Need info on frame crossmember

[PTS Kustoms]

Hello!

I am building a frame off 71 Chevy. The crossmember above the rearend housing which also incorporates the upper spring pads seems to be lower on the passenger side. I have the chassis square front to rear and side to side and noticed the crossmember. Is the frame purpose built this way regarding preload etc... or do I have a bent frame. There is absolutely no indication of any damage on the frame. I even measured the chassis in a L pattern and flipped over to the other side to see if there is any difference. None! I would appreciate the feedback.

Thanks,

Perry
PTS

[68LSS1]

Wish this was last week when my frame was leveled. I loaned my other jack out so I have just the one in the garage but I'll try and get it level again (it's still sitting on jackstands) tomorrow. I have a digital protractor that works pretty good for this. Maybe I can just level it side to side and measure to the floor. I'm sure the floor isn't perfect but how much are you talking about? Worst case scenario Ed @ Mothertruckers has the frame specs from GM and the local Ford dealership by him charges $75.00 to put the rolling frame on the alignment machine to check it out.

[PTS Kustoms]

Thanks for the reply! With chassis square, the crossmember drops about 5-7 degrees according to my digital level. What started me to look was when I was installing the rear fuel cell. The cell to make square would require the right tank mount area to me modified at the frame. No way! When I leveled the crossmember the tank mounted properly. I am puzzled. Is the tank mounts indeed wrong or is something bent. Please let me know...

Thanks,

Perry
PTS

[Spoof]

I'm not certain which cross member your refering to but if it's the one above the rear axle which is factory installed at a vertical angle, in other words not parrellel to the other cross members this could account for your horizontal deviation. The differences in mounting locations on the frame rail may drop one end in relation to the other. If your not refering to this particular frame rail perhaps your refrencing your measurements off of it and this accounts for the variation.
That's all I can think of anyhow?

[PTS Kustoms]

The crossmember is above the axle. I did square the chassis off the other crossmembers. So if I understand correctly the crossmember does drop to the pass side. Man I am glad because I was starting to stress over the hours thus far in the frame. This forum is great for info...

Many Thanks to everyone!

Perry
PTS

[68LSS1]

PM sent

[68LSS1]

I leveled the frame with a bubble level. Then using the digital I checked along the length of the frame and all readings were within three tenths of a degree. Using the bubble level again I checked the front and aft three crossmembers. The aft three were pretty god but a little off on the front. I started taking measurement zeroing the digital to various places and this is what I found. It seems the crossmember in question on my frame is slightly bowed in the middle few tenths. The passenger side may be a little lower but not more than half a degree. It slopes down were it attaches to the frame. I place my protractor with the edge up against the frame on the middle of the crossmember but to get a good reading I have to appply pressure to the top inboard side of the protractor. Personally by using different zeros and comparing crossmembers everything is within a degree or a degree and a half. I don't think this is enough to cause any issues. My biggest split is between the front crossmember and the last but I had the frame suspended by a floor jack in the back and two stands in the front. Be carefull with the digital protractors as they are so precise you can get a different reading if it is removed and not put back in the same place. I will leave everything as is so if you need anything give me a call. What sort of rading do you get going from that crossmember to the back of both sides of the frame? Another thing I noticed is that comparing the frame diameter right to left there is alot of variation especially when it gets close to this crossmember and the rest of the way back. By diameter I mean measuring from the top to the bottom of the "C" and comparing to the other side. Could this be giving the illusion it is off?

[PTS Kustoms]

Brian - you have done more than anyone could ask and I most definitely appreciate your effort. I will measure my frame again tomorrow evening and see what comes up. The C may be what is throwing me off and also my crossmember as well as yours is bowed in the center. Ditto on the digital protractor being sensitive. I found a webite that sells a level that houses the digital protractor and they also sell many other cool items. www.vansantent.com.

Thanks for your help and I will keep you posted...

Perry

[purple gas]

and on the 8th day god created shims.

[68LSS1]

Ya, and?

[djracer]

I'm glad to know that all the crossmembers are not square as mine over the rearend is not even close!

[PTS Kustoms]

Brian - I resquared the chassis today and got the crossmember within 1 degree of square. The fuel cell however is another story. I will have to remove the right front pad, lower the mount, smooth the area and reweld. I will send you pics later this week of what I have done so far. I appreciate your help! When you are ready for wheels, please let me know and I will make sure to get you the best deal on what I sell if you are interested. Bonspeed, Budnik, Billet Specialties, and ARE.

By the way purplegas when we are discussing problems on a chassis that is held together by factory rivets, please let me know how you would use shims. VERY CURIOUS!!!

Perry
PTS

[68LSS1]

Looking forward to the pictures. I appreciate the offer on the wheels.

[PTS Kustoms]

Can you PM your e-mail address?

Perry