Full Float Rear Axle Conversion - and FF mods

[mrlocksmith]

I am considering putting in FF Rear Axles in my Expo Rig. And have a few ?'s

1) I read a post that said the Semi Float 3rd Member I have on my '85FJ60 will take the FF axle... does anyone know any different?

2) I can get a used hub to hub one from SOR for $450, and a "Reconditioned" one for $1250.00 from Man-A-Fre. If you buy used and get the seal/bearing kit you still come out way ahead over the $1250.00, what's up with that ???

3) I assume I can still use my stock '60 drum brakes and wheels? (Disc's to come later)


Thanks


Mark

 

[ntsqd]

Did you include the new/rebuilt brake parts that MAF includes in the rebuilt axle price?

 

[euclid]

1. I haven't bolted up a 3rd from a sf into my FF, but I can't think of why it wouldn't work if the splines match up. Others have said here on mud that it should work.

2. Neither site is clear on what is included in the reconditioning. Check with them and SOR and find out exactly what is included in the sale. If MAF ships a full axle and 3rd with a disc conversion for 1200, thats a better deal than a striped down axle with no brakes. Find out exactly what they are selling you and holler back.

If you have rebuilt a front axle before then rebuilding a FF with new seals and bearings should be no problem. It's basicaly the same process without a birfield. I'm not sure what else MAF does to recondition them.

3. The FF axle should have drum brakes on it. Wheels are the same.

 

[ntsqd]

I called MAF a couple months ago about their FF axle. No 3rd in either case. The low priced one's condition is luck of the draw. The $1200 axle has all new wear items.

 

[euclid]

I called MAF a couple months ago about their FF axle. No 3rd in either case. The low priced one's condition is luck of the draw. The $1200 axle has all new wear items.

What about brakes? brake lines?

 

[ntsqd]

I was given the impression that the calipers were either new or rebuilt (suspect the latter), no idea about the plumbing. Though the impression that I was left with is bolt it in, bolt in a 3rd, fill with oil, hook up the brakes, and drive it.

 

[euclid]

That's not a bad deal if that's what they are selling. If for no other reason than the convenience.

 

[GLTHFJ60]

$OR is charging $450 for a stripped FF housing? Damn, I guess I got a good deal.

From my research, putting a FF in is a bolt in operation assuming you have a complete axle. You should be able to use your SF thirds in the FF housing, but the thirds will be arguably weaker due to the slots needed in them for the c-clips. The housing bolt patterns are the same as far as I know.

 

[ntsqd]

That's not a bad deal if that's what they are selling. If for no other reason than the convenience.

I am very tempted to go with their low dollar option and deal with the rebuilding myself. Then, right or wrong, I know what went into it.
The one thing that I'm unclear on with this is what exactly the caliper is. It may be that MAF is the only source for it, I do not know. IF that is the case I'll 86 it and find something more common.

 

[euclid]

$OR is charging $450 for a stripped FF housing? Damn, I guess I got a good deal.

From my research, putting a FF in is a bolt in operation assuming you have a complete axle. You should be able to use your SF thirds in the FF housing, but the thirds will be arguably weaker due to the slots needed in them for the c-clips. The housing bolt patterns are the same as far as I know.

It is a houseing plus the shafts, isn't it? I would think using SF thirds would make the whole thing weaker by a neglidgable amount at most.

I am very tempted to go with their low dollar option and deal with the rebuilding myself. Then, right or wrong, I know what went into it.
The one thing that I'm unclear on with this is what exactly the caliper is. It may be that MAF is the only source for it, I do not know. IF that is the case I'll 86 it and find something more common.

If I bought an axle with no brakes on it I'd go ahead and do rear disks on it before install rather than move brake housing stuff over.

Isn't there a brake backing plate on SF axles? The part that the calipers bolt to. Is it bolted on like on the FF, or is it welded on? I'm haveing a hard time picturing it in my head.

 

[DirtyLittleSecret]

Geez, you could get Poly axles for the cost of shipping alone, and still have commonly available parts availability wherever you go...why go with the FF?

 

[Spook50]

I am very tempted to go with their low dollar option and deal with the rebuilding myself. Then, right or wrong, I know what went into it.
The one thing that I'm unclear on with this is what exactly the caliper is. It may be that MAF is the only source for it, I do not know. IF that is the case I'll 86 it and find something more common.

My money is on that caliper being a GM of some sort. It looks very similar to a Mone Carlo caliper (which I run on my SF), but not quite identical.

Someone a while back modified steering knuckle housings to mount 60 series front calipers on a FF rear end. Looked like a damn good way to go. That's what I plan to do once I get a FF, and I'll run my SF 3rd while I try to source an 80 series e-locked 3rd.

Greg, IIRC the backing plate is bolted to the axle housing on a SF. I remember having to pull my shafts completely out to do the disc conversion, and I'm pretty sure this was why.

DLS, one big reason: cool factor. Just like with my Aussie sliders. I didn't need 'em, but I'll be damned if they don't look cool as hell (and unique) on my 62 and are worth every penny I spent on 'em.

 

[ntsqd]

We're testing my sometimes fragile memory here. What I recall is that the low dollar option also has all of the brake stuff, hub stuff, and axle shafts. They just have not been rebuilt. B4 spending money I would confirm this.

Typically an OE caliper bracket bolts on like a drum backing plate. If an axle started out with drums and then got discs usually the disc assembly is retrofitable to an earlier housing. Not always, but usually. Given that the drum brakes will work on these axles, the disc assembly could probably be fit to an SF if available separately. Only issue would be piston knock-back from the axle being able to move slightly. If it really is a sliding caliper (picture is poor) then this is much less of an issue as the caliper is more likely to 'follow' the rotor.

