I've been searching all over the forum trying to answer my own question, but can't seem to find it.
I'm replacing my struts on my 2011 4x4 Dakota and was trying to find a tutorial on the strut assembly/upper tower installation to make sure I'm doing it right?
Do I keep the spring compressed when installing the upper tower?
What is the torque spec for the center nut that holds the upper tower on, and is the torque set while the spring is compressed, or after it's released?
Seems like it would be easy to screw this up by screwing the center nut on too far while the spring was compressed, and end up with a partially compressed strut afterwards, but doesn't seem like you will be able to mount the top without the spring compressed first?
thanks
Steve

 

From the '05 Factory Service Manual (see sticky)

SHOCK
DIAGNOSIS AND TESTING
SHOCK
A knocking or rattling noise from a shock absorber may be caused by movement between mounting bushings and
metal brackets or attaching components. These noises can usually be stopped by tightening the attaching nuts. If
the noise persists, inspect for damaged and worn bushings, and attaching components. Repair as necessary if any
of these conditions exist.
2 - 30 FRONT ND
A squeaking noise from the shock absorber may be caused by the hydraulic valving and may be intermittent. This
condition is not repairable and the shock absorber must be replaced.
The shock absorbers are not refillable or adjustable. If a malfunction occurs, the shock absorber must be replaced.
To test a shock absorber, hold it in an upright position and force the piston in and out of the cylinder four or five
times. The action throughout each stroke should be smooth and even.
The shock absorber bushings do not require any type of lubrication. Do not attempt to stop bushing noise by lubricating
them. Grease and mineral oil-base lubricants will deteriorate the bushing.
REMOVAL
1. Raise and support the vehicle.
2. Remove the tire and wheel assembly.
3. Support the lower control arm outboard end.
4. Remove the upper shock nuts (1).
5. Remove the stabilizer link lower nut (5) and then
separate the stabilizer link (1) from the lower control
arm (6) to gain access to the lower shock nut
(3) (Refer to 2 - SUSPENSION/FRONT/STABILIZER
LINK - REMOVAL).
6. Remove the lower shock bolt (4) and nut (3).
7. Remove the shock (2).
ND FRONT 2 - 31
INSTALLATION
NOTE: All suspension components should be tighten with the weight of the vehicle on them (curb height).
1. Install the upper part of the shock (2) into the
frame bracket.
2. Install the upper nuts (1). Tighten to 102 N·m (75 ft.
lbs.).
3. Install the lower part of the shock (2) into the lower
control arm shock bushing.
4. Position shock module clevis (2) to lower control
(6). Install bolt (4) so head of bolt is facing rear of
vehicle and hand start nut (3). Tighten the bolt (4)
& nut (5) to 81 N·m (60 ft. lbs.).
5. Install the stabilizer link lower nut (5) to the lower
control arm (6) (Refer to 2 - SUSPENSION/
FRONT/STABILIZER LINK - INSTALLATION).
6. Remove the support from the lower control arm outboard end.
7. Install the tire and wheel assembly (Refer to 22 - TIRES/WHEELS/WHEELS - STANDARD PROCEDURE).
8. Remove the support and lower the vehicle.

 

Thanks for replying, I appreciate it, but I must not have made myself clear because I don't see anything there that will help me?
I'm looking for info on assembling the strut, not just installing it. Specifically, the center nut that holds the top of the strut on, not the three bolts that hold it to the control arm.
thanks
Steve

 

To answer your question the spring has to be compressed in order to fit the strut mount on. After breaking the tie or in some cases a turn of the shaft, this will extend the strut rod out to it's max travel distance. if you place the spring and mount over the strut you will notice that the threads have yet to protrude out in order to secure the nut. you have to compress the spring first then place the bump stop, dust bellow, spring seat and strut mount on, then securing with the center nut. Torque spec may differ from manufacture.

That all being said and done, be forewarned not all spring replacements and spring seats are compatible with the struts you have chosen. Even if they say they are ... Rancho 5757 strut, Moog spring and Monroe strut mount kit do not work together. This combo changes the angle ever so slightly causing the strut to bow and lose it's ability to compress naturally.

 

Are you replacing the central shock on the strut assembly? I strongly recommend you replace the entire assembly rather than deal with the compression on the spring. This is one of the jobs I can do, but don't WANT to do. Compressing springs and replacing tires on split rims can cause some major injuries, if not death. There is a LOT of kinetic energy stored in that spring. After all, it holds the vehicle up.

Now, if the tower has to be replaced when replacing the strut assembly, I would say around 90 ft. Lb. with some blue thread locker. Personally, I go with "gudentite" but I've been doing it for decades.

 

I am putting Rancho struts on, so I need to change out the strut, and use the same spring.
Just need to know what the center nut should be torqued to?
thanks

 

At the risk of offending you once more: a) download the factory service manual,
where you will find b) the following torque chart.

SPECIFICATIONS
TORQUE CHART
TORQUE SPECIFICATIONS
DESCRIPTION N·m Ft. Lbs. In. Lbs.
Shock Absorber
Upper Nut 102 75 —
Shock Absorber
Lower Bolt 81 60 —
Lower Suspension Arm
Frame Nuts 244 180 —
Lower Suspension Arm
Ball Joint Nut 75 55 —
Upper Suspension Arm
Frame Nuts 102 75 —
Upper Suspension Arm
Ball Joint Nut 75 55 —
Stabilizer Bar
Frame Bolt 61 45 —
Stabilizer Link
to Lower Control Arm 169 125 —
Stabilizer Link
Stabilizer Bar Nut 37 27 —
Hub/Bearing
Bolts 163 120 —
Tie Rod End to Knuckle
Nut 75 55 —
Tie Rod End
Jam Nut 75 55 —

 

I think he's referring to the actual strut, not the strut pinch bolt connecting to the lower control arm, nor the 3 strut mounting bolts for attaching the strut to vehicle ... but the assembly of the strut components. In any case the strut is not going anywhere once installed. I would compress the spring until you can tighten the nut with maybe one or two extra threads using blue thread locker, then decompress the spring. The strut is now loaded and should be equal in length to the other side and now ready to install. Good luck

<cough>quickstrut<cough>
<cough>monroe<cough>

 

Hi! No offense! I didn't know there was a download for a factory service manual, but I'll look for it.
The stuff you copied only says "shock absorber" so I don't know if that is for front or rear?

 

Correct, the center nut at the top of the strut. My concern was that the strut shaft has quite a bit of thread, and if I compress the spring enough, I'm guessing I could then screw down that top nut further than it is supposed to go, which is why I was asking how to determine how tight it should be?