The truth about Spools/Welded thirds vs. the myths/urban legends...
02-10-2005, 07:29 AM
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The truth about Spools/Welded thirds vs. the myths/urban legends...
It seems to me that there is a huge misconception about how a spooled or welded third member acts on a daily driver/trail rig driven on pavement.
I feel I'm qualified to give an opinion on the topic- my rig now has over 40,000 miles of use as a daily driver and hard core trail rig with a full spool. I had a Detroit Locker prior to switching to a spool, so I'm familiar with the characteristics of an auto-locker too.
First and foremost, if you don't plan on wheelin' your rig HARD, there are much better choices for a locker. If money is no object, the Toy E-locker or ARB is always a better choice. For the casual wheeler, a drop in lunchbox locker will be a huge improvement over an open diff.
---------------------
REALITY:
You WILL wear out tires quickly. I got 14,000 miles on a set of BFG M/T's, and 19,000 on a set of MT/R's before they were shot...
MYTH:
Wet roads and a fully locked rear can be scary, I'd hate to try snow/ice.
REALITY:
Wet roads are a total non-factor.
A spool is much better in snow and ice than a Detroit Locker. A spool is 100% predictable since it never unlocks. You have to understand how it will perform on slick surfaces, and that takes a short while to learn. It tends to push the vehicle straight when turning on slick surfaces. This shows up the most on transitions between dry/wet surfaces to icy/snowy surfaces. I'll take a rear spooled vehicle over an open diff'd vehicle in snow every time.
MYTH:
At 45 mph trying to go around a curve with a spool is downright dangerous.
REALITY:
I've driven up and down curvy mountain roads for years with no problems- be it on pavement or dirt. In fact, if I didn't have 10 to 15 degrees of body roll because I don't have a sway bar, I'd bet it sticks better than an open diff does. There is a reason circle track racers use spools..
MYTH:
A welded diff on pavement will probably break axles, even full time lockers unlock some when turning.
REALITY:
Not saying it can't happen, but it's rare. I've twisted up the splines on rear axle shaft- it took one hell of a bind at the Hammers to do it.
MYTH:
Tight maneuvering on pavement sucks in a parking lot.
REALITY:
Kinda true, but it's not really any worse than it was with a Detroit. Sure it squalls and barks tires, but so did the Detroit Locker. With a P/U, the light rear end didn't unlock the Detroit as often as it might w/ a Runner. To turn into a tight parking spot, I carry enough speed into the turn to complete it with the clutch in. It seems to help unload the binding somewhat.
More Reality:
Off camber loose or slick conditions suck- but they do with any locker. Either a spool or Detroit will tend to make the rig slide down hill. A hard locked front end makes it worse...
I like a spool over a selectable in the rear diff because there is no chance of a non-catastrophic mechanical failure.
I'm currently running a front spool too. Without hydro assist it sucks. My turning ratio is horrible...
So, that's my take on the whole spool debate. As I mentioned at the top, unless your are gonna wheel hard, there are better choices, but for the ultimate in dependable, predictable, cheap traction, nothin' beats a spool.
Later
Mark
I feel I'm qualified to give an opinion on the topic- my rig now has over 40,000 miles of use as a daily driver and hard core trail rig with a full spool. I had a Detroit Locker prior to switching to a spool, so I'm familiar with the characteristics of an auto-locker too.
First and foremost, if you don't plan on wheelin' your rig HARD, there are much better choices for a locker. If money is no object, the Toy E-locker or ARB is always a better choice. For the casual wheeler, a drop in lunchbox locker will be a huge improvement over an open diff.
---------------------
REALITY:
You WILL wear out tires quickly. I got 14,000 miles on a set of BFG M/T's, and 19,000 on a set of MT/R's before they were shot...
MYTH:
Wet roads and a fully locked rear can be scary, I'd hate to try snow/ice.
REALITY:
Wet roads are a total non-factor.
A spool is much better in snow and ice than a Detroit Locker. A spool is 100% predictable since it never unlocks. You have to understand how it will perform on slick surfaces, and that takes a short while to learn. It tends to push the vehicle straight when turning on slick surfaces. This shows up the most on transitions between dry/wet surfaces to icy/snowy surfaces. I'll take a rear spooled vehicle over an open diff'd vehicle in snow every time.
MYTH:
At 45 mph trying to go around a curve with a spool is downright dangerous.
