Fj80 axle/coil swap

ChuckB · 10-10-08, 11:55 AM

Nice build! I have been waiting for someone to do this recently. I would love to pick up another 60 and do the same thing.

DBS311 · 10-10-08, 01:23 PM

Putting coils on my 62 has always been in the plans, but it won't happen for a few years. I will probably end up keeping my factory front axle and using Cage Offroad radius arms, a one-off panhard and some nice coilovers. I'd love to compare the ride of the coils to the standard leaf springs. I'm betting it will be cush.

Mor4wd · 10-16-08, 08:07 PM

Well not much new as of now. I had a few hours to work on it this week but it looks about the same. I do have a question though, might be better to ask in the 80's section, but oh well. Im looking into running FRONT 80 coils in the REAR due to it being very tight back there. What are the differences in the front and rear springs? The front should be stiffer due to the motor no? Any help would be great. Cheers

ginericLC · 10-16-08, 08:33 PM

Cruiser Outfitters

This should help you if going OME. It doesn't have the stock rates. Actually the rates vary quite a bit by year and whether it had 3rd row seats. Even the number of wraps on the coils varies from application and year. Maybe one of the 4Runner guys has figured them out? The later model ones are using the front stock 80 coils to get about a 3.5" lift for their 4 Runners.

I hadn't seen your project before I'm definitely interested. I'm working on dropping a 60 body on an 80 chassis right now, I have a new set of OME J springs sitting on the shelf for that part of the project. But that isn't why I'm interested. I think I picked up another 60 today and I immediately thought to myself I need to put coils on it.

And I've been there and done that, hacking up an 80 frame for the mounts. A friend of mine is putting 80 suspension under his 55. It is a pain. However, I came away with a real respect for how stout Toyota frames really are.

The coolest suspension set up I've seen is a military jeep buggy running air shocks (no coilovers). It flexed awesome but what I liked about it is that it was completely quiet. The only thing you could hear was the tires squeeking on the rocks. No clanking or binding suspension sounds. It would be tough to engineer something like this in a full bodied wagon.

One last thing, dropping down on rocks with 80 front control arms is no big deal (someone commented on this). They actually slide better than leaf springs, especially if you have to go backwards.

Mor4wd · 10-16-08, 08:54 PM

The later model ones are using the front stock 80 coils to get about a 3.5" lift for their 4 Runners.

They are putting the front 80 coils in the rear of the 4 runners?

And I've been there and done that, hacking up an 80 frame for the mounts. A friend of mine is putting 80 suspension under his 55. It is a pain. However, I came away with a real respect for how stout Toyota frames really are.

Amen. The fzj80 frame is BEEF. In some spots its triple walled!

The coolest suspension set up I've seen is a military jeep buggy running air shocks (no coilovers). It flexed awesome but what I liked about it is that it was completely quiet. The only thing you could hear was the tires squeeking on the rocks. No clanking or binding suspension sounds. It would be tough to engineer something like this in a full bodied wagon.

That would be nice but I plan to load this thing up with gear and tow. Neither of which would be too nice with air shocks.

One last thing, dropping down on rocks with 80 front control arms is no big deal (someone commented on this). They actually slide better than leaf springs, especially if you have to go backwards.

Exactly what i thought! Cheers

ntsqd · 10-16-08, 09:21 PM

So long as they are not a progressive wound coil spring, it is fairly easy to calculate the rate. A qwik google turned up this on-line calculator:
Pro Shock Coil Spring Rate Calculator

Another that might be a real bonus when fine tuning time comes along:
Sway-A-Way Calculators

If you want to see the math going on behind the scene:
Suspension Coil Spring Rate Design Equations Formulas Calculator

Others:
F-O-A OFF-ROAD Shock Absorbers
Coil Spring Rate Calculations by Wallace Racing

I believe that the air shocks mentioned are an air spring built into a monotube shock. Quite robust, but typically those are not good at carrying much weight or going very fast (temperature largely varies the spring rate). They are quite popular in light weight crawlers as they are simple and effective for that application.
What a friend has talked of doing, but has yet to actually do, is to put a single (large?) air spring at the center of the rear diff. It would carry the weight w/o having a huge effect on articulation. FFT

Mor4wd · 10-16-08, 09:51 PM

Thats would all be great if i knew the weight of my 60. As far as i understand, by figuring out spring rate ill know the static height of the spring when put under the weight of the truck, correct? Now a progressive spring(which an 80 spring is??) is another calculation? Math was never my best subject.
I really just want to know if it will work, what are the pros/cons.

