Powertrax No-Slip Question

[Robert]

Powertrax No-Skip Question

For those of you that are also running the No-Slip, do you get a very harsh and loud "bang" when coming to a stop. I know it is my locker unlocking right before I stop. it is bad enough that the rear end of my truck changes directions. My locker has about 1500 miles on it and it didn't do it when first installed. I took it back to Desert Rat and they claimed that all it needed was to change the differential fluid. They said that after 1000 miles with new gears the fluid breaks down. They said the locker looked fine and there wasn't anything to be conserned about. It drove great on the way home from there, but the next day the problems started up again. Also, when going from reverse to drive or vice-versa, I get a very harsh "clunk" like there is way too much slop in it. I had the same type of clunk before I had my transmission rebuilt, but before I had the locker put in. The clunk remained after the transmission rebuild so I took it back to the transmission shop. They pulled my rear driveshaft off and showed me the extreme amount of play in my differential yoke. I told them that I would be getting a locker and rebuilding the rear end in a couple of weeks. They said that should take care of the play. Well it didn't and I'm getting tired of Desert Rat telling me there is nothing wrong. The reason I chose the No-Slip was because it was supposed to be almost invisible. I get comments from people all the time that are standing outside while I drive away asking me what the heck is wrong with my truck.

I would like to know if anyone else's No-Slip does this also?

 

[JDraper]

I had a no-slip in the back of my '01 for a while, and it did occasionally thump when it released under power. It also chirped the tires quite a bit when I left a stopsign and turned. There is definitely more slop in the drivetrain than with the factory rear, and you will feel the truck "Change Direction" as it locks and unlocks because the power is being applied differently and it's changing the force vector. They aren't completely invisible, and it does require you to change your driving habits a little to maximize how smoothly it operates.

For comparison, I now have a Lock-rite in the back of my Sammy, and it's far noiser and has a lot more thumps and bangs than the No-slip did.

 

[Robert]

Yeah, I'm aware of it changing directions as I get on and off the gas. I first noticed it while pulling my tent trailer up into the mountains to go camping. Lots of up and down hills along with many (many ) turns. It was constantly affecting my steering whether I was on the gas or not. I've learned to live with that. My concern is when completely off the gas and on the brakes when I come to a stop. It makes a very loud metalic "bang" when I get down to about 10 MPH accompanied by a change in direction which requires a steering wheel adjustment. Since it didn't do this for the first 500-1000 miles, I don't believe it should be doing it now. When I am off the gas and coasting (or braking) now power is going to the locker so it should just slip apart and free-wheel. Instead it is acting like it doesn't want to unlock like it should and when it finally does, I feel and hear it.

 

[JDraper]

Hmmm, mine didn't do that. I don't remember it popping when I stopped. I wonder if one of your springs or locking pins broke or popped free. I just installed one in the rear of ExplorerEB 96's X, and it works just like the one I had installed.

I think I'd be tempted to pop the rear cover and make sure no parts came loose, and then check to make sure the gap between the couplers is within tolerance.

 

[Robert]

Do you happen to know what the tollerance levels are? Desert Rat didn't give me a shred of paperwork when they installed my No-Slip other than a receipt. They said they checked everything out when they pulled the cover off to change the gear oil two weeks ago. If there was something broken, they should have seen it. I do plan on pulling the cover off anyways once the weather cools off enough to a comfortable level, just because I want to put the 75W140 synthetic gear oil back in. My locker doesn't seem to act up for the first few miles so I am wondering if as the temperature rises up a bit, it is causing the problem. I do know they just put in 80W dinosaur oil in it. I also sent an e-mail to Powertrax's Technical Service department. Hopefully, they will reply with something to the affect that the noise isn't right so I have something I can take back in to Desert Rat to get them to make it right.

 

[JDraper]

With each unit, Powertrax sends out a small rectangular metal bar that is used to check the min/max tolerance between the drivers. When I get home tonight, I'll measure it and let you know what the limits are.

FYI, here's a link to a Powertrax installation manual: Dead Link Removed

 

[Lifted95X]

Did you have to notch the pin to get it in?

 

[GJarrett]

Mine has never done that - you have a problem. I do wonder if it coincided with the gear change. If they DID notch your carrier pin instead of grinding out clearance on a ring gear, we have learned that the locker will not operate properly unless that pin is in original condition and perfectly round. You can't screw around with it and do anything to it.

