Topic: To SAS or not to SAS, that is the question

[Brazos Bill]

What I meant to convey is that If I had an IFS truck, the most I would do is single case gears, a rear locker, and possible traction aid up front. If you are going to spend the money and effort for dual cases, gears, lockers, driveshafts etc...I would go straight axle now. Whether it be changing the frame to pre 86 or 2wd frame wSAS, modifying your frame wSAS or getting a different truck altogether. You'll eventually break and have to upgrade every part of the IFS with that much torque on it. Not adding a locker to the front doesn't mean you won't break the front gears not to mention all the steering and axle components. If you had a 96 or later it would make more sense to keep the IFS. This is my honest opinion and I hope I don't sound like a jerk.

Thanks for the clarification.  I appreciate your honest opinion - you don't sound like a jerk at all!  This is exactly what I am trying to evaluate before spending $.

[Brazos Bill [OP]]

It’s the only TG product that I will recommend, but I have their skid plate from when Marlin sold it first and it’s like tank armor.

Thanks,  I will check it out!

[Snowtoy]

I didn't know that you can do 2wd low with the dual cases.  I have never seen a video or explanation on shifting with dual cases and how to use them for gearing options.  I understand the theory and have seen many videos of performance on the trail but how do you select shift locations in the cab with the duals?

The front case is H-N-L, the rear case works just as it does now.  Under normal driving conditions, the front case is left in H, rear case is left in 2wd.  If you shift the front into L and the leave the rear in 2wd, you have 5 2wd low range gears and reverse.  If you have 4.7's in the rear case, for for oem 4wd-L, you shift the front case into low and leave the rear in 4wd-H, from there you have multiple gear choices to find the right gear/combo for the speed you need/want.

Yes, I have tried the power braking trick, but I usually can't do it without killing the engine.  Like you, I am thinking that with the dual ultimate I can do that to engage the front - another reason I am now leaning toward doing the rear ARB and just regearing the front.

The dual cases will make it a lot easier to power brake, I usually increase the idle speed when in the rocks, and will have a hand throttle whenever I get around to running the cable.

[cbeers]

mount and skid i went front range off road but that involves welding. for bolt on I'd look at Budbuilt for starters.
CB

[Brazos Bill [OP]]

It’s the only TG product that I will recommend, but I have their skid plate from when Marlin sold it first and it’s like tank armor.

mount and skid i went front range off road but that involves welding. for bolt on I'd look at Budbuilt for starters.
CB

So I found this Heavy Duty Toyota Bomb Proof Transfer Case Mount Kit (105100-1-KIT):
http://www.lowrangeoffroad.com/heavy-duty-bomb-proof-transfercase-mount-kit.html

I assume I should use this to mount the dual transfer case and then install this Trail Gear T-Case Crossmember skidplate  (I assume that this is the one you are referring to):
http://www.lowrangeoffroad.com/toyota-off-road-parts/79-95-4runner-hilux-pickup/transfer-case/dual-transfer-case-crossmember-skidplate.html

I also found this one by BudBuilt:
http://www.lowrangeoffroad.com/toyota-off-road-parts/79-95-4runner-hilux-pickup/transfer-case/1984-1995-toyota-4cyl-dual-transfer-case-crossmember-by-budbuilt.html

Recommendations on which is better?  The Trail Gear cross member appears heavier duty…

[Brazos Bill [OP]]

The front case is H-N-L, the rear case works just as it does now.  Under normal driving conditions, the front case is left in H, rear case is left in 2wd.  If you shift the front into L and the leave the rear in 2wd, you have 5 2wd low range gears and reverse.  If you have 4.7's in the rear case, for for oem 4wd-L, you shift the front case into low and leave the rear in 4wd-H, from there you have multiple gear choices to find the right gear/combo for the speed you need/want.

The dual cases will make it a lot easier to power brake, I usually increase the idle speed when in the rocks, and will have a hand throttle whenever I get around to running the cable.

Thanks, that really helps.  So the stock 2.28 is in front and the 4.70 add on is in the back.

I have quite a few questions about the dual transfer case install, tips, and operation.  This thread is getting a bit long.  AS I am new to the forums, is it better to start a new post in the Transfer Case forum?

Thanks!

[toyodaaddict]

I run a budbuilt and it has never let me down. I used a TG on my dads 4runner, no complaints. I would recommend the budbuilt because it isn't TG  . Sky's crossmember looked like the one to get but i dont think it's still offered.

You can get those tcase mounts from 4xinnovations for a few bucks less than your link and get a better product. Or just run stock mounts.