Quote:

Originally Posted by ntsqd

So long as they are not a progressive wound coil spring, it is fairly easy to calculate the rate. A qwik google turned up this on-line calculator:
Pro Shock Coil Spring Rate Calculator

Another that might be a real bonus when fine tuning time comes along:
Sway-A-Way Calculators

If you want to see the math going on behind the scene:
Suspension Coil Spring Rate Design Equations Formulas Calculator

Others:
F-O-A OFF-ROAD Shock Absorbers
Coil Spring Rate Calculations by Wallace Racing

I believe that the air shocks mentioned are an air spring built into a monotube shock. Quite robust, but typically those are not good at carrying much weight or going very fast (temperature largely varies the spring rate). They are quite popular in light weight crawlers as they are simple and effective for that application.
What a friend has talked of doing, but has yet to actually do, is to put a single (large?) air spring at the center of the rear diff. It would carry the weight w/o having a huge effect on articulation. FFT

silicon_toad2000 · 10-16-08, 11:23 PM

please excuse the noob question...
what's the advantages of doing this over just buying an 80 in the first place? is it just a $$ thing?

Mor4wd · 10-17-08, 01:08 AM

Quote:

Originally Posted by silicon_toad2000

please excuse the noob question...
what's the advantages of doing this over just buying an 80 in the first place? is it just a $$ thing?

Im doing it because I want to.

Reason enough? I just enjoy trying new things. Plus i like the 60 more than an 80. I have both but have always liked the 60 more. Cheers

ginericLC · 10-17-08, 06:00 AM

Yes, Late model 4runners use the front 80 springs in the rear. Pre98 use the rear ones in rear. It has created a market for used 80 springs.

I saw your post over in the 80 section too. You might try to find some matched 80 springs. Get one Left Front from one rig and another Left Front from another. This would balance it out as the 60 rear end is pretty well balanced with the tank centered. And like I posted earlier, spring rates changed both front and rear several times. You can match them up by the colored dots. I'm thinking the tallest springs I've seen have been out of the FJ80s. I've parted a few 80s and lifted a lot of them. The lowest ones I've seen were out of an 97 LX w/ 3rd row seats. I've heard mixed reports about whether or not the LXs have the same springs. I've never done a 97 Cruiser so I couldn't compare them to the LX springs.

Mor4wd · 10-17-08, 10:51 AM

Well it good to know that they run the fronts in the rear. The thing is, I plan to run lift springs. Do they also come in a right and left? Id assume the driver side is a bit taller due to the fuel tank? If thats the case, I think Id need to swap right for left and viseversa since i have all off my tools and what not on the passenger side drawer system. I guess when I figure out what lift springs I need, Ill have to play around with swaping them around. Thanks for all the help. Ill try and get some more pictures up this afternoon.
Aaron

Quote:

Originally Posted by ginericLC

Yes, Late model 4runners use the front 80 springs in the rear. Pre98 use the rear ones in rear. It has created a market for used 80 springs.

I saw your post over in the 80 section too. You might try to find some matched 80 springs. Get one Left Front from one rig and another Left Front from another. This would balance it out as the 60 rear end is pretty well balanced with the tank centered. And like I posted earlier, spring rates changed both front and rear several times. You can match them up by the colored dots. I'm thinking the tallest springs I've seen have been out of the FJ80s. I've parted a few 80s and lifted a lot of them. The lowest ones I've seen were out of an 97 LX w/ 3rd row seats. I've heard mixed reports about whether or not the LXs have the same springs. I've never done a 97 Cruiser so I couldn't compare them to the LX springs.

