Needed: Front frame crossmember (1 Viewer)

[sdb999]

1987 4Runner
I"m trying to fab one without much to go on, the one I have is pretty beat up. I"m looking for either:
A. Straight member I can buy.
or
B. Straight member close enough I can come and get measurements (I'd have to remove/reinstall bumper)

I'm in Jasper GA, just north of Atlanta.
Thanks, S.

 

[jynx]

Do we know if 87 and 90 frames are close enough. I know body changed, but I was thinking the frames stayed the same. If so I can get some measurements for you off my 90 pickup. Just let me know.

Also, front range off-road sells a brace that might get you started. Front Frame Brace - https://frontrangeoffroadfab.com/front-frame-brace/

 

[sdb999]

Do we know if 87 and 90 frames are close enough. I know body changed, but I was thinking the frames stayed the same. If so I can get some measurements for you off my 90 pickup. Just let me know.

Also, front range off-road sells a brace that might get you started. Front Frame Brace - https://frontrangeoffroadfab.com/front-frame-brace/

@jynx Thanks for the offer and the hook up with Front Range Off Road!! That brace is exactly what I need to act as a template to confirm my measurements (assuming Front Range did a good job capturing dimensions). I've contacted them as to availability and lead time, we'll see. I also asked for digital version, which would actually be more useful to me but they probably won't turn loose of a drawing.

As for 1990 frame.....I have no idea but I'll research that end and find out.
Thanks, S.

 

[88repo]

I have an '88 frame fully exposed at the moment.
LMK what dim's you need and I can get them for you.

 

[bkg]

Not sure what the question is…

You want to replace the crossmember or reinforce?

They are the same 1986-1995….

 

[sdb999]

Building one from scratch, thanks for confirming frames @bkg. It's hard to get accurate dimensions from bent up original so I will be getting a brace from Front Range to use as a template, but it won't give me all the numbers I need. I'll pull together a drawing of the most important dimensions I'm looking to confirm. Thanks @88repo, @jynx for the offer to compare to your frames.
S.

 

[gnob]

pmd you

 

[sdb999]

@88repo @jynx
Well, if anyone wants to take a stab at it, pdf attached. This isn't easy or fun, so please don't feel obligated. If you decide to capture a few measurements, don't feel like you have to capture them all, grab a few easy ones and move on. I will say, one easy number that I can't get is the set back of the crossmember in the frame rails (page two). It's not welded in flush at the front but should be easily accessible and looks to be about .220 - .250. All my dimensions are in inches, captured with digital calipers unless it was over 24". Because I can't get metric square tube (2.5" square is what I'll use) the critical datums (A and B) are center of the cross member and front face. Everything will be referenced from there.
Thanks, S.

 

[88repo]

Nice work!

Figuring setback off the frame ends will be a crapshoot I think. My ends are clearly out of square and not parallel, top to bottom.
Mine were a tad over .250 (.258 I think) on the high end (pass side) to as little as .160 on the low (drv's).

You may be better off pulling setback off the front faces of the body perches, IDK.
I'll take a look at it tomorrow and see what a gage block and depth mic pulls, kinda leap-frogging the frame ends.

Are all the dim's in your drawing hard #'s are do you need those confirmed?

 

[sdb999]

Hard numbers? Hahahaha, well as you experienced the fronts of these rigs have taken a bit of abuse. Dents, twists, warps are all things to contend with. My numbers are averages of what I measured. I made assumptions, like the holes on the bottom "appear" to be on a common centerline. The front face of my cross member has so many undulations it's very hard to define a "datum" per se so i took multiple measurements looking for a trend/average.

So no, there are no real hard numbers here, I'm hoping for more data to see what is most likely the actual dimension. While all the dimensions I have are close, I have greater faith in some more than others.
Thanks for the efforts!
S.

 

[88repo]

Dim A of 19.578" is more like 19.690", +/- .010.
B of 19.244" is 19.320", +/- .010.

Allowing for tolerances, these were probably target #'s of 500mm and 490mm, respectively.

If you're real picky, tram in a known straight bumper bracket to tie down that 5mm +/- offset figure.

And your E of 25.125" is more around 25.250, +/-, really moot IMO as mine are not used.

 

[jynx]

Do you know if 85 SA frames are the same as 87? I just had the bumper off my 85 and the cross-member looks clean and straight. I can see about pulling some dimensions off it this weekend.

Picture for reference.

I know the spring mounts and all are different, but that cross-member seems pretty similar from what I've been able to see.

 

[88repo]

My bet is the c/m's are identical.

 

[aztoyman]

This is how I fixed mine.

 

[88repo]

2-1/2" slip in there no problem?

 

[aztoyman]

Yep. I tack welded braces to hold the frame position before I cut out the old one.

 

[88repo]

Yep. I tack welded braces to hold the frame position before I cut out the old one.

Good deal...good to know.

 

[sdb999]

Yep, 2-1/2 square tube is what I'll use, just going to tap all holes before welding in.
I've been told 85' frame crossmember, at least what we care about, is the same. Thank you @gnob for sharing (image below) from 85' fsm. It was hard to be sure but with @88repo measurements I'm going with A=19.69 (500mm), E=25.20 (640m), which both match 85' fsm. I've got straight bumper brackets so I'll take offset measurements from A to confirm B=19.320.

Thanks to all, this is getting pretty close. Would still like to have a better idea of the setback in the frame rail Dimension H. When it's all done I'll wrap up with images and share my drawings and 3D model if anyone cares.
S.

From 85' fsm. (oddly enough my 87' fsm doesn't include these two dimensions)

 

[sdb999]

Down to just one dimension to confirm. Front Range part showed up and confirmed 3mm 5mm offset (Dimension D), and that solid axle cross member is different (at least the upper bumper bracket thread). Using good bumper brackets, and @88repo advice I got picky and nailed down all front face holes. Fixture shown below allowed me to use the (2) M12 tow hook threads to place the crossmember relative to frame rails eliminating the need for the setback measurement. Only one more to double check is center to center M12 holes on bottom (Dimension F). Thanks for all the help and advice, traveling this week so I won't get back on this till next week when I'll start fabrication.
S.

 

[88repo]

Down to just one dimension to confirm. Front Range part showed up and confirmed 3mm offset (Dimension D), and that solid axle cross member is different (at least the upper bumper bracket thread). Using good bumper brackets, and @88repo advice I got picky and nailed down all front face holes. Fixture shown below allowed me to use the (2) M12 tow hook threads to place the crossmember relative to frame rails eliminating the need for the setback measurement. Only one more to double check is center to center M12 holes on bottom (Dimension F). Thanks for all the help and advice, traveling this week so I won't get back on this till next week when I'll start fabrication.
S.
View attachment 3276680View attachment 3276681

A little cumbersome to measure, but I got around 20.200".
This may have been a targeted 513mm.
I'd confirm first if possible.