J-Rod

From JLA-

Had work done that involved removing the suspension cradle? (Tranny rings) READ THIS!
As many of you know from reading the epic of the many repairs on my 01 Z06 by GM, my car has been torn apart many times.

Many of these warranty repairs involved removing either or both of the front and rear suspension cradles.

After each repair I have experienced problems with popping noises coming from the front of the car like the suspension was loose, creaks, groans and adverse handling.

Each time, I have taken my car back and various dealers have told me that the suspension cradle bolts had come loose and the noises I was hearing were from the suspension cradle moving as a result of any significant weight transfer of the vehicle.

Each time they have told me that they retightned the bolts and that it should clear the problem up, but the cradle may come loose again over time and that it was PERFECTLY normal.

Well, I started to think to myself

How come Corvettes coming off the line that have had no repair work done we do not hear about problems with the suspension cradle coming loose? If it was a PERFECTLY normal problem, wouldn't this be a fairly widespread and spoken of problem?

I decided to call Corvette Brand Quality Manager Dave Peacy and he agreed that the suspension cradle should not be coming loose and that there were probably some type of bolts on the suspension that should not be reused after removal but instead replaced.

I went back to Performance Chevrolet in Chapel Hill, NC and informed them of this and they contacted GM technical assistance, some of the suspension engineers and apparently Mr. Peacy was right on the money with his idea.

The techs at Performance were told that ANYTIME **EITHER** of the suspension cradles are removed, the bolts MUST BE REPLACED AND NOT REUSED! PERIOD!!!

The techs did not know about this and I have spoken to other dealerships in the area and they also have never heard of this.

How many C5's that have had oil rings jobs, transmission jobs or anything else that involved removing either of the suspension cradles are experiencing these problems due to the lack of the dealer's knowledge of this information?

The items replaced today on my car were

(10) 3537773 Nut ASM-C
(6) 11515744 Nut-Hex
(5) 11516383 Nut-Metri
(2) 10282253 F-Nut

To all of those out there that are experiencing these sorts of problems, I recommend you take this information to your dealer. Someone may want to post this information at the other forum as I am still banned!

JLA

66ImpalaLT1

Sounds like the nuts are made slightly out of round to keep them locked in place. GM does this on a lot of parts (master cylinder for example). I guess after enough times being removed they're just too round and start loosening up.

Thanks for the tip. I'll be sure to buy new ones when I swap rear ends.

Eric

Ling_650vette

iTrader: (1)

Its not really the dealers lack of knowledge about it, its just the fact that if they do a lower end job on a motor, and remove the pan, do they go and get new oil pan bolts? No. So if GM doesnt specify that they need to replace the bolts, what are they to do?

I understand exactly what you're saying being that the suspension bolts should be replaced, and im not tryin to be an *******, but the blame cant be put fully on the dealership, because in all honesty, its not their fault. When they do work, if bolts arent with the new parts, what are they supposed to use? Granted, i know they've got nuts, bolts, screws and so on in the back, but its just easier for them to reuse the bolts that they removed off the part versus seeing what they've got in the back.

Like i said, im not tryin to be an *******, just givin a different opinion

J-Rod

JLA posted it, I am simply passing along what he found.

I will probably jack mine up and check it. If they are loose, I will retighten them and use some Loctite on them. But sometimes folks get funny noises from the rear. This could help in finding out why...

Ling_650vette

iTrader: (1)

Talked with a few techs @ work (where i still am) and asked them if they had heard of any particular noises like you said...

They said they hadnt heard of anything being a major problem, just some owners complain from noise from the fuel pump. But, GM does specify using new bolts on some applications, like brake replacements and some other jobs. So if GMs service report had said "replace bolts w/ new 3/4" hex head part # 11405050" (just an example) then it would be a technician/dealer problem, but they could've just overlooked the report...either way, i still dont personally blame the dealer/technician, but if it was reported to use new bolts and they didnt, then its their fuckup.

Either way, i hope you get your problem fixed. This doesnt sound like a re-occuring problem among C5 owners, but hopefully you can get yours fixed soon so you can enjoy 'er

By the way, im @ Chevrolet Cadillac of Goldsboro and if he's ever down this way, tell him to let me know, and maybe one of our techs can give him some input..we've got 4-5 ASE Master Techs and a few w/ Corvette experience, and one w/ the GM Mark of Excellence award, im sure they'd love to help JLA fix the problem

<small>[ March 19, 2003, 06:26 PM: Message edited by: Ling_650vette ]</small>

ToplessTexan

<img border="0" title="" alt="[Confused]" src="images/icons/confused.gif" />

The service manual specifies NEW nuts, tighten with hand tools only.

J-Rod

Actually this has been discussed on the Z06 site. Lots of folks have had the rear cradle out, and lots of them have popping sounds from the rear area afterward. I know that right now I do. I had the rear out for a clutch change. I can fix it by jacking the car up and tightening the bolts again, or get new ones and fix it. I have even thought of getting some nyloc nuts to do the job, or apply some loctite to the bolts to ensure they don't come loose.

JohnL

I had my clutch replaced about 75,000mi. I don't think the shop that did the install put new bolts in, at least there was no charge for it. I'm over 125,000 now and I don't hear anthing like that.
Can anyone be more spicific about which "Cradle bolts" these are so I can check them the next time I'm up on Jack-stands?

ToplessTexan

I didn't mean my reply to indicate that I was confused about whether or not this was an issue.

I am confused though about why this is perceived as anything either unusual or undocumented. Again, it's described in the service manual.