[fjrohrs]

Hopefully this is in the correct place, if not Mods please feel free to move.

I am contemplating moving to a new rear-end and have a few questions for those that are either smarter than I or have already done it. The Currie rock jock 60 is the obvious choice however there are a few more out there such as Diamond that could fit the bill as well.

My question centers around upgrading now using the stock 4-link and then changing down the road to a more 'extreme' setup with an SAS or a redesigned 4 link/3 link. Will 2 inches wider on each side ( total of 4 inches ) be enough when I want to go more extreme down the road?

I'm thinking, put the new rear-end on, regear to 4.56 or 4.88, continue to run my 295's or maybe move to a 35" tire and then later when the SAS comes still be able to use the 60. What kind of widths should I be looking for and would it be possible to remove the stock geometry bracketry without harming the housing?

Not sure why people are going high-pinion either, isn't there a loss of strength with that versus a traditional setup? I imagine there is a small ground clearance increase but is an inch worth the strength loss or am I overanalyzing here?

One more question: Is it possible to go full floater and still retain all the electronics? I understand the difference between semi-floater and full but don't understand why one is better than the other if that makes sense.

As always I have much to learn to feel free to tweak my questions as you all see fit. Thanks! :cheers:

 

[Hornsfan]

Hopefully this is in the correct place, if not Mods please feel free to move.

I am contemplating moving to a new rear-end and have a few questions for those that are either smarter than I or have already done it. The Currie rock jock 60 is the obvious choice however there are a few more out there such as Diamond that could fit the bill as well.

My question centers around upgrading now using the stock 4-link and then changing down the road to a more 'extreme' setup with an SAS or a redesigned 4 link/3 link. Will 2 inches wider on each side ( total of 4 inches ) be enough when I want to go more extreme down the road?

I'm thinking, put the new rear-end on, regear to 4.56 or 4.88, continue to run my 295's or maybe move to a 35" tire and then later when the SAS comes still be able to use the 60. What kind of widths should I be looking for and would it be possible to remove the stock geometry bracketry without harming the housing?

Not sure why people are going high-pinion either, isn't there a loss of strength with that versus a traditional setup? I imagine there is a small ground clearance increase but is an inch worth the strength loss or am I overanalyzing here?

One more question: Is it possible to go full floater and still retain all the electronics? I understand the difference between semi-floater and full but don't understand why one is better than the other if that makes sense.

As always I have much to learn to feel free to tweak my questions as you all see fit. Thanks! :cheers:

I am guessing FJNewb wished he went 7" wider about now. Good to think long term (I know he changed direction mid-build so not his fault).

I am surprised you want to go SA given how much you talk about the ride quality of your new LT IFS. IMO* you will never get as good a ride quality on a solid axle as a high quality IFS set up. That said, in my opinion*, IFS will never get the articulation of a good SA set up.

I am guessing Newb, Belly Doc or SeanK will jump in on this one soon...


*notice I said "in my opinion"

 

[SouthTexasCruiser]

Diamonds were hard to get when I ordered mine. I'm not 100% sure on the other questions, but I think the 4 inches wider should be enough. You might have to mess with backspacing and maybe small spacers depending on what is included in "more extreme"

 

[fjrohrs]

I am guessing FJNewb wished he went 7" wider about now. Good to think long term (I know he changed direction mid-build so not his fault).

I am surprised you want to go SA given how much you talk about the ride quality of your new LT IFS. IMO* you will never get as good a ride quality on a solid axle as a high quality IFS set up. That said, in my opinion*, IFS will never get the articulation of a good SA set up.

I am guessing Newb, Belly Doc or SeanK will jump in on this one soon...


*notice I said "in my opinion"

You do make some good points Ryan and while I do love and have no immediate plans to change the current +2" LT suspension up front the rear will need done to give me the strength and flexibility I want now and in the future. I think if the SA is done correctly you can have a great truck for on and off road. While I have great ride quality now I will expect it in the future as well.

The nature of the beast is I love this sport and the more I get into it the more I end up challenging myself and the equipment. More opinions are always welcome buddy!