REALITY:
I've driven up and down curvy mountain roads for years with no problems- be it on pavement or dirt. In fact, if I didn't have 10 to 15 degrees of body roll because I don't have a sway bar, I'd bet it sticks better than an open diff does. There is a reason circle track racers use spools..
MYTH:
A welded diff on pavement will probably break axles, even full time lockers unlock some when turning.
REALITY:
Not saying it can't happen, but it's rare. I've twisted up the splines on rear axle shaft- it took one hell of a bind at the Hammers to do it.
MYTH:
Tight maneuvering on pavement sucks in a parking lot.
REALITY:
Kinda true, but it's not really any worse than it was with a Detroit. Sure it squalls and barks tires, but so did the Detroit Locker. With a P/U, the light rear end didn't unlock the Detroit as often as it might w/ a Runner. To turn into a tight parking spot, I carry enough speed into the turn to complete it with the clutch in. It seems to help unload the binding somewhat.
More Reality:
Off camber loose or slick conditions suck- but they do with any locker. Either a spool or Detroit will tend to make the rig slide down hill. A hard locked front end makes it worse...
I like a spool over a selectable in the rear diff because there is no chance of a non-catastrophic mechanical failure.
I'm currently running a front spool too. Without hydro assist it sucks. My turning ratio is horrible...
So, that's my take on the whole spool debate. As I mentioned at the top, unless your are gonna wheel hard, there are better choices, but for the ultimate in dependable, predictable, cheap traction, nothin' beats a spool.
Later
Mark
Last edited by crawler#976; 02-10-2005 at 07:56 AM.
02-10-2005, 02:16 PM
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Airing down tires is perhaps more beneficial in snow/ice than in any other situation we drive in. If I know it's gonna be icy, I'll drop down to 10 to 12 PSI. Deep snow over18 or so generally requires lower pressure than I run on rocks. 4 to 6 PSI seems to work great. In the attached pic, I was stuck. After going to 4 PSI, I drove out with no problems.
I don't slip or slide on corners, and in general, seem to have fewer problems in 2x4 than a lot of people do in 4x4. I don't even bother to lock in the hubs when driving in snow until it gets over 6" deep. Its rare to see snow much deeper than that on our main roads- they get the plows out pretty quick. If it is deep, its no different than wheelin off highway.
I don't slip or slide on corners, and in general, seem to have fewer problems in 2x4 than a lot of people do in 4x4. I don't even bother to lock in the hubs when driving in snow until it gets over 6" deep. Its rare to see snow much deeper than that on our main roads- they get the plows out pretty quick. If it is deep, its no different than wheelin off highway.
02-10-2005, 02:30 PM
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well I don't want to dick around with airing down everytime it snows here. Especially when you drive from snowy roads to wet roads.
Do your roads get "greasy?" They salt the ˟˟˟˟˟ out of the roads up here in NH and makes the snow greasy, gets clogged up in the tires and can make you hydro plane in a way.
Are you running a 22R(E) in your rig? My 2.7ltr is know where as dangerous as my TRD in 2WD because of the power, I must be even lighter on the peddle with the TRD.
Do your roads get "greasy?" They salt the ˟˟˟˟˟ out of the roads up here in NH and makes the snow greasy, gets clogged up in the tires and can make you hydro plane in a way.
Are you running a 22R(E) in your rig? My 2.7ltr is know where as dangerous as my TRD in 2WD because of the power, I must be even lighter on the peddle with the TRD.
02-10-2005, 04:48 PM
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The only thing dangerous about a spooled rear end is if you don't know how to drive it. Most road racers use spools and the run all sorts of conditions. The proper cornering method is to brake before the corner, easing off the brake as you turn in, and then accelerating through the apex and out of the corner. If you don't accelerate through the turn the rig wants to push straight through, accelerating causes the outside tire to drive around and it can actually be felt as the rig squares off the corner. Of course to much throttle causes massive oversteer, or "fun" 
I run a spooled rear end and am going to do the front this weekend, I also go skiing in this same rig twenty or more times a year and love my spool! I have driven auto and "lunchbox" lockers and far and away prefer the spool. The unintentional lane changes and clank and bang and worries about breakage are gone, in their place is fabulous, magnificent, traction! 
I run a spooled rear end and am going to do the front this weekend, I also go skiing in this same rig twenty or more times a year and love my spool! I have driven auto and "lunchbox" lockers and far and away prefer the spool. The unintentional lane changes and clank and bang and worries about breakage are gone, in their place is fabulous, magnificent, traction!
