0RAAMaudio

I spent hours and hours dialing in a perfect all around alignment and want to keep it but the floating subframe bolts move thus my reference marks are of no use.

I had to drop the subframe to swap diffs, while apart did a bunch of high level thermal and acoustical deadening, now I just want to bolt it back up in the same location but.

I have the full factory service manuals and they do not address it, not to pleased to spend that kind of money on incomplete manuals

Anybody know the reference points? There should be some marked on the frame somewhere or else these things are just slammed together (which would not surprise me with GM, sorry if I am stepping on any toes, I love my Vettes and my dually but not some of the half arsed things GM does)

Working on my lift is pretty easy, redoing the alignment on the floor is tough since going in for surgery on both knees soon, trying to get this done before I do! (and a ton of other stuff

Thanks
Rick
801-829-4997

c6 batmobile

There are no alignment points. Those bolts only go on one way there is very little margin for movment there. Ive had mine down twice and it did not affect the alignment

cranky

rear subframe will only go up one way. there are guide pins on it that go into the frame. have done many of them without alignment problems.

9secz

And yet ... Custom Alignment in Mountain View noticed that my rear camber settings didn't seem symmetric. The tech loosened the bolts, used a long bar to pry the cradle a bit, then locked down the bolts. The result was closer to being symmetric, meaning that the same amount of eccentric rotation produced the same alignment specs on each side.

I've never heard of a way to align the cradle with the frame.

Jeff

0HorsePowerAddicts

You could have marked exactly where the subframe was before you removed it. Your only option now is to put it back in and then have it checked if you think the alignments off. The subframe can not move much because of the two centering pins that line it up.

0RAAMaudio

No offense meant in the least but there is more to this than most realize it seems but some have it figured out or close to it

The pins actually have a much bigger hole than the size of the pin, seems rather small unless you have spent years doing your own race alignments, then it is a very big issue. I spent many long hours, on torn knees, dialing this car in and now lost it and I cannot settle for that. Redoing it will be painful to say the least, going in for surgery on both knees soon, if I cannot get it done I may trailer it to a real shop to get a real alignment in SLC, 50 miles from me, the only one I know in this state I would ever let tough my cars and trucks.

NOTE: If you want the best from these cars you need a true performance alignment to the right specs and done by a real car guy, not the average shop, average employee, average settings, just not acceptable. The few times I had average joe alignments done because I was in a hurry, etc, I ended up redoing them shortly after, over the past 38 or so years since my first autocross car. Luckily I was taught by a master alignment tech that raced cars

I got a call last night from Randy at DRM, very very cool for him to call me, very much appreciated! He told me a trick to use, makes absolute sense, before taking it apart though, next time I know!

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As for marking it, I have been used to working on subframed cars with welded in studs or nuts, I just marked around the washers or bolt heads, put it back where it came from, no worries. I forgot this car has floating bolts, my marks are useless, oops!

I can barely see the marks from the subframe to frame contact areas, I am going to drop the subframe as low as I can and see if I can get in there and highlight them so I can line it up much closer, maybe I will get lucky I do all this on my lift, not to hard on the knees.

Thanks
Rick

c6 batmobile

I hope you get it down to your satisfaction. I dropped mine twice like I said before and I didnt even mark it and It lined back up perfectly both times.

0RAAMaudio

C6bat

I am glad it worked out for you, really am

I do have to ask though, can you be more specific with some details please?

1) "stock" alignment or true performance alignment?
2) checked after the subframe was put back in place?

These are very important issues, why I spent the time posting what I did as for the average driver, even most Vette drivers, do not really push their cars hard enough to tell much difference.

On sticky tires, even just good tires, on the track, solo, or probably going faster than advisable on public roads, there is a huge difference in what can be obtained or lost depending on how true the setup is.

No offense meant, again, just most drivers do not have much experience in true high performance driving, even if they drive pretty hard it is something most take a great deal of experience to really know just how critical this stuff is.

These are amazing cars, maximizing their potential makes not only going fast easier, it makes it safer.



Sincerely
Rick

c6 batmobile

It was factory alignment. But there were marks (bare metal) that was left by the washers and subframe that lined up exactly when I re installed it.

0RAAMaudio

Great, if you mean where the subframe goes up against the body, that is what we are referring to. The nuts that go onto the bolts, in the holes in the subframe are not an accurate way to align it as the bolts are free floating and can move a fair amount.

That is why I am going to lower my subframe on the nuts as far as I can and try to establish where the subframe actually sat against the frame, that is the only way to do this correctly.

