Cross Member Drop?

[HotRodYJ]

Surely this has been done before but so far I've not seen where anyone else is doing it. I'm new to the lowered truck stuff so I still have allot to learn. Has anyone else ever sunk the front cross member up over the frame rails instead of Z-ing the frame? In hind site this would have been much easier to just Z like everyone else, but I like to do things a little different and thought this might look a little bit cleaner once completed. Sectioning the cross member was actually really easy to do but steering becomes a much bigger issue since now the frame is in the way. I've seen the "dropmember" that is available for purchase but why not just sink the factory cross member? If you don't go as far as I did, steering issues would be pretty much identical to what one would use with the dropmember. The Dropmember seems VERY expensive at least for my tastes, but I am a cheap kind of guy. I'll spend 2 weeks fabing something up to save a little coin.

Here's some pics of what I've done so far. This front suspension is actually from a 77 C10, basically I sectioned 3.5" out of the cross member and 1.5" from the bottom of the frame rails. Then boxed the frame and slide the cross member up over and welded them together to get a total 5" of cross member drop. The first pic it's not finished but you can see more of how it went together. I have since finished the upper A-arm mounts and gusseted them in place and ready now to fit the motor and mount the rack. The biggest issue obviously is steering since the frame gets in the way. I decided to go with rack & pinion and picked one up from a 95 Camaro Z28. To get correct steering geometry I sectioned and boxed into the frame pretty deep then fab'd these bridge pieces to bolt back on top to regain the lost strength. I think it should work out fine this way. I can jump up and down on the front frame section and nothing moves so I'll call it good. The steering set-up is the only advantage I see so far to Z-ing rather than simply dropping the cross member as I have done.



Back on the ground with RE7 bags and unmodified Suicide Doors bag brackets and 29" tires. Everything else is stock including spindles. I'm actually not looking to lay frame, I just want a very low comfortable ride. This is the first time I've ever used bags on anything so I am curious where ride height will be when the bags are aired up for driving? I can always add spindles to get more drop at a reasonable cost. I'm sure I can get another 1" safely by trimming the lower bag cups without getting into trouble.





Still a long way to go but I'm interested in your thoughts and comments. Anyway, here’s my project. I'm working on a 66 step side that will get tandem rear axles. I know the mini truck guys did a lot of tandem trucks back in the early 90's and I wanted to add some of that flare to a classic truck. I don't see the point of using dummy trailer axles just to get the look so in my case both rear axles will be driven via a divorce mounted transfer case turned backwards. This will allow each rear axle it's own dedicated driveshaft. The rear-most axle will have an offset pinion to help keep the d-shafts in-line and clear the forward axle. Should be a unique set-up and here's what I hope to end up with one day. I'm using a pair of 9" Ford axles and a Ford NP205 t-case. The rear will be triangulated 4 link and bags on each axle. I'm also planning an engine driven York On Board Air system for the bags. Same type OBA system used in the Jeep world for real air power while offroad. You can actually run air tools off of these things and it will save me the cost of a decent electric compressor since I have a York compressor laying on the shelf that I picked up at a swap meet a few years ago.



Thanks for looking.

[gringoloco]

Looks like a cool way to get some drop. I think you may run into some oilpan clearance problems- looks like you have the skills to find a way around it though. The tandem axle isn't really my cup o' tea, but I can appreciate the concept you described for two live axles.

Good luck!

[HotRodYJ]

Oil pan shoudln't be any different than Z-ing the frame. I know most guys don't Z a full 5" but if you did you'd probably have to cut and raise the trans tunnel to make room. I'll probably have to modify the tunnel to make room for the t-case anyway and keep it above frame bottom. I should be getting into that this weekend so hopefully I can show progress by Monday.

[Scott68-93-97]

When you z the frame motor to crossmember clearence doesn't change since they both move up in this case motor is in same spot and crossmember came up, but new motor mount hats will fix that some oil pan clearencing you definatly have the skills to do it, maybe a dry sump setup just to have it and clear the crossmember?

By the way very nice work I like the rack mounting also good idea I am thinking of going to rack and pinion on my 97 but I just dont want to add to the list of things to do

[willis0107]

by doing this the engine will sit higher as well will you have an issue with the hood?

[slammed1]

Im with willis on this one,by doing this you may have to do a lot of reworking for engine and tranny clearance in the floor,firewall and rear cab wall from what I am seeing. I like the originality of it though as it looks like you do good work.

[XXL]

Originally Posted by HotRodYJ

Surely this has been done before...

If you spend a little time in this forum (or Search feature), you'll see that this type of mod is quite common (though most people don't cut as deep as you did due to engine/steering/everything clearance issues).

[HotRodYJ]

Originally Posted by Scott68-93-97

When you z the frame motor to crossmember clearence doesn't change since they both move up in this case motor is in same spot and crossmember came up,...

Not true. Motor will come up also with the crossmember exactly the same as a Z since motor mounts are based mostly on crossmember location. The only issues will be tunnel clearance and staying under the hood. I think I can still clear the hood no problem but it will be much closer. I saw one other on here who Z'd 4". I'm only 1" taller than that.

