1972 MC 350/Auto - Suspension Upgrade

[SPLATT71MC]

3 hours ago, B-Man said:

@SPLATT71MC QUIT SPENDING MY MONEY!!!!!! Haha

Man, this looks awesome. Thank you for posting the link

QUESTION: What steering ratio (number) did you buy?

It says that 3 turns is stock  and that they offer a 2.5

It also says they offer more ports for an after market steering ram of some sort. Did you do that?

I bought the quickest one they offered at the time which was like 10 years ago so I don't remember exactly. I liked it enough to go back to them for a box for my K5 Blazer cross over conversion.

[B-Man]

@SPLATT71MC, you probably got the 2.5 then.  Hmm, I will keep this in mind for sure.  I still want to research the Jeep OEM options too.  Thank you though!

[B-Man]

Update: the clip nuts purchased at Advanced Auto looked questionable, and they are!!  Looks like both of the 3/8-16 bolts pulled right out. Perhaps due to heavy loading in hard turns (well, I never ... :).

I built my own airplane, believe it or not. A Cozy MK IV. And I worked in aerospace for a few years out of college. In aerospace the bolt spec's are either inboard, downward or aft - where the bolts point when installed.

In this application the bolts point upward, which goes against the aerospace install theory. The result probably would have been the same since the nut plates are the likely failure point though.

I'm going to throw some new bolts in, along with some washers and maybe lock nuts. If I can, I will put the bolts through the springs and point them downward. We shall see

[cny first gen 71]

I have never seen that happen before.  Back when I worked in The shop when they broke we would just drop 5/16 bolts down through tha A frame and put nuts on the bottom, washers if needed. 

[MC1of80]

Like Steve, I have never seen both bolts fail. I have seen one bolt holding the shock in but never both fail. 

Would do what Steve stated, put a bolt through the hole and shock and rebolt. 

[B-Man]

@cny first gen 71 and @MC1of80, the bolts likely did not fail.  I believe the 'clip nuts' failed (a package from Advanced Auto down the street from me; see link below).  My guess is that the load of the shock just pulled the bolts right down and through the threads of the clip nuts.  The clip nuts that were in there when I went to replace the shocks disintegrated as I pulled the bolts out due to corrosion.

As I mentioned above, I plan to through-bolt with washers and lock nuts going forward.  Screw the clip nuts!!  Maybe I was just replacing somebody else's bad idea.  The clip nuts were probably not stock.

https://shop.advanceautoparts.com/p/dorman-clip-nut-wide-panel-3-8-16-in.-45422/22147595-P?searchTerm=3%2F8+clip+nut

[jft69z]

Those clip nuts you linked are more for sheetmetal/body panels.

Get some that are made for shock mounting (or use nuts & bolts as above)

[MC1of80]

58 minutes ago, B-Man said:

@cny first gen 71 and @MC1of80, the bolts likely did not fail.  I believe the 'clip nuts' failed (a package from Advanced Auto down the street from me; see link below).  My guess is that the load of the shock just pulled the bolts right down and through the threads of the clip nuts.  The clip nuts that were in there when I went to replace the shocks disintegrated as I pulled the bolts out due to corrosion.

As I mentioned above, I plan to through-bolt with washers and lock nuts going forward.  Screw the clip nuts!!  Maybe I was just replacing somebody else's bad idea.  The clip nuts were probably not stock.

https://shop.advanceautoparts.com/p/dorman-clip-nut-wide-panel-3-8-16-in.-45422/22147595-P?searchTerm=3%2F8+clip+nut

Sorry, but, yeah no. Possible, yes probable, no. Although I have seen stranger things happen. 

Guess what I'm saying is, it's a definite possibility of an almost maybe. 🤔

[B-Man]

@jft69z, yeah exactly.  If I had good, local source for the correct / better clip nuts I would do that.  But I'm going for some GR8 bolts, washers and lock-nuts!!

I just wanted to share my experience so that others dont follow :).  Mounting these dang Bilstein shocks has been a real pain the butt for sure!