Mor4wd · 10-17-08, 07:52 PM

A bit of an update. Got the front end pretty much done. Slee diy panhard adjuster came today as long as so 2" coil springs, even though I should have gotten 3" springs. Just shocks and finish work up front left. The rear, ugh. Things are tight back there but I'll make it fit. Actually everything is not bad but I have no idea where I'm going to place the shocks yet, there is just no room. Still waiting on a drill bit to come in the mail so i can tap my links for the ends.
If anyone has a lead on a stock front coil bucket of an fj80 let me know! They would work perfect in the rear.

Mor4wd · 10-17-08, 07:53 PM

more....

Mor4wd · 10-17-08, 07:54 PM

last two...

ginericLC · 10-17-08, 10:25 PM

I think you can order the coil buckets new from Toyota. I think they aren't too badly priced if you get them from CDan or Toyota of Dallas etc... I think this is what Christo Slee did when he built his solid axle 100.

Mor4wd · 10-17-08, 11:13 PM

Quote:

Originally Posted by ginericLC

I think you can order the coil buckets new from Toyota. I think they aren't too badly priced if you get them from CDan or Toyota of Dallas etc... I think this is what Christo Slee did when he built his solid axle 100.

Well I guess if you consider about $160 a piece from Dan not to badly priced. A little much for coil buckets. I'd like to find a frame that I could cut up or I'll just get some universal buckets. Cheers

ntsqd · 10-19-08, 07:26 PM

If you know the spring rate of any given spring then you can either predict what it's ride height will be if you also know the weight on the spring or you can calculate the weight on the spring by measuring how much the spring compressed.

To be honest, short of laboriously measuring each different section of the spring and doing the calc separately I'm not sure how to calculate the spring rate of a progressive wound spring. I'd have to look it up.

If the weight on each respective tire is roughly the same from your 60 to a representative 80 it's probably not worth doing the calcs. If you want something that doesn't have a close match then it might be.

Wow! I ordered the very last stock front upper shock bracket crash replacement part in the U.S. for my Xcab mini and was only something in the $30 range!
Might measure the OD of the springs that you want to use and compare them to the spring buckets used on Ford TIB's & TTB's under the pick-ups and Broncos from 1965 thru sometime in the mid to late 80's. I'm thinking that they are really close in spring size, and they should be a simple find in the JY. Their coil spring buckets are usually riveted to the frame. Would probably want/need to trim the Ford parts down as they are a bit klugey, but it's one option.

Mor4wd · 10-19-08, 07:39 PM

Quote:

Originally Posted by ntsqd

If you know the spring rate of any given spring then you can either predict what it's ride height will be if you also know the weight on the spring or you can calculate the weight on the spring by measuring how much the spring compressed.

To be honest, short of laboriously measuring each different section of the spring and doing the calc separately I'm not sure how to calculate the spring rate of a progressive wound spring. I'd have to look it up.

If the weight on each respective tire is roughly the same from your 60 to a representative 80 it's probably not worth doing the calcs. If you want something that doesn't have a close match then it might be.

Wow! I ordered the very last stock front upper shock bracket crash replacement part in the U.S. for my Xcab mini and was only something in the $30 range!
Might measure the OD of the springs that you want to use and compare them to the spring buckets used on Ford TIB's & TTB's under the pick-ups and Broncos from 1965 thru sometime in the mid to late 80's. I'm thinking that they are really close in spring size, and they should be a simple find in the JY. Their coil spring buckets are usually riveted to the frame. Would probably want/need to trim the Ford parts down as they are a bit klugey, but it's one option.

Thanks for the info. I ended up ordering some custom coil buckets. Now I need to find LOWER spring mounts which I think might be more difficult since the springs are not flat on the bottom. Ill update the tread tomorrow.

ntsqd · 10-21-08, 09:45 AM

The Ford option might still be a good one. Those with radius arms and live axles have a lower spring seat that bolts onto the top of the radius arm where the cap also bolts to the radius arm. The TIB/TTB's bolt the lower spring seat with the radius arm to beam bolt.

