So based off of @Woodchuck 's recommendation, I am a few clicks away from ordering my new rear end from 8and9fordrears.com and I wanted to know everyone's opinion on Tru-Trac vs Trac-Loc. As I understand it the Trac-Loc is a friction disc style posi and the slightly more expensive Tru-Trac is a helical gear posi. I want to know which would best suit spirited street driving. I have never tracked my car and have no plans to in the near future. Its my weekend driver or occasionally go to work in it, so I don't need much. I see that the Trac-Loc is $995 and the Tru-Trac is $1300. So I just want to make sure I'm not missing something before I pull the trigger. Let me know your experiences to help me make a decision.
Tru-Trac VS Trac-Loc
OneTireFire
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10,722 Posts
I have had a Traction Loc in my car since about 1987 it has held up find and still burns two with zero service in that time.
Ok fellas, I just spoke to Alan on the phone and he agreed that 3.25s are a good ratio for me. As well as getting the Tru-Trac. Thank you for all the replies and helpful insights! Now we wait....
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1,285 Posts
I was recommended a truetrac so that's what I bought for my build.
Looks like I made a good choice
Looks like I made a good choice
My car the PO put in a 2.95 T5 and a Detroit Locker. he thought he had bought some 3.55s but were only 3.00s. It is not enough rear gear especially in slow speed 2nd gear times. He bought some 3.55s and I bought them brand new in the box for $100. Though where I live, seems nobody wants to work on them as soon as I say it is a Ford 8. I want to keep the Detroit Locker even though it really hates my gravel driveway.
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6,434 Posts
Everything I have read suggests clutch type is better for the turns while a helical-type is better for the straights.
I've used Trac-Loc, Detroit Lockers, and I currently have a Tru-Trac. My Tru-Trac is behind a 500+hp stroker 351W with a TKX tranmission with 4.11 gears. I love the Tru-Trac. Performance is very similar to a Trac-Loc without the wear issue that Trac-Loc differentials have.
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4,550 Posts
Going on 6 years with my True-Trac, 3.55 behind 4sp top loader. I also bought mine from 8&9 when TJ was still alive. Have had no issues whatsoever and have not regretted the decision.
Can't wait until you get your new unit in and you give us a video of two tires smoking!
And yes to the name change
John
Can't wait until you get your new unit in and you give us a video of two tires smoking!
And yes to the name change
John
I am using 3.25's with a toploader, 216-60-15 tires. I installed a new tach last month so I went for a spin today to see how it was working. At 60 mph it was 2400 rpm; at 70mph it was 2800 rpm. I think you'll be happy with the 3.25's.
2400 RPM at 60 MPH seems low for a four speed and 3.25. I think your speedo is reading a bit high or your tach too low.
Edit: should be 56 MPH in theory. A little off, but less than I thought initially.
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137 Posts
I've got a T5 with 3.35 1st gear and 3:00 open now. Considering the Eaton TrueTrac. I may move to a 3:25 because of what I saw on the Eaton website. Quick Performance does include 3:00 as a choice for the Truetrac 8" rebuild kit. I wouldn't mind keeping the 3:00 but I guess a question to QP is in order.
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I verified my speedo with my GPS. I guess I could verify the new tach with my Dwell/Tach meter. I have an Autometer 3708, full sweep tach.
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4,226 Posts
I'd say it depends on what you're doing with it. What do you expect from it? Some observations from driving both extensively, are full differential (no preload) with Tru-Trac, but it is geared (without clutches), so there is a "take-up" of the low-traction tire to the high-trac tire. No problem at speed or wide curves, etc. However, on sudden application (pop the clutch or decel with unequal traction surface), it can pull to one side momentarily or delay traction while it gears-up.
I've seen this effect when launching across some drips or slick spots, where it can jerk as it enters and leaves the slick spot, being low-bias then suddenly needs equalizing and it takes a tire rotation or two to get it. Likewise on pavement with ice under one tire, it will spin the slick tire then bias for more to the hi-trac side, but as soon as it grips it can unload and start that process all over again.
I'd say the point is that you probably won't care unless you're really using it, and usually the effects are not that bad and driving technique can minimize weirdness - but it can be weird. There are multiple "bias" settings built-in (non-adjustable), so choose what you need for your use. They can wear out, but that's unlikely for the typical hobbyist.
Trac-Loc is softly on all the time, locks harder with torque instantly, and stays that way until torque reduces. No "slack" to drive through. This makes it more predictable and natural feeling in a way. Yes, you can fool it, and very biased traction can result in no limiting and eventual damage (donut burnout). They are cheaper and rebuildable.
Only my opinion and only for the "average Joe" classic car owner generally driving but occasionally tracking or a burnout for the buddies, I would lean toward the Trac-Loc, but either certainly "works". For more specific use (auto-x, track days, bracket racing, etc), you should make more specific choices. I have 1 Trac-loc and 2 True-Tracs in the driveway. This is a bit random, but because I can't use a Detroit Locker in anything the wife drives. I love DLs, but they are a "driver's" solution.
Whatever you choose, learn about it and how to drive it before you get to where you need to suddenly know all that.
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1,508 Posts
I love the smell of friction modifier in the morning. Later that night & the next few days. Happy with my Traction Loc, but it's what dropped in my lap many years ago.
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