Exciting day - rebuild of 78 coupe

Chris Sale

CCCUK Member
Same here - I have a scanned copy but no indication of the source. The page format looks like it's from a GM Service Manual. The illustration numbers start with '3a' and Front Suspension was usually in Section 3. However, I have been through the C2 Service Manuals I have here and I can't find either of the illustrations in any of them. The only place I have found them is in my copy of Chilton's 'Corvette 1963-82 Repair Manual', but my scanned copy is not from this.

Chris Sale
'64 Coupe
 

Forrest Gump

CCCUK regional rep
Look at the set-up this idiot has got. 1 shim at front, 5 shims at the back, so a difference of 4 x 1/8” = 0.5”
I was unaware of the 0.4“ rule and just went as far as I dared.
If I add a 1/16” shim at the front and swap one of the 1/8” shims for a 1/16” in the rear pack then I will be legal again.


E5748008-FDB0-4FF0-A956-2005E59E6C63.jpeg
 

johng

CCCUK Member
Looks like you don't have a radiator shroud either Andy. That does make access to the front shim stud easier. I take it you don't have overheating problems.
 

Forrest Gump

CCCUK regional rep
No shroud, just a powerful Kenlowe fan on stock radiator. I’ll generally only need it if stationary or stop start traffic.
B1FEF3E8-7071-4B68-AE6E-A88C71E90D3A.jpeg
 

johng

CCCUK Member
Good news and bad news. Took the car for a drive yesterday, having adjusted the caster angle and centered the steering box properly the steering now feels much better. Bad news is that as Andy predicted the rear camber bolts have moved and I've now got a couple of degrees of negative camber again. I want to take the strut rods out to see if there's anything I can do to stop them turning. With the car jacked up can I just remove the camber bolts, or do I need to disconnect the spring?
 

kentvette

CCCUK Member
Good news and bad news. Took the car for a drive yesterday, having adjusted the caster angle and centered the steering box properly the steering now feels much better. Bad news is that as Andy predicted the rear camber bolts have moved and I've now got a couple of degrees of negative camber again. I want to take the strut rods out to see if there's anything I can do to stop them turning. With the car jacked up can I just remove the camber bolts, or do I need to disconnect the spring?
John, I think you'll find it easier to disconnect the spring as I think it would put a bit of "pressure" on the tie rods and at the very least, make it difficult to re-fit.
I confess I have never had problems with the cam moving once I've have set them so can't offer any help to stop them doing so! :) :rolleyes:
 

Adtheman

Well-known user
Good news and bad news. Took the car for a drive yesterday, having adjusted the caster angle and centered the steering box properly the steering now feels much better. Bad news is that as Andy predicted the rear camber bolts have moved and I've now got a couple of degrees of negative camber again. I want to take the strut rods out to see if there's anything I can do to stop them turning. With the car jacked up can I just remove the camber bolts, or do I need to disconnect the spring?
I changed mine for smart struts, made a huge difference on the handling.
 

johng

CCCUK Member
Stephen, have you got rubber or poly bushes? I know the rubber ones have a serrated end on the inner sleeve, I can't remember what is on my poly bushes it's 3 or 4 years since I fitted them, hence why I want to take them out.
Adam any idea why the smart struts made such a difference? Were your old bushes knackered? Have the smart struts got poly bushes?
 

kentvette

CCCUK Member
Stephen, have you got rubber or poly bushes? I know the rubber ones have a serrated end on the inner sleeve, I can't remember what is on my poly bushes it's 3 or 4 years since I fitted them, hence why I want to take them out.
Adam any idea why the smart struts made such a difference? Were your old bushes knackered? Have the smart struts got poly bushes?
John

I have poly bushes on mine and I think that, as you say, there is a serration on the sleeves. But I thought there was also some sort of serration on the brackets that made contact with the cam inner face?
 

johng

CCCUK Member
Are you doing them up to the required torque?
Check the bolt isn’t bottoming out.
Yes doing it up to the correct torque, although I'm finding that impossible to do at ride height. I need to remove the wheel, hold the bolt end in place with my foot stopping the wrench from turning and using both hands on the torque wrench on the nut. The nut is definitely not bottoming out, it's near the end of the bolt. Since the sleeve can rotate inside the poly bushes, I don't think it matters that I'm doing it at full hang. I am wondering if I could put a serrated washer between the cam and the bracket, if the brackets aren't serrated as Stephen suggests.
 

