LX470/100 Series Doug Thorley Headers Install Tips, Tricks, Lessons, Parts List, and Tools (3 Viewers)

[FXJ 96]

Also, there isn't much clearance above the driver's motor mount either.
View attachment 2956896

My driver's side is touching and it's causing a lot of cabin vibration when I come to a stop at a light. If I shift to neutral that vibration goes away, but I don't want to shift to neutral every time I come to a stop - and the vibration has become bad enough that I want to.


Not sure how to address this other than a prybar and bending/indenting the header a bit. All the bolts are tight, I have new motor mounts, but I've had the headers for over 3 years and the vibration has just really gotten bad in the past year or so. I'm not sure why.

 

[ryan470]

I ended up installing some fender washers between the block and the motor mount along with slightly longer bolts to compensate. This netted probably 1 mm of clearance between the header and the control arm mount when hot (2-3 mm when cold). It took a little effort to get the motor mount to mount to the frame, but the rubber has a little flexibility (these were new mounts). Because of the angle, it tilted the engine away from that side, so it would probably increase clearance from the engine mount as well. I'm not a fan of doing it that way but for me it was the best option. I'd rather replace the mount on a more frequent basis than cause a failure in the header or suffer increased NVH.

PS- I also had to loosen the two trans mount frame bolts and then re-tighten, but even the trans is tilted by a mm. I might still slip a thin washer on the bolt for the side its tilted up.

PPS- you could try replacing the motor mounts if they're old. The rubber in mine was collapsed. The photo of mine you quoted was of the clearance between the motor mount and the header after the new mounts. It was paper-thin clearance before.

 

[FXJ 96]

I ended up installing some fender washers between the block and the motor mount along with slightly longer bolts to compensate. This netted probably 1 mm of clearance between the header and the control arm mount when hot (2-3 mm when cold). It took a little effort to get the motor mount to mount to the frame, but the rubber has a little flexibility (these were new mounts). Because of the angle, it tilted the engine away from that side, so it would probably increase clearance from the engine mount as well. I'm not a fan of doing it that way but for me it was the best option. I'd rather replace the mount on a more frequent basis than cause a failure in the header or suffer increased NVH.

PS- I also had to loosen the two trans mount frame bolts and then re-tighten, but even the trans is tilted by a mm. I might still slip a thin washer on the bolt for the side its tilted up.

PPS- you could try replacing the motor mounts if they're old. The rubber in mine was collapsed. The photo of mine you quoted was of the clearance between the motor mount and the header after the new mounts. It was paper-thin clearance before.

I have new motor mounts, vibration before and after seemed unchanged. Thanks for the washer suggestion, I need to weigh my options.

 

[Jram100]

Been considering this mod, but really not into dealing with clearance issues w the mounts. seems like some experience it and some don't?

 

[udubfl]

When I installed my DT headers, no issues with clearance. No rubbing or anything close to it. Couple things that I could think of that could cause issues are 1) Motor is mounted little off so it's closer to the driver side than passenger side. This could be due to various factors I guess. 2) Maybe the DT header piping is little different/varies perhaps because its hand-made so it's all the same.

FWIW: I did not change the engine mounts on either side when I did my DT Header work. It's original and didn't find the need to replace it for this project or for any other reasons. My LC had over 200K and 2001 model. Just checked some of my pics to see if I could see some clearance issue. It's hard to tell from the pic but the top piping with DT stamp has at least 1/2 inch clearance above control arm bolt area. Not sure about the piping next to the the control arm bolt area.

 

[Jram100]

Ive heard about improved mpg, anyone notice a change?

 

[ryan470]

When I installed my DT headers, no issues with clearance. No rubbing or anything close to it. Couple things that I could think of that could cause issues are 1) Motor is mounted little off so it's closer to the driver side than passenger side. This could be due to various factors I guess. 2) Maybe the DT header piping is little different/varies perhaps because its hand-made so it's all the same.

FWIW: I did not change the engine mounts on either side when I did my DT Header work. It's original and didn't find the need to replace it for this project or for any other reasons. My LC had over 200K and 2001 model. Just checked some of my pics to see if I could see some clearance issue. It's hard to tell from the pic but the top piping with DT stamp has at least 1/2 inch clearance above control arm bolt area. Not sure about the piping next to the the control arm bolt area.

