Guys,
Figuring the loud CRACK or smack sound on my rear sunroof is a not s good thing.

Press the open button and first sound is the crack sound ..
then the window goes back smooothly.

When I hear a loud noise like this - seem a matter of time.

I have never looked at this assy or lubed it.
Any ideas?

 

Mine does the same thing. Must be the "sunroof open" alarm.

 

I never had this with my previous D2 but I do have this same issue with the current 4th Gen 4Runner I have. I noticed this issue did not start on my 4Runner till after I tried to open the sunroof/moonroof on a cold cold winter day. That day it made a really rough pop sound and ever since then it's made a crack or smack sound when it first lifts up to slide open but as you said it slides open the rest of the way smoothly. I assume a gear or lever or something may have a crack or possibly it needs lubed up really good.

I would stick my head up through the sunroof when open and check for any moving parts that may look cracked or out of sync looking. Maybe clean the whole sunroof area and lube all moving parts up really good. Possibly after you lube everything up, open and close the sunroof a couple times to get the moving parts lubed up really good.

I plan on buying another D2 soon and I will be cleaning and lubing the two sunroofs up very good.

I'll try and get some video of my current 4Runners sunroof opening and post it and you can see if it's the same sound or issue your getting. I know it's not the same vehicle but all in all it's a sunroof.

 

If it's any consolation, mine does the exact same thing on the first opening. After that, no cracking sound. When my wife tries to turn on the dome light, she always accidentally hits the rear sunroof button for some reason (women...) and that loud crack always scares me. I don't think it's a big deal as long as it all functions, though.

 

Hey jfall:

That loud crack you hear on your disco's second sunroof is letting you know you have worn rails. I had the same noise on my '03 disco. Not to throw sand on your face, but I have an extended warranty for my '03 and had the dealer replace the frame and rails less than a week ago. My out-of-pocket deductible was $200. The frame and rail price through the dealer was $842.18. The labor was $459 (4.5 hours @$125 p/hr), for a grand total of $1,321.18.

No more loud clicking.

Don't know how necessary it was to have the loud clicking continue before something really major might happen, but thought it best to go ahead and green light this project with the dealer.

Looking at the work order receipt, the dealer has a part number of EFP100253 with a product description labeled "Frame-sliding, frame with rails, upper tray." So if you wanna try and DIY your 2nd sunroof so no more loud cracking, maybe rover's north or BPU has what you need if you offer them the part number that the dealer listed on my work order.

I guess you could try lubing the rails and such to avoid the hefty price tag of replacing your sunroof rails. I suppose it can't hurt and maybe that will Band-Aid the loud click you hear when 1st opening the 2nd sunroof. Oh yea, one thing I did notice prior to the repair was that the sunroof only blurted our one loud crack sound; the initial opening. But when I sat in the captains chair and pressed the open/close button repeatedly, the loud click was gone. Hmmmm....

gbob

 

Not sure where you may be able to lube these, as mine has begun to do the same, but on my old MB they was something like "lube glide" lubricant IRCC that kept them running smooth and helped minimize wear on the rails.