Working on the passenger side suspension rebuild.

In order to free the rear bolt of the lower A-arm, when I removed the diagonal cross member a flat oddly shaped spacer fell out. The driver side had no such spacer. Attached are 2 pictures of this spacer and the marks impressed in the diagonal cross member. Whata baffles me, is when I align the spacer with the marks on the cross member, it blocks the hole the stud goes through.

Unfortunately, spacer fell off several seconds after I'd removed the cross member, so I didn't see where it fell from. I only can see the impression in the cross member where that spacer appears to have been... Also, interesting, this spacer has "Padar" stamped in it... And a part number? 08193 also stamped on it.

Has anyone seen this bracket when you've worked on your car?

Thanks in advance.

 

Think it's a motor mount brace, Steve.

I don't have a FSM for your year, but maybe look at a diagram of that specific area of yours if you have one. Should at least give you a look at it.

It would be mounted between the frame and the engine cradle.

I would think that there would be one on each side, though.

 

@Natty C Thanks, I'll refer to the FSM. After discovering this spacer, I searched all the recesses where it could have possibly fallen (be hiding) but could not find it, assuming it was ever there. I'll probably remove the driver's side cross member and see if it has marks like passenger's side.

 

I was just looking around on Google images for a diagram but couldn't seem to find one.

Somebody on here knows, though, so see if anyone else chimes in in the mean time.

You might have to stop/pause your work until you figure it out, depending on where you are in the order of operation of things.

Sounds like you're digging into it nice and good, though.

 

Thanks for your kind words. Yes, I'm very step-by-step procedure and process oriented. The passenger side is completely disassembled, so I can pause before further proceeding. I won't rest until I can rule in/rule out whether or not driver's side has one. I also have the massive, nearly 3,000 page all-years C4 parts manual i can refer to. It's just frustrating, as I'm almost carefully methodical to a fault. The other puzzling thing about this spacer is when I align it with the marks it left on the cross member, the hole is blocked that the engine mounts stud fits through.

 

This should help and it wouldn't be uncommon to find one only regardless the side OR maybe none,

 

@WVZR-1 Thank you so much for sharing that and also your thoughts on this spacer. Although I envy your proficiency finding and loading pages from the parts manual, I'm still going to find this page to increase my familiarity navigating the manual.

 

Yeah, that parts manual/catalogue is good to have. I have one myself and it's served me better than the FSM at times.

 

Familiarizing myself with the massive amount of details associated with these cars is a labor of love. Said manuals related to motorcycles of which I've had lifelong association with pale in comparison to these wonderful cars. I've always joked my red blood cells are shaped like "M's" but they do seem to be morphing into "C's"

 

@WVZR-1 In Parts Manual now, looking at Chassis Group 7, Section 7-H7, page 1742, year models 1992-1996, these spacers appear to be not shown.

I note, upper RH corner of page you shared, 1Y00 - 101195. The manual I'm looking at, upper RH corner, 1Y07-011 - 090392. The last 6 numbers must be dates the factory compiled this information when they were preparing the parts manual for eventual publication, as page 2 of my manual shows a later date of 122192 which must be the date the factory had the manual ready for publication...?

So, apparently, you have for your reference a manual with a later publication date (101195) than the one i'm looking at?

Are there, per chance, availablity of year specific parts manuals? If so, then i would like to find copies of the 1994 and 1996 manuals.

 

It is a "shim". In production, shims are utilized to fill gaps or voids between parts that exist because of production tolerances.

The engine sits on the pad on the front crossmember. When the car is produced, the engine is sitting on the crossmember and the entire driveline and most of the suspension is raised into the body/frame from below. The crossmember bolts to the frame, and the 'braces' are then installed between the front crossmember and the frame rails. If the brace can't be raised enough to be installed without a gap, a shim is put between the brace and the pad to fill the gap. The brace supports some of the weight on the engine mount.

It looks like the shim was not fully inserted before the mount nut was torqued. Hence the deformation of the brace and the shim. There may or may not be some deformation on the crossmember pad. I'd pound out the shim and the brace flat again. When you reinstall the brace, install the nut on the mount stud first, loosely to take up all the clearance. Attempt to install the other 4 bolts. If they wont align, loosen the mount until the 4 bolts can be installed. Now check for a gap between the pad and the brace. If there is one, fully insert the shim to take up the clearance. Same with the other side.

These types of procedures for assembly are contained in the Product Description Manual (formerly called Assembly Instruction Manual) which is basically the instructions for building and assembling the car at the assembly plant. I have a PDM for the 1985, but generally the PDMs are tough to find in the wild. GM seems to have been pretty good at not letting them get out. Without a PDM, I'd do it the way I described in the above paragraph.

Very interesting. Especially that the assembly image WVZR provided shows shim(s). Thanks for sharing. Cheers.

EDIT/ADD: I've had the braces off of both my 90 LT5 and 92 LT1 cars. Neither side had shims between the braces and the mount pads. The 92 had been apart prior to my purchase so if it originally had shim(s), Mr. Goodwrench may have neglected to put them back.

 

With all of the shims installed all over the place on these cars, and as was mentioned, sometimes there's one, sometimes two, sometimes none, in a single place, it's always been in the back of my mind that the cars realy can't be mathematically true to their original design and testing.

Seems like that if they needed to shim so much, then soething went wrong some place else along the assembly line.

There's actually a stack of shims on one side of my engine. Maybe like four of em stacked. But that's just kind of an aside thought there. Maybe I'm just thinking too much into it. I dunno...

 

Maybe at the time their manufacturing processes weren't sufficiently precise to anticipate the stacked tolerances of the all the components assembled so the shims were the final fudge factor to compensate for it? Dunno, but four shims seems like alot!

 

I was just overthinking it, Rusty. lol. I think because the first spot I thought of on my own C4 when he mentioned about the shim was one cetain spot where there's 4.

 

Now that would definitely be something cool and handy to have.