 

[Lifted95X]

Originally posted by GJarrett
Mine has never done that - you have a problem. I do wonder if it coincided with the gear change. If they DID notch your carrier pin instead of grinding out clearance on a ring gear, we have learned that the locker will not operate unless that pin is original and perfectly round.

Exactly what I was gettin at.

 

[GJarrett]

Yep, that's an excellent theory and that's why I further explained it.

Also.... Robert, the small rectangular bar that Jeff is referring to is a go-nogo gauge that you insert in betweeen the two drivers. The measurements of the bar are .135" and .170". The .135" side has to fit in between them, but the .170" cannot.

I have an extra one if you want me to mail it to you, just shoot me a PM with your address. I think there may be an excellent chance that your gear man left a thrust washer in the carrier or something like that may be wrong, and your minimum clearance may be less than .135". I stand by what I have always said and mine is "almost" transparent in on-the-road operation. The only time it ever engaged hard and clunked was during the first day as it was breaking in, or if I hammer the throttle really hard on purpose.

 

[Robert]

What pin are your referring to? If you are referring to the cross shaft, then yes they ground down my original cross shaft to fit the 4.56 gears. I asked Desert Rat about it since Superior Gears stated that a modified cross shaft was required for 4.56 ratios and up and they didn't include one on my receipt. They said that they grind them down in house and do it on a case-by-case basis. Not all of them need to be ground. I didn't see my cross shaft, but if it was in a similar condition that my 4.10s were in, I can't help but think it was in excellent shape.

If there is another pin related to the Powertrax that also needed ground down, then they didn't say anything about having to grind anything else down.

 

[Lifted95X]

you cannot grind down the pin. You must grind the gear!!

 

[Robert]

Thanks for the link JDraper. I remembered seeing the instructions on-line a couple of years ago, but when I browsed through Powertrax's web-site, I couldn't find it anymore.

 

[GJarrett]

BINGO!

Yep, now you have to get a new cross shaft from Powertrax and grind down a small spot on the ring gear to get it in. You can do that without removing any metal that the pinion actually touches. You MUST use the Powertrax cross shaft and leave it in original condition.

 

[taxx]

AHHHHHH!
I am gonna put a link to my lesson learned thread in my sig....

I spoke to powertrax in great detail about this when I netched my pin and it did what you are describing. I was instructed by them and told by gear instalers that it is common practive to grind the innr tips of 2 or 3 teeth to get the pin back in. The locker works off cams engaged by a perfectly round pin. You can get a new on efrom Randys for about $20. You HAVE to have a round pin. Notch the gears. You can do it yourself in your driveway with a die grinder just a little at a time till the pin can be punded in or slid in....

Heck you are lucky. I got stuck at a couple lights mine was so bad it wouldn't engage either side sometimes.

 

[taxx]

Link to my thread about this:
http://www.explorerforum.com/forums/showthread.php?s=&threadid=81371&highlight=powertrax

 

[taxx]

I really think a mod needs to make something about this a sticky thread or a writeup somewhere. Too many people are making this mistake (myself included) and there are too many idiotic installers out there telling you everything will be fine.

 

[offroader_69_me]

well see what happens when you leave for a while, I got my gears and axles and stuff swapped and my no-slip is acting like hell, I have pulled and swapped shafts, redone the locker a few times, new springs, hell almost everything, then I finally get a chance to get on here and the very top thread answers my question, well time to order a new pin!!!

 

[offroader_69_me]

Originally posted by taxxman2k
I really think a mod needs to make something about this a sticky thread or a writeup somewhere. Too many people are making this mistake (myself included) and there are too many idiotic installers out there telling you everything will be fine.

sad thing is that idiot installer was me, in my case, and while i never got stuck at a light, people would really stare when I spun the right tire leaving every stop!!

 

[Robert]

Thanks everyone, it sounds like that is what the problem is then. Is there a write-up for getting the cross pin in and out (first time opening up my rear differential)? I will first try Desert Rat and see if they will do it for the price of a new cross pin since they should have done it this way the first time. If not, then I'll do it myself in a couple of weeks when the temperature drops below 100.

Should I get the "modified cross shaft" from Superior Gear and Axle (same place my gears came from) or is the modified one they sell just one that is ground down in which case I should get the perfectly round one from Randy's?