Second Generation Nissan Xterra Forums banner

1 - 15 of 15 Posts

·
on line
Joined
·
1,416 Posts
Discussion Starter #1 (Edited)
OME Coil-over Assembly and Installation

Warning: Compressing the coil spring is potentially dangerous. If you don’t have training or are not aware of how dangerous the operation is, let a shop do that work.

I just finished installing the OME suspension kit with the light duty coil springs and medium rear springs. The kit was purchased from Kurt at Cruiser Outfitters and he assembled the coil-overs with new Nissan parts. There was a slight misalignment of spring bracket and the spring insulator from an oversight on his part, this was the first Xterra coil-overs he had assembled. I have the tools to compress the springs so it was easy to address the misalignment. It was clear how easy it is to make this type of error.

The FSM is not very clear on the alignment and sequence of assembly. Even the online parts diagrams are misleading.

I’m not familiar with the non-OR/Pro4X shock cover or how it is attached to the shock. The bottom main washer is slightly different than the OR/Pro4x bottom washer but they are both the same thickness and can perform the same function without the cover. The OME shocks are not designed for the covers or the hardware to attach them, more on this later. The shocks have a wiper and don’t need the cover.

For reference, the shock body is down or the bottom, and the threaded end of the rod is up or the top. I’m also going to use the FSM alignment of the shock orientation in the chassis even though some have flipped the orientation 180 degrees without obvious problems or issues.

The OEM coil-over can be removed after removing the sway bar links to lower the bar, removing the lower shock bolt and the three nuts on the spring seat. It isn’t necessary to remove the knuckle from the upper control arm to have adequate room. The coil-over can be easily removed by careful maneuvering. The coil-over can then be disassembled, compressing the spring is an exercise left to the student. Minus the spring, the parts from an OR/Pro4X are in order removed from left to right.

bottom side facing up


top side facing up


The tube spacer may not slip from the shock separately. It will probably remain in either the upper bushing or the lower bushing/seat insulator.

Non-OR/Pro4X would be the same except for the large bottom washer and cover and adapter. The bottom washer is also the adapter for the cover and is a larger diameter. Either bottom washer installs concave side facing down.

I would recommend replacing at least the two rubber parts, the spring insulator seat and bushing, unless you have new vehicle. If the metal parts are in good condition they can be re-installed

Assembly order is from right to left, don‘t forget the compressed new spring before stacking parts. Do not use the OR/Pro4X cover or adapter. The bottom washer is concave side down. The tube should be installed next to aid in proper alignment of the spring insulator, spring seat, and upper bushing. The spring insulator and spring bracket are best attached paying attention to the alignment of the relief’s for the stud heads, and the tab and indent in the bracket. The upper washer is also concave side down. Tighten the lock nut.

All of these parts must be used for the assembled coil-over to function properly; lower washer, tube spacer, spring insulator, spring bracket, upper bushing, upper washer, lock nut. OME uses a nut and small heavy washer rather than the Nissan shouldered nut.

Assembly order, top side facing up


Before releasing the spring, the spring bracket needs to be aligned to the lower shock mount and step in the spring seat. If not correctly aligned the coil-over will be difficult or impossible to install. If forced in place, the will be a pre-load that could lead to problems later, such as increased wear or noise.

The stud at the apex of the isosceles triangle should point towards the step in the spring seat and perpendicular to the axis of the lower mounting eye. The arrow, opposite of the apex stud, on the bracket faces the other side of the mounting eye. If correctly aligned, the three studs in the bracket will easily slip into the coil bucket holes and lower shock eye will slip into the lower A-arm bracket.





After the coil-over is installed in the coil bucket and the lower shock bolt is in place without the nut, I prefer to preload the lower mounting eye against the bolt. I lift the lower A-arm with a jack to seat the eye against the bolt. The top nuts are torqued to spec and then the lower nut is torqued to spec, all with blue Loctite. In addition to resisting loosening, Loctite acts as a sealer and helps prevent corrosion.