4.70 goes in the rear case. Or you can just run a stock rear case and skip the 4.70 gear set. You wont be disappointed either way.

[cbeers]

MC offers mounts. you will want 2 for duals. if you end up going this route pm me. i have 2 brand new i will be selling at some point. i was going to go budbuilt for my build but went FROR instead.
https://www.marlincrawler.com/armor/crossmember/crossmember-mount-hd

i prefer not to buy TG unless needed but that's just an opinion.

CB

[joeyf]

Budbuilt offers a crossmember for a rotated dual case adaper.

[Brazos Bill [OP]]

I run a budbuilt and it has never let me down. I used a TG on my dads 4runner, no complaints. I would recommend the budbuilt because it isn't TG  . Sky's crossmember looked like the one to get but i dont think it's still offered.

You can get those tcase mounts from 4xinnovations for a few bucks less than your link and get a better product. Or just run stock mounts.

4.70 goes in the rear case. Or you can just run a stock rear case and skip the 4.70 gear set. You wont be disappointed either way.

Thanks for the feedback!

[Brazos Bill [OP]]

MC offers mounts. you will want 2 for duals. if you end up going this route pm me. i have 2 brand new i will be selling at some point. i was going to go budbuilt for my build but went FROR instead.
https://www.marlincrawler.com/armor/crossmember/crossmember-mount-hd

i prefer not to buy TG unless needed but that's just an opinion.

CB

Thanks!  Didn't realize MC had them - prefer MC...  Will PM you when I finalize my plans.

[Brazos Bill [OP]]

Budbuilt offers a crossmember for a rotated dual case adaper.

Thanks,  what is a rotated dual case?  I haven't heard of that before.

[joeyf]

Thanks,  what is a rotated dual case?  I haven't heard of that before.

https://board.marlincrawler.com/index.php?topic=5755.msg53975#msg53975

[cbeers]

just so nobody else learns the hard way like i did...mc does not offer clocked anymore.
see my build for how that went   

CB

[Snowtoy]

Thanks, that really helps.  So the stock 2.28 is in front and the 4.70 add on is in the back.

Doesn't have to be that way, just that is just how most used to build them.  I see Marlin sells their bolt-in crawl box w/either, so you if you buy one with 4.7's, then you would have 4.7's in the front case and stock 2.28's in the rear.

I have quite a few questions about the dual transfer case install, tips, and operation.  This thread is getting a bit long.  AS I am new to the forums, is it better to start a new post in the Transfer Case forum?

Thanks!

New thread might be helpful depending on what path you go once you get the parts, buying crawl box vs buying a used t-case, gears and installing them yourself, for now you are good, 2 pages isn't long.

[Brazos Bill [OP]]

Doesn't have to be that way, just that is just how most used to build them.  I see Marlin sells their bolt-in crawl box w/either, so you if you buy one with 4.7's, then you would have 4.7's in the front case and stock 2.28's in the rear.
 

Got it – Thanks!

New thread might be helpful depending on what path you go once you get the parts, buying crawl box vs buying a used t-case, gears and installing them yourself, for now you are good, 2 pages isn't long.

Thanks for the feedback, will keep on going for now!

[Brazos Bill [OP]]

So while looking at some of the mounts mentioned earlier I found this triple stick for dual transfer cases:

http://www.lowrangeoffroad.com/toyota-off-road-parts/79-95-4runner-hilux-pickup/transfer-case/top-shift-dual-case-triple-stick-kit-by-radesigns-rd-tsk.html

Seems like a great solution to clean up the install in the cab.  Has anyone used this?  Any thoughts?

I also saw these replacement motor mounts:

http://www.lowrangeoffroad.com/toyota-off-road-parts/79-95-4runner-hilux-pickup/engine-upgrade/bomb-proof-motor-mounts.html

Are motor mounts an issue with the dual transfer case as their write-up suggests?  Should I change them out?

Finally, I also found this extended speedometer cable they claim is needed with a dual case:

http://www.lowrangeoffroad.com/dual-transfer-case-speedo-extension-cable.html

Is this also recommended?

[emsvitil]

Another reason for a 4.7 rear is that you put a 23 spline 4.7 in the rear for more strength.   

The crawler box is then set up with a 21 spline input to mate with tranny and 23 spline output to mate with transfer.

[cbeers]

new motor mounts are a good idea. my driver's side was sheared which is somewhat common. especially with lower gearing. i bought oem but they are spendy. i bought cheaper mounts from LROR but never used them.
you might be able to reroute the speedo cable and avoid the extension but i just bought it for ease.

