Reproduction Frame rail installation

[bullet18]

We've finally got to installing the driver's side frame rail on my 70 Challenger. I bought a Sherman frame rail thinking that it would be better than the off brand torsion bar crossmember I bought but it was made by the same company "CHL". Either way the frame rail is isn't sliding into place. It's about 1/8th of an inch of and I was wondering if anyone has any tips on how to get it all the way in.

 

[aussiemark]

With these frame rails and panels your better off buying the best you can get NOS being the best, if you can't find it move down to good used original, if you can't find it AMD is probably the next best because any money you save on the cheaper stuff will soon be forgotten when you waist hours of your time trying to fit the stuff that wasn't made to fit properly and if you have to pay someone to fit it the situation is even worst. If you are like me and have very basic metal working skills you need all the help you can get and it pays to get the best parts or at least ones that fit without a ton of work.

 

[AUSTA]

Do you mean length ways it is not going all the way home have you checked the tags that weld onto the torsion bar sometimes they are not bent at right angle & need some adjusting.

 

[bullet18]

Do you mean length ways it is not going all the way home have you checked the tags that weld onto the torsion bar sometimes they are not bent at right angle & need some adjusting.

The tabs are completely flush with the torsion bar crossmember. It's an 8th inch to low. Thanks for the help!

 

[bullet18]

Here's a picture of the tabs
I'm also wondering how accurate do you have to be with frame rails. Obviously an 8th inch is completely unacceptable but is 1/32nd okay? We have a level with digital readout accurate to .1 degree and I want to know if that is enough. Thanks for the responses so far!

 

[AUSTA]

1/8 do you mean compared to the other rail is the vehicle level
Is the rail getting hung up on the inner fender

 

[bullet18]

1/8 do you mean compared to the other rail is the vehicle level
Is the rail getting hung up on the inner fender

When we put the digital level between the frame rails it's .1 degrees off level. The upper control arm is 1/8th inch further from the bottom of the frame rail than the one on the other side.i think it's catching on the upper control arm mount tabs the go weld to the frame rail.

 

[AUSTA]

i guess the closer the better
I just checked mine while i had it on the hoist the r/h is about 1/8 different to the l/h side
From the inside of the top outer edge of the shock tower to the bottom of the frame rail is 14"
the same on my original A66

 

[moparlee]

I am not sure what the assembly line tolerances were in the factory back in the day, but I doubt very much it was +/- 1/32". Looks like you have a major rust out area in the firewall/cowl area. Are you sure that the inner fender panel and shock tower are in the correct location?

 

[bullet18]

I am not sure what the assembly line tolerances were in the factory back in the day, but I doubt very much it was +/- 1/32". Looks like you have a major rust out area in the firewall/cowl area. Are you sure that the inner fender panel and shock tower are in the correct location?

The inner fender is most likely what has to move because the frame rail is bolted to the k frame and tacked to the torsion bar crossmember.

 

[quapman]

Judging by all the cars I've torn apart and a few I've rebuilt, I'd say factory tolerances in the 70s were around +/- 3/16", maybe 1/4. If you can get within 1/32, that's medical grade work.

 

[bullet18]

Judging by all the cars I've torn apart and a few I've rebuilt, I'd say factory tolerances in the 70s were around +/- 3/16", maybe 1/4. If you can get within 1/32, that's medical grade work.

Thanks! I wont be able to get it that close but if it's level I'll be able to sleep at night.

 

[bullet18]

Thanks! I wont be able to get it that close but if it's level I'll be able to sleep at night
If I stick a screwdriver in between the frame rail tab and the upper control arm tab and pull towards the firewall (sketchy, I know) everything levels out.