Powertrax problems-anyone using this?


Obsession or Digression?
Sep 19, 2001
Anyone using the Powertrax "no-slip" traction system encountered a problem of only the left tire spinning? I put this unit in about 2 months ago to replace the non-posi rear end, and it worked well until now. I have only been to the track once and it worked then. Now it is not locking up, and I don't seem to notice it making the clicking noise unlocking in turns now. The car is drivable with no other noticeable problems with the rear end. I will be getting out the info on it to check the troubleshooting guide and warranty, but any personal info you have is as always more beneficial. Thanks
Gotta be someone using the PowerTrax. I need to do more testing, but on a very slick asphalt surface, it only would spin one wheel. Maybe not enough surface friction to engage? On a concrete surface it seemed to grab with both wheels, but wheel hop stopped me from continuing. I am running Nittos. Any personal info using the PowerTrax is appreciated.
I feal your pain!


Mine broke after 3 months of driving in a 12.5
street car. It spun only the left wheel. Interesting
to spin the wrong side tire for a full 1/4 mile. I think
this unit is a POS!!!

John Wilde

BTW A good friend almost killed himself in a mid 9 second
car when one of these units went out. His car got so out of
control they asked him to leave the track.
Thanks John for the info. Speaking with John by PM, he gave me the info that the teeth rounded in his broken PowerTrax unit. Sounds like the same problem I am having since his was spinning the left wheel only. I will post my results of what kind of shape my PowerTrax is in when I remove it. This should be valuable info for anyone considering using this unit.

Has anyone been using this unit for a long period of time with good results, and how much "real use" has it been subjected too?
Tim that's all you need now the posi going out the car was really starting to run. Should of bought a eaton posi for 340 bucks i now its cheaper then that power traxx. hindsight you no the saying. Let me know what you find out and i can come take a look at it. Later Sean
sorry to hear


Sorry to hear about your Power Trax problems, bud! That sucks! I had not been involved in anything to do with rear-ends (no pun intended :D) until we did your P-Trax unit.

Hope things turn out for you. Sean says the Eaton unit is less money than the PTrax. I thought it was more for some reason. Hope the warranty covers your repair $$$$. Any damage or metallic sounds coming from back there? Get Dog down there to inspect the wreckage, he's good at that!
Thanks for the comments. I think the Eaton would have been more once I paid for the labor, since it may take special tools or skills. I wanted to try something new anyway, and it "sounded" like a good unit. If I do find out there are problems once I remove it, I will try to get something worked out with PowerTrax, and be sure and let everyone know the results. They make these units for hundreds of vehicles, and there should not be a problem with their products. There are not any weird noises yet, just the lack of proper functioning, so I will do some more "testing" before removing it.
Hi Tim, I've run the Powertrax diff's in several different 4X4's with great success. These have typically been large tire, hi torque, low gear vehicles heavily abused and I never broke a Powertrax piece despite cracking carriers and snapping axles.

I CAN tell you that if you have only one wheel spinning when you're on the throttle, something is DEFINITELY broken. No doubt about it. The Powertrax dif is a positive locking diff. ie. when torque is applied to the carrier any difference in tire velocity causes the couplers to engage and forces both axles to rotate at the same speed. When you let off the gas, and torque at the carrier goes away, the couplers disengage and allow the tires to rotate independently.

From experience, I would suggest pulling your diff cover and inspecting the fluid and Powertrax diff. If all looks well with the diff have a friend rotate each wheel one at a time while you watch to see whether the axle and Powertrax coupler are rotating at the carrier.

Good luck

Charles Brooks
Sounds like the right side coupler broke, or possibly stripped the axle splines. My Dad's been using one in his 3700 lb, 13.0 sec car for about 6 years of weekly bracket racing with no problems. A friend has also been using one in his 3400 lb 11.9 sec Nova for at least 4 years of racing two days a week as well as driving to work. Seems like a pretty good unit when set up well. Sorry 'bout the tough luck! GB
Finally took the rear dif cover off tonight and checked out the Powertrax unit. A couple of friends helped me diagnose the car. As it turns out, there did not appear to be any damage to the unit, and no metal shavings or anything in the fluid. Tom read the instructions on performance :eek: (good idea), and discovered that if a wheel slips due to poor tire-surface contact, the system will immediately transfer more torque to the other wheel to maintain traction. Therefore on an extremely slick surface, such as the recently seal coated asphalt road I was on, this was normal to spin only the left tire :rolleyes:. The right wheel was apparently turning but not leaving a black mark due to transfer of torque.

