Getting ready to put a 4 link in the truck advice needed

Any good words of advice on putting the 4 link in the truck? I am getting a partial kit with axle brackets, and tubes. The frame brackets are being made special for a truck application. I have never done anything like this before, and would like some advice from those that have as far as do's and do not's. After it is in, I'm sure I'll have a lot of questions on how to properly adjust it too.

A simple trick for getting all the rod-end holes of the 4 housing brackets (and 4 chassis brackets) as close to being in line as possible before welding is to assemble the brackets & rod-ends with long all-thread rods & nuts (in place of the bolts & nuts).

Thanks Dave. I was wondering if there wasn't a trick to doing that, and that will be simple and easy to do. I think I have quite a few sticks of 1/2" all thread laying around. Should have the stuff here by next week and get started on it then.

Verify your housing is in square now and make several reference points (punch marks etc ) to measure to after the 4 link is tacked in place.

I have a brace to weld on the back of the housing. Is there anything special to welding these on, or just take the time and small distances on the welds at a time?

If you have access to a housing bearing C/L alignment bar, it would be smart to find out just how straight the housing & tubes might/might not be as it sits now before doing any welding.

When installing a back-brace I preload the housing axle tubes forward a slight amount on a rigid housing jig table to offset the amount the housing tubes will pull backward from the back-brace welding heat.

Without a dedicated jig table you can do something similar (if you're careful) and preload the housing tubes forward by clamping/tacking the housing to a decent sized "I" or "H" beam with a few spacers wedged in the right places.

How much "forward" bend do I need. I can make a jig. Is 1/4" too much?

schmitty wrote:How much "forward" bend do I need..........

It kinda depends on the housing specs & application (how straight the housing is to begin with, the housing width, the axle tube OD & wall thickness, box tube vs round tube back-brace, etc, etc, etc). But each tube might end up being preloaded forward from the "perfect" axle bearing/center section bearing centerline (alignment bar C/L) anywhere between 1/16" to 3/16" from "perfect" center if the housing is dead-nuts C/L straight to begin with. If your starting with a bent/bowed housing, the amount of foward preload could end up being a lot more/less depending on how tweaked the housing tubes are to begin with.

So as an example lets say you have decided you want to preload each housing axle tube/housing end 1/8" forward from "perfect" center to offset the back-brace weld pull. But the alignment bar shows your used housing isn't 100% perfectly straight to begin with & the axle tubes/housing ends are (for whatever reason) actually pulled/bowed backward a given amount. In this situation you would have to pull the tubes forward the amount they were bowed backward plus the additional 1/8" before welding the back-brace on.

Is there some way to make a housing C/L bar? I don't think there is one anywhere around here that I'm aware of. I can make just about anything with the tools I have at my disposal. Lathe, mill, etc. Do you put in the center bar, and then measure from the face of the housing?

schmitty wrote:Is there some way to make a housing C/L bar?..........

Here's what my ancient home made bearing/housing end C/L alignment bar & housing welding jig table looks like.

https://www.429-460.com/t8369p15-9-inch-tech-questions#109859

From the angle that pic was taken, I can't tell if that is a solid shaft. What size is it? I can't thank you enough for all of this help Dave.

I use both a piece of solid bar stock & a piece of cm tubing as the center bar, in that pic it's the cm tubing. The solid bar only gets used for the actual final tack & finish welding of the housing ends. The cm tubing is used during all the other repetitive initial setup/fit up "grunt" work on the housing so there is less chance of scratching/gouging/screwing up the good solid bar.

Only reason I do it this way is it's a lot easier/cheaper for me to replace a piece of cm tubing if I should fuuk up & accidentally dance a disk grinder across the surface of the center bar while working on a housing.

[edit] The bar is currently 1-1/2" OD. I have been thinking about increasing the bar OD to 1-3/4" to work with Strange full floater spindles so I won't have to mess with making some 1-3/4 to 1-1/2 adapters for the old 1-1/2 bar........but I'm lazy & havent taken the time to look for any bigger bar stock.

Schmitty, contact this guy Addicted2blnalky@aol.com he makes and sells housing narrowing jigs. They look like they are well made and the price is affordable. I'm going to get one myself as soon as my taxes come back. Here's a limk to his ebay add http://cgi.ebay.com/ebaymotors/FORD-9-GM-10-12-BOLT-REAR-END-NARROWING-JIG-/220747299803?pt=Motors_Automotive_Tools&hash=item3365907bdb. I figure doing my own housing and a couple for friends and it's paid for.