Diamonds were hard to get when I ordered mine. I'm not 100% sure on the other questions, but I think the 4 inches wider should be enough. You might have to mess with backspacing and maybe small spacers depending on what is included in "more extreme"

I see your point Nick, it is difficult to pinpoint where I will want to be in the future but doing things twice like axles is probably not in the cards at 5k a pop. I'd probably be comfortable with 37" tires on a SA but would like the option to move to 38" or 39" in the future as my needs/wants increase.

Yes some will say get a new vehicle or it's not meant to do these things but to them I say, it's only money and as long as I'm happy that's what matters. Thanks for your input and I'm excited to see the continued evolution of your truck.

 

[FJNewb]

My question centers around upgrading now using the stock 4-link and then changing down the road to a more 'extreme' setup with an SAS or a redesigned 4 link/3 link. Will 2 inches wider on each side ( total of 4 inches ) be enough when I want to go more extreme down the road?

I'm thinking, put the new rear-end on, regear to 4.56 or 4.88, continue to run my 295's or maybe move to a 35" tire and then later when the SAS comes still be able to use the 60. What kind of widths should I be looking for and would it be possible to remove the stock geometry bracketry without harming the housing?

To be honest. I'd say it depends on what you are planning to do to the rear in the long term. Will you run shocks and coils, or will you switch to coilovers. If the latter, are you going to use a shock hoop or tower and mount everything outside the wheel wells? Or are you willing to chop the wheel wells?

Those questions will help determine if your axle width is enough. Also keep in mind those tight trails you might have trouble fitting on with stock width...how much wider do you really want to go?


I'll comment on the welding, cutting, and rewelding of the axle, but the only reason I'm doing so is cause I asked the same question a week or two ago. I wanted to remove the unused shock pads from my axle that Currie welded on (reduce some of the weight). Dave's feedback was that you don't want to weld, cutoff, reweld anymore than you have to on the axle. Reason being the more heat cycles and heat you are putting into areas, the more likely you'd be to tweak the axle a bit (my shock pads remain on the axle even though they have no use, ok the one holds the track bar, but that could have been modified). That being said I'm sure a competent builder is able to chop off the mounts and reweld them without an issue most of the time. Dave was willing to and said he could, but clearly outlined the concerns in doing so.

Not sure why people are going high-pinion either, isn't there a loss of strength with that versus a traditional setup? I imagine there is a small ground clearance increase but is an inch worth the strength loss or am I overanalyzing here?

Yes to some degree, but driveshaft angles, clearance, etc are all considerations as well. Also consider your comparison from a complete perspective. Yes a standard pinion is stronger than a HP, but how much stronger is a HP 60 than the stock axle from the get go? From a relative perspective there is a substantial difference in the latter, but not the prior.

HP Currie actually has a nice oiling design for a HP.

One more question: Is it possible to go full floater and still retain all the electronics? I understand the difference between semi-floater and full but don't understand why one is better than the other if that makes sense.

As always I have much to learn to feel free to tweak my questions as you all see fit. Thanks! :cheers:

Yes, anything is possible with $$. I'll get on my old "weight" horse again and note that you should look at the weight difference between the two. Yes a full floater is stronger, but there are other tradeoffs to consider.

I am guessing FJNewb wished he went 7" wider about now. Good to think long term (I know he changed direction mid-build so not his fault).

As I mentioned in my PM, I've got ~1/4" clearance on my setup. I'll play with the b/s on the wheels a bit to mess with that, but that would be more than enough for a 35" tire (my axle is only 4" wider than stock). I don't HAVE to run wheel spacers, but I probably will to have a track width a bit closer to matching the front....the front is driving the spacers more than the rear axle setup.

But you comment alludes to my question on how he would setup the rear axle in the long term and what compromises he is willing to make. That will drive the rear axle width more than anything.

I am surprised you want to go SA given how much you talk about the ride quality of your new LT IFS. IMO* you will never get as good a ride quality on a solid axle as a high quality IFS set up. That said, in my opinion*, IFS will never get the articulation of a good SA set up.

You can make it (SA) drive well and perform well at speed. But the unsprung mass is always going to have its effect. Would it be equivalent to a similar IFS setup....nope (unless its a poorly put together IFS), but then again you'd probably have to really push the vehicle to realize that. No doubt though it'd still be better in the rocks, but at high speeds it'd wouldn't be quite the same as a LT IFS.