02-10-2005, 05:00 PM
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from what i have learned..... a spool is basically like a locker that is always locked... if you figure out how to drive it, it becomes a non issue..... yes it is a lot different from an open diff or lsd, but with any modification comes the pros/cons
the part that sucks about spools is they eat tires a little more then a locker....
the part that sucks about spools is they eat tires a little more then a locker....
02-10-2005, 05:03 PM
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Mark, the only thing I would add to your explanation is that you are EXPERIENCED at driving a locked up rig. If you were to drop in a driver who had only driven rigs with open diffs before, they would put it in the ditch.
The key takeaway I got from your post is that it drives differently from an unlocked rig. as such, those who are considering putting a spool in for that matter an autolocker need to realize that and learn to drive their rigs all over again. Once they get a feel for it, they will be able to anticipate it like you do.
I think that some of the "misconceptions" that you hear are actually good advice. People weld their diffs, then expect to hop in and drive it like they used to. It's going to handle differently and they need to be aware of that. It's going to eat tires and they need to be aware of that as well. You can learn to drive pretty much anything from a fully locked rig to a rig with sloppy steering to a rig with soft brakes, but you have to give it time to "soak in".
Good explanation, based upon experience.
The key takeaway I got from your post is that it drives differently from an unlocked rig. as such, those who are considering putting a spool in for that matter an autolocker need to realize that and learn to drive their rigs all over again. Once they get a feel for it, they will be able to anticipate it like you do.
I think that some of the "misconceptions" that you hear are actually good advice. People weld their diffs, then expect to hop in and drive it like they used to. It's going to handle differently and they need to be aware of that. It's going to eat tires and they need to be aware of that as well. You can learn to drive pretty much anything from a fully locked rig to a rig with sloppy steering to a rig with soft brakes, but you have to give it time to "soak in".
Good explanation, based upon experience.
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02-10-2005, 06:22 PM
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Im a occasional wheeler. Am I crazy to place a spool in my front diff and leave the back open? With manual hubs and 2wd on-road, my performance on-road should act like open diffs. But once I engage my hubs and 4wd my front will be locked. Is this reasonable?
02-10-2005, 06:26 PM
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a spool in the front is not a good idea... the street situation will be fine, but you need to be able to turn offroad. and a welded gear up front wont allow that, well other than something liek a 100 foot turning circle.....
also another common misconception is that welded rears is unsafe... well it could be.. done properly its fine... none of this crap of just dropping the cover and welding though, take the whole thing out and do it the right way... make sure there is no grease residue or any of that.... welds dont stick to grease
also another common misconception is that welded rears is unsafe... well it could be.. done properly its fine... none of this crap of just dropping the cover and welding though, take the whole thing out and do it the right way... make sure there is no grease residue or any of that.... welds dont stick to grease
02-10-2005, 11:30 PM
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Originally Posted by herbsblue4x4
Im a occasional wheeler. Am I crazy to place a spool in my front diff and leave the back open? With manual hubs and 2wd on-road, my performance on-road should act like open diffs. But once I engage my hubs and 4wd my front will be locked. Is this reasonable?
That guys rig was beat and went a LOT farther than mine up that trail that day! But, 
on an IFS front end I would really not recommend it, I ripped all the teeth off my IFS ring gear just running open in front. Not real strong up there. Which brings up my second favorite on the trail quote "don't spin swampers, stuff breaks" (sage advice) Try like a truetrac or something like that in back if you want to maintain good manners on road if you can't spring for the ARB, I've seen good limited slips do alot of stuff off-road, especially in both ends.
02-11-2005, 05:18 AM
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Anyone have any writeups or pictures of how you welded your diff? I see people mentioning it is okay as long as you do it "right" can someone please show me what the correct way is so I will not have any problems.
02-11-2005, 06:01 AM
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http://www.pirate4x4.com/forum/showt...ghlight=welded
Some of the original pic's are gone, but it still has some good info.
The best way to do a welded diff is to pull the carrier, clean it w/ brake parts cleaner or a super degreaser, preheat it to 400 deg is a gas grill, then burn it as shown. Then put it back in the grill and slowly bring it back to room temp.
more tips/tricks:
http://www.pirate4x4.com/forum/showt...=welded+spider
Some of the original pic's are gone, but it still has some good info.
