How to replace the rear cross sill

There were no posts on this, so I decided to write it myself.
NOTE: I AM NOT RESPONSIBLE FOR ANYTHING YOU DO TO YOUR TRUCK. That said, here we go.

So if your truck has spent more than 5 years in a heavy snow/salted area, you may want to look into this. Ive already posted about how to replace the rear bumper support, which is the first to go. Mine spent 12 years in PA, so the rear sill was also bad. I was able to poke holes in it easily and it made a dead sound, not a ping metal sound when hit.

Before you look under your tailgate and assume yours is good, get up under the truck and really look at the area that faces the front of the truck by the tire. Pull your tail lights or cargo boxes and look around. Then you'll really know. Dealers can hide rust by repainting visible areas. Like they did to me....see later pics.

Didnt take a ton of pics, but teardown is a continuation of this post https://www.tacomaworld.com/threads/process-to-replace-rusted-rear-bumper-support-with-pics.549906/

Be aware that having a shop do this will cost nearly $2000! (Which is why I did it myself) So why do it? Well, because I just got my truck and I dont want the rust to extend. I plan on keeping it at least 10 years, so its worth it to me. Ive had my 07 4runner 11 years btw.

So here goes. First identify the part. Aka 6524004161 Its also referred to as 65241 in other diagrams. It sits at the back of your bed, just behind the spare tire. It holds your tail lights in. Its big and fairly heavy. It also rusts easily. You cant see all the rust until you remove your tail lights and ultimately the whole thing. If you have rust on your frame, guaranteed you have it here too. Now go check yours out...Ill wait.


So, if it looks like $hit, heres the game plan.

Step 1. Find a salvage part. I got my from a salvage yard in Conover, NC at the recommendation of another TW member. Make sure its not more rusted than the one you have. The one I bought had minimal surface rust. So I sanded it down, used some rust remover and repainted. Looked good as new.

Sure you can but a new one. But they run $300-600.

Step 2. Get some estimates and ultimately decide youll do it yourself.


I got 2 estimates, one from a local chain, and one from an independent one. One was $620, one was $1019. The problem with this repair is that very few people know how to do it efficiently. There is alot of guesswork when they are looking at the diagrams. And there is overbloated time frames. Eg 1 hour to remove bumper, 5.5 hours to remove driver side bed panel, 4.5 hours to remove right panel, and 0.4 hours to remove the plastic piece on top of your bed rails...really?

So this is what I did.

Step 3. Find minimum 6 hours, and perhaps a buddy to help you do the repair. Buy a few nice 6 packs of craft beer.

Youll need.
10mm socket.
Long ratchet with flex head *thanks Harbor Freight*
T55 torx
Impact wrench
T30 Torx
Crow bar or wrecking bar
Power drill
Penetrating fluid
Patience
19mm socket
17mm socket
Cut off tool (HF)
Old clothes you can drench in sweat (esp here in NC)

Process
Loosen star bed bolts with T55, remove
Loosen D rings with T30, remove
Loosen tail light assemblies, remove (see video)
Disconnect wiring plug.
Pull the tail light wiring down through the lower hole in the side of the cross sill.
Remove tailgate
Remove license bulbs from socket in bumper
Remove wiring above cross sill, that sits just under the bed. There are about 6 spots it connects with a little plastic piece to the sill.

Remove bumper 6 bolts. 4 mount to trailer hitch frame that are 17mm, 2 mount to just in front of trailer hitch receiver, 19mm. Then wiggle the bumper /reinforcement assembly out. Weighs about 50lbs together.

Remove the plastic lowermost corners held in with plastic push rivets.

Remove or loosen bed fenders. This is where things get interesting. There are about a dozen bolts that matter. Many are not actually bolted to the bed. Some are bolted to the wheel liner. It is essential to remove the ones in front of the fender, in the channel behind the cab. This can be difficult. In fact, most places wanted to charge you 5 hours labor to remove the bed entirely and place it on a lift. THIS IS NOT NECESSARY

All other bolts are 10mm. Have a good 3/8 socket, not a 1/4. Put penetrating fluid on all bolts prior to removal. Several will break. (this is why you need the drill).