View attachment 3013076

The 05-06 are a little different with the secondary air tube. They didn't have as much room to go up, so the tubes project out and down more vs. the standard ones I think. Hence, issues with the motor mount and control arm mount. Those look great, though.

Ive heard about improved mpg, anyone notice a change?

I haven't noticed anything too significant, but I'm in the 11's anyway...

 

[FXJ 96]

The 05-06 are a little different with the secondary air tube. They didn't have as much room to go up, so the tubes project out and down more vs. the standard ones I think. Hence, issues with the motor mount and control arm mount. Those look great, though.



I haven't noticed anything too significant, but I'm in the 11's anyway...

Dang, that's a great 1/4 mile time - these headers are legit.

 

[FrankieJoe14]

Drivers side: 10 hours
Passenger side: 2 hours

What a freaking day. This was probably the least fun project I've done on this truck. Even replacing the whole engine has better clearance than this

I appreciate everyone's tips, they helped tremendously. I will add one - the drivers side nuts are a thing from the devil. Be careful with one on cylinder 5. If you use your 14mm ratchet wrench on it, you will not be able to get it out once it's tightened. You will have to shoehorn another wrench in there to loosen the nut and get your wrench out, burning close to 2 hours.

I didn't need to remove the steering shaft, it can be persuaded to let the header in slowly.

Also, I probably would have bought new o2 sensors for the headers, cause I'm never going back in there again.

But they look nice! And my tick is gone!

The cylinder 2 manifold had a hairline crack almost 40% the way around.

I'm going to bed

 

[94SRUNNER]

Drivers side: 10 hours
Passenger side: 2 hours

What a freaking day. This was probably the least fun project I've done on this truck. Even replacing the whole engine has better clearance than this

I appreciate everyone's tips, they helped tremendously. I will add one - the drivers side nuts are a thing from the devil. Be careful with one on cylinder 5. If you use your 14mm ratchet wrench on it, you will not be able to get it out once it's tightened. You will have to shoehorn another wrench in there to loosen the nut and get your wrench out, burning close to 2 hours.

I didn't need to remove the steering shaft, it can be persuaded to let the header in slowly.

Also, I probably would have bought new o2 sensors for the headers, cause I'm never going back in there again.

But they look nice! And my tick is gone!

The cylinder 2 manifold had a hairline crack almost 40% the way around.

I'm going to bed

What year is your 100?

 

[FrankieJoe14]

What year is your 100?

It's a 2001, 231k.

 

[abuck99]

Hi all,

I wanted to do a thread detailing my install of my Doug Thorley headers on my 2003 LX470. I haven't seen this much detail anywhere that I could find showing the tools that make this job easier so I hope it will be helpful for someone looking to do this job by themselves. This won't be a how-to per-say but I will share some of the tips and tricks I learned while doing this job as well as some of the tools that I found invaluable! It will also cover some of the things I did wrong that others should keep in mind while doing this job.

I will say that this job was not as daunting as I had originally believed. After all, it's just nuts and bolts, right? (/s)

Amazingly, my stock headers were not cracked but I could have sworn they would be.

What was getting installed...I ordered the DT headers and exhaust from the recent group buy on FB. This will focus on the headers as the exhaust install is very straightforward.
View attachment 2701744

Parts I ordered for the header install. All Toyota OEM parts.

Manifold Gasket	1717350021	2	$36.32
Front Pipe Gasket	9008043036	2	$19.34
Exhaust Manifold Stud	9008012008	16	$56.00
Exhaust Pipe Lock Nut	9008017187	16	$24.96

Total cost of parts from McGeorge Toyota - $136.62

Tools I used:

I used a lot of various extensions, ratchets, breaker bars, swivels, etc... But these tools listed are ones that not everyone may have on hand but made this job MUCH easier!

1. Flex ratcheting wrenches. I ordered some GearWrench stubby and normal length ratchets which I used extensively as they were great for accessing and snugging down the new manifold nuts in hard to reach areas. I bought these but any good quality flex ratcheting wrenches should work. I had some cheap HF ones previously and the ratcheting mechanism broke on 2 of them in another job I was doing the week before...buy once, buy quality!
Amazon product ASIN B000HBAI40 <-- Stubby wrenches
Amazon product ASIN B07Y49L5PS <-- normal length wrenches

2. Note on spline sockets...I know most people are recommending these to remove the stubborn factory manifold nuts but I did NOT have good luck with them in my experience and stripped two nuts using them. I used my Kobalt 6-pt sockets and they worked great for me on all of the other nuts! Definitely use good quality 6pt sockets as I was exerting A LOT of torque to remove many of the manifold nuts. Don't use 12pt sockets for obvious reasons.