The OR/Pro4X cover and metal adapter is not used with the OME shock, it will effectively increase extended shock. This may allow the upper control arm to contact the coil bucket. The following two pictures illustrate the increase in length. Because of the lever arm distance of the shock mount, the gap at the coil bucket with be reduced more than the thickness of the adapter.

Without the adapter


With the adapter


The shock hasn’t changed length with the adapter. The upper bracket is moved further from the shock lower mounting eye. Adding the adapter doesn’t increase the ride height, it only allows the lower A-arm to drop further before the internal stop on the shock limits travel.

The following information in not needed for assembling a coil-over, but may provide some understanding about the function of the various components.

OEM parts usually use rubber isolators in suspension parts to reduce vibration and shock into the passenger compartment. The upper shock mount needs to be able rotate as the lower arm moves through it’s arc. The lower bushing is part of the spring seat and the upper bushing is separate. The lower bushing is centered in the bracket by a lip . The tube spacer aids centering and ensures proper compression of the two bushings. The lower washer stops against the lip on the shock rod and the upper washer mates with the nut. After the nut is tightened, the washers will be compressed against the tube spacer. The shock rod can now move as the lower a-arm moves. There is no metal to metal contact.

If the bottom washer is installed concave side up it alters the completed assembly. The bushings are compressed asymmetrically and change the position of the spring bracket. Whether on not this will lead to increased wear or other issues is not known.

Non OR/Pro4X lower washer, bottom view, left with washer concave up and right concave down


Non OR/Pro4X lower washer, top view, left with washer concave up and right concave down


OR/Pro4X lower washer concave down


The difference in the compression of the top bushing is visually apparent between the concave up and down orientations of the washers. Both the OR/Pro4X and non-OR/Pro4X washers concave down look similar. The reason I mentioned this is it is not intuitively obvious which orientation is correct. Older shock absorbers with a similar threaded rod end with two similar bushings used the support washers with the concave side facing the bushing. This is to re-enforce the correct orientation of the washers on the shock rod.

Omitting the bottom washer leads to a different set of problems than have plagued members. The problems don’t present themselves during the assembly of the coil-over or installation into the suspension. Spring pressure keeps the parts appearing to be properly assembled. The bushings can’t be compressed to keep the tube spacer centered. The missing washer also allows the rod and tube spacer to move into the bushings making the loose fit even worse. The spacer can move around enough to contact the spring bracket. This contact won’t be visually noticed unless the coil-over is disassembled.

Jeff
 

·
Registered
Joined
·
5,042 Posts
Good writeup man. I'd like to stress that if you don't know what you're doing, leave it to professionals. I had done this a couple times and had a wall mounted unit that had never failed me before but when I was building my OME 608's a finger snapped and sent the coil right by my ear.
 

·
Registered
Joined
·
4,309 Posts
Wait. I had similar issues with my Bilstein shock assembly. In the third to last pic, which is correct? I installed my like the one on the right because it "molded" into the upper boot.
Posted via Mobile Device
 

·
on line
Joined
·
10,980 Posts
Wait. I had similar issues with my Bilstein shock assembly. In the third to last pic, which is correct? I installed my like the one on the right because it "molded" into the upper boot.
Posted via Mobile Device
As I read Jeff's notes, the right-side is the correct assembly.

And that comment brings up a good note that I was thinking to myself as I read through this: these assembly notes will help the guys installing the adjustable Bilsteins as well, I believe they require the same OEM parts from the original assembly (or new equivalents) as the Old Man Emu parts require.

Excellent write-up, as usual Jeff ... this should be required reading for anyone installing an OME or Bilstein front lift; or replacing coils on their stock shocks.
 

·
on line
Joined
·
1,416 Posts
Discussion Starter #6
Wait. I had similar issues with my Bilstein shock assembly. In the third to last pic, which is correct? I installed my like the one on the right because it "molded" into the upper boot.
Posted via Mobile Device
As I read Jeff's notes, the right-side is the correct assembly.