 

[Jim_D]

You might check with Jason (Demello) and see what he has to say. He just installed a Currie RockJock 60 rear-end on Graham's (gsgmac) FJ and was keeping the OEM front-end intact, as I understand it.

Jim

 

[fjrohrs]

To be honest. I'd say it depends on what you are planning to do to the rear in the long term. Will you run shocks and coils, or will you switch to coilovers. If the latter, are you going to use a shock hoop or tower and mount everything outside the wheel wells? Or are you willing to chop the wheel wells?

Those questions will help determine if your axle width is enough. Also keep in mind those tight trails you might have trouble fitting on with stock width...how much wider do you really want to go?


I'll comment on the welding, cutting, and rewelding of the axle, but the only reason I'm doing so is cause I asked the same question a week or two ago. I wanted to remove the unused shock pads from my axle that Currie welded on (reduce some of the weight). Dave's feedback was that you don't want to weld, cutoff, reweld anymore than you have to on the axle. Reason being the more heat cycles and heat you are putting into areas, the more likely you'd be to tweak the axle a bit (my shock pads remain on the axle even though they have no use, ok the one holds the track bar, but that could have been modified). That being said I'm sure a competent builder is able to chop off the mounts and reweld them without an issue most of the time. Dave was willing to and said he could, but clearly outlined the concerns in doing so.






Yes to some degree, but driveshaft angles, clearance, etc are all considerations as well. Also consider your comparison from a complete perspective. Yes a standard pinion is stronger than a HP, but how much stronger is a HP 60 than the stock axle from the get go? From a relative perspective there is a substantial difference in the latter, but not the prior.

HP Currie actually has a nice oiling design for a HP.

Yes, anything is possible with $$. I'll get on my old "weight" horse again and note that you should look at the weight difference between the two. Yes a full floater is stronger, but there are other tradeoffs to consider.




As I mentioned in my PM, I've got ~1/4" clearance on my setup. I'll play with the b/s on the wheels a bit to mess with that, but that would be more than enough for a 35" tire (my axle is only 4" wider than stock). I don't HAVE to run wheel spacers, but I probably will to have a track width a bit closer to matching the front....the front is driving the spacers more than the rear axle setup.

But you comment alludes to my question on how he would setup the rear axle in the long term and what compromises he is willing to make. That will drive the rear axle width more than anything.




You can make it (SA) drive well and perform well at speed. But the unsprung mass is always going to have its effect. Would it be equivalent to a similar IFS setup....nope (unless its a poorly put together IFS), but then again you'd probably have to really push the vehicle to realize that. No doubt though it'd still be better in the rocks, but at high speeds it'd wouldn't be quite the same as a LT IFS.

Brian, You make some very good points so I'll address as many as I can.

Coilovers vs. Shocks and springs with or without chopping: I am going to do my best to leave the interior of the truck unmolested, but depending on how your setup comes together that may change.

Tight trails: Honestly I don't really want to go any wider especially if I run more trails in Missouri and Illinois. Lots of trees and stumps get in the way out here and the +2" setup with my slightly different backspacing I am reaching the limit.

High Pinion strength: This was just a general question since you read something here and there and form opinions. Good to see that Currie has done their homework on cooling/lubricating though. :bigthumb:

Width I can say with certainty that before I would go to a +3.5" system I'd slap on a new front axle. The costs are so similar (fiberglass and all) and the gains in the rocks are huge with a SA. I guess I've answered the width question by talking this out haha. Just depends on whose build you look at and what your own personal goals are for the truck.

LT vs. SA I'll have to bow to your expertise on this since I've never even been in a solid axle anything but a Jeep or Superduty. Granted with the +2" setup I can't cruise at 70mph in the dirt anyway so as long as it meets my specs then I will be happy. Again this is very far down the road.

You might check with Jason (Demello) and see what he has to say. He just installed a Currie RockJock 60 rear-end on Graham's (gsgmac) FJ and was keeping the OEM front-end intact, as I understand it.

Jim

I will definitely check with the professionals when it comes down to making a final decision but wanted to get some of the veteran opinions before pursuing it further. Thanks!

 

[fjrohrs]

Forgot to address the FF vs. SF axles. What are the benefits of this on or offroad? I'm only familiar with the 91-97 Land Cruisers and most tend to swap in the FF for some benefit???