3. Extraction sockets - I tried using some spline sockets to remove the manifold nuts and it stripped two of them. I had to buy some deep extraction sockets to remove them and these worked a treat! The short extraction sockets I had already were not long though to fully seat on the nut. Longer ones pictured below.
Amazon.com - https://www.amazon.com/dp/B083FSBFQ6?psc=1&ref=ppx_yo2_dt_b_product_details
View attachment 2701766

4. Socket depth... I found that my Kobalt 1/2" 14mm socket was the best option for accessibility and seating fully on the manifold nuts to remove them. It is longer than a 3/8" short socket but still long enough to cover the entire manifold stud and nut fully while still being shorter than a deep 3/8" or 1/2" socket. This shows the length difference between the various sockets I had on hand.
View attachment 2701757

5. Swivel sockets - Honestly, I found that the hardest part of this job for me was reinstalling the dip stick tube retaining nut on the driver side. With the new header in, it leaves very little room to access and install the bolt. I used a swivel socket I had in my toolbox which made this easier after trying for way to long to do it by hand or with a 1/4" short socket. After messing with the other methods for the better part of an hour, I got it in with a 1/4" swivel socket in a under a minute fishing through the fender well around the shock mount. Swivel socket I used is pictured below on the far left.

6. Extensions - I found that I had to use a breaker bar and my jack handle as an extension to break 12/16 of the manifold nuts loose. They were well aged in place after 18 years. If you have a "weathered" truck with some corrosion, be prepared for this. I had to bring the extensions outside of the fender to use my jack handle to get enough leverage which required probably ~24-30" or more of extensions to make this work. Have some on hand!

7. E10 socket to install new manifold studs and re-torque any stock ones that didn't pull out with the nut. I had these on hand from my BMW days but get some if you don't have them already.

Picture of the maybe uncommon tools I used. Not including the standard ratchets, extensions, etc.
View attachment 2701758

Tips/Tricks/Lessons Learned:
1. This may be obvious but soak everything in PB blaster for days ahead of time. My truck has minimal if any rust and I had a 1/2 breaker bar with the top of a jack handle for 12 of the 16 header bolts to crack them loose.
2. Take out the catalytic converter pipes for extra working space and to remove the driver side header easier. It's only 2 more bolts and disconnecting the 02 sensor and it made it much easier and allowed for greater accessibility from below. It also makes removing the factory headers and fishing the new ones into place very easy.
3. I didn't remove the steering linkage or heat shield on the driver side like some of the how to's tell you to. I took the shield out with the header and had no problems. I wasted far too much time trying to remove these two things before starting on the driver side header nuts and ended up not needing to remove them at all to do the job.
4. RELEASE AND REROUTE THE O2 SENSOR WIRING HARNESS ON THE PASSENGER SIDE AFTER YOU REMOVE THE STOCK HEADER AND BEFORE YOU PUT THE NEW HEADER BACK IN. Makes it WAY easier to undo since it's virtually unaccessible with the new header installed. I learned this the hard way...
5. Route the passenger side O2 sensor harness ABOVE the header. I did mine below initially and found that it rubbed the header and would melt due to heat. I rerouted it above and have no issues and plenty of clearance. There may be other ways to do this but I found this to be the best way. I released the 2 harness clips and ran the wiring up towards the top of the engine bay and then back down above the collector to the O2 sensor.
6. I used virtually all of the 3/8" and 1/2" extensions, swivels, adapters, ratchets, breaker bars, etc that I had. To get the jack handle and breaker bar outside of the fender to crack many of the bolts loose, I was using ~24-30" of extensions. Use good quality ones that don't flex or have a lot of slack. You need socket swivels to get the socket to seat flush on the manifold bolt or else you don't stand a chance.
7. For access to a couple of manifold nuts, I combined both of my swivels to fully seat the socket on the nut.
8. I loosened (don't completely remove) the trans mount bolts and passenger engine mount bolts to allow engine to flex up high enough to put in a 2x4. I couldn't get mine high enough to get a 2x4 in there without doing this. Be careful not to crack your rad fan shroud when jacking up the engine. I rotated the top fan fins to 11 and 1 o'clock and it was fine. By not fully removing the passenger side and trans mount bolts, you don't have to worry about the engine seating back down in the correct location and having to fight the engine to drop into place when you put it back down.
9. The flex ratcheting wrenches are a life saver. They made this job a lot easier.
10. I removed the air box for easier access to some of the front top manifold bolts on the passenger side. I got a few of the top bolts through the top of the engine bay as it was easier. Removing the air box allows for more space to cycle the ratchet/breaker bar.
11. Buy 16 new manifold studs and 16 new nuts. I pulled 9 of the 16 manifold bolts out with the nuts.
12. The "LX AHC" factor wasn't really an issue for me. I'm sure that by not having the AHC line in the way, it may be easier but I didn't find it a problem for my install.
13. Remember that if you're using factory manifold gaskets, to have the white mark facing OUT towards the manifold.
14. Torque the new header nuts down in a pattern to evenly snug down the header onto the gasket. Personally I start in the middle and work my way out alternating between top and bottom. Don't fully torque the nuts down 1 at a time. Do it in a series of 2-3 passes and snug them down more and more each time until you finally reach your target torque.
15. Lift up an secure the AC line running on the driver side. It is the larger diameter line running right above the new header tube and it can rub and burn through over time. I zip-tied mine to the fuel filter.
16. When you remove the dip stick tube to remove the factory header, plug the hole in the drain pan with a shop towel to prevent debris from falling into your oil pan. I cleaned the area before I removed it to wipe away the debris.

