Eaton TrueTrac axle play

[fish337]

Anybody running an Detroit TrueTrac , mine has a lot of axle movement , driveshaft play(clunking when you on an off the gas). The backlash is .008
The play is in the helical gears
I was wondering if anybody else has this annoying issue, and what they did

 

[skwerl]

Stock driveshaft or aluminum 1 piece? I don't believe your noise is coming from the TrueTrac.

 

[fish337]

It's the stock axles which look fine, checked with angle gauge on axle hub today it has 6 1/2 * movement in axle , I have the cover off you can see it

 

[skwerl]

Oops, sorry. I meant driveshaft. I edited my earlier post.

Unfortunately I can't see anything, your picture isn't showing up.

 

[fish337]

Aluminum 4" axle exchang driveshaft, but play is in the helical spyders

 

[Whiskey11]

How old is the unit? Helical gear diffs still wear out, they just do so at a much slower rate than other diffs do. The primary wear points are the worm gears and the diff case itself. Drag racing exacerbates the wear on those components since the launching literally rams the worm gears into the diff case pockets they sit in which puts a ton of wear on both.

I would call Eaton and see if they think it is normal. Some movement in those helical gears is normal, but a lot wont be. I wouldn't think it would be enough to cause a audible from the driver's seat clunk though.

 

[fish337]

Less than a year old , 10 passes on the drag strip. That's why I'm disappointed.

 

[kevinatfms]

this is why I will never run a worm gear diff. another story of one failing after light dragstrip use.

OP, call eaton and ask them for specific measurements for the gear deflection. take your measurements and figure out if its worn out. if so, you may need to look into another differential.

 

[Whiskey11]

this is why I will never run a worm gear diff. another story of one failing after light dragstrip use.

OP, call eaton and ask them for specific measurements for the gear deflection. take your measurements and figure out if its worn out. if so, you may need to look into another differential.

There really isn't much "light use" at a drag strip from a gear diff's perspective. It's all a comparative hell. The fact the TruTrac even lasts there is a testament to the build quality of the unit. Other units don't last as long there either.

Clutch based, Locker, or Spool for drag racing if you want longevity.

 

[fdjizm]

this is why I will never run a worm gear diff. another story of one failing after light dragstrip use.

OP, call eaton and ask them for specific measurements for the gear deflection. take your measurements and figure out if its worn out. if so, you may need to look into another differential.

I don't see anyone in this thread saying their trutrac is broken....

Can you post a link to the other one failing?

Over 50 passes and 5k+ clutch dumps and burnouts here on the trutrac.
Maybe my unit didn't get the memo?

 

[skwerl]

Mine is solid as well, and I beat the hell out of it.

 

[fdjizm]

^can't be man. lol

 

[BIGCHRISS197]

My tru-trac came out of a na 10 sec 3v and has been holding up

 

[kevinatfms]

I don't see anyone in this thread saying their trutrac is broken....

Can you post a link to the other one failing?

Over 50 passes and 5k+ clutch dumps and burnouts here on the trutrac.
Maybe my unit didn't get the memo?

ill try and find it. I also know a few people who have shredded the internals on slicks. they are not bulletproof.

I didn't say it was broken. I said it was worn out. worn out to me is a failure. don't put words in my mouth. broken to me would be undriveable.

it seems like lots of people have them that work great, then there are a few who don't have a lucky enough time with them and they WEAR OUT prematurely.

 

[fdjizm]

Worn out is by all definitions NOT a failure.
You can have worn out tires you still drive on, worn out spark plugs the engine still fires on, worn out shift knob you still shift with, worn out shirts you still wear, worn out clutch that still drives etc...

A failure is A FAILURE/BROKEN.


I definitely will be waiting on them links.

 

[kevinatfms]

if its worn and not working correctly, then whats the point of the diff? you cant drag race or track the car=failure of the unit. it would be the same for any clutch type, lunchbox locker or other type of diff. if it doesn't work correctly, its failed.

one in a jeep, failed and sounds like the OP's description, an 8.8 too
http://www.jeepforum.com/forum/f9/clunking-rear-ford-8-8-tru-trac-unit-rebuild-kit-1314314/

a few of the GM guys have destroyed them
http://ls1tech.com/forums/gears-axles/871868-whos-broken-truetrac.html

post #131, post #132, all are 8.8 FORD differentials
http://forums.corral.net/forums/road-racing-auto-x/1059371-whats-best-diff-autocrossing-4.html

youtube video of a FAILED unit.
www.youtube.com/watch?v=AX1pz31A-h0

Toyota unit destroyed the entire rear end, failed to warranty anything
http://www.tundrasolutions.com/foru...ucks/55096-beware-eaton-true-trac-bolts-fall/


they aren't the exploding differentials you consider "broken" but they fail to do what they are advertised as, which is a FAILURE. I know they aren't all the 8.8 ford rear, but its the same design and downfalls.

Worn out is by all definitions NOT a failure.
You can have worn out tires you still drive on, worn out spark plugs the engine still fires on, worn out shift knob you still shift with, worn out shirts you still wear, worn out clutch that still drives etc...
A failure is A FAILURE/BROKEN.
I definitely will be waiting on them links.

your going to beat this to death, huh?

face it, the OP's diff is taking a nice fat dump. if he measured excessive axle deflection, I would place bets that eaton will ask for the unit back to rebuild. if they need to rebuild it, its failed.

oh and to show im not a 100% hater of the true-trac, I had one installed my old lightning with 4.10's and it held up to 100's of passes on a 4600+lb truck with 500-700whp. also used to hit it off the line with 150 shot on 30" slicks.

never had an issue.

EDIT:
here is the operating manual. read the warranty part.
http://www.eaton.com/ecm/groups/public/@pub/@eaton/@per/documents/content/ct_128482.pdf

Tractech Engineering approval for use of TrueTrac differentials in various vehicles is established with the
understanding that the vehicle will be operated with approved factory engine and driveline components,
as specified for that vehicle by the vehicle/axle manufacturer.​

​

​

​

Any increase in the size of the vehicle's
engine, tires (over 32" diameter), weight, etc. may void the Tractech Limited Warranty on page 6.​

Any such vehicle modification should be reviewed by Tractech Engineering before using the product.

 

[fdjizm]

thanks for the links! I'd say the truetrac is working for alot of people just fine and will definitely let you know when mine "fails" I would think if they were that bad you would have found them all over the net. good stuff I will keep on beating mine.

 

[fish337]

Talked to eaton , guy said they have no tolerances for the axle gear movement Thought that was odd. He told me send it back to summit because it is under warranty for 1 yr. then they'll send it to eaton & back and forth. Summit told me they'll just replace it & send m a new one. When I talked to the guys a eaton they told me this was the rear I should use for what I do . So well see if I just got one with excessive play, (it made clunking at slower shifts like bad universals)

 

[05stroker]

Mine has been great! I have several 1.5 60s and a 1.48 last weekend on it with 800 rwhp and a 3800 stall in a 4r70w. It has about 80 passes and 6k on it now. The auto may smooth out what you are feeling though. I thought mine had a lot of slack too when I installed it. Good luck with the new unit.

 

[AutoXRacer]

My TruTrac has been performing great!!!

But I do have to admit I do not like the driveshaft play. I thought it was the ring to pinion play. There is a significant play between contacts/clunks.

But I have taken the car to several shops and they all have told me its within specs.
I recently got a gear change and they verified everything was within specs... Still have the play... I just ignore it now.