4.5 Rusty's Long Arm

[drewsky_87]

Hello Everyone!!! I am officially new to the site, but have been browsing for quite some time as this is the best source of information for my new jeep project. I few months back I was lucky enough to pick up an 88 MJ in good shape. it has the 2.5L, so it is kind of a dog but I'm not trying to race anyone or do any rock crawling at the moment. However, I am in the process of installing a 4.5 Rusty's long arm kit, and ran into an issue late into the project last night; I set the lower arms to right specializations (35 3/8" eye to eye only about 3 full rotations of the joint) and mounted them from the cross-member to the axle, but the axle seems too far forward. After calling it a night I have been doing some research; and I know my geometry on the front axle is all jacked up currently, but could my lower arms be too long? I am pretty sure my manual transmission is an AX5 (since it is the 2.5L), but I recall that the trans cross-member is in different locations of about 2" between the AX15 and the Peugeot(87-89???). The only years that Rusty's notes a difference is 87-89 due to the Peugeot mounting  a couple inches forward, but does the AX5 and the AX15 mount at the same location?

 

Thanks!

[Pete M]

pictures of what you're seeing?  I don't understand how the trans mount location would affect the control arms or front axle.

[drewsky_87]

So here are the pictures after we sat back on the ground... I know the uppers aren't adjusted right, but I had wrap things up in a hurry.

[drewsky_87]

One more that give a better picture of the angle of the spring.

[HOrnbrod]

L & R LCA drop brackets are installed on the wrong sides?

[Pete M]

13 minutes ago, drewsky_87 said:

So here are the pictures after we sat back on the ground... I know the uppers aren't adjusted right, but I had wrap things up in a hurry.

 

 

 

so the LCA mount keys in to the trans crossmember some how?  that big side plate doesn't look like it can go back any further.

[drewsky_87]

5 minutes ago, HOrnbrod said:

L & R LCA drop brackets are installed on the wrong sides?

The LCA brackets are mounted to the new cross member, so the way it is installed is the only way... and the cross member matches up perfectly with the transmission mount as it is now.

[Pete M]

so... everything lines up right, the install pdf does indeed say 35.5", but it's clearly jacked up somehow...   hold on, I think we have an emoji for that.  yup, here it is:   

[drewsky_87]

5 minutes ago, Pete M said:

 

 

so the LCA mount keys in to the trans crossmember some how?  that big side plate doesn't look like it can go back any further.

Correct the crossmember is sandwiched w/the LCA brackets is sandwiched between the frame rail and frame strengthening bracket. The two silver hex bolts running vertical into the frame use existing crossmember threaded holes in frame rail. Would not be able to move this forwards or backwards, because then the crossmember would not line up with transmission.

[Pete M]

you may need to call rustys about this one.    is there a difference in XJ versus MJ in this kit and they sent the wrong part?

[drewsky_87]

6 minutes ago, Pete M said:

so... everything lines up right, the install pdf does indeed say 35.5", but it's clearly jacked up somehow...   hold on, I think we have an emoji for that.  yup, here it is:   

Well the crossmember is lined up with the bracket and holes in the frame rail, but the axle does not seem to be... LOL

 

Link to the pdf directions: http://www.rustysoffroad.com/media/instructions/RK-405LT-XJ.pdf

 

[drewsky_87]

2 minutes ago, Pete M said:

you may need to call rustys about this one.    is there a difference in XJ versus MJ in this kit and they sent the wrong part?

The only difference i was told was if it has a Peugeot transmission the crossmember would sit two inches forwards so it comes with 2 inch shorter LCAs ... same with the XJs i beleive.

[Swampy]

If the bumpstop is centered in the coil you are golden. if its not then we have an issue. Have you tired running them as short as possible? I would start from there and just try to get the bumpstop centered in the coil. Your control arms maybe different lengths on each side so try not to stick to a specific measurement

[DirtyComanche]

I'm fairly certain you needed the shorter control arms.  You can tell by looking at what set of threaded inserts you crossmember installed into from the factory, there is 2 sets of them (4 inserts total) in the bottom of the frame.

 

You have to cut that extra cab brace (extra compared with an XJ) to install a bracket setup like his with the crossmember in the rear set of inserts.

 

If you take the brackets off and look, I bet you will see the other inserts...  They may be packed full of undercoat or mud though.

[89eliminator]

5 hours ago, DirtyComanche said:

I'm fairly certain you needed the shorter control arms.  You can tell by looking at what set of threaded inserts you crossmember installed into from the factory, there is 2 sets of them (4 inserts total) in the bottom of the frame.