Use (long flex head) from harbor freight for the top 3 bolts. The head is just thin enough to fit in the tight space, and long enough to reach the bolt heads. Put the socket on after you get it in the channel. Go under the truck and attack there for the lower two. It is tight but possible. If youre rough or sloppy, but some masking tape on the back of the car so you dont nail it 100x.



Also remove all bolts that come through the tail light assembly, towards the back. They are a bitch. This is the hardest part of the repair. Take the side storage areas off and go through there. The bolt heads sit there. Do not try to grind them off from the back. Doesnt work. Most of them will be shit, so plan on cutting the heads off or drilling them out.

Once all those are done, get a T30 torx again, slowly remove plastic piece on top of your bed rails (they pop up) and undo the bed rail bolts that contain the sliding clamps. There are 5 on each side. There are also a few plastic rivets on each end.

Undo the lower mounts of the steel L shaped brackets that come out of each side of the bed, they attach in front of the tire on lowest point of the side panel. Mine was also rusted, and needed drilled out.

Remove support bracket bolts near bottom rearmost part of fender behind the rear wheel.

Now. Heres the trick. Wobble and wiggle your right side panel a bit. There should be some play, and yet it is still attached at the wheel liner. If you like, put a towel or blanket over the fender if you think it is too loose and could fall. My wheel well supports were extremely rusted, but they still held on to the fenders for this to work. I replaced them a few weeks later.

Stand at the back of your truck. You have to get enough clearance to get the side fender out to the right of the cross sill. Approx 6 inches. You need some clearance on the left, but not necessarily a full 6 inches. You only need this briefly. Take a look and make sure you've go the clearance. Once you have this, on to the big part. Pulling out that rusted MOFO!

The sill has been in there for over a decade and partially adhered to the bed. Catch the lip of the bed with a crow bar or wrecking back and go up and down across the back. Youll hear some groaning and snaps. When its loose, go all the way to the right with a crow bar and slip it up high enough to allow the molding where the T55 bolts sat to pass under the bed. I did this myself, working it back and forth, but a friend would help at this point.

He prys with wrecking bar, you pull the sill, he slides to another spot, you pull the sill. When it gets close to clearing, pull the right fender to the side and slide out the right part of the sill from under the fender. If you dont have enough clearance, take out more bolts.

Youre half out. You can now see daylight.

Now the left side. TAKE OFF YOUR GAS CAP! Wiggle and draw the left panel out. It just slides over the fuel filler. I didnt believe it, but it did. Super easy.

Now twist the cross sill to about a 75 -90 degree angle so it comes out from the left fender between the two end pieces.
Its easier than the right side.

Biggety bam. Its out.





Will complete reinstall process with next post. At this point, have a beer. Potentially hold cross sill above head and scream like Conan. Or make the sounds from your favorite Street fighter 2 character. Just an option.

 

Step 4. Replacing the new sill.

Note you may want to get a bunch of extra 10mm bolts. If your sill was rusted, so will be your bolts.

Clean up any residual rust on bed, frame and fenders. I used loctite naval jelly. Clean em up and prep for reinstall.

Get your buddy to help. Pick up the sill and set it on top of your trailer hitch, line it up to where it should be. Jam it under the bed, it wont be fully seated, but will be about half in.
Use a wrecking bar and pry the bed up a few inches while your buddy pushes on it. Itll move forward a bit. Watch the rear fender outer metal pieces and slide outside the outer right part of sill. The inner part can stay put.

When its almost in, youll see the notches for the bed bolts are not yet coming through. Keep pushing and prying and sure enough theyll pop into place.
Now begin the reinstall process. Do everything you did before in reverse.

