LC100 headers install and tcase regear

[frawstme]

Both the parts for my transfer case and headers are arriving this week, which is kind of unexpected since the gearset was on backorder. Initially I was going to do both of these jobs seperately as I am not a super experienced mechanic and they both feel like large jobs to me. I'll be the first to admit that I wildly overthink things, but is my logic right in thinking that this will be easier to do both at the same time?

I went with Rhino exhaust headers and cats

Click here to skip 80 posts straight to write up for Rhino exhaust long tube headers install
For the regear im doing 10% under drive + 3.3:1 low range from cruiserteq. I also picked up their rebuild kit, although I'm unsure if it is necessary with my car having just over 100k miles. I just don't ever want to have to do this again so figured better safe than sorry.

I'm going to start this on weds and I wanted to have a plan. I'm going to document everything here and use the thread to keep track of my bolts and parts order.

Here's the order that I'm thinking:

1. Drain tcase
2. Put front on jack stands and remove wheels + wheel stoppers at rear
3. Remove all underguards and splash guards in wheel wells
4. Remove exhaust midpipe (mine is aftermarket and this will give more clearance for removing the tcase)
5. Remove both cats, this is required for headers but also gives more access to tcase
6. Label o2 sensors
7. Remove fan shroud- it's unclear but seems that you need to lift the motor to access some header bolts
8. Remove transmission mount bolts at bottom of crossmember (dont actually know if this is needed to lift motor)
9. Remove both driveshafts/propellors. I'm going to clean my ujoints here too, they are in poor shape
10. Remove transfer case
11. Disassembly + run through parts cleaner
12. While tcase exterior parts are in cleaner start on headers
13. Remove heat shields from headers
14. Remove any bolts that I have access to without lifting motor
15. Lift motor from bellhousing between pans to get access to remaining bolts, then repeat steps 10-12 on other side
16. Reassemble tcase
17. Install new headers
18. install tcase
19. install cats to headers
20. reinstall steps 3-9, fill tcase

Am I overlooking anything that I'll need to remove for more clearance with the headers? Any tips before I get started on this job?

I'm going to take it slow and try my best to document everything, but I am starting to feel like this job is going to be a big headache so i've got some anxiety about it

 

[omarsky1980]

Quick question... Is your cruiser RHD?

Last I heard the exhaust headers are drive side specific so I was curious whether you actually had to get a specific version of it the rhino headers are universal.

 

[frawstme]

Quick question... Is your cruiser RHD?

Last I heard the exhaust headers are drive side specific so I was curious whether you actually had to get a specific version of it the rhino headers are universal.

I got the RHD version, although rhino does offer a LHD version. They'll be in tomorrow, I forgot fedex doesn't ship on memorial day

currently wondering how much import fees and duties I'll have to pay them when they deliver, I thought they would notify me ahead of time but they haven't yet

 

[frawstme]

It didn't occur to me until yesterday but step 13 should be step 1. The heat shields have to come off to be able to soak the manifold studs in PB blaster ahead of time.

Doesn't require much, it's 4 short 10mm bolts. The top two you get to using a socket with a swivel adapter and 3 inch extension. The bottom two you get to from under the truck with a swivel adapter and a long extension (I used a 2 foot), but be careful of the wiring down there.

My LC has a hard time with the passenger side top front bolt, I have a lot of extra wires there that US 100s won't have so I had to use a stubby 10mm wrench

Alternatively to the top bolts you can cut the wheels all the way to the right or left and try to get to them from the wheel well but that didn't help much on my model with the wiring on the passenger side

For the passenger side once the bolts were off I manipulated the shield through the front gap and downward between fan blades while being careful of the radiator. The driver's side pretty easily came out by squeezing the rear end of the shield and pushing it down and back through a gap where the cat is

The entire removal doesn't require the truck to be lifted or tires off, takes about 15 minutes.

 

[Dirt J]

I used a press and large pullers when I re-geared and rebuilt my tcase. Make sure you lock the CDL in before reinstall to save a headache later.

 

[frawstme]

I used a press and large pullers when I re-geared and rebuilt my tcase. Make sure you lock the CDL in before reinstall to save a headache later.

I think I have all the tools that I need (hopefully)... but can you elaborate on locking the center diff ? do you lock it before removing and keep it locked when you reinstall?

what happens if you don't lol

 

[Dirt J]

The front shift fork that engages the front driveshaft needs to either be fully rearward (unlocked) or fully forward (locked) when reinstalled. You can do this by hand by manipulating the teeth in the top of the fork through the port on the front extension housing. That way, when you reinstall the little actuator motor for the CDL it is already in the appropriate position.

If the fork is somewhere between foremost and aftmost, when CDL is engaged/disengaged in will be "midway" of the throw on the fork and the fork may catch on the front output gears. Info here.

 

[frawstme]

The front shift fork that engages the front driveshaft needs to either be fully rearward (unlocked) or fully forward (locked) when reinstalled. You can do this by hand by manipulating the teeth in the top of the fork through the port on the front extension housing. That way, when you reinstall the little actuator motor for the CDL it is already in the appropriate position.

