Talk me into/out of a Coil Conversion (1 Viewer)

[matmattmatthew]

I'm going to start a build thread soon, But I wanted to get a big question mark with my build decided sooner rather than later. I've parked my 62 in my detached garage for what will likely be at least a year-long rebuild/resto-mod. The truck already has significant upgrades from previous owners, suspension lift, 33's, rear mechanical locker, H55 tranny, ARB bumper, rear swing out bumper, 40 gallon (homemade) long range tank, body lift (sigh), sliders and a few other items. I'm going to start by stripping nearly everything from the frame down, dealing with some surface rust on the frame (por-15 or similar), rebuilding the axles while they're off the vehicle, and all-new suspension components before reinstalling the axles.

So I've starting thinking, if I'm already planning to remove everything from the frame, rebuild both axles, possibly install air lockers, strip/paint the frame, install all new suspension components, and get new wheels and tires. Should I just go all in and source some 80 axles, rebuild them instead of my 60 axles, and do a coil conversion?

Another thing that is tipping me to the coil conversion is my gas tank. When I bought the cruiser, the long range tank was a plus, but the gas gauge has never worked and the fuel sending unit isn't accessible from the access panel, I've also had issues overfilling the tank. Additionally, I'm not crazy about how it attaches to the truck, it has thru-bolts from the bottom of the tank up into the floor boards. So I've recently added a new long range tank to my list of things to replace. I know that if you do a rear coil conversion it requires a custom gas tank, so that fact nudges me a little more to coils.

 

[Roonie]

I don't have much to add other than it is on my list as well. I want to do it simply for ride quality. There is a reason most vehicles no longer have the old school suspension. I would love to be able to go on longer road trips (after fixing seats) and enjoy it.

 

[matmattmatthew]

I don't have much to add other than it is on my list as well. I want to do it simply for ride quality. There is a reason most vehicles no longer have the old school suspension. I would love to be able to go on longer road trips (after fixing seats) and enjoy it.

That's actually a reason I want to do it as well. I want my 62 to be an offroad rig/family camping/road trip vehicle, and if I have any hope in my wife and kids wanting to take it on trips over our other vehicles I need to make it as comfortable as possible for long trips. Lots of the work/mods I'll be doing during my build will take into account driveability and comfort.

 

[Roonie]

We have a Tesla and I absolutely hate the ride of it. It is worse than the Fj62 if you can imagine. Way too stiff. Like a sports car feel where you feel every bump and crack in the road. My modern truck fees amazing and would love the coil suspension feeling of that ride. I really enjoy driving my 62 around but I want to enjoy it even more and be able to take it on longer road trips. My max is about and hour right now.

 

[SteveH]

Simple - drive an FJ40 and your FJ62 will suddenly feel very advanced in the suspension department.

If the current suspension is a hack, perhaps you should drive someone else's FJ60/2 and see how it could feel with good/proper suspension.

 

[matmattmatthew]

Simple - drive an FJ40 and your FJ62 will suddenly feel very advanced in the suspension department.

If the current suspension is a hack, perhaps you should drive someone else's FJ60/2 and see how it could feel with good/proper suspension.

I don't disagree. My current suspension, even though its an OME kit is at least 20+ years old with blown shocks, bushings and somewhat flat springs. I have no doubt that new suspension components will make it feel 10X better. Unfortunately, I'm a chronic tinkerer, whenever I'm doing a project I always think "well, while I'm in here doing ABC maybe I should just do XYZ as well."

 

[dbbowen]

Im doing it to mine. I have some of the stuff needed. To do it right its a very very large expense. So far ive got the front and rear coil kits from Jason at trail tailor. They should be arriving anytime now. I also got some 80 series springs from him. I also have a complete 1994 unlocked FZJ80 parts truck sitting in my back yard with good condition axles. Im still WAY WAY out on funds after all of that and the brackets are pretty spendy.