Torque Values - stolen from the TLCFAQ write up but putting them here for completeness. (@RobRed)
-32 ft-lbs on the manifold bolts
-32 ft-lbs on the front O2 sensors.
-14 ft-lbs on the rear O2 sensor nuts
-46 ft-lbs on the manifold to cat flange nuts
-30 ft-lbs on the cat to exhaust flange nuts
-22 ft-lbs on the engine mounting brackets to the frame brackets


Hope this is helpful for those looking to tackle this job! Happy to answer any other questions about my experience if anyone has any. I'll edit this post with anything else I can think of.

Great write up- very complete ! Should be in the FAQ.

 

[Hokie LX]

Great write up- very complete ! Should be in the FAQ.

I'm glad it was helpful for you!

 

[abuck99]

I'm glad it was helpful for you!

I'll probably not do headers but I truly appreciate a well written instructional post- most of us don't take the extra time to go into the detail at the level you gave the forum. Again- nice work and definitely FAQ worthy- even if used for a stock header R&R.

 

[Berkut10r]

I did not know there were tips and tricks for DT headers install, I thought there was only pain and misery.

 

[tornadoalleycruiser]

2000 installation, drivers side learning opportunity, remove motor mount and dip stick to slide header in position, reinstall motor mount and dip stick b4 installing header. Top back bolt of motor mount will not go back in if header is already mounted. I found one a few mm shorter to use.

 

[Fickelson]

Hi everyone, I just did this last weekend, my thoughts are below. 2000 Land Cruiser, spent most of its life in Colorado, just a smidge of crust, 230k:

• I thought that the driver's side and passenger's side were similarly terrible. Neither one was fun, but they were more similar in difficulty than other commenters have said.
• Driver's side requires the engine mount to be unbolted, but try and jack it up just enough that it's still hanging on the stud. If you jack it up too high, it becomes very difficult to get re-aligned. We used two ratchet straps to align the engine back with the mount.
• The oil dipstick tube isn't fun to get on after installation, but it's not that hard.
• The driver's side catalyst MUST be removed. The passenger's side does not need to be removed. Check the rear O2 gasket and replace as needed, mine was nearly disintegrated.
• The steering shaft does not need to be removed. It didn't even get in the way for me.
• I used the exhaust gaskets that came with the headers. It's nearly impossible to torque the new headers on, and the graphite gaskets that come with the DT headers seem to have a wider torque range of acceptability. I have the OEM gaskets I'll sell for cheap if anyone wants a new set.
• DO NOT USE THE SPLINE/UNIVERSAL SOCKETS that are recommended by OP. I stripped two of the nuts before abandoning those terrible sockets.
• Pursuant to the above comment, the Irwin extractor sockets (can be purchased at Lowe's) are incredible. You'll want a 3/8ths to 1/2 adapter in order to get the torque on the extractor, but it's beefy and great.
• Harbor freight sells a swivel metric socket set. Don't bother with these, the sockets aren't deep enough (3/8 in. Drive Metric Impact Swivel Socket Set, 7 Piece - https://www.harborfreight.com/38-in-drive-metric-impact-swivel-socket-set-7-piece-67908.html).
• Get the swivel adapters instead: Universal Impact Joint Socket Adapter Set, 2 Piece - https://www.harborfreight.com/universal-impact-joint-socket-adapter-set-2-piece-67920.html
• Get the flex head ratcheting wrenches, they're critical for this job. Flex-Head Metric Ratcheting Combination Wrench Set, 5 Piece - https://www.harborfreight.com/flex-head-metric-ratcheting-combination-wrench-set-5-piece-60592.html