You may of done that, I am being very specific here so nobody misunderstands and things they can align it using the nuts on the bottom of the subframe(like I mistakenly thought until I dropped it and remembered the bolts are free floating

Randy at DRM called me the night I made this post, he concurred, you have to mark the subframe to frame attachment points, it is the only way.

Sincerely
Rick

0Randy@DRM

Rick with any luck I will be going back together with my car this weekend. I will snap a couple pictures of the ninja way of doing this. We used to keep everything to ourselves and customers until I got into the office. As you know, we have became very lose with our advanced thinking

Randy
PS I have a package on it's way to you!

Randy

0RAAMaudio

Thanks buddy, sure better to do it right, I just goofed when I forgot about the bolts, your way is the best for certain but I was not going to post it, leaving that up to you

I told my wife what is on the way, she said YUMMY!

I need to hook you up on some deadening stuff for your tow rig, it is the single best way to make a truck, car, whatever a far nicer place to be, really!

Rick

0Randy@DRM

This picture was a couple weeks early, but you get the idea!!!

HANNY

There is room to wiggle a bit back there that can be adjusted doing an alignment. The camber of course and the thrust angle (the dog leg affect where the rear seems to be shifted to one side or the other from behind). The camber shouldnt change but should be checked and I could see the thrust angle being off but like i said that can be fixed by doing a thrust angle alignment (setting the toe up to the front or if its way out sliding the cradle over)
For me if someone didnt check it after or even if they did and did a correct alignment then that would be fixed. Having done 100's of alignments over the years and an ASE master tech my experience is really toward normal situations (never fixed bent frames or pulled cradles) so thats as far as my knowledge goes.
Sounds like you are on the right track, i assume your dropping the camber a bunch to get better cornering and even toed out seems to help the contact point of the tires thru corners as well. Regards, paul

0RAAMaudio

By lowering the subframe carefully on the bolts I was able to use my sons fine line paint brush and mark 3-4 spots per corner where the subframe was mounted to the frame. Then I raised it up to nearly touching the car, used maginfiers, mirrors, etc and about an hour later was able to put it back within a very very small tolerance of where it used to be

Of course I will check it once I am done with a few other things but am quite sure it is most likely close enough to not need readjusted.

There may be more movement on some cars than other but I had to move it forward and to the drivers side, more on one side than the other, more than enough to have a dramatic effect on the alignment, you would at least double or triple the amount moved once you get out to the ends of the suspension arms, more at the outer edge of the tire contact patch

Once I am sure it is correct I am doing the NINJA mod on it

Rick

jatolbert

Rick, how has it been turning out? I just pulled my rear cradle and Im worried about the realignment as well. I was planning on taking it somewhere to get aligned afterwards. If you could share your advice/experience in your result, I would really appreciate it.

Josh

0RAAMaudio

I have not been able to work on it much, I will finish up lining up the mufflers today and tack them in place so the clamps do not slip, sure great to have a lift, good welder, cut off tools, etc....., then lower the car and drive it up the street after I tape the front fenders down a bit. Once settled then I can check the alignment.

Oh wait, I have to tighten the control arm bushings, take the wheels off, drop it down on jacks so they can roll around a bit....Or maybe I will just drive it up on ramps after going up and down the street to let it settle first, etc......some things are harder to do just right but preload is not something you want in a bushing!

Then I can check the alignment out

All I am trying to do is save the many many hours it took to get this just right, I had not dropped a Vette subframe for a couple of years and forgot about the movement it could have

Rick

RichieRichZ06

Anytime the front or rear cradles are dropped or removed, it is a very good idea to perform an alignment. Yes, you can get it close enough, but that is not good enough for those of us that like to do things right. Even GM pays for an alignment after a repair requiring the cradle to come out so if they are willing to pay and think it's a good idea, you should probably do it.

0RAAMaudio

I had to drop the front a bit yesterday but I marked it very very well so I can put it back where it came from

Rick

CamarosRus

I know.........OLD Thread....

I'm ordering custom offset FORGED Wheels and have a rear cradle (??)
offset problem.....My right rear tire is 6mm OUT further than the left rear.

Is moving the cradle over 3mm realistic and worth the time & effort on a
street car OR do I just order the wheel offsets to best fit Right side and
then left wheel will be IN 6mm from Right ????

To clarify right side rear side wall is OUT board 6mm more than Left Side Wall
so would moving cradle over 3mm make them the same ????