Moving Front Axle Forward

[zainyD]

Hey everyone, I'm the soon to be owner of a 1970 EB buggy. I'd like to stretch the wheelbase to between 102-108".

My question is specific to the front axle. How far forward can I move it forward from the factory location before I have issues with the steering? Obviously, the coil buckets will also be moved forward from their original locations. I plan on using a 4x4x2 steering box, but I also have access to a 1979 F150 2wd steering box and a Nissan Xterra box. Drag link will probably be Chevy 1-ton TRE and DOM tube.

Rear will probably be 4-link with coils.

Thanks for your input.

 

[The Far Side]

I would see the only way to get there would be to cut and add to the frame. 1” front and or 1” back might be doable.

 

[jamesroney]

Hey everyone, I'm the soon to be owner of a 1970 EB buggy. I'd like to stretch the wheelbase to between 102-108".

My question is specific to the front axle. How far forward can I move it forward from the factory location before I have issues with the steering? Obviously, the coil buckets will also be moved forward from their original locations. I plan on using a 4x4x2 steering box, but I also have access to a 1979 F150 2wd steering box and a Nissan Xterra box. Drag link will probably be Chevy 1-ton TRE and DOM tube.

Rear will probably be 4-link with coils.

Thanks for your input.

In stock configuration, you can move it forward about 1/2 an inch.

More than 1/2 inch farther forward causes the tie rod to collide with the pitman arm. Lots of ways to get around that, but that's the answer to the question.

James.

 

[JSmall]

I moved my axle forward about 3 inches. I moved the 4x4x2 box on the frame to make it work. It was very easy to do.

 

[bchesley]

I wonder, could you use a Scout box and have the Pitman arm on the front then move it way out?

 

[Scoop]

I moved mine 1 1/2 inches forward without changing the steering box or coil buckets. I get a slight touch of the pitman and tie rod at full articulation but nothing that interferes or binds. I did a rear frame stretch and kept the leafs. No body stretch. I ended up at about 103 1/2", just shy of my 104" goal. Stock pitman arm (no drop) and WH track bar riser.

A wheel base of about 104" is about ideal for a Bronco. It makes a HUGE difference when wheeling and helps in almost all situations.

 

[Apogee]

I too pushed my front axle forward about 1.5" when I installed my CAGE arms, factory '77 steering box, but aftermarket steering linkage and track bar.

 

[Spaggyroe]

You mentioned that this was a buggy. Will it be a dedicated trail rig? If so, are you opposed to going with full hydraulic steering? It would free up a lot of options for moving the axle forward.

 

[SavageBurro]

I have a 4x4x2 box w 1 ton steering w 64"wms d60. I was able to push forward 1" with just using adjustable long arms. Upper Coil mount is in stock location (modified front of coil bases so coils sit flat) and shock location is close to stock. I trimmed the wheel wells some but the 37s fit nicely at full stuff and turn.

How about instead of swapping the 2wd internals into the 4x4x2 box, keep the stock 4x4 internals so the pitman faces forward? That's my plan when I go to 40's so I can push another 1.75" for a total of 2.75" forward. That's the max I can go before interference with cross member and serious tire interference w front core support and body mounts.

The forward pitman will get your drag link forward enough to eliminate any tie rod/drag link/pitman interference. For me however that will also cause me to move the tracbar frame mount, either upper coil mount forward (or lower mount back) and lower shock mount back.

You said buggy - so maybe that's all gone on yours?

There are a handful of other older threads on this topic that have good info btw.
Few:
https://classicbroncos.com/forums/showthread.php?t=104690
https://classicbroncos.com/forums/showthread.php?t=244711
https://classicbroncos.com/forums/showthread.php?t=67821
https://classicbroncos.com/forums/showthread.php?t=213627
https://classicbroncos.com/forums/showthread.php?t=115867

 

[zainyD]

Thanks for the good information guys! I'll continue to do more research and look at your build threads.

By buggy, I mean that the back half has been dovetailed and comp cut. Also, a few inches have been cut off the rear. It has a fuel cell and roll cage, but the drivetrain and suspension are stock. I have plans to pick up a full size 78 Bronco rolling chassis on Monday, which will be a good source of parts. I also have a pair of 1-ton axles (D60/10.5) that might find their way under the EB. In all, it's a very long term project.

 

[mp]

Very cool project.

 

[1badd73]

I moved mine forward 4" and my rear 6". I cut off the coil mounts and track bar mount and moved everything forward. I have a 4x4x2 box with the pitman arm facing forward. In the rear i cut the rear cross member off and moved it up and back 6 inches to clear the upper links on my 4 link. The gas tank is flush with the end of my frame rails.

 

[zainyD]

Excellent info guys! I will be doing a lot of research.

I picked up a 1978 Bronco rolling chassis yesterday, no motor. It has a small-block C6 trans, NP205, HP D44, 9", and the steering box all there though. Looks like I have somebody interested in my 1-ton axles, so I may use the full-width 1/2 ton axles out of the 78, we'll see. I also picked up a 2wd NP435 with the long tail shaft. Pretty sure the internals are too rusty to use, but the case is fine. The guy I bought the 78 Bronco rolling chassis from has a 4wd NP435 I can get for $100 so I'll probably grab it too.

 

[sprdv1]

right.. when I hear buggy, I automatically think, it's linked and extended wheel base

Good luck to you

Thanks for the good information guys! I'll continue to do more research and look at your build threads.

By buggy, I mean that the back half has been dovetailed and comp cut. Also, a few inches have been cut off the rear. It has a fuel cell and roll cage, but the drivetrain and suspension are stock. I have plans to pick up a full size 78 Bronco rolling chassis on Monday, which will be a good source of parts. I also have a pair of 1-ton axles (D60/10.5) that might find their way under the EB. In all, it's a very long term project.

 

[Mdsuits]

I moved mine forward quite a bit...but I used a scout box with a forward facing pitman arm and ended up cutting the frame and rebuilding it. I did a 3 link with king coilovers. Keeping it a full bodied bronco a 106” wb was about as good as I could do....

 

[zainyD]

sprdv1 - I use the term 'buggy' very loosely. You're right though, the term usually refers to links, coilovers, tons, extended wheelbase, etc. I may end up doing a 3-link front, 4-link rear. Just depends on how deep I end up going on this.

Mdsuits - I can get a Scout steering box. There's a wrecker yard north of me that has a mid-70's Scout that's still complete.

 

[Mdsuits]

Mdsuits - I can get a Scout steering box. There's a wrecker yard north of me that has a mid-70's Scout that's still complete.

Might be worth picking up if you think you wanna push the front forward much.....keep in mind the headlights can get in the way if you push it to far even with wider axles.

 

[nvrstuk]

Savageburro- how did you move the axle that far forward with 64" WMS w/o the tire having major clearance with the front body mount? I am at 65 1/2" frt WMS w/D60 and my body mount had to go, I had to cut half of my side marker light out, and my 40" at full stuff is almost in contact with my headlight/wiring.

I run a 4x4x4 box so the pitman faces forward. The box has to be back far enough so my tire doesn't come into serious contact with it...

I also had to trim off the bottom of the crossmember flush with the frame so my track bar and tie rod don't hit it. My track bar is only 1/8" away at full stuff now.

Just don't know how you can get thst much forward movement to work?


Here's a pic pre-ram that can show location