CB

[Brazos Bill [OP]]

new motor mounts are a good idea. my driver's side was sheared which is somewhat common. especially with lower gearing. i bought oem but they are spendy. i bought cheaper mounts from LROR but never used them.
you might be able to reroute the speedo cable and avoid the extension but i just bought it for ease.

CB

Thanks!  Any other tips when installing Dual cases?

[OVRAROK]

 My advice is, take your time. Also..., I like to use something to support the engine. Make sure to check gear engagement before installing. Be careful with the transmission output seal when installing. Also, your rear pinion angle... make sure to get a 2° drop, compared to the rear driveline angle. Triple measure. Hope all turns out well. 

[Brazos Bill [OP]]

My advice is, take your time. Also..., I like to use something to support the engine. Make sure to check gear engagement before installing. Be careful with the transmission output seal when installing. Also, your rear pinion angle... make sure to get a 2° drop, compared to the rear driveline angle. Triple measure. Hope all turns out well. 

Thanks!   

[Brazos Bill [OP]]

Another reason for a 4.7 rear is that you put a 23 spline 4.7 in the rear for more strength.   

The crawler box is then set up with a 21 spline input to mate with tranny and 23 spline output to mate with transfer.

So I have looked at the MC Case options and noticed the spline options on the site.  I see what you are referring to.  I understand that the 23 spline is stronger than the 21.  I do not understand how the splines work from the Transmission thru the Tcase to the output.  Will I need any modifications on either end of the case to make this work with my Tranny, etc?  Does my stock have 21 in and 21 out instead of the 21 in and 23 out that you reference?   

Also, I understand that I will need a longer front drive shaft and a shorter rear drive shaft with the dual Tcase.  Do I have to replace both?  If not, how do I get these modified to fit?

[Brazos Bill [OP]]

In considering the dual case and rear locker setup, I am concerned with another issue.  Last October we drove up to the top of Kendall Mountain overlooking Silverton, CO.  The trail wasn’t particularly difficult, but just short of the peak at about 12,800 ft. there was a pitch of a couple hundred yards that was a very narrow and very steep loose shale shelf road with a very steep and long drop off to the driver’s side.  I started up just fine, but about half way up it got a little bit steeper and suddenly the back end broke loose and started bouncing – towards the edge of the trail.  I have had this happen 3 or 4 times before.  Once on steep slick rock in Moab and on a couple of very steep climbs when I was on the gas to get up the incline.  Every other time I was in a spot that I could stop safely.  On this one it was downright dangerous.

Because of my previous experience I was quick off the throttle, punched the clutch and slammed on the brakes, looking at nothing but blue sky through the windshield.  I looked out the driver side window and could see straight down the mountain.  I could not see the side of the trail without opening the door.  I managed to stop a couple of feet from the edge.  The several thousand foot view down to Silverton below me was beautiful but nerve wracking.  After catching my breath I called up a spotter on the radio and carefully backed down.

Here’s a link to a photo backing down:
https://www.dropbox.com/s/jx64tt8wjzimnjo/Kendall%20Mtn.png?dl=0


Doing some research I now realize that the tire hopping I have experienced is most likely due to axle wrap caused with the rear leaf springs.  It has happened when I am on a very steep pitch and the weight of the truck is loaded on the rear axle with a lot of throttle generating heavy torque.  My concern is that with the dual Tcase and a rear locker, will I be adding to the axle wrap/wheel hopping problem in the future?

I understand that the best solution to minimize axle wrap and wheel hop (other than beefing up the Leaf pack) is to install some type of traction bar to keep the axle from turning and prevent the springs from overloading in an S configuration.  I have seen the BudBuilt traction bar and a few other solutions on line.  Has anyone  used the BudBuilt bar?  If so, can you give me some idea if it will do the job to minimize wheel hop before I proceed with the Tcase/diff changes I am considering.

Are there any other/better solutions anyone has used to eliminate or substantially reduce rear wheel hop?