 

[FJNewb]

Coilovers vs. Shocks and springs with or without chopping: I am going to do my best to leave the interior of the truck unmolested, but depending on how your setup comes together that may change.

It all comes down to tradeoffs in the end.

Without chopping the wheel wells you basically have the following options:

1. Run a 12" or 14" shock. Won't need any wider than a 4" extension on the axle. 35" tires should just clear the top of the shock. Downside is with the 14" shock you are well below the bottom of the axle tube...pretty much a rock magnet and you aren't going to be using full travel of a 14" shock (unless you get custom springs). A 12" travel shock might be more realistic....travel numbers won't be affected too much and your gaining 2" of clearance.


2. Run a 12" or 14" coilover. 12" is more realistic than anything else without cutting the wheel wells and still keeping the axle mount fairly high. However, you need to start looking at a much wider axle. I'll have to take exact measurements as to how far recessed Dave chopped the frame on mine, but if I recall it was close to an 1". Chopping the frame and angling the tower allows it to clear by ~1/4" or so with an axle 2" wider on either. However, since you don't have that flexibility you'd need at least another 2" on either side of your axle if not more (top of the coilover takes up a lot of space if you have it in the wheel well). Unless you've got some crazy low backspacing on the wheel.

Tight trails: Honestly I don't really want to go any wider especially if I run more trails in Missouri and Illinois. Lots of trees and stumps get in the way out here and the +2" setup with my slightly different backspacing I am reaching the limit.

Sounds like you've got a good idea on the tradeoffs of going wider. Talking with Nick he's said his setup (and soon to be mine) is almost too wide for most tight trails. Speaks from experience. Also if you go wider you are getting pretty far outside the fenders, so keep in mind what your state (or others you'll be driving through) regulations are on how far outside you could be. Otherwise get ready to spend a few $$$ on fiberglass and a few more on actually getting it to fit.

High Pinion strength: This was just a general question since you read something here and there and form opinions. Good to see that Currie has done their homework on cooling/lubricating though. :bigthumb:

Either one will be much stronger than stock assuming you are running half decent shafts. I don't think you'll have an issue with going to a HP (not aware of anyone with an FJ who has).

Width I can say with certainty that before I would go to a +3.5" system I'd slap on a new front axle. The costs are so similar (fiberglass and all) and the gains in the rocks are huge with a SA. I guess I've answered the width question by talking this out haha. Just depends on whose build you look at and what your own personal goals are for the truck.

I think you might want to get some accurate estimates/quotes on a SA conversion. Yes, fenders and paint on a LT front end would offset some of the Fab costs for a SA, but the LT is also basically a bolt on mod. I'll put it this way, with the 3.5" LT front kit, I'm well under the cost of a SAC (based on the several quotes I got and feedback from those who went that route).

Unless your doing the fab work yourself, getting some sick rates, or the cost simply came down since last year a SAC and 3.5" IFS setup with fender are not going to be around the same cost.

LT vs. SA I'll have to bow to your expertise on this since I've never even been in a solid axle anything but a Jeep or Superduty. Granted with the +2" setup I can't cruise at 70mph in the dirt anyway so as long as it meets my specs then I will be happy. Again this is very far down the road.

I think SA FJ's are awesome. I'd sure love to own one, but imo its a whole lot of cost for a vehicle thats still going to be quite limited on trails (unless your willing scrape your body panels). My decision was based on the fact that, until I was ready to make the FJ a trail rig and not mind body damage, I couldn't justify the cost of a SA, for the few additional trails it'd enable me to run down here (over the LT IFS). After hearing about Nick's stroll through the rock garden at Jambo I'm happy with what the IFS can do for now. Nonetheless I'd be eager to see a well thought out SA FJ Build...go for it!:bigthumb:

 

[FJNewb]

Spenser - shoot me a PM when you get a chance. If you are really interested in a 3 link I'll make you a good deal on all the Metal Tech 3 Link parts I have (links, hoops, shocks, coils (think you already have), spacers, etc. All you'd need is upper and lower mounts for the axle and extended brake lines (have to check as I might need longer ones anyways).

Oh and I bet shipping is a whole lot cheaper when its shipped alongside a lefty transfercase!