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-   -   Notching front crossmember? (https://67-72chevytrucks.com/vboard/showthread.php?t=29872)

Slammed67 11-11-2002 02:58 PM

Notching front crossmember?
 
Has anyone notched their front crossmember (as a lowering method)? I saw this done in a Street Trucks magazine (done my Bill Turner Enterprises). Looks pretty simple to do. My only concern is the oil pan to cross member clearance. My engine is already sitting in a lower "custom" location, so I'd need to address that problem. Also think there may be some steering linkage-to-frame interference. Why would I want to do this? Well, I'd like my truck to sit a little lower at ride height and this seems to be the easiest (and safest) way to do it. Other option would be to modify my lower a-arms, but I think I'll leave those alone. It'd be a 1-1/2" notch by the way. I've got a spare crossmember that I can cut up so I can take my time and keep my truck on the road. Just curious if anyone on here had tackled this modificaiton.

73GMC 11-11-2002 05:02 PM

lowering
 
If you really want to drop it without probs, have someone "z" your front clip. that you maintain ride, steering, etc...

good luck!

:bowtie:

low 84 11-12-2002 01:33 AM

hehe, wait one sec while i dig up a pic

low 84 11-12-2002 01:42 AM

this was done by board member captkaos. i hop chris dosen't mind me sharing his pics

http://www.captkaoscustoms.com/images/crossorig.jpg

http://www.captkaoscustoms.com/images/crosssection.jpg

http://www.captkaoscustoms.com/Jimmy/chopcross2.jpg

as you can see tis eliminates the oil pan clearence problem, b/c you are moving down the whole center section.

jay-dawg 11-12-2002 02:08 PM

I almost couldnt see the difference at first. Hey slammed, what issue was that in? Turner enterprises sells it (dropped cross members) for $300.

jay

Slammed67 11-12-2002 02:14 PM

Low84: Thanks for the pictures! I might consider doing it that way.

jay-dawg: That artilce was in Street Trucks January 2000 (I think). I'll have to veryfy that. It was a multi-part article, but I only have the first one.

GMC JUNKIE TOO 11-14-2002 12:50 AM

It was only a two parter they installed it in the second one. That would come in handy if the crossmember drags before the frame does.;)

Slammed67 11-14-2002 12:59 AM

GMC Junkie too..... Do you still have that second issue of Street Trucks? It's pretty straight forward as to how to bolt it up, but after looking at mine, it seems like there'd be some steering linkage inferference. Do they mention that in the article? If you still have the issue, any chance you could scan that and e-mail it to me?

GMC JUNKIE TOO 11-14-2002 01:14 AM

They did more than I rememberd in part 2 they allso put a notch in the front of the crossmember for tie rod clearance and put some small nothces on the inner frame raills and cut down the motor mounts. they have an ad in this months issue but no web site? sorry I dont have a flatbed scanner.

70 Jimmy 11-16-2002 04:12 AM

I did it but I literally did a notch. I didn't have a plasma cutter so I just notched where the frame meets.

You'll run into clearance problems if you dont' notch for the steering linkage (I don't think it's an issue with the entire center section notched like the pic).

I like the way the one in the pic was done better because it leaves the same clearance for the engine and you won't have to shorten the motor mounts. I wish I had thought of that!

You'll have to raise the frame surface where the upper A arm bracket normally bolts to the frame.

Good Luck and post pics!

lofly'a 11-27-2002 03:25 PM

PICS PLEASE
 
70 jimmy or anyone else have pics of your frame notch, can you show us. thanks

70 Jimmy 12-02-2002 03:13 PM

Can someone post a pic of my crossmember notch if I email it to them? It says it's too big (I get that all the time!).

Slammed67 12-02-2002 03:15 PM

Send it to slammed@jayspot.com and I can post it for you.

Slammed67 12-02-2002 04:37 PM

Here are 70 Jimmy's pics.......

http://www.jayspot.com/images/temp/_Notchcut.jpg

http://www.jayspot.com/images/temp/_...mounttest1.jpg

http://www.jayspot.com/images/temp/_Notchedmounts.jpg

70 Jimmy 12-02-2002 05:03 PM

On the first pic. I bolted the crossmember up to the frame and drew a line where they meet. After unbolting the xmember, I continued the lines down the front and rear of the xmember. Next, I drew perpendicular lines where the the crossmember goes vertical to the ground. This gave me a reference line that wasn't interupted by curves on the edges of the xmember. It is also a cut line, so keep it. I measured 1.5" down from that reference and drew a parrallel line. When the drawing is done, you should have a rectangle that "wraps" down the front and the back of the xmember where the frame rail will sit.

Next, I cut the upper "rectangle" out, checked my measurements (1.5") and cut the rest of the rectangle out. You should end up with one rectangle with the crossmember bends at the ends and two squares for each side. You can toss the squares.

Now match the rectagular peice to the notch. It won't be perfect, but it's definetly weldable. Weld it in.

