Detroit Tru-Trac

[76-cj7]

Bought a Tru-Trac for my dana 30.........i know i know......shoulda just put a cut down D60 under her But im no guy for settin up ring and pinion since that is also new, but the dude settin em up ran into a bit of a problem. The Tru-Trac has holes for the ring gear bolts drilled at 7/16"? or 1/2"? and the ring gear bolts are at 3/8".........this leaves a lil bit of slop IMO........called Detroit and they said thats how its supposed to be and they have been making them like that for 2+ years and i shouldnt worry bout it. My only ? is under hard abuse will the bolts shear off due to the slop in the bolts holes? And would it be ok to make a thin sleeve to put in the bolt hole to take up the slop?

[ironman_gq]

I dont like sloppy holes but most of the holding power of the bolts is in clamping force not in the shear strength of the bolts. bushing the holes shouldnt cause any problems and i would go for it if it makes you feel better. You would be supprised at the amount of clamping force generated by the ring gear bolts. at 50ft/lbs there is over 7000lbs of clamping force per bolt holding the ring gear in place. I would do whatever makes you comfortable,

[76-cj7]

HAHA sloppy holes he says! But thats the same exact thing the guy from Detroit said to me.......im still going to have the holes bushed just to satisfy myself.

[tufcj]

Like ironman said, the ring gear is a slight press fit onto the carrier, and you need to overcome the clamping pressure of the bolts before shear strength even comes into play. Use plenty of locktite on the bolts during install.

I installed a true-track into a friends 30 several years ago, and noticed the same thing. He hasn't had a problem, although he has snapped a couple of axles (on a XJ).

If the holes are 7/16, and the bolts 3/8, that's only 1/16 (.0625") total, that's only .03125" shim around the bolt, about the thickness of a beer can. I truly wouldn't worry about it.

Bob
tufcj

[mike4089]

I just had a detroit true trak installed in my dana 30...and it was 25 bucks for these little rings that pressed into the bolt holes to make the holes smaller that way there was no slop...a very reputable 4x4 shop did it and he knew right away that i needed them and told me to buy them not to mess around with putting the smaller bolt in the larger hole...

[ironman_gq]

I think the holes are made larger so that it is easier to line them up when putting the ring gear on. Its kind of a PITA to start the gear on and find that the holes are just slightly off.

[76-cj7]

Hmmm......the guys has a metal lathe and is goin to make me some sleeves so no worries i guess! but hell.....it's only a 30, im just wondering how long it'll last this time!

[mike4089]

the holes are larger becasue the new dana 30's in the wrangler use a larger bolt then the old 30's in the cj's

[76-cj7]

Thats what i had figured....but i still dont like sloppy holes =D>