If the fork is somewhere between foremost and aftmost, when CDL is engaged/disengaged in will be "midway" of the throw on the fork and the fork may catch on the front output gears. Info here.

That sounds like a nightmare, i appreciate you giving me a heads up. At work right now but I'll read into that and I might have some more questions later

 

[frawstme]

The front shift fork that engages the front driveshaft needs to either be fully rearward (unlocked) or fully forward (locked) when reinstalled. You can do this by hand by manipulating the teeth in the top of the fork through the port on the front extension housing. That way, when you reinstall the little actuator motor for the CDL it is already in the appropriate position.

If the fork is somewhere between foremost and aftmost, when CDL is engaged/disengaged in will be "midway" of the throw on the fork and the fork may catch on the front output gears. Info here.

So I read through and I think I understand, but quick question- you said to lock the CDL before installing. I don't intend on starting my truck at all because my headers will be off when I reinstall the tcase. I could lock the center diff before starting the whole project but is there a reason to do that instead of just starting it normally and then making sure the fork is fully rearward when I install it?


Off topic from that but the headers came in today,

The description said it came with new gaskets and hardware. The only new hardware is for the exhaust flanges.. I thought it was gonna have new studs and bolts for where the headers meet the motor. Those aren't reusable right?

edit;
seems they are reusable so ill just pray nothing snaps

 

[GTV]

The description said it came with new gaskets and hardware. The only new hardware is for the exhaust flanges.. I thought it was gonna have new studs and bolts for where the headers meet the motor. Those aren't reusable right?

Well... depends on who you ask. If you want the added comfort/insurance then replace the studs/nuts with OE Toyota. But your original stuff will *probably* be just fine.

 

[frawstme]

Well... depends on who you ask. If you want the added comfort/insurance then replace the studs/nuts with OE Toyota. But your original stuff will *probably* be just fine.

I have to go to toyota tomorrow morning before I start the tcase, I will pick up new nuts at least

I want to replace the studs honestly. I'm just worried that one might break off into the head, and that's not a job that I'm really prepared to deal with. I don't think i'm capable of tearing the motor down to the heads while also dealing with the header install and tcase rebuild

 

[GTV]

I have to go to toyota tomorrow morning before I start the tcase, I will pick up new nuts at least

I want to replace the studs honestly. I'm just worried that one might break off into the head, and that's not a job that I'm really prepared to deal with. I don't think i'm capable of tearing the motor down to the heads while also dealing with the header install and tcase rebuild

Can confirm, that’s a huge and very not fun job.
My hardware came out easily and I reused it. Maybe I got lucky. Put some Kroil on the studs, let it soak in. Give them a try.

 

[ben322]

We replaced all the studs after snapping several on each side. Don't know how the left side is routed but in my LHD DT header install, the AC line needed to be wrapped and secured closer to the fuel filter.

 

[frawstme]

We replaced all the studs after snapping several on each side. Don't know how the left side is routed but in my LHD DT header install, the AC line needed to be wrapped and secured closer to the fuel filter.

I'm about to start on this job and getting progressively more anxious about it lol. You were able to get the studs out without motor disassembly? With the lack of space I didn't feel like I would be able to get an extractor bit and drill in there if something broke

Also how many miles did yours have?

edit:
Toyota wants $245 for 16 studs and nuts. They're $2 per on amayama..

 

[ben322]

Motor in place with a right angle adapter. Should have just heated them all before applying too much torque. I have an induction heater but was too lazy to get it out from storage so I paid the price. I used aftermarket 10.9 studs with just a touch of anti seize. I had 245K when this job was started and it was an east coast LC so it had seen some weather.

 

[frawstme]

Annoying start to the day, spent 5 hours at Toyota for a brake flush and new lines. So super late start to this project.

I got my cats out (10x 14mm bolts)
Both drive shafts out (16x 14mm bolts)
Midpipe out

Concerned about the size difference of the cats but we will see. All parts are disconnected from the tcase and all except one bolt is out.

A few things. My drive shafts were entirely void of grease. Not a single bit, which is super concerning. I will look up maintenance on them later before reassembly.

The other is that I was planning on using my jack to get the tcase away from the trans but that doesn't seem to be an option. How heavy is this thing? Am I gonna be ok trying to bench it?

 

[Dirt J]

Tcase is pretty heavy. Think maybe 100lbs?

I used a transmission jack cradle for handling mine.

 

[frawstme]

Tcase is pretty heavy. Think maybe 100lbs?

I used a transmission jack cradle for handling mine.

Dang I'm probably too weak for that

I think I'm gonna use my floor jack and a 2x4, Ive been sitting here thinking of what to do and I don't really have any great ideas

 

[Dirt J]

If it's on the ground, you can balance it on a regular floor jack.

 

[GTV]

It’s very heavy and awkward. I used a trans jack and it was still a PITA.