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WHICH LOCKER? NO SLIP or Limited Slip?

10K views 26 replies 14 participants last post by  markmitch 
#1 ·
#2 ·
you do not want a solid lock posi you want limited slip. A solid lock or fully locking differential will be horrible on the street Think of both tires as your turning the inside tire as you turn would go less distance then the outside tire therefore you would eventually break something inside the axle housing and it would eat tires very quickly. I will let someone else tell you what they have and how well or badly they like it.
 
#3 ·
If you want to really improve your off-road chops a part time locker is a great choice. I'm not sure if there are any drop in's for our vans, but I used to have Tacomas with air lockers and e-lockers. Either will seriously improve your off-road capability, and do nothing for you on road. A "posi" or similar style of LSD (clutch or cone) will help you in both conditions, but is generally not recommended for heavy offroad use. You will burn up the friction material, and it will never perform like a locker.
 
#4 ·
Already have an AWD van, so you probably don't need any more limited slip than that. If you are wanting more offroad performance, then a locker is most likely what you want.

markmitch said:
you do not want a solid lock posi you want limited slip. A solid lock or fully locking differential will be horrible on the street Think of both tires as your turning the inside tire as you turn would go less distance then the outside tire therefore you would eventually break something inside the axle housing and it would eat tires very quickly.
oh my
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#5 ·
So the van sees mostly street. But I want to be able to climb hills and articulate the front and rear axles and keep traction. Same goes for when I get stuck in a deep snow bank. Anyone have experience with the powertrax No Slip locker? There are also two options available from powertrax with limited slip.

The no slip is a real locker with a spring system that unlocks it when not under much throttle.

The limited slips have two options one seems more street driven and one is more snow/off road oriented.
 
#7 ·
The item you posted is a full time locker, for a 10 bolt. It works very well, but can be difficult for some to install, especially if they are not a mechanic. Even me,being a mech. had an issue, a while back,installing one, until I reread the instructions. These "full time" "lunchbox lockers" work very well, are very strong, but you will have to learn how to drive the van differently. I could go on, but now you have to decide if you want a full time locker. Yes, 2 of my vans have them, the same part # of yours, and last summer took a 7 state road trip, in my summer AWD van. Ignore what Mark said. I hope this does not get me evctied.
 
#8 ·
Hi guys! Ok so to re connect I accidentally ordered a gm 8.5" sized LS powertrax. The astro has a 7.6" diff. This is all new to me. Ive never pulled apart a diff in my 33 years on this rock.

I read into it on the powertrax website and some amazon reviews.

The limited slip differentials and the LS and the PRO GRIP

Sounds like alot of jeepers have put the PRO GRIP in their front axles and have made plans to put it in the back axle.

I want the locker but I like turning and gassing it I am always in a hurry and this is my parts run work truck rip a round town rig.

I ordered the pro grip option. It here if you want to check it out: https://www.powertrax.com/traction-syst ... ze%3A_ANY_
 
#9 ·
I have a Eaton Detroit truetrack.

I have had it for years. It is considered a locker. It makes a very quiet sound at low speed.

Nothing ever broke. It goes sideways at will. Very drivable under normal conditions. Nail it and any slip it is locked. It is listed as a limited slip. But it isnt slipping much. Unlike a limited slip if your playing and sideways and things get hairy. Just let off the gas and it instantly unlocks and control is there no more sideways. Limited slips because of the clutches continue the side to side motion till momentum wears off.

I am abusive to it and I give it a A plus got durability and drivablility. It is rated to 850 hp.

posi.png


My tahoe has 4wd and a locker in the front axle and a limited slip in the rear. All ordered from the factory. It works just fine it isnt getting stuck. So if it is what you want it worked in that truck for 300 thousand miles so far. GM thought it was a good idea.
 
#10 ·
VanLifeFreedom said:
Hi guys! Ok so to re connect I accidentally ordered a gm 8.5" sized LS powertrax. The astro has a 7.6" diff. This is all new to me. Ive never pulled apart a diff in my 33 years on this rock.
Ohhh, gotcha, your first order wasn't what was linked in your first post. Makes more sense now.

VanLifeFreedom said:
I ordered the pro grip option. It here if you want to check it out: https://www.powertrax.com/traction-syst ... -gt247528/
:thumbup:
Hope you like it! Looks like it's the same type of limited slip(helical-gear style, limited-slip differential) as ChevyMaher has in his van. Seems like a good deal for ~$365 shipped.

Just make sure that you follow the directions exactly and set up your gears properly like you are installing a new carrier, because you are. Otherwise you won't be a happy camper for very long.
 
#11 ·
IF you are looking for the ultimate in traction and street-ability you can go twin torsens like myself and a few others have done. Constantly self adjusting torque to all four wheels ( when AWD kicks in or you 4x4 tc swap) and perfect road manners
 
#12 ·
Ah, you ordered the wrong size, got it. There is no Powertrax "pro Grip", but a "Grip Pro". it, as stated above, a helical gear limited slip, no clutches, same as the eaton truetrac, designed by gleeson/torsen many years ago,I believe. It was(may still be? used as a center differential in german cars, to split the load between front and rear differentials. I actually have heard of very few serious off roaders using them in the rear diff., but have in the front diff. Why? Because they generally require at least a small resistance on the side that is "slipping", if a tire is "up in the air", or on sheet ice, it may not function properly, unless you feather the brakes to put some resistance into the side that has no resistance. This is where a true locker, or factory gov-lok shines. However, you said you like to hot rod coming out of corners, you defiantly would not like a full time locker. A clutch type limited slip might have been your better choice, but the helical limited slips have a good reputation for being strong, being used in street muscle cars, for quite some time. Just some more info for you to digest.
 