[Scott68-93-97]

Arent the top two bolts into the frame and just the lower bolt into the crossmember
You might be able to fab in newer style mounts to keep the motor lower as long as there is enough clearence

None the less I like it, it also makes the design look more like a modern truck frame

[Dinos63]

we installed a pancaked cross member in my panel at nates(porter built) few years back and i used the stock steering and box, we had to notch the top control arm for the steering rod, and it wasn't as sectioned as far as yours,worked fine,but thats about the time nate had a better plan for bigger wheels, better steering and narrower track. looks good, nice work, this photo before dropmember and 15" with the pancake cross member

[HotRodYJ]

No question I still have alot to work out, but I have faith. I've learned alot already and there are things I could have done, should have done, maybe might have done different, but that's part of the experimentaion and design process. Anyway thanks for the all the words of encouragement and stay tuned for what I end up with. Hopefully it wont be long till all of this front-end "engineering" will be complete and we'll all see either how bad I screwed it up, or what a genius I turned out to be

Scott, yes the motor mounts will be crossmember based, doing away with the top bolts that used to go to the frame. Limiting factor for how low I can get the motor is the steering arrangement. I may even end up reworking where the rack will sit to gain more room. If the steering was out of the way I could easily section down into and replate the crossmember if necessary. The rack isn't even mounted yet it's just laying in the notches waiting for motor placement. I jumped the gun a little by notching before I set the motor so I may have to rework those nothes.

[jlaird]

holy crap. That gets the record for biggest crossmember chop!

Lookin good.

[HotRodYJ]

This is my first test fit of the motor using 100% factory motor mounts and in the factory location on the crossmember. Since the crossmember was raised 5" the motor is exactly 5" higher than stock. It actually fits REALLY REALLY well. The Camaro headers I'm using just touch's the firewall on the passenger side, there is perfect clearance above the rack and for steering shaft, and it looks like hood clearance will be no problem at all. Obviusly the tunnel will have to be cut and raised to fit the transmission and you may notice the distributor cap wont actually fit because of the recess in the firewall and the dist being so close near the top. I could notch the firewall for the distributorbut I took some measurements and it looks like if I move the motor 2" forward, everything will clear including the distributor (still have to cut the tunnel no matter what). Notice the passenger side valve cover at the firewall, there is a factory recess here as if it was ment to be.

I'll build dome new crossmember side mount plates to move the motor forward a tad and see if that wont remedy the distributor clearance.

[jkaylor68gmc]

Cool

[gringoloco]

Glad that worked out for you. Have you thought about using an external coil distributor? They are much shorter than the HEI units.

[HotRodYJ]

Originally Posted by gringoloco

Glad that worked out for you. Have you thought about using an external coil distributor? They are much shorter than the HEI units.

I thought about it yes but that's out of my budget. I went back down to the garage and looked a bit more and if I move the motor forward any at all the headers will hit the LCA, so I made the decision to go ahead and notch the firewall for the distributor. A different set of headers would have worked but I like to use what I already have rather than buy more stuff with money I don't have. I also wonder about clearance to the radiator. I'll be using an electric fan and they are typically about 4" thick. Things could get tight up front so for a couple hours work I can leave the motor where it is and know everything else will fit like a glove. More pics when there's enough progress to show over the weekend.

[Frizzle Fry]

I like what you've done so far. Is it me or does that rack look way high in relation to the xmember? Not trying to criticize, just curious how you determined the placement. I'm sure you know how crucial it is in it's effect on bump-steer.


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[HotRodYJ]

I set the rack so the links are parallel to the pivot points on the lower control arms adn lower BJ's. When the LCA's are flat the rack is flat. It's actually very simlar to where the factory steering links were located in relation to the crossmember. You have to remember how high my crossmemebr is compared to your dropmember. Your LCA bushings are still below frame bottoms. Mine are actually above the bottom of the frame rails. I sectioned 1.5" out of the bottom of the rails for LCA clearance, therefore mine loks much higher.

Edit: I retract my previous statement, my LCA bushings actually are still below the frame rails just a little. I set the rack parallel so I think bumpsteer will be taken care of. Only time will tell.

[HotRodYJ]

This is still at that Booty Fab stage (even more so than the rest of the truck) where I'm relunctant to even show it yet because it will be better with more work but, this is the recess I cut into the firewall for distributor clearance. I tried to give it a little shape so it didn't look like a boring square cut out. I like the way it turned out and even though it's perfectly centered on the firewall, the distributor look's offset. That's because the distirbutor is actually offset in the motor. Plenty of clearance but I'm debating recessing further to the passenger side so keep it from looking so funny. One other contributing factor, the HEI distributor wont work with this old style manifold. It still lack's about a 1/2" from seating therefore it really is sittting lopsided and not seated in the motor. I'll be using a different intake obvioulsey.




This shows the start of the trans tunnel. Still A TON of work to do here but this gives you an idea of how far it must be relocated.

[HotRodYJ]

Didn't get very much done this weekend. The late model motor mounts I had planned to use were way to bulky. Not only were they ugly but they made it difficult to work out the steering shaft the way I wanted so I cleaned it up by going back to the old style mount on the engine block and a little fab work on the frame side. Looks much cleaner and will give me a bunch more room for steering.

Bulky late model mounts...


The new old style mount...


I did get a little mor clean-up around the transmission tunnel for clearance and looked at what I want to do for trans mount but sadly that's all I got accomplished.

[jlaird]

Originally Posted by HotRodYJ

but sadly that's all I got accomplished.

more than me

[Slmd92DIME]

Does your motor mount have bushings in them? I have wondered if bushings make a big difference or not. I will be needin to build some before long just gettin some info here and there.

[HotRodYJ]

Originally Posted by Slmd92DIME

Does your motor mount have bushings in them? I have wondered if bushings make a big difference or not. I will be needin to build some before long just gettin some info here and there.

Yes these are factory 66 motor mounts bolted to the motor straight from Advance Auto. These old style mounts have the rubber element on the motor and the frame side of the mount is just a steel bracket with a hole in it for a single bolt.

[FnLow69]

Looks good, but are you going to gusset that mount any?

[HotRodYJ]

Originally Posted by FnLow69

Looks good, but are you going to gusset that mount any?

No need to, it's plenty strong. The tube is 1.315" OD, only about 5" long and a wall thickness of .180" (3/16"). Not much chance of it going anywhere.