I recall asking about the caliper's origins and being told that it was toyota, but not common in the U.S. Which is why I would likely dump it unless a common U.S. application (like a Supra) caliper was found to fit & work. I have zero interest in a GM caliper. Even the Metric version is too big to get a near ideal hydraulic balance match w/o prematurely resorting to a proportioning valve. Early 2wd minis with disc brakes used a fixed 2 piston caliper that is very similar to the 4 pistons used on all of the older 4WD's. I suspect that these would be a good rear brake option, but I've yet to get one & measure it's piston OD. The later front disc mini's used a sliding caliper and those in general tend to be harder to adapt.

Unless the C-Clips are eliminated a sliding caliper is the best choice. Part of why personally would want to do this would be pedal feel and sliding calipers just aren't rigid enough for my taste. Frankly, for an SF rear disc conversion I would seriously look into the Explorer conversion. They have a pair of drum parking brakes, which is a far better static location holding design than a disc, and they have a reasonably small caliper piston, which puts the hydraulic balance closer to where it needs to be. The one up/down side is that it would require going to a C-Clip eliminator, specifically the 'Torino' Ford bearing housing. Which likely would require new axle shafts.

In my case, no shipping. I can make it there on a weekday (just barely!) before they close.

 

[GLTHFJ60]

Oh, if the low dollar option is everything without the third then go for it. As euclid said, the FF vs SF third strength issue is negligible.

I got my FF from a friend complete hub to hub for a little less than that, but I had to drive 6 hours to get it.

 

[DirtyLittleSecret]

My money is on that caliper being a GM of some sort. It looks very similar to a Mone Carlo caliper (which I run on my SF), but not quite identical.

Someone a while back modified steering knuckle housings to mount 60 series front calipers on a FF rear end. Looked like a damn good way to go. That's what I plan to do once I get a FF, and I'll run my SF 3rd while I try to source an 80 series e-locked 3rd.

Greg, IIRC the backing plate is bolted to the axle housing on a SF. I remember having to pull my shafts completely out to do the disc conversion, and I'm pretty sure this was why.

DLS, one big reason: cool factor. Just like with my Aussie sliders. I didn't need 'em, but I'll be damned if they don't look cool as hell (and unique) on my 62 and are worth every penny I spent on 'em.

The cool factor definitely lays with the FF.

 

[euclid]

We're... <snip>
In my case, no shipping. I can make it there on a weekday (just barely!) before they close.

I've never considered the floating caliper as the source of the less-firm pedal. Makes sense. The swap to fj80 master cylinder firmed mine up enough for my tastes. A risidual pressure valve would do it even more.

On the issue of the SF to FF conversion: cool factor is certainly part of it, but not all for me. There's no doubt that the FF has a heavier load capacity. The bearings and seals are all available in the US parts system. The spindle is the only thing that isn't avalible, and you have to be as careless as me to trash one of those. Put all that together with the fact that a broken rear axle shaft on a FF doesn't keep you from driving home like a SF does and I think there's a reason behind the cool factor.

All that being said, if you don't wheel your truck it is just cool factor.

I went to FF, RDB, front locker, 4:88's and longfields in a package deal from sixty (cory) for around 2K. It was a no brainer enough that I used a credit card, which I don't do very often. All I had to do was re-weld the spring pearches and bolt it up.

 

[HighPlainsDrifter]

I've been thinking about putting an 80 series rear FF with the factory locker and factory disc brakes in mine. If memory serves correct it is a total of 3 inches wider, so that would only be 1.5" on each side. No big deal right? Plus you could get all the factory Toy parts that you need here in the U.S. You would have to change the master cylinder and maybe the booster. The only real problem I can see is welding new spring perches on, which really ain't a problem ,just an obstacle. Anybody out there already done a swap like this before?Of course the cool factor for a factory 60 FF with discs is probably a little higher than with a swapped in 80 series.

 

[GLTHFJ60]

I've been thinking about putting an 80 series rear FF with the factory locker and factory disc brakes in mine. If memory serves correct it is a total of 3 inches wider, so that would only be 1.5" on each side. No big deal right? Plus you could get all the factory Toy parts that you need here in the U.S. You would have to change the master cylinder and maybe the booster. The only real problem I can see is welding new spring perches on, which really ain't a problem ,just an obstacle. Anybody out there already done a swap like this before?Of course the cool factor for a factory 60 FF with discs is probably a little higher than with a swapped in 80 series.

Fogblanket did in his 62. If memory serves me correctly, he used a sky widening kit on the front axle to offset the difference in width.

He's selling his rig, so it should be in the Vehicles classified section.

 

[Spook50]

I've been thinking about putting an 80 series rear FF with the factory locker and factory disc brakes in mine. If memory serves correct it is a total of 3 inches wider, so that would only be 1.5" on each side. No big deal right? Plus you could get all the factory Toy parts that you need here in the U.S. You would have to change the master cylinder and maybe the booster. The only real problem I can see is welding new spring perches on, which really ain't a problem ,just an obstacle. Anybody out there already done a swap like this before?Of course the cool factor for a factory 60 FF with discs is probably a little higher than with a swapped in 80 series.

Not a bad idea. You'd have to weld spring perches to it though for the leaf springs.

I was just talking with a couple guys last night about how cool it would be to convert to coil springs on a 60 series. Be a helluva lot of work though...

 

[HighPlainsDrifter]

Fogblanket did in his 62. If memory serves me correctly, he used a sky widening kit on the front axle to offset the difference in width.

He's selling his rig, so it should be in the Vehicles classified section.

Sky widening huh? I'll have to check that out.I was planning on just living with difference but that might change my mind. I got to do a cut and turn first anyway so the rear is a ways out....its all just $$$$$$$... and time of course.