posi unit - ZR-1 Net Registry Forums

1LEZ · 10-21-2017

I'm about to change gear ratios in my Z and was wondering if anyone used a Trutrac post until instead of a regular factory one when making higher hp numbers? Thanks for the advice

Jagdpanzer · 10-21-2017

I’ve been running a Trutrac for 3 years and have had no issues. No more nightmares of spider gears exploding and wiping out the whole differential.

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RichS · 10-21-2017

I'm on my 3rd trutrac in the GS. They do hold up better than the stock posi, but depending how much abuse you give it it's not bulletproof.

Jagdpanzer · 10-23-2017

Rich,
Can you tell us which components were failing in the TruTrac that lead to replacing the unit and stress were you putting them through?

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RichS · 10-23-2017

Phil, Each time the torsion gears looked like they were twisting. Then it would get noticeably harder to turn by hand. I have some pics of the gears I'll try to post (on Photobucket) I contacted them a few times about rebuilding it but no one gets back to me at Eaton. They did cover the first one under warranty, and said no one has ever broke one....... Story of my life. lol

Lets see if this works, I have another somewhere that I think shows the damage better.

gears by Rich Shuleski, on Flickr

10-21-2017	#1
1LEZ Join Date: Nov 2016 Location: Tx Posts: 101	posi unit I'm about to change gear ratios in my Z and was wondering if anyone used a Trutrac post until instead of a regular factory one when making higher hp numbers? Thanks for the advice

10-21-2017	#2
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,648	Re: posi unit I’ve been running a Trutrac for 3 years and have had no issues. No more nightmares of spider gears exploding and wiping out the whole differential. Sent from my iPhone using ZR-1 Net Registry __________________ Phil Wasinger 1994 Torch Red ZR-1 WAZOO Member George Braml Intake Last edited by Jagdpanzer; 10-21-2017 at 01:11 PM.

10-21-2017	#3
RichS Join Date: Nov 2013 Location: Wilkes-Barre, PA Posts: 148	Re: posi unit I'm on my 3rd trutrac in the GS. They do hold up better than the stock posi, but depending how much abuse you give it it's not bulletproof. __________________ 1994 ZR-1 #198, sold [img]https://live.staticflickr.com/65535/48400173802_2a6f122cfb_n.jpg[/IMG] [COLOR=RoyalBlue]96 GrandSport#857[/COLOR],[COLOR=Red]Red Gut[/COLOR] 397 LT4, AFR heads,3:90 gears, DRM longtubes, Sepanek 700R4, Yank 3600, bla-bla... Best ET w/396 & 6-speed 11.02 @126.57 w/1.60 60' Best ET w/396 & 700r4 10.82 @124.87 w/1.48 60' 2003 DarkShadowGray Ford Lightning 460rwhp/550rwtq 12.11 @112.18 w/1.71 60'

10-23-2017	#4
Jagdpanzer Join Date: Apr 2007 Location: Northern VA Posts: 2,648	Re: posi unit Rich, Can you tell us which components were failing in the TruTrac that lead to replacing the unit and stress were you putting them through? Sent from my iPhone using ZR-1 Net Registry __________________ Phil Wasinger 1994 Torch Red ZR-1 WAZOO Member George Braml Intake

10-23-2017	#5
RichS Join Date: Nov 2013 Location: Wilkes-Barre, PA Posts: 148	Re: posi unit Phil, Each time the torsion gears looked like they were twisting. Then it would get noticeably harder to turn by hand. I have some pics of the gears I'll try to post (on Photobucket) I contacted them a few times about rebuilding it but no one gets back to me at Eaton. They did cover the first one under warranty, and said no one has ever broke one....... Story of my life. lol Lets see if this works, I have another somewhere that I think shows the damage better. gears by Rich Shuleski, on Flickr __________________ 1994 ZR-1 #198, sold [img]https://live.staticflickr.com/65535/48400173802_2a6f122cfb_n.jpg[/IMG] [COLOR=RoyalBlue]96 GrandSport#857[/COLOR],[COLOR=Red]Red Gut[/COLOR] 397 LT4, AFR heads,3:90 gears, DRM longtubes, Sepanek 700R4, Yank 3600, bla-bla... Best ET w/396 & 6-speed 11.02 @126.57 w/1.60 60' Best ET w/396 & 700r4 10.82 @124.87 w/1.48 60' 2003 DarkShadowGray Ford Lightning 460rwhp/550rwtq 12.11 @112.18 w/1.71 60' Last edited by RichS; 10-23-2017 at 12:05 PM.