No need to narrow my housing, actually full width is best for the mud tracks I run. I am thinking about building one like Dave has there, I have most of the parts to do it and can make the rest. I don't know if there would be much demand for doing more in my area, but I would be set up if it was needed.

Mike R wrote:Schmitty, contact this guy Addicted2blnalky@aol.com he makes and sells housing narrowing jigs. They look like they are well made and the price is affordable. I'm going to get one myself as soon as my taxes come back. Here's a limk to his ebay add http://cgi.ebay.com/ebaymotors/FORD-9-GM-10-12-BOLT-REAR-END-NARROWING-JIG-/220747299803?pt=Motors_Automotive_Tools&hash=item3365907bdb. I figure doing my own housing and a couple for friends and it's paid for.

I wonder why their alignment bar is only 1-1/4" OD? Sounds kinda small too me. But maybe it has to be that small to be "universal" & work on other housings like the chebby 10/12 bolt C-clip crap.

Well I have the shaft for the table. My brother has a well drilling side of his irrigation business and they had a 10' long chunk of 1.5" well stem that they donated to the project. I don't know if it's chrome moly, or just cold rolled, but it is straight and clean, and heavy as heck. I am thinking about what to use for the base. Would a piece of say 12" channel iron with some heavy gussets across the bottom work? I'm thinking of say 1/2" strap welded the length of the channel and boxing in around where the center section bolts to. Is this enough or should I find something more substantial?

I guess most any steel "beam" shape, H/I beam or T beam (angle iron welded back to back) could make for a decent jig table as long as the part that is used as the "backbone" was tall/deep enough to make it as rigid as possible so it won't bow when you have to push/pull/force housing tubes around.

With channel iron, if laid flat with the two "legs" facing down (like an upside down "U") it might not really be tall/deep enough to form a strong enough "backbone". But if you take two pieces of channel iron welded back to back (to form an improvised H/I beam shape) it could be more rigid/stronger.

4 link kit finally showed up.

I finally got the 4 link kit this week and assembled the pieces to start measuring for fit on the chassis. I have 9" travel shocks and am wondering about how much initial compression I should see when installed.

No idea where to set the shock's "at ride height" center-to-center length if this is a mud/dirt truck. On a drag car depending on the shock brand (& who you talk to) you might run the shock with about 60-65% of the shock travel in the shock. But then there are some guys that just leave only 1" to 1.25" of shock shaft showing regardless of what the maker calls for. The mud/dirt stuff's shock lenght requirements could be way different than the drag stuff. If the shocks are Afcos you probably should call them for the C/C ride height length ball park.

Compared to a normal drag racing setup that 4-link layout looks kinda strange, kinda up side down. I guess it's the high ground clearence the mud/dirt trucks need.

Schmitty when I converted to ladder bars and coil overs I talked to several of the pro drivers around here and they said to put the shocks in the center of your travel so a 9 inch shock would have 4.5 inches of rod showing, then adjust your ride height by moving the lower mount up or down. Also an expensive lesson I learned is make sure you put limit staps on with the shocks to keep them from over extending and ruining the valving inside, I didnt and first night out had a rough track and jumped the truck shocks have to be sent off and rebuilt now. Bump stops for bottomimg out would be a good idea also.

Todd

I put it together like this and it doesn't look as good of a fit to the chassis.

A lot is going to depend on what wheelbase and weight percentages front and rear. We see more seperation on our rear shocks than compression. 6 or 7 inch travel shocks with only about a quarter to a third of the rod showing at ride height. mostly smooth drag type mud/dirt tracks. The above pic is putting the instant center way out front. that probably won't be too ideal.

simpleman wrote:A lot is going to depend on what wheelbase and weight percentages front and rear. We see more seperation on our rear shocks than compression. 6 or 7 inch travel shocks with only about a quarter to a third of the rod showing at ride height. mostly smooth drag type mud/dirt tracks. The above pic is putting the instant center way out front. that probably won't be too ideal.

I just put the stuff together to see what it looked like. I didn't do anything as far as try to figure out the I/C yet.

Looks like the frame mounts are adjustable also. Good idea!