[blackdiamond]

So I found this Heavy Duty Toyota Bomb Proof Transfer Case Mount Kit (105100-1-KIT):
http://www.lowrangeoffroad.com/heavy-duty-bomb-proof-transfercase-mount-kit.html

I assume I should use this to mount the dual transfer case and then install this Trail Gear T-Case Crossmember skidplate  (I assume that this is the one you are referring to):
http://www.lowrangeoffroad.com/toyota-off-road-parts/79-95-4runner-hilux-pickup/transfer-case/dual-transfer-case-crossmember-skidplate.html

I also found this one by BudBuilt:
http://www.lowrangeoffroad.com/toyota-off-road-parts/79-95-4runner-hilux-pickup/transfer-case/1984-1995-toyota-4cyl-dual-transfer-case-crossmember-by-budbuilt.html

Recommendations on which is better?  The Trail Gear cross member appears heavier duty…

That’s the crossmember that I have and am impressed with. There are other non-TG options that are also excellent. This is just a favorite of mine and the one TG product that I would probably buy that I could get from another vendor.

You don’t want the HD mounts because they don’t have the rubber to dampen the vibration unless you’re into a buggy ride.

[Snowtoy]

Doing some research I now realize that the tire hopping I have experienced is most likely due to axle wrap caused with the rear leaf springs.  It has happened when I am on a very steep pitch and the weight of the truck is loaded on the rear axle with a lot of throttle generating heavy torque.  My concern is that with the dual Tcase and a rear locker, will I be adding to the axle wrap/wheel hopping problem in the future?

I understand that the best solution to minimize axle wrap and wheel hop (other than beefing up the Leaf pack) is to install some type of traction bar to keep the axle from turning and prevent the springs from overloading in an S configuration.  I have seen the BudBuilt traction bar and a few other solutions on line.  Has anyone  used the BudBuilt bar?  If so, can you give me some idea if it will do the job to minimize wheel hop before I proceed with the Tcase/diff changes I am considering.

Are there any other/better solutions anyone has used to eliminate or substantially reduce rear wheel hop?

What you experienced on trail was due to the engine speed you needed to have to keep the engine from stalling while moving the rig forward, combined with the loss of traction, in that situation, traction bars wouldn't have prevented the wheel hop.  With dual cases you will be able to travel slower over the same terrain with a lower engine speed, think of it as trying to climb something in 1st gear 4-H vs. 4-L.  With the 4.7's and both cases engaged, your truck should be able to move over obstacles at idle rpm, or with it turned up a little.

[Brazos Bill [OP]]

What you experienced on trail was due to the engine speed you needed to have to keep the engine from stalling while moving the rig forward, combined with the loss of traction, in that situation, traction bars wouldn't have prevented the wheel hop.  With dual cases you will be able to travel slower over the same terrain with a lower engine speed, think of it as trying to climb something in 1st gear 4-H vs. 4-L.  With the 4.7's and both cases engaged, your truck should be able to move over obstacles at idle rpm, or with it turned up a little.

Well, that makes sense. 

I was heavy on the throttle to keep it going up the hill without stalling and was moving faster than was comfortable.  Going slower would have been much less scary and increased my control while improving my reaction time. Preventing the hop is a big bonus.

Another reason for the dual cases...  Now I am really getting excited about getting this done!  Sounds like this will solve many of my trail challenges.

[Brazos Bill [OP]]

You don’t want the HD mounts because they don’t have the rubber to dampen the vibration unless you’re into a buggy ride.

Thanks!  Should I upgrade the mounts?  To OEM or is another recommended?

[Brazos Bill [OP]]

your rear pinion angle... make sure to get a 2° drop, compared to the rear driveline angle. Triple measure.

Thanks!  Since installing my Old Man Emu lift I have had a vibration in the back end, particularly at high RPMs - could that be due to a steep rear pinion angle?  How do you control the driveline angle - lowering the Tcases, change the Tcase mounts, modify the axel/diff?  How do you measure/set the angle to get it right?

[OVRAROK]

Thanks!  Since installing my Old Man Emu lift I have had a vibration in the back end, particularly at high RPMs - could that be due to a steep rear pinion angle?  How do you control the driveline angle - lowering the Tcases, change the Tcase mounts, modify the axel/diff?  How do you measure/set the angle to get it right?

I purchased some new leaf spring perches. Also purchased a magnetic angle finder. Took a few measurement where old perches where located. Cut off old. Cleaned up. Tacked new perches. Installed ubolts, just enough to snug it all up. At this point. With vehicle on all four tires. I loaded roughly half my stuff that I take wheeling. Then used my floor jack and a piece of wood, placed on pinion housing. Make sure your on the housing. Using jack. I broke tack welds. This allowed me to adjust my pinion angle. Afterwords I tacked again. Then removed axle so that I could finish welding.
Regarding getting the angles dialed in...  I positioned my pinion exact with driveline angle. After triple measuring, and writing a few notes I then positioned rear pinion 2 degrees down.