Originally, I put plates on the outter sides of the notch but then I decided that i didn't like flat metal on metal. The insides are "boxed" Rust is always an issue around here. Besides, there is alot of strength in the other components after it's bolted up.

On the steering rod clearance, I just notched it 1.5" down and back from the edge. When in doubt, go alittle further.

Because of the notch, I had to cut the motor mounts and make a plate to bolt them onto the xmember. I will be strengthening these because I have a big block. I may actually make my own if I'm not happy with the modified SBC ones. I couldn't bring myself to cut up a pair of BBC brackets. As a 4x4, my truck ran a BBC in it for 5 years on SBC mounts (slightly modified) with no problem. I wouldn't do it unless you're confident in your fab skills.

The last two mods are not necessary for the other style of notch (from frame rail to rail). However, after thinking about it and talking with a few fabricators, I think, over all, this is stronger. Do what feels right.

I've meant to write up an entire article on this but I really haven't had time. Plus I haven't finished yet. Plus, someone's already written one.

Hope this helps

lofly'a 12-11-2002 08:10 PM

fine job
 
i liked the first mod., and thought it could'nt be done better, but 70 jimmy's looks as good and less cutting and welding....nice job.

low 84 12-13-2002 02:49 PM

Re: fine job
 
Quote:

Originally posted by lofly'a
i liked the first mod., and thought it could'nt be done better, but 70 jimmy's looks as good and less cutting and welding....nice job.
actaully you will run into less problems doing it the first way. with just notching you run into clearence problems with the motor i.e. oil pan. especialy with a big block.

ol skool 68 12-14-2002 12:25 PM

i now wish i had notched my crossmember before i had my frame powder coated..........i am not doing and airbag setup but i did decide to slam it with coils and spindles and i know thatclearance is gonna be an issue.......already have a hard time getting the joack under the crossmember and i still don't have the motor or body set on it........lol damnit i always see these things after i finish something however i did want to say that both of those crossmembers look nice..........

SCOTI 12-14-2002 02:30 PM

I have to drive up on 2x6 homemade ramps to get the jack under my crossmember. I consider them part of the tire changing kit :)

lofly'a 12-17-2002 11:33 AM

i'm not trying to take anything away from the first job low84, and i'll probably do mine that way and i won't have any probs cuz i'm a small block lover, but for the guy that does'nt have all the equip. and is a do-it-yourselfer (i.e. a plasma cutter) the second option is best for them.

anyone else done this mod. and have pics to show? are there any other variations to this mod.? show us.

Truckstr 12-17-2002 09:19 PM

I have to agree with ya, lofly'a, on the second job being "easier" for the novice - in some respects. But... hear me out.

I have a good friend that owns a machine shop and I approached him about doing a notch job on my spare crossmember. We looked at both ways of approaching the "problem". We looked at the one installed under my truck and talked about it. We both decided that, all things considered, cutting all the way across (i.e., the first approach) would be the way to go.

Here's "why."

First off, a plasma cutter isn't required (although it would be nice). A Sawzall with a good high quality metal cutting blade will suffice for the large part of the cutting. Getting the Sawzall into the corner for the cut across can be accomplished by drilling a hole at the corner into the portion that will be removed.

Second, there wouldn't be any clearance problems with the oil pan or tie rod - therefore no notches. The engine mounts wouldn't have to be cut because the dimensional relationship between the frame and their mounting surface of the crossmember would be the same.

No offense, just my "two cents worth".

--

woohoo, 100 posts. :D

low 84 12-18-2002 12:18 AM

Quote:

Originally posted by lofly'a
i'm not trying to take anything away from the first job low84, and i'll probably do mine that way and i won't have any probs cuz i'm a small block lover, but for the guy that does'nt have all the equip. and is a do-it-yourselfer (i.e. a plasma cutter) the second option is best for them.

anyone else done this mod. and have pics to show? are there any other variations to this mod.? show us.

i didn't think you were i was just pointing out the problems that have to be overcome with the just notching method. :bowtie: :D

bill_ont_canada 12-18-2002 04:39 AM

Re the Big Low Down by Bill Turner
 
Part 1 of the Big Low Down by Bill Turner in Street Trucks Magazine was Jan 2000 issue, and part 2 was supposed to be February 2000 BUT... they forgot to put it in so it was in the March 2000 issue.
The whole article was filled with good pics really easy to understand even the Stepped A - arms are easy to figure out.
By the way Turner sells the templates for the whole operation...
and I dont have a scanner or any other way to post the pics.

just in case anyone is interested...

lost wages 12-18-2002 05:35 AM

im going to cut an extra i have but my concern is the peice the a-arms bolt to, they are usually bolted to the frame, after you notch the crossmember it is hanging above the frame. Is there any thing else that needs to be done? i have a plasma cutter so im going to try it.

lofly'a 12-18-2002 12:01 PM

point taken low84, thanks


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