Make sure all your holes line up well. Wiggle the sill a bit to move it if needed.
Reinstall the bed bolts. T55 torx. May want to add antiseize for future access.
Reinstall the D rings. T30 torx.
Pull the tail light wiring back up through the lower hole in the side of the cross sill.
Reconnect wiring plug. Put the tail lights back in.
Mount all the wires/ plugs into the new rear cross sill
Replace the plastic lowermost corners held in with plastic push rivets.
Put the 6 bolts back in and remount the bumper. 17mm and 19mm. Torque to 67ft lbs.
Put the license plate lights back in.
Install the 10mm bolts into the side storage areas.
Install all the bolts from the tailgate area, latches, etc
Test rear lights for function.
Put all bolts back into side body fender pieces. All 10mm.
Put bedside plastic tops and rails back in with T30 Torx.
Put your tailgate back in.

If any bolts are broken, drill out and replace with new bolts and nuts as needed.
For me most of these occurred in the tight space behind the cab.
Drill from the underside of the bed with a right angle drill and add bolts as needed.
Use cutoff tool for dead bolt remnants/nutserts.

And thats it. Your savings, over $1000 on the repair and probably several hundred $ on the part.
And you learned alot about your truck.
Time to crack that 6 pack!

 

Great write up! Thanks for taking the time to prepare & present!

 

Glad to help. I suspect there are alot of Tacos in snow and salt areas that could find this useful.

 

Do you happen to know what length the 10mm bolts should be? I’m about to do this, but wanna make sure I have bolts to replace any that may break.

 

I'd say they are all about an inch on the bumper, but longer in the front of the bed. Perhaps 1.5 -2 inches. Toyota dealer and Lowe's helped out alot. I got most of my 10mm bolts from Lowe's, cheaper and faster. (No waiting on parts). Just take a few with you and match up the threads.

Also a $26) helps alot for rusted bolts. I used a hacksaw at first, but it took forever. Do not use a Dremel, will also frustrate you. I later redid some where the heads broke off and drilled them out, put fresh ones on, with the cutoff tool.

Take your time. Be patient and make sure they're all out before trying to pull off a part. Youll be fine.

 

Yeah, I’ve learned to take my time before pulling something off. Broke a perfectly good sled engine because there was a bolt in. Luckily it wasn’t gonna be used again, but still, would’ve been nice to have for just in case it was needed. My second biggest issue is whether or not the drivers side quarter panel will line up. The cross sill I have on is pushed in due to being backed into a loading dock, the quarter panel is dented and pushed forward a bit too, so I’m hopeful it’ll fit over the new one just fine. I’m probably going to replace it eventually anyways, but I would like to be able to actually use my tailgate, so that’s why I’m doing this.

 

It should work. They are surprisingly light and flexible. Cross sill weighs alot more.

 

That’s good to know, just gotta get through my classes first

 

this! Buy a few nice 6 packs of craft beer.

 

Is fireball a better option?

 

Well, haven’t removed anything and already fucked up. Those POS t55 screws, one stripped completely. Not sure what to do or how to get it out now... might have to drill it

 

I took it to a shop for those. Happened to me as well. $20 and an air hammer got them out. Replaced them. Only shop expense I had but figured it was my fault.

 

I got two of em, do I need to loosen all of them?

 

No just the rear 2.

 

Sweet, so far I’ve sheared 6 bolts, i haven’t even gotten the bumper off yet. I’ll update when I’m at the sill itself

 

So, I’m on the install of the new one, but cannot for the life of me, get the left side to move in all the way, any tips?

 

Use the pry bar and lift up to create room.. Really helps to have a friend push. It has to get above that elevated ring on the cross sill or it won't go! Also begin to move the right side in under the lip of the bed as you push in on the left into final position.
Congratulations on getting half way!

 

I'm about to replace this part as well would it be easier if I just pull the whole truck bed off? Id really like to not remove my rear bumper its aftermarket.