Rear wheel alignment

[Dr. T]

I did not see this discussed and I apologize if I missed it.

For non-fender (scout cars), I typically attach the rear wheels first, slide down a board and align them 'till the car runs straight, then do the fronts for my desired drift.

I assume no one does this as the front fenders drag right?

To get around this I made a little "sled" that the front end (without wheels) sits on while I slide it down to align the rears. Anyone do that? I would post a photo but my dog recently chewed it up

Dr. T

 

[GravityX]

I would think the "sled" would have too much influence on the "rear wheel tuning" due to drag.

But I would have to see this "sled" to determine if it has any factor in the "sliding" of this rear wheeled body down the tuning board.

 

[B_Regal Racing]

Dumb question, but...

Why not check if the rear alignment is straight prior to putting on the fenders (and before paint, graphics, final weighting, etc)? I'm more in favor of canted rear axle holes (I've tried bent rear axles and had a dickens of a time getting it to run correct, if it was at all). If the holes are drilled correctly, there's not much more you can do to the rear alignment. If it is good, you're free to put on an old set of wheels for fender mounting or or cut the body up and build another car. When you re-install the race wheels/axles, the rear alignment should be the same.

For me in particular, because I drill my rear axles holes with a jig, its important for me to check before I go too far. I have been known to chuck a block of wood or two in the trash.

Take it for what its worth - I'm far from the best builder or even being good, but I get by. Now that I want to compete, I might have to step up my game and get a drill press, but the jig / rear alignment test has served me well locally. Just my 2 cents, so I'm really interested on what others have to say.

 

[ngyoung]

I heard of using a front sled to check rear alignment as well as using tuning weights to change the dominant rear wheel to check that both are tracking together. There's a Stan Pope video about it but I think that it is based on bending the rear axles. Would be good to have a way to check alignment early on since it may be easier to re-drill or start a new block then do mess with wax paper shimming or trying to use any inherent bend in the axle to fix it.

 

[pony express]

I've tried all types of rear alignment and nothing beats zero toe. Achieve zero toe on the rears and you've won 90% of the battle.

 

[Obsessedderbydad]

I've tried all types of rear alignment and nothing beats zero toe. Achieve zero toe on the rears and you've won 90% of the battle.

+1

 

[ngyoung]

I've tried all types of rear alignment and nothing beats zero toe. Achieve zero toe on the rears and you've won 90% of the battle.

I think that is the point of checking the rear alignment. To make sure you have zero toe from your drill job.

 

[pony express]

I check my rear alignment as I drill the holes. Drill one and insert a six inch aircraft #43 drill bit and use a good machinist square while it's still in the silver bullit. If it's perfectly square you have zero toe. If it's not perfectly square then you have to drill another site. If all your holes are not square then you have to go back and square up your drill press. If the drill press is perfectly square and your holes are not square then you have a cheap chuck that allows the bit to walk.

 

[B-4 Racing]

When Pony talks, I listen. /images/boards/smilies/wave.gif

 

[TRE]

Its like E F Hutton

 

[IAE Racing]

When Pony talks, I listen. /images/boards/smilies/wave.gif

There's a reason he's ranked #4. +1

 

[Guest]

I like that he doesn't have an avatar.

 

[GravityX]

I like that he doesn't have an avatar.

Here we go....

 

[ngyoung]

Not really sure how I got my avatar. Just showed up one day. This site must have a magic avatar fairy.

I like that he doesn't have an avatar.

 

[Guest]

I like that he doesn't have an avatar.

Here we go....

Sorry,
I know that I am good at changing topics mid sentence.
It was meant sincerely though.

 

[Guest]

I did not see this discussed and I apologize if I missed it.

For non-fender (scout cars), I typically attach the rear wheels first, slide down a board and align them 'till the car runs straight, then do the fronts for my desired drift.

I assume no one does this as the front fenders drag right?

To get around this I made a little "sled" that the front end (without wheels) sits on while I slide it down to align the rears. Anyone do that? I would post a photo but my dog recently chewed it up

Dr. T

Hey Seth,
This is a cool idea!
I am going to make one too!
Thanks,

 

[Guest]

I check my rear alignment as I drill the holes. Drill one and insert a six inch aircraft #43 drill bit and use a good machinist square while it's still in the silver bullit. If it's perfectly square you have zero toe. If it's not perfectly square then you have to drill another site. If all your holes are not square then you have to go back and square up your drill press. If the drill press is perfectly square and your holes are not square then you have a cheap chuck that allows the bit to walk.

Sweet tip.

Thanks Pony.

 

[davet]

Lightninboy has a great method for aligning rears. He helped me confirm our rears were aligned with this method.

Take your front wheels off and place a thumbtack under the front end centered between the front axles. Place a triangle carpenter's square up against the straight edge of your tuning board. Place some double stick tape onto the head of the thumbtack and stick your car to the square. Make sure the height of the front end is the same as with wheels. I just made the double stick tape about 6 layers thick to accomplish this. Now make sure the rear edge of your car is perfectly perpendicular to the side of your tuning board. Push rear wheels to the body and pull the triangle square along the edge of your tuning board and drag the car down the tuning board. Watch the rear wheels. If they go to the head, do they go at the same rate? Now put wheels back to the body and push the car backwards with the angle square still tight against the side of the tuning board. If the wheels go to the head are they are at the same rate as each other and at the same rate as the forward reading?

This is a complicated explanation that's hard to picture I'm sure. He has a video of this on another site. Maybe he'll see this and post it here to.

 

[aircooled]

I hope Lightninboy, see this and can give use the link for the video. I remember seeing it and the video makes it all a lot clearer.

 

[aircooled]

So from what I'm reading when you roll the car forward both rear wheels should move out the the axle head at the same time. Seems like I always have one that is a little later than the other moving out. Is that telling me that my drill job is a little off?