#13 ·
x2 what Bob said. Used the brake technique with our HUMVEEs. Helical gear limited slip, gleeson/zexel/torsen/truetrack/mfactory/grip pro, and whatever other brands/models there are out there.

Edit: I made a list of all that I could find for our vans here: https://sites.google.com/site/astrosafa ... ferentials
 
#14 ·
Got a helical limited slip (Quaife) in my Sebring. Eliminates torque steer in FWD, however, as CM says, break traction on slippery roads and you go sideways real quick. However, on dry ground I get both wheels squawking from a start and as I shift to second...

-Andrew
 
#15 ·
Captn.Crunch said:
IF you are looking for the ultimate in traction and street-ability you can go twin torsens like myself and a few others have done. Constantly self adjusting torque to all four wheels ( when AWD kicks in or you 4x4 tc swap) and perfect road manners
I was wondering when you were going to chime in. :clap:
 
#16 ·
Ok I changed plans after hearing recommendations from multiple sources on the detroit trutrac. There were just too many signs that it was the one. It looks more heavy on the engineering side so I said WTH and just changed to the trutrac.

Eta feb 21-25 here is the link:

https://www.amazon.com/gp/aw/d/B003XJ80 ... prod_image

Right now the vans pulled apart at my shop at work. I will post up a hill climb video when I get it alp done. Thanks for the advice.

PS what happened was Monday my new guy came in and said he had the same LSD put in his ranger and he made it up a 2' deep snow covered fireroad hill climb and thought he was in 4 but he was in 2.

Good times love you guys smooches
 
#17 ·
LOL have fun. hard to compare different vehicles, different traction devices. Want to get serious? Buy some Ox-Lockers. We have informed you about what works, in these vans, not other vehicles. You could not give me a helical locker(limited slip, which is actually what they are),because i live in snow country. But they are great for other applications.Have fun.
 
#19 ·
Captn.Crunch said:
IF you are looking for the ultimate in traction and street-ability you can go twin torsens like myself and a few others have done. Constantly self adjusting torque to all four wheels ( when AWD kicks in or you 4x4 tc swap) and perfect road manners
Have you had issues on trails where you get wheel lift and the torsens have trouble sending any power to the wheels on the ground? Wondering if the "brake feathering" technique used with torsens on other vehicles works just fine on the astro/safari with the twin torsen setup.
 
#20 ·
I have yet to have to do the wheel in the air brake pedal thing. I'm not sure if that's because I've never lifted a wheel due to the amazing articulation built into our vans( sarcastic wink nod) or because the remaining axle with both wheels on the ground got us through without a hiccup. Torsens all act the same so if riding the brakes worked in a military humvee it'll work in an astro van.
 
#21 ·
Captn.Crunch said:
I'm not sure if that's because I've never lifted a wheel due to the amazing articulation built into our vans( sarcastic wink nod)
LOL, come on, the body flex gives us an extra 2" ;)
 
#23 ·
Captn.Crunch said:
I have yet to have to do the wheel in the air brake pedal thing. I'm not sure if that's because I've never lifted a wheel due to the amazing articulation built into our vans( sarcastic wink nod) or because the remaining axle with both wheels on the ground got us through without a hiccup. Torsens all act the same so if riding the brakes worked in a military humvee it'll work in an astro van.
Cool beans, thanks for the input.
I figure there would be a decent amount of wheel lift offroad with these vans (due to the wonderful articulation you mentioned), so I wasn't sure if that would be the achilles heel of the twin torsen setup
 
#24 ·
Avoid the Auburn Limited Slip Carrier, I installed one in my 1965 Impala, 383CID, Muncie M20, 12Bolt. The Center Bolt safety pin is always Sheared off. I found this problem twice, NOT GOOD. This could allow the pin to walk out and really destroy everything!
Beware...
 
#25 ·
I did the Eaton Posi Traction. I wanted the best setup for running snow covered roads over the sierras. the advantage of the posi is that it is always in limited slip mode. the time that traction is going to break loose at highway speeds is when you engage or disengage force to the drive wheels. On a manual trans I have seen jeeps spin around when people let out the clutch on up or downshift. the Torsen is constantly locking and unlocking between open and limited slip giving muliple opportunites for that sudden traction loading to break a wheel loose. So far the van has been amazing on my multiple snow covered trips over I80 and Carson pass (88) over the sierras in CA. I have had it off on the logging trails to get firewood and I just can't get the thing stuck you just keep power to the wheels and load up the LS differential and it just works it way out. I think the eaton posi was an option from the factory on these vans but not totally sure. I thought abotu doing the Torsen as well but opted for the one that met my needs the best. I run the Kumho AT51's https://www.tirerack.com/tires/tires.js ... nture+AT51
and the combination of this mountain snowflake rated tire and the posi are a great combination. The treadwear is not great on them but that is the trade off for traction. they are also cheap. I got a set of 4 installed at sams club for $442 OTD with their free install deal.
The torque biasing is 35/65 front/rear so I felt that the front LS was not really needed. I would probably do the Torsen in the front if I did as it is basically an open diff for most street driving and turning. U can feel the LS grip if you do a slow full lock turn on the dry pavement as well. you have to apply the gas to get through the turn else the resistance with bring the van to a stop.
 
#26 ·
The Trutrac/Torsten is definitely not a locker, it is posi-traction/limited slip. I've been running one for over a decade now. While it improves traction when both wheels are on the ground, it is useless when one wheel is off the ground as is quite common in trail situations. The "braking method" has had no significant affect in reducing off ground wheel spin.

There are currently no selectable lockers for the GM 7.5" which has always been surprising as there are hundreds of thousands of these rear ends under S-10s. I can only guess the manufacturers feel the rear end under built for locking with large tires.

This is the sole reason I'm currently building a Ford 8.8 with Eaton locker (if they ever send it).
 
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