Forrest Gump

CCCUK regional rep
It was after changing to poly bushes in the stock strut rod that I had these issues, and did wonder if there is something about the poly bushes or washers in the kit that makes them prone to moving, even when torqued up very tight.
I’ve been thought the same trial John, and adjusting those poxy cams is so hit or miss and faffing about. Threaded strut rods make it a cinch - you’ll probably get the camber set in two goes. All the threaded strut rods come with poly as far as I’m aware.
Btw The “smart” strut bracket (ie modified dropped mounts) won’t fit around the exhausts on some cars.
 

johng

CCCUK Member
I don't like to be beaten Andy, but if I can't find a way to make it stay in place then it will have to be threaded strut rods. Mind you I have seen people say that the lock nuts come loose on those due to the twisting of the strut rods as they articulate. Think I'm going to try cutting some serrations in the back of the cam washer to see if that makes it grip better.
 

Forrest Gump

CCCUK regional rep
I put a drop of Loctite on my threaded strut rod lock nuts and they’ve been okay.
As I expect you have noticed, there is definitely twisting and binding going on when the wheels are off the ground and suspension is hanging, I can see that could cause the locknuts to undo.
 

johng

CCCUK Member
Took off one of the the cam washers today with the intention of filing some serrations on the back of it, to encourage it not to rotate. I was thinking that the washer is around 45mm diameter, which means there is a big clamp area and hence pretty low clamp pressure. However, having taken it off I found that it is extremely hard, a file wouldn't touch it. I was going to try a die grinder on it, but noticed that my washer is dished and that the convex side was fitted against the bracket. This wasn't going to help it clamp properly, but fitting it the other way round with the concave side against the bracket might do the job. So it's now all re-assembled and waiting for me to take the car out to see if it works. Does anyone know if the cam washers are meant to be dished? They are so hard and thick it's hard to imagine that mine has just got bent.
 

Forrest Gump

CCCUK regional rep
Good luck this time! As a last resort maybe you could pin the cam in the correct position. Split pin or roll pin into the edge of the cam?
 

kentvette

CCCUK Member
John, I've been a little pre-occupied with guests and garden work, but this morning an nipped downstairs and grovelled under the car to take a few photos of the set-up on ours.
As you know, we have poly bushes and I am able, when the cam bolt is fully tightened, to "swing strut rods down out of the way (as I did when we were removing the diff etc), with relative ease. But, touch wood, I have never had issues with the cams moving once set, so I wanted to remind myself of what I had!

This is the right side strut rod cam, from the rear of the car, the bolt correctly coming from front to back, with the "loose" cam washer, lock washer and nut all at the rear:
IMG_0130.JPG
There is nothing between the "loose" cam washer and the bracket. And, the lock washer is a fairly simple "spring" type, albeit, a fairly hefty one. The loose cam washer has a "half-moon" inset in the hole, which locks into the slot on the bolt.

This the front end of the bolt (the other side of the car in this case as the heat shield is in the way on the right side):
IMG_0139.JPG
Again, nothing between the cam face and the bracket.

I bought a "fancy" six point ring spanner when we tackled the strut rod bushes back in about 1992(!) and I continued to use that, although I do now have nice six point deep sockets.

As i mentioned, I did put the car on ramps to tighten the cam bolts in the early days, but now, as the rods clearly are free to move when the bolt is tight, I have tightened them with the car on axle stands or the Quick-Jack.

You may well have this all sorted now, but I thought it may help a little to see another car's set-up.
 
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