[jft69z]

1 hour ago, B-Man said:

I just wanted to share my experience so that others dont follow :).  Mounting these dang Bilstein shocks has been a real pain the butt for sure!

I'm going to be installing a set of Bilsteins in the next few days on the Monte. The KYB's I put on there when I built it are fine, but maybe a little softer than I prefer (more like a stock upgrade shock perhaps). I have the Bilseins on my Camaro & they seem good.

I'll pop up some pics as I get the opportunity. The front shocks won't be here 'til Tuesday, but I plan to try the rears today.

I have until May 11th to return the rears to Amazon if I don't like them, so I need to get on them soon 😁.

[B-Man]

@jft69z, awesome!  Yeah, so far so great with the Bilsteins.  Between them, the boxed in lower rear control arms and the rear sway bar, my MC is handling incredibly well.

Remember, if you ordered BIlstein P/N 24-009294 for the rear shocks you will have to buy the set of Dorman bolt / bushing / stud assemblies that I mention earlier in this post.  But perhaps you ordered a different part number that comes with proper hardware.

Do you have the boxed rear lower control arms and sway bar?

[jft69z]

25 minutes ago, B-Man said:

Remember, if you ordered BIlstein P/N 24-009294 for the rear shocks you will have to buy the set of Dorman bolt / bushing / stud assemblies that I mention earlier in this post.  But perhaps you ordered a different part number that comes with proper hardware.

Do you have the boxed rear lower control arms and sway bar?

I have the F41 suspension on the car already (72 Customs came with it), so yes, boxed rear arms.

I have the same shocks you do: PN 24-009294. I already test fit them on a spare 12 bolt I have in the basement. I'm not anticipating any troubles. If anything, maybe that rubber dust boot may need to be trimmed an inch or two so it doesn't rub on anything, no big deal.

[jft69z]

So I put one rear shock in as a quick test, because I'm going to pull it back out to paint them black (or dark gray, not sure yet).

Anyways, as expected they went in fine. First thing I did was put the top mount in a vice to rotate it at the correct angle.

After that, bolt it all up. 

Pics are in order. Vice, top mount, bottom mount with car in air, bottom mount with car on ground. No washers or spacers needed, but enough thread there if required.

Blue rubber sleeve is a couple inches longer than the KYB it replaced, but still no clearance issues at all.

 

 

 

Car in the air, with wheels hanging free:

 

Car on the ground:

 

[Dtret]

Very nice. I’ll bet rotation of the shaft was the key. 

[jft69z]

Just now, Dtret said:

Very nice. I’ll bet rotation of the shaft was the key. 

It helps with the install, but has nothing to do with the lower mounting stud.

[cny first gen 71]

What was wrong with the old ones they look new?

[jft69z]

16 hours ago, cny first gen 71 said:

What was wrong with the old ones they look new?

They are new, about 500 miles on them. KYB  Gas-A-Just.

The car just seemed a little too soft. They'd be perfect for a stock rebuild or something like that. Maybe I'm just too used to a stiffer ride my newer cars provide. I haven't taken the car for a spin with the Bilstein's, but either way, I'm keeping them.

If someone wants them cheap, I'll bring them to Carlisle next month, or Syracuse after that. It'll be the set of 4.

Edit: Shocks are SOLD.

[B-Man]

@jft69z, dang your MC looks SO CLEAN underneath!!!! Impressive.

It looks like you ended up with an installation issue with the Bilsteins too. Similar to what I ran into.  On your MC the angle on the bolt / stud going through the bushing seems off to me. It will probably be fine, depending on your driving habits I suppose. That would drive me nuts though. 

Going back through my pics and yours it's hard to tell what's going on. Seems the geometry is just slightly different maybe. I introduced the Dorman assembly and the bolt / stud going through the bushing (it's a 2-piexe bushing mind you) is much straighter than yours. But the yellow cylinder is stood off from the bracket the same amount. 

 

EDIT by Joe T: This is with my car in the air, wheels hanging free.

