I recently bought an I beam suspension out of a 66F100 to rebuild and replace the worn out one in my 66. I noticed that the beams I got are are straight when you look at them from the front, and the ones on the truck have a curve to them. Can anybody tell me what is going on here?

66Rex

 

In loking at the I Beams lengthwise they should be straight to the bolt hole that ties it to the radius rod. looking facing them as installed they also should be straight...I was wondering that too until I looked at enough trucks to realize mine were basicly crap...more curves and bends then a mountain highway.


- cs65

 

I get that, but the I beams on the truck are both bent identically and the ones I got off of craigs list are straight. They have different part numbers but I haven't found anywhere to cross reference them to see if they will work. The king pin set I bought didn't fit and the mechanic and to order a different set.

66Rex

 

King Pins.... 65 I beams have a different location for the pinch bolt on the pin and are 65 only, check your beams for a C5xxx part number to see if you have the correct ones before you go much further.

 

king pins on 65's are 65 only...As to the casting numbers on the I beams...post them and I can help ID what they came off of...
The beams shouldnt be straight as an arrow end to end either as i noted above. straight with the exception of where they angle at the radius rod/arm attach point.


- cs65

 

The one that came off the truck isC5TA-9-B space 9 and has a curve to itthat looks factory (the one still on the truck has the same curve) and the one that I got off of craigs list is C5TA-9-B space 12A and is straight.

66Rex

 

The beams are slightly curved in the middle to allow them to clear each other as the mounting points are on opposite frame sides. If the beams are straight they may intersect. The beams will also be forced forward or rearward by the radius arms to maintain the wheelbase and stress the bushings.

They are left and right as forged so do not mix them up.

Garbz

 

You can align twin I beams by bending them. That may be what happend to them.

 

I know they have a bend in them as you look from above, but these are bent as you look at them straight on.

 

They are bent due to alignment. Each truck differs as to just how much caster and camber is bent in to the axle, as things wear and settle. It is the number one reason that if your truck is in alignment there is no reason to change out the beams to something else.

Stock caster is +5 degrees.

Stock camber is 5/8 Degree +/- 3/8 degree.

Garbz

 

i had to replace the i beam i got, found out when i was done, to set camber, the heated i beam to correct, so ,maybe that'l help, explain bend??m those are corrective bends for that truck the part came from,

 

The only way to know really is to set the truck up on an aligner. I've bent 3 degrees of camber into my beams after cutting coils to lower (not recommended). Like Garbz says, the only reason to replace the beams is if desirable alignment settings can not be obtained due to a damaged beam. Unless of course your replacing yours with 73-79 beams which have disc brake spindles attached to them.

 

Thank you all for the information.
66Rex

 

All twin i beams need to be alined if any work is done to the springs or bushings to bring them back in to spec.

Beams are supposed to be alined cold by using jacks and shackles. here pretty tough forges steel. Heating is not recommended but will not hurt the beam if cooled correctly. Any shop that provide larger truck alignment can do this as the same procedures are used in the large trucks.

Garbz