINER - smaller metal cups that retain the lower insulator and acts like a washer for the bolt
6 25636517 RETAINER - little plastic bolt keepers that fit into the upper spacers just to help hold in the bolt for easier installation
6 upper INSULATOR - wide rubber donuts that cushion between the upper retainer and the cradle
6 lower INSULATOR - smaller rubber/metal pieces that kinda press-fit into the cradle from the bottom that cushion between the lower retainer and the cradle
6 11609712 NUT - caged nut assembly that's integrated into the body of the car so the cradle mounts can screw into them (these are fixed to the body from the factory)

AA wrote:

Can I do one or two cradle bolts at a time, without needing to support the engine?

How do the zzp spacers work? Where do they install exactly?

qty (3) spacer #25654083 (is this qty right? Will I even need to replace these?)

PS - Ed Morad does not have these parts for sale; they say the used ones they see aren't worth reusing.

1 I would say yes but getting the old lower insulators out might be tough without having a lot of room to beat/pry them out of the cradle from the top and it's common for the bolts and upper retainers (all the way at the top) to rust together which makes things harder still.

2 The spacers will fit right between the body and the top of the cradle mount assembly (so it doesn't affect the cradle mounting at all really). The original bolts are long enough to use the 1/4" or 5/16" spacers without a problem.

3 There's 6. You definitely want all of those; unfortunately they are expensive

4 Amen to that!

Cool, thanks for the info. I only spent $7.40 on 10 nuts, so no big deal if I don't use them all. What about the bolts - did any of yours need replaced?

AA wrote:

Cool, thanks for the info. I only spent $7.40 on 10 nuts, so no big deal if I don't use them all. What about the bolts - did any of yours need replaced?

I was originally only going to replace the location 2 bolts that I could clearly see were rusted away with the rest of the mount pieces but guess what, all the bolts were rusted to the 25654083 spacers since the bolts run through the spacer's shaft. You'll know right away if that's the case because when you loosen the bolt, the upper retainer will be spinning along with the bolt. I tried the usual PB blaster and such but the corrosion was too heavy - most of the bolts had lost a good bit of girth to corrosion.

Assuming the bolts are rusted too the spacers like you say, do you think there is any salvaging either of the parts?

AA wrote:

Assuming the bolts are rusted too the spacers like you say, do you think there is any salvaging either of the parts?

IMO no. Consider, not only are those parts going to be in some degree of iffy condition when you remove them but then you have to put them back and continue using them for who knows how many more miles. I wouldn't take the chance.

I'm going to hope mine are not rusted that badly. I cannot see throwing away an extra $80+ just for these spacers, unless I know for sure they can't be reused. You're probably right, but I'd hate to order them all only to find I didn't need some or all of them. I can go to the dealer for two or three. Were all six of yours bad?

I took a look at my sub frame bushings today. Much to my surprise they all looked really good. no cracks in the rubber and the bolts had no rust (always a FL car though).
My concern is that there seemed to be 2 bushings missing COMPLETELY. The inner rear top isolators were not there like in the pic above (#8). Not sure if its something 96's didnt have or what, but gmpartsdirects picture shows a bushing there for my 96.
I just find it really odd that those 2 deteriorated to nothing while the other10 bushings were fine.

A second concern was that with the car up on ramps the upper isolators can rotate. Shouldn't everything be tight with the wheels down on the ramps?

Maybe the bolts have become loose? Could try re-torquing to spec. I'd try that before replacing them. Does your front end seem loose or make knocking sounds when turning?

between the eibach lowering springs, 100% poly bushings on front suspension and bad side motor mount i have all kinds of little knocks and noises when i jump off the line, hit the brakes and sometimes while turning. Most of which only i notice, but it bugs me.
I dont think i can get any more turns on those bolts without a breaker bar. Maybe because the other top isolators are missing the rear isolators have worn thin and now the frame droops even though the bolts are all the way up??

I replaced all my upper and lower insulators and some of the hardware last weekend. It took me and a helper TWO 12 hour days to finish the job (to be fair, we also replaced front struts and front/rear motor mounts). I think we could have installed just the cradle insulators in one day.

Thanks to Codith and others for advice on how best to approach this project. I used an engine hoist for support while the cradle was loose - great idea! Hats off to those who have attempted and succeeded at this job. I have a new level of respect for you!

After it was all done, I will say I'm very happy with the result. This is the maintenance fix that effectively takes 50-100K off the car's chassis. I also took the opportunity to coat parts of the cradle with rust converting primer + black paint in order to help prevent future corrosion issues.

The cradle noises are completely gone. The front end of the car feels firm, like it's one solid piece. After my alignment, the SEARS auto tech seemed surprised at the way my car drove during the test. For having close to 225k miles, the words I heard: "drives like a new car". Of course, the tech who drove the car didn't know I'd replaced the cradle insulators or motor mounts.

I came out of it with two smashed fingers, thanks to tipping over a 4-ton jack stand onto my hand. No kidding, this was the very last thing did before cleaning up the garage - figures. At that point I was getting tired and careless, but it was well worth the pain. And that's why I'm slow to report my progress. I couldn't use the keyboard until today! Pictures to follow.

Congratulations! I myself am really excited to see the pics. This job is one I'm dreading, but would seem to make the biggest difference. So you had the motor supported and crawled around on the garage floor to do this?

Not exactly inside the garage... then it started to rain. That was part of the reason we ended day 1 after 12 hours. You really don't work as fast when it's dark, you're soaking wet and cold. Sunday was a much more productive day.

Yes, we supported the engine, lifted the car up about 12" and rolled around on our backs in the driveway. Here's the initial set-up:



Modified after the rains came:

I just ordered the 2 upper inner most bushings from the dealer today. I am really hoping it makes my front end more solid and less noisy.

That should cure it. Cant remember, did you do the uppers on the other four cradle bolts?

All of the other bushings and bolts looked to be in great shape.

Imo, do them all, upper and lower, to be sure. I honestly couldn't tell mine were that bad until I lowered the cradle and checked them. I still don't know which one(s) were causing the noise, but I know at least one per side. Or, try doing the backs only - good practice for if/when you need to do the rest!

Anyway I'm glad it went well enough for you. How did all your cradle hardware look?

AA, what does your garbage can say on it???

It says: Directions to house with lots of tools in garage!