Had another, simpler thot on how to find the spring rate, but I suspect that you're past that point.

ginericLC · 10-25-08, 06:58 PM

I was watching the new Dodge truck ad. Their coils look similar to an 80 set up. Finding a Dodge to steal coil buckets off of would be easier than finding an 80 to do it. Ah, idea. PM rockreeper He's got some 80 axles he's stuffing under his 40. He might have what you need.

rdublt1 · 10-26-08, 09:39 PM

Quote:

Originally Posted by Mor4wd

A bit of an update. Got the front end pretty much done. Slee diy panhard adjuster came today as long as so 2" coil springs, even though I should have gotten 3" springs. Just shocks and finish work up front left. The rear, ugh. Things are tight back there but I'll make it fit. Actually everything is not bad but I have no idea where I'm going to place the shocks yet, there is just no room. Still waiting on a drill bit to come in the mail so i can tap my links for the ends.
If anyone has a lead on a stock front coil bucket of an fj80 let me know! They would work perfect in the rear.

You may be able to run the shocks tucked up just behind the coils springs or actually mount them to the radius arms?

ntsqd · 10-27-08, 07:50 AM

EB's & F-100's run the shocks mounted on the radius arms. Not ideal, but it works. Ideal is as close to the tire as is reasonably possible. Reality will probably want something different.

Mor4wd · 11-05-08, 07:42 PM

Well no pictures but some update. Sadly it will not be finished for surf&turf. Ill have to drive up in my, ugh, range rover.

Anyway, I found some upper coil buckets from ballistic fab that fit and used them for the rear. For the lower mounts I modified the stock mounts by cutting them in half both ways and sectioning out enough to make them fit in the coils. Right now I'm painting all the parts for final assembly, but will do that after surf&turf. I need to get some pictures for you guys, Im terrible at remembering to take pictures.

Mor4wd · 11-05-08, 10:09 PM

btw, what kind of grinding disc does this?

mtntoys · 11-06-08, 06:07 PM

Flap disc

chappysfj40 · 11-07-08, 07:22 PM

you can get them flap disc in a few differnt grits, like 60, 80, 100, 150, and maybe a few more. great little discs

flyology · 11-09-08, 05:25 PM

Any more updates on this conversion? I am very interested, considering this swap also, but would like to keep the 60 series large diff centre. Do 80 series swivel hubs fit on a 60 diff? Do you have to have the hi pinion centre for this conversion? reason is I have a factory cable locker front axle in my 60....

Mor4wd · 11-19-08, 10:07 PM

Update:
Ill try and get some pictures up tomorrow.
Im nearing the completion! finished up all the shocks and both sway-bars today. Still left to do: fuel lines, brake lines, front drive-shaft, still need rear brake rotors, and I'm sure plenty of small things will show up.
I masked my fenders today where I'm going to cut but didn't make a cut yet, cutting the body is a bit unnerving.

I did find something of concern though, I pulled the drain for the front diff and found what the pictures show

. Some small metal shavings and the magnet seems to be exploding? Are the shavings normal? Any thoughts on the plug? I really dont want to pull the diff out.

Mor4wd · 11-19-08, 11:39 PM

One more question. Im about to order some air bumps and Im not sure which ones to get. Ive got it set up for 4" of up travel in both front and rear. The question is, do it get the 2" bumps and have 2" up travel before i hit the bump; or do i get the 4" bump and have the bump making contact at ride height? Seems if i did the later it would firm up the suspension too much maybe? But a 2" bump seems sooo short? Help.

Also, are the bumps designed to bottom out or what?

GLTHFJ60 · 11-19-08, 11:51 PM

Bummer about the front diff. If it's going to be part time, which I can only assume since it's going to be in a 60, then I'd say leave it but make sure to change the gear fluid after the first 4wd venture.

As for the bump stops, I'm pretty sure it's not a good thing to have the truck ride on them. How's the 80 set up as for stock height up travel?