 

You have to cut that extra cab brace (extra compared with an XJ) to install a bracket setup like his with the crossmember in the rear set of inserts.

 

If you take the brackets off and look, I bet you will see the other inserts...  They may be packed full of undercoat or mud though.

 

this

 

most XJ/MJ kits were really only ever installed on an XJ.  the MJ gets cab supports that are often in the way of the long arm mounts.  i bet what you have will work, it will just need some trimming.

[drewsky_87]

Ok, so what I will try and do is lift the truck get the axle set on jackstands in the exact position (or close too) it would be sitting using weighted string from bumb stop meathod; making sure caster is correct. Thread the lollypop all the way into LCAs and if they are too long I will have to shorten the arms. 

[DirtyComanche]

I'd just ask him to send you the correct arms and leave it installed as it is.

[88whitemanche]

What it looks like in the picture 

 

not sure if that kit comes with separate tie-in brackets or it’s just a whole pce 

but the crossmemeber looks to be too far forward and you need to notch the bracket itself to fit in the factory location and not hit that frame part that gets in the way 

[88whitemanche]

Here’s one that shows someone notching a tie-in bracket to fit on a Comanche although it’s the cavfab 3-link system but it’s the same concept 

[drewsky_87]

1 hour ago, DirtyComanche said:

I'd just ask him to send you the correct arms and leave it installed as it is.

I'll see about that... I doubt they will want to just send replacements since I have installed on the Jeep already, but I'll see what they say. Thanks👍

[drewsky_87]

11 minutes ago, 88whitemanche said:

What it looks like in the picture 

 

not sure if that kit comes with separate tie-in brackets or it’s just a whole pce 

but the crossmemeber looks to be too far forward and you need to notch the bracket itself to fit in the factory location and not hit that frame part that gets in the way 

 

8 minutes ago, 88whitemanche said:

Here’s one that shows someone notching a tie-in bracket to fit on a Comanche although it’s the cavfab 3-link system but it’s the same concept 

This makes sense but if you look at my bracket there are two silver hex bolts that that threaded vertically into the existing holes used for the stock crossmember, and the replacement crossmember with LCA mounts went in the exact same location. If I notch the bracket and move everything back then my crossmember will not line up with the transmission mount; which leaves me to believe my frame brackets are in the right location but my arms are too long or my front axel's geometry is totally off. 

[88whitemanche]

12 minutes ago, drewsky_87 said:

 

This makes sense but if you look at my bracket there are two silver hex bolts that that threaded vertically into the existing holes used for the stock crossmember, and the replacement crossmember with LCA mounts went in the exact same location. If I notch the bracket and move everything back then my crossmember will not line up with the transmission mount; which leaves me to believe my frame brackets are in the right location but my arms are too long or my front axel's geometry is totally off. 

Right just read your first post about you having a 2.5 

most xj/mj longs arm systems are meant for the 4.0s wether auto or manual so anything for a 2.5 would have to be custom 

you would have to make a plate that ties in the trans mount to the crossmember 

similar to what I did when I swapped an nv3550 into it....

I currently have this set up with my cavfab 3-link and it works with no issues

 

 

[Eagle]

9 hours ago, DirtyComanche said:

I'm fairly certain you needed the shorter control arms.  You can tell by looking at what set of threaded inserts you crossmember installed into from the factory, there is 2 sets of them (4 inserts total) in the bottom of the frame.

 

 

^^^ This. Step one is to verify which set of holes your cross member is mounted to. Step two is to confirm with Rusty whether or not you got the right length arms for that set of holes.

[drewsky_87]

19 minutes ago, 88whitemanche said:

Right just read your first post about you having a 2.5 

most xj/mj longs arm systems are meant for the 4.0s wether auto or manual so anything for a 2.5 would have to be custom 

you would have to make a plate that ties in the trans mount to the crossmember 

similar to what I did when I swapped an nv3550 into it....

I currently have this set up with my cavfab 3-link and it works with no issues

 

 

I could do that... But since I already have the bracket mounted would it be easier to get the tubes replaced or cut the ones I have? By cut I mean cut the welds remove insert then cut tube 2” and weld the insert back into place. 

[DirtyComanche]

47 minutes ago, drewsky_87 said:

I'll see about that... I doubt they will want to just send replacements since I have installed on the Jeep already, but I'll see what they say. Thanks👍

 

Tell him it's his fault because this is a known issue and he's too lazy to update his literature.  It is NOT just the Peugeot tranny that uses the forward mounting location.