The best way to do a welded diff is to pull the carrier, clean it w/ brake parts cleaner or a super degreaser, preheat it to 400 deg is a gas grill, then burn it as shown. Then put it back in the grill and slowly bring it back to room temp.
more tips/tricks:
http://www.pirate4x4.com/forum/showt...=welded+spider
02-11-2005, 06:45 AM
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Originally Posted by jimabena74
a spool in the front is not a good idea... the street situation will be fine, but you need to be able to turn offroad. and a welded gear up front wont allow that, well other than something liek a 100 foot turning circle.....
Its harder to turn on pavement than offroad... Because there is too much traction on both tires on the pavement, when your offroad, your tires slip with less resistance...
02-11-2005, 11:29 AM
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My bad on that post. I dont even think they make a spool for the front of a toyota.
On the pavement you would have your hubs unlocked. This means that your axles up front wont be turning. Therefore, when you turn the wheel your tires will not be spinning in unison.
On the pavement you would have your hubs unlocked. This means that your axles up front wont be turning. Therefore, when you turn the wheel your tires will not be spinning in unison.
02-12-2005, 06:53 AM
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Originally Posted by herbsblue4x4
My bad on that post. I dont even think they make a spool for the front of a toyota.
On the pavement you would have your hubs unlocked. This means that your axles up front wont be turning. Therefore, when you turn the wheel your tires will not be spinning in unison.
On the pavement you would have your hubs unlocked. This means that your axles up front wont be turning. Therefore, when you turn the wheel your tires will not be spinning in unison.
The previous owner welded my front diff. SUCKED. CV axles kept popping out, on tighter trails with sharp turns I would have to do 10 point turns. So I took the front drivetrain off and drove in 1wd for a few months before I rolled my truck (if I still had 3wd it shouldnt have happened...
) I did miss my 3wd on dune climbs and other small hills but dont know what it feels like having an open front end. Im saving up for an ARB in the rear, I think my rear end is up in the air more often.
02-13-2005, 05:28 PM
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crawler#976- Good post. I'm sick of hearing people without spools (or even without lockers) talk about the pros and cons of spools. A drunk monkey can safely drive a spooled rig.
Spools kick ass.
p.s. One thing that will definitely wear out faster with a spool or locker is the rear u-joint on your rear driveshaft. I just noticed a couple days ago that mine has gotten sloppy. It's getting replaced this week.
Spools kick ass.
p.s. One thing that will definitely wear out faster with a spool or locker is the rear u-joint on your rear driveshaft. I just noticed a couple days ago that mine has gotten sloppy. It's getting replaced this week.
02-17-2005, 07:24 AM
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i have a spool in the rear of my 86 and for a trail rig i wouldnt trade it for anything 100% locked = 100% traction/strength/reliability, ARB's are sweet but the dependability and fact there are no moving parts to break is sweet. On road manners in slow moving situations (turning) are not nearly as bad as people say, yes it takes some getting used to, faster moving situations its almost a non-factor. i have yet to encounter ice here in AZ with the spool, however wet roads are not a factor in my experience. its just like driving a lifted rig vs. non-lifted - it takes time behind the wheel but it comes quickly
only downfall i have experienced is excessive tire wear and my father hates the black marks on the nice clean driveway... ha
the strength/reliability/cost-effectiveness of a solid front axle front or rear in moderate/hard-core offroad situations will outweight anything an IFS has to offer 95% of the time...in my experience...
someday IFS will get closer to the capability but not without ALOT of R&D and $$$ for manufacturers...
only downfall i have experienced is excessive tire wear and my father hates the black marks on the nice clean driveway... ha
the strength/reliability/cost-effectiveness of a solid front axle front or rear in moderate/hard-core offroad situations will outweight anything an IFS has to offer 95% of the time...in my experience...
someday IFS will get closer to the capability but not without ALOT of R&D and $$$ for manufacturers...
Last edited by westy44runner; 02-17-2005 at 07:36 AM.
06-11-2005, 06:52 AM
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Well I should be picking up a rear 3rd member with 4.88s and lockright in it. I live in Nebraska where we get snow, ice, rain...lots of slick situations. I guess I am excited to get it locked up b/c of the ลลลล I will climb up compared to an open diff but after ready this I guess it makes me alittle nervous. Last thing I want to have happen is to push through a corner and smash up my truck. I was told by the guy who I should be buying this 3rd from that as long as I use minimal gas around the corner it is not really any different from driving my open diffs now. Any more tips you guys can give for driving a lockrite on snow/ice? Thanks.