According to the instructions :eek: , if a tire slips on an open or limited-slip differential, that slipping tire will spin the most. On the Powertrax, the slipping wheel causes more torque to be transferred the the wheel with more traction. Anyway, this is the update, and I now have the rear cover off again and will clean and paint it before the reinstall. Thanks for all the input. I'm sure it will work correctly when I get the cover on and fluid in. I will test it immediately :cool: and post the results soon. Always read your instructions thoroughly ;).
Thanks for the follow up...it's nice to hear the resolution to problems...glad it worked out in your favor.
hee hee

Hey, don't forget to power brake the T in it's parking spot in the garage so that you have rubber in both bays! :D

We almost hit two deer on the way home from your place last night. That would have cost you! If you happen to need my pump to fill the differential, let me know. I can ship it to you or drop it off to Sean at the course on Tuesday's.
Another update, maybe some info for the PowerTrax owners in a previous, present or future similar situation. Called Powertrax today, tech support friendly and helpful, and said the gap between the drivers should be 0.135 to 0.170 inch (I lost the little Powertrax metal tool that checks the allowable clearance :rolleyes: ). Just checked mine, it is at around 0.140" :). And if for some reason the driver gap is excessive, they can provide shims to place behind the couplers (between the side gear and case) to tighten it up to correct specs. The shims would be similar to the stock thrust washers behind the spider gears that you remove to install the new couplers and Powertrax unit. This would be the time to give a special Buick thanks to Ramin for the correct, clean and precise initial installation and tech tutoring during the beer and Buick mechanic work :p .

The tech guy did reconfirm our discovery on the wheel slip--if it is a very slick surface, it does transfer torque to the non slipping wheel and may only show one black mark. I can confirm that previous tests on less slippery surfaces, it did leave two big Nitto marks (a few hundred miles worth ;)) I'll get this thing back together now and post the final test. And Tom, thanks for the offer, but I had bought a $10 dollar metal dif fluid pump today.
Good to hear that you're getting things sorted out with your PTrax unit.

Now don't forget to get some of the differential fluid in your hair when your putting things back together (that's how I would do it)!
Got it back together for testing tonight. It is still only leaving a black tire mark on the left side on an asphalt road. Did some more powerbraking in the garage on a slick concrete surface with a "spotter" and he says the left wheel is spinning more. The black mark for the left wheel is much bigger and it pulled to the left/drivers side.

I'm going to contact Powertrax again with these results. As I posted previously, the gap between the couplers was within specs and the teeth on the unit were not rounded. Maybe I need the shims behind the couplers, I don't know. I'll call them tomorrow. Any suggestions, ideas or opinions, let me know. Thanks
Tryed to reach Powertrax a couple times today but their customer service line is busy with calls. I waited 20 minutes with no reply so I will try again. Powertrax owners or anybody, let me know what you think about the problem I am experiencing with a majority of the torque being transferred to the left wheel. TIA
Hope that you get some good info from the PTrax people bud! That sucks that you are still having a problem with it. :mad:

Keep me posted.

Took the drivers and spacers out last night. Talked to Powertrax today. I am sending the unit in to have their engineers look at it. The unit parts from the outside towards the center of the diff case are the coupler, active spacer, driver, then the pinion shaft. You can see the exploded view at http://www.powertrax.com/nsop.htm. Here's what I found. The passenger side driver has some rounded off teeth. Not real bad, but I guess enough to keep the right rear from leaving a black mark. They have a two year limited warranty so I am sending it in with a return authorization they gave me. They will diagnose the partial failure and let me know the cause of the problem and I will post the results.

Their tech support said sometimes the unit is installed with the spacer paddles facing the same way, not 180 degrees like they should be. I checked for this during the removal and it was installed correctly. If it is installed wrong, the paddle will break and cause one wheel not to spin. The paddles on my unit are not broken either. With how the drivers fit together with the protuding pins and pin openings, I do not see how it could be installed backwards. The spacers with the paddles fit into the back of the drivers and can only fit one way, and the drivers only fit together one way, but they said there have been cases where installation was wrong.

I still think this is a good unit and maybe I had some bad luck. The spacing between the drivers checked out before I removed the unit also. I bought the unit based on reading their tech info on operation, ease of installation, and from a recommendation of a TR drag racer (low 11's) that has used Powertrax for 5 years with no failures of the unit. I will keep the thread updated with my progress. I am sending it in today.

I feal your pain. They only had a 3 month warrenty when mine
broke. I don't think I would have put one back in my car though.
yeee haawww

Now were getting into the technical gumbo baby! Let me know if the unit was installed incorrectly, and then I can tell Ramin that he FINALLY DID SOMETHING WRONG on a Turbo Regal! I don't look for the installation to be the culprit though.

Good luck buddy!