Here is my estimated remaining expense. Im trying to fund this by doing side jobs only so its taking me a long long time to fund it. Ironically, the way the brackets are designed, the install looks like the least of my worries. The picture below is teh largest concern

 

[Haggis]

I considered this until I recently purchased an 80. I don't feel my 60 rides that much worse than the 80. I just want my 60 to go faster, whole nether topic for discussion...

 

[dbbowen]

I considered this until I recently purchased an 80. I don't feel my 60 rides that much worse than the 80. I just want my 60 to go faster, whole nether topic for discussion...

my end goal is ls swapped 60 on coils. It basically takes all of the best things of the 60, 80, and 100 series and puts them into one.

 

[matmattmatthew]

I considered this until I recently purchased an 80. I don't feel my 60 rides that much worse than the 80. I just want my 60 to go faster, whole nether topic for discussion...
Im doing it to mine. I have some of the stuff needed. To do it right its a very very large expense. So far ive got the front and rear coil kits from Jason at trail tailor. They should be arriving anytime now. I also got some 80 series springs from him. I also have a complete 1994 unlocked FZJ80 parts truck sitting in my back yard with good condition axles. Im still WAY WAY out on funds after all of that and the brackets are pretty spendy.

Thanks for sharing your spreadsheet, very helpful. I saw a thread somewhere and the poster said they were about 10k all-in on their coil conversion, which I think included axles.

Yes, its obviously more expensive. Part of my rationale is that with some of the costs associated with the coil conversion, I will be spending that money on the same things but for my 60 series axles and suspension. (rebuild kits, seals, brake components, shocks and other suspension items) The 2 big costs with the 80 suspension vs the 62 suspension are acquiring the axles and the Trail Tailor conversion kits.

I considered this until I recently purchased an 80. I don't feel my 60 rides that much worse than the 80. I just want my 60 to go faster, whole nether topic for discussion...

Thanks for your perspective. The H55 definitely helps the 62 feel like less of a dog, but an engine swap is planned in a couple of years.

 

[Godwin]

I considered this until I recently purchased an 80. I don't feel my 60 rides that much worse than the 80. I just want my 60 to go faster, whole nether topic for discussion...

Somewhat similar experience. My FJ60 has had an OME heavy lift with Bilsteins for a few years, after swapping out the OME shocks. Bilsteins > OME. Also have a FZJ80 that has been on stock coils, OME stock height, and now Iron Man 2" coils with Bilsteins. I've never found the ride of the 80 to be better than that of the 60. Running coils from a different manufacturer may improve the 80's ride but would the ride be substantially that much better?

 

[matmattmatthew]

Somewhat similar experience. My FJ60 has had an OME heavy lift with Bilsteins for a few years, after swapping out the OME shocks. Bilsteins > OME. Also have a FZJ80 that has been on stock coils, OME stock height, and now Iron Man 2" coils with Bilsteins. I've never found the ride of the 80 to be better than that of the 60. Running coils from a different manufacturer may improve the 80's ride but would the ride be substantially that much better?

Thanks. My original plan if I keep the 62 suspension was to get Bilstein shocks. My front shocks actually have aftermarket hoops so I can't even use front shocks made for a 62, I'll need to take measurements and order them accordingly. I'm honestly not sure why one of the previous owners changed the front shock mounts. Was that a common Mod in the 90's?

 

[Devils Paw 80]

Having owned a 62 for 20 years and now with an LX 450, my impression is about the same as Haggis said. The 80 has a wider stance, making it more stable, but otherwise the ride quality isn't significantly better than the 62. I haven't run aftermarket springs on either one of these vehicles. The stock springs, both coil and leafs, translate road bumps quite well. On the other hand, suspension flex seems much better with 80 series.

After market hoops on your 62? Lets see a photo. I've never heard of front shock mount modifications for a 60 series, so not likely a common thing.

 

[SNLC]

You can get leaf spring suspension to ride very good. It just usually takes building your own leaf packs, nice shocks and a few other things. It will still have that bumpy truck feel but it can be very minor with dialed in suspension.