This job is tough, but it's worth it. It's very doable, you just need time and perseverance. Both manifolds were cracked on my truck. Sounds so much better now. I'll edit the post if I think of anything to add.

 

[Hokie LX]

Hi everyone, I just did this last weekend, my thoughts are below. 2000 Land Cruiser, spent most of its life in Colorado, just a smidge of crust, 230k:

• I thought that the driver's side and passenger's side were similarly terrible. Neither one was fun, but they were more similar in difficulty than other commenters have said.
• Driver's side requires the engine mount to be unbolted, but try and jack it up just enough that it's still hanging on the stud. If you jack it up too high, it becomes very difficult to get re-aligned. We used two ratchet straps to align the engine back with the mount.
• The oil dipstick tube isn't fun to get on after installation, but it's not that hard.
• The driver's side catalyst MUST be removed. The passenger's side does not need to be removed. Check the rear O2 gasket and replace as needed, mine was nearly disintegrated.
• The steering shaft does not need to be removed. It didn't even get in the way for me.
• I used the exhaust gaskets that came with the headers. It's nearly impossible to torque the new headers on, and the graphite gaskets that come with the DT headers seem to have a wider torque range of acceptability. I have the OEM gaskets I'll sell for cheap if anyone wants a new set.
• DO NOT USE THE SPLINE/UNIVERSAL SOCKETS that are recommended by OP. I stripped two of the nuts before abandoning those terrible sockets.
• Pursuant to the above comment, the Irwin extractor sockets (can be purchased at Lowe's) are incredible. You'll want a 3/8ths to 1/2 adapter in order to get the torque on the extractor, but it's beefy and great.
• Harbor freight sells a swivel metric socket set. Don't bother with these, the sockets aren't deep enough (3/8 in. Drive Metric Impact Swivel Socket Set, 7 Piece - https://www.harborfreight.com/38-in-drive-metric-impact-swivel-socket-set-7-piece-67908.html).
• Get the swivel adapters instead: Universal Impact Joint Socket Adapter Set, 2 Piece - https://www.harborfreight.com/universal-impact-joint-socket-adapter-set-2-piece-67920.html
• Get the flex head ratcheting wrenches, they're critical for this job. Flex-Head Metric Ratcheting Combination Wrench Set, 5 Piece - https://www.harborfreight.com/flex-head-metric-ratcheting-combination-wrench-set-5-piece-60592.html

This job is tough, but it's worth it. It's very doable, you just need time and perseverance. Both manifolds were cracked on my truck. Sounds so much better now. I'll edit the post if I think of anything to add.

Those ratcheting wrenches are definitely a cheat code for this job and make it way easier. I'm really glad I picked up a set for mine.

To clarify, I DO NOT in any way shape or form recommend those spline sockets. My original post states to avoid them as I had seen them recommended in other threads and I stripped multiple nuts before switching to a good quality 6 pt socket.

 

[Fickelson]

Those ratcheting wrenches are definitely a cheat code for this job and make it way easier. I'm really glad I picked up a set for mine.

To clarify, I DO NOT in any way shape or form recommend those spline sockets. My original post states to avoid them as I had seen them recommended in other threads and I stripped multiple nuts before switching to a good quality 6 pt socket.

Gah! My bad. You're right. I was thinking of another post that I read -- probably the same one that you referenced when you were doing your research.

Yeah the spline sockets are so terrible.

 

[AlpineAccess]

Has anyone noticed less ticking when turning off their vehicle? I'm assuming my slightly leaking manifolds are causing some weird heating up/cooling of my cats.

Also, still assuming these DT headers are not going to be SMOG compliant. Has anyone found a way to use them and clear emissions? Specifically any CO folks?