And that comment brings up a good note that I was thinking to myself as I read through this: these assembly notes will help the guys installing the adjustable Bilsteins as well, I believe they require the same OEM parts from the original assembly (or new equivalents) as the Old Man Emu parts require.

Excellent write-up, as usual Jeff ... this should be required reading for anyone installing an OME or Bilstein front lift; or replacing coils on their stock shocks.
As usual, skibum315 displays excellent reading skills. The picture on the right, the one with the lower washer concave side down, is correct.

If the adjustable Bilsteins list the same part for all 2nd gen Xterras, I would expect the above description holds true for them also.

Jeff
 

·
on line
Joined
·
1,420 Posts
Just wanted to add the top plate mounting orientation using your pic..hope you dont mind, also added the FSM (factory service manual) section that aids in supporting your explaination of how its meant to be oriented........

I'm just researching this stuff as I purchased new top plates off ebay to prep for my TS.

Hope this helps others along the way.




-J
 

Attachments

  • Like
Reactions: sanmarko

·
Premium Member
Joined
·
61 Posts
Just wanted to say what a great post/thread this is. Focused, helpful, detailed, augmented by clear photos and input from other. WOW.

I have OME coils, Bilstein 5100 shocks, new bushings and top plate inbound. Now I know what the end product should look like.

But, also going with those additional sage words of advice: (Warning: Compressing the coil spring is potentially dangerous. If you don’t have training or are not aware of how dangerous the operation is, let a shop do that work. ) I think I will take these components up to 4WDParts in Tacoma, and get them to assemble the struts together for me.
 

·
Registered
Joined
·
9 Posts
Would anyone be able to tell me if these look like they are assembled correctly? I ordered them preassembled, and they look a bit different than than the photos in this thread which makes me think they are not. I'm not a suspension expert by any means, but it looks like there is a spacer underneath the top plate rather than on top of it?

Any help would be greatly appreciated!
 

Attachments

·
on line
Joined
·
1,416 Posts
Discussion Starter #11
That doesn't look right, it appears that the top rubber bushing is installed below the insulator. It's hard to say what else may be either missing or out of place. Is the dust cover part of the new shock or was it from the original shock that was replaced.

Who did the assembly? If you don't want to name them in the open forum please pm me.

Jeff
 

·
Registered
Joined
·
9 Posts
The dust cover is part of the new shock, should it not be used? I ordered a complete OME kit from OK4WD who ordered all new parts to assemble the coilovers so that it could be a drop in replacement for the old ones (at least that was the idea...haha).

I guess I will have to find someone local to me that can rebuild them correctly, since I already replaced the rear leafs and am in a time crunch now.

Thanks Jeff!
 

·
on line
Joined
·
1,416 Posts
Discussion Starter #13
There was a difference between the Off Road Bilstein shock/coil assembly and the X, S, SE assembly. The Off Road used a spacer to locate the dust cover, shown in the pictures above, and the others used the bottom or lower washer. There were a number of cases where the original shock/coil assembly was swapped and the dust cover was eliminated. Unfortunately the washer wasn't separated from the dust cover and wasn't used in the reassembly of the shock/coil. If OME now uses a dust cover the lower washer may be included with the dust cover.

The way your coil/shock is assembled doesn't allow for some movement between the shock and the spring bracket. You may want to take copies of the pictures to the shop doing the work to ensure parts are assembled in the correct sequence and orientation.

Good luck,
Jeff
 

·
Registered
Joined
·
127 Posts
Would anyone be able to tell me if these look like they are assembled correctly? I ordered them preassembled, and they look a bit different than than the photos in this thread which makes me think they are not. I'm not a suspension expert by any means, but it looks like there is a spacer underneath the top plate rather than on top of it?

Any help would be greatly appreciated!
Don't run that. Not correct.
 
1 - 15 of 15 Posts
Top