 

 

 

[B-Man]

And relative to the issue I'm having with those clip nuts on the front shocks, I picked up some Grade 8, flanged nut and bolt sets to throw in there this afternoon. I guessed at the length and went with 1 1/4 long bolts - we shall see. Fortunately we have a small Ace Hardware store with one of those awesome aisles of every bolt and screw you could ever want!

[jft69z]

1 hour ago, B-Man said:

@jft69z, dang your MC looks SO CLEAN underneath!!!! Impressive.

It looks like you ended up with an installation issue with the Bilsteins too. Similar to what I ran into.  On your MC the angle on the bolt / stud going through the bushing seems off to me. It will probably be fine, depending on your driving habits I suppose. That would drive me nuts though. 

 

Thank you Brenden! It's clean because I did a frame off a couple of years ago. Spent a couple of hours yesterday removing all the molten driveway sealer and rubber from the antics the day before. That sucked, lol. Still need to clean the Z/28 too.

As far as the shocks, the picture you referenced is with my car in the air with wheels hanging free. The KYB shocks that were on there do the same thing. I went back and edited my post to label the pictures. Also added a note to the picture you posted.

With the car on the ground there are no issues with the Bilstein shocks as far as I'm concerned. I compared the mounting stud on them with the KYB's on the bench before installing, not a whole lot of difference as far as clearances, though the designs are obviously different.

The Bilstein's actually had a longer thread than the KYB, which would have allowed a washer on the shock side if the tube was close to the mounting bracket. The Bilstein shock tube is noticeably wider than the KYB, but still no issues though.

[B-Man]

@jft69z, aha ... yeah, in the air and on the ground - I get it.  I just looked and my assembly is straight on the ground, while the pic I posted was on jack stands. Whatever though, as long as it works!

I got the Grade 8 flanged nuts / bolts in and replaced the clip nuts and 'body bolts' that someone else had put in. I'm not sure how I convinced myself that was ok to repeat. Probably all the rear shock nonsense I ran into

So all is right with the world, and I'm headed out for a drive to the parts store for some other projects I have today. It's a beautiful day for a drive up here in Connecticut!!

[jft69z]

1 minute ago, B-Man said:

I got the Grade 8 flanged nuts / bolts in and replaced the clip nuts and 'body bolts' that someone else had put in. I'm not sure how I convinced myself that was ok to repeat. Probably all the rear shock nonsense I ran into

So all is right with the world, and I'm headed out for a drive to the parts store for some other projects I have today. It's a beautiful day for a drive up here in Connecticut!!

 

So you used nuts & bolts on the lower fronts? Should work, but the proper J-nuts would have made the installation easier than fiddling with nuts, washers, etc. As long as it holds, you'll be fine.

Have a nice ride. Supposed to rain a bit here today, but the rest of the week looks great.

[B-Man]

@jft69z, yeah just nuts and bolts. Grade 8 and flanged. Access is a little tricky but not horrible. I'm sure future Brendan will be cursing at past Brendan at some point :). If I ever do a full suspension kit I will chase down the proper clip nuts, or J-nuts as you call them

Bummer on the Sunday rain. But enjoy your week then!!

[B-Man]

Jumping back into the suspension work now that winter has set in and I have my new 3-may garage fully functional!! Today I pulled the rear coil springs out. They look original but the rubber isolators up top are indecent shape. I wonder if they were replaced at some point ... hmm.

Anyway, here is a picture of new spring compared to one of the old ones. An obvious height difference. And I'm sure the spring rate is quite different as well 

I was able to get the old springs out by dropping the rear end down and releasing the lower shock bolts. I then used a pry bar to pop them out since they weren't under much compression 

To get the new ones in I will have to borrow some spring compressors from a coworker tomorrow. They should go in pretty easy though. Then I will have to fight the suspension again to get the lower shock bolts back in.

Next up after the springs - new tires ... finally!!

[cny first gen 71]

If you put a jack on the opposite side jack it up a bit it should slide right in then do the same on the other side you don't need spring compressor. Of course with any spring installation be careful they can jump out and bite.