We certainly would do the conversion for a customer but I usually try to talk them out of it because I have built some very very nice riding leaf spring suspensions.

Cheers

 

[matmattmatthew]

Having owned a 62 for 20 years and now with an LX 450, my impression is about the same as Haggis said. The 80 has a wider stance, making it more stable, but otherwise the ride quality isn't significantly better than the 62. I haven't run aftermarket springs on either one of these vehicles. The stock springs, both coil and leafs, translate road bumps quite well. On the other hand, suspension flex seems much better with 80 series.

After market hoops on your 62? Lets see a photo. I've never heard of front shock mount modifications for a 60 series, so not likely a common thing.

Ask and you shall receive...

Parked in her home for the next 12+ months. Still doing some cleanup and shop setup before digging too much into the build. My parents have been living at my house for the last 4 months while their house was being finished, I can't wait to get a bunch of their stuff out of the garage and get it completely set up.

 

[Haggis]

Somewhat similar experience. My FJ60 has had an OME heavy lift with Bilsteins for a few years, after swapping out the OME shocks. Bilsteins > OME. Also have a FZJ80 that has been on stock coils, OME stock height, and now Iron Man 2" coils with Bilsteins. I've never found the ride of the 80 to be better than that of the 60. Running coils from a different manufacturer may improve the 80's ride but would the ride be substantially that much better?

I've got an OME medium suspension on my Tacoma that rides a bit too stiff for my liking. Do you think if I tried going with some Bilsteins my ride would improve? Bone stock, the truck had Bilsteins from the factory and felt great. I don't do any extreme offloading with it anymore.

 

[dbbowen]

If you want to minimize road chatter digressive shocks like bilsteins are the opposite of what you want. You want a linear shock like a fox2.0 or even a progressive valved shock.

The bilsteins will give you better handling at the expense of ride comfort. Linear shocks will do the opposite

 

[dbbowen]

Thanks for sharing your spreadsheet, very helpful. I saw a thread somewhere and the poster said they were about 10k all-in on their coil conversion, which I think included axles.

Yes, its obviously more expensive. Part of my rationale is that with some of the costs associated with the coil conversion, I will be spending that money on the same things but for my 60 series axles and suspension. (rebuild kits, seals, brake components, shocks and other suspension items) The 2 big costs with the 80 suspension vs the 62 suspension are acquiring the axles and the Trail Tailor conversion kits.


Thanks for your perspective. The H55 definitely helps the 62 feel like less of a dog, but an engine swap is planned in a couple of years.

man whoever is doing the swap for 10k including brackets and axles in the purchase has got to know some people and getting deals on parts. I got my 80 series parts truck for next to nothing, and im still in way more than that haha. I also didnt include all the little nicknacks that ill need to get too such as:

Steering stabilizer, ABS blockoff plugs, potentially lengthening/shortening driveshafts, welding consumables, paint, etc haha

 

[NCFJ]

I agree with @dbbowen that doing this swap for $10K is a good deal for somebody.

I go a different route in that I put the 60 body on the 80 roller rather than 80 suspension and axles on the 60 chassis.

When you put the 60 on the 80 roller you wind up with what appears to be a stock 60 with a 2-3" lift while maintaining the stock spring height on the 80 roller. I use stock height Dobinsons progressive springs with OEM 80 series shocks most times. The result is a very well behaved, smooth riding truck. Hands down my favorite truck to date is that set up with a 6.0L and Tremec 4050 5 speed to split case.
Keep in mind that my customers are not running hard trails.

I agree that you can build a leaf spring truck that rides well. Given the choice, I'll go with the coils. Being able to swap out coils with relative ease and dial in just the ride you want is a huge selling point.

 

[Godwin]

If you want to minimize road chatter digressive shocks like bilsteins are the opposite of what you want. You want a linear shock like a fox2.0 or even a progressive valved shock.

The bilsteins will give you better handling at the expense of ride comfort. Linear shocks will do the opposite

So linear shocks degrade handling while improving ride comfort?