3.55 Gears: Unitrak and Splicer?

[ZYellow01RT]

I had 3.55 gears put into my ’01 about three weeks ago, but forgot to ask my tech which type he put in at the time.

When I asked him that question a few days ago, he said "either Unitrak or Splicer"...he didn’t recall which one he actually put in.

So, just wanted to know everyone’s input on those two brands, pro or con...

BTW...they seem to be running well, and am loving the "get thrown back in the seat" experience!

Thanks for any input you can provide!

 

[JohnnyViper]

i have unitrak, i have had then in a box since xmas and still have not found the time to install

 

[ZYellow01RT]

i have unitrak, i have had then in a box since xmas and still have not found the time to install

So, in that sense, I guess they are not giving you any problems?

 

[mattdillon]

Andrew I'm still fighting it, I want that seat of the pants feel too (have heard some having a problem with hummin noise, guess it just depends on who does it) Did you change out the whole differential or just put the gears in yours. I've also been told that yellowbox calibration unit is better than unitrax (heard unitrax was noisy?) maybe somebody on here can go in to detail a lil' more. It does seem like it would be alot easier just replacing the whole units though, also I think its better to upgrade with the larger 7/16 from the 3/8? Maybe depends on what year. Also when puttin the 3.55's in its best to get the Dana 44 LSD Unit? Hopefully somebody will come on here & clarify all this!

 

[ZYellow01RT]

I heard that Dana was good, but haven't heard anything (good or bad) regarding Unitrack or Splicer gears.

As for humming...mine "hum" a little in 4th gear, at around 3000 RPM, but nothing really out of the ordinary. I tried to break in the gears gently, and was pretty nice to them for the first 200 miles or so, but then couldn't help myself and starting driving pretty aggressively after that.

The jury is still out as to how many miles (if any) are required for gear break-in, so I figured after 200 miles, I was covered...

So, still wondering if anyone has any input on those two gearsets.....

 

[JohnnyViper]

yup no issues and no hum

So, in that sense, I guess they are not giving you any problems?

 

[Paul Hawker]

Unitrax does not make gears. They are a dealer for Dana/Spicer/etc.

They are a driveline company in Orange county that has a tremendous reputation for high quality installs, good advice, and technical expertise.

They will advise you on the best gears/half shafts etc.

Set up on gear set replacements is both an art and a science. Set them up too tight and they run hot and loud. Set them up too loose, and they are weak and subject to driveline lash.

They understand cryo treatments, heat treating, chemical treating etc.

Many Viper suppliers use Unitrax to set up the gear sets for their customers.

Good value for money here.

 

[ZYellow01RT]

Thanks for the info.

I should have asked my Viper tech more questions before they were installed, but sounds like he put in a good set.

 

[mattdillon]

Thanks Paul for clearing that up, I guess thats why I still haven't put any in my car yet Andrew, cause I'm STILL trying to find out everything I can (cause if I do put them in & I hear hummin' I can't tell you how ********** I would be at myself for fooling with them to start with) I guess I'll wait a few more months & see what you still think about yours. Can you tell that much difference in having to shift more, gas mileage, etc...(not that it matters)

 

[Jack B]

Thanks Paul for clearing that up, I guess thats why I still haven't put any in my car yet Andrew, cause I'm STILL trying to find out everything I can (cause if I do put them in & I hear hummin' I can't tell you how ********** I would be at myself for fooling with them to start with) I guess I'll wait a few more months & see what you still think about yours. Can you tell that much difference in having to shift more, gas mileage, etc...(not that it matters)

A few insights:

1. When Unitrax installs the Dana gear set they drill out the ring gear 3/8" thread to 7/16". There is approximately 20 bolts.

2. Break-in is not just taking it easy, it is a heat cycle issue. When Unitrax does the set-upl, they normally give you a one page set of instructions on heat cycling.

3. Unitrax will give you the option of drilling the ring gear bolts heads for wire ties. This stops them from loosening. I actually had all the bolts loosen before I had mine drilled.

4. Humming comes from an improper gear contact patch. This is caused by either a bad install or improper heat cycling where the the gear face wears and changes the contact patch.

 

[JohnnyViper]

i wonder who makes my gears.....I will have to dig out and look at the box again

 

[mattdillon]

Would it be better to get a whole new differential with the gears already in (I guess that way you would still have the stock set up to change back out if you wanted) & do you recommend who to get the complete set up from. I also heard that if you are changing the gears out, that is the Best time to go ahead & get the Quaife done? It just never stops does it!

 

[ZYellow01RT]

My Viper tech never mentioned any break-in procedure, and basically said to take it easy for the first 100 miles or so, and that's it.

So far, no issues...