reamer vs drill bit for 1 ton upgrade

98zjstroker

Well-Known Member
Joined
Oct 14, 2009
Location
concord nc
So I finally got the 1-ton upgrade tie rod and drag link setup for my ZJ. I have to drill the knuckles and pitman arm to 5/8". Is there that big of a difference between the reamer and a drill bit? I am only going to use it for this. Wondering if it's worth it to through the extra cash at a reamer if its only getting used once
 
Take my opinion for what its worth as it is just an opinion. i did a heavy duty steering setup from IRO on a 97 ZJ and opted for UTK steering as it used standard hardware. If i were to buy OTK, i would buy the reamer because in my opinion, they sell it for a reason over just a drill bill. i have broke a few drill bits while trying to drill through an axle tube and i wasnt drilling fast and used oil. id imagine a drill bit and knuckles are going to be a headache to drill.
 
You'll definitely need a reamer, tie rod sits in a taper and not a straight bore. Only way to make a tapered bore is a reamer.
 
So I finally got the 1-ton upgrade tie rod and drag link setup for my ZJ. I have to drill the knuckles and pitman arm to 5/8". Is there that big of a difference between the reamer and a drill bit? I am only going to use it for this. Wondering if it's worth it to through the extra cash at a reamer if its only getting used once
Is it a 5/8" straight bore, or a tapered bore for a TRE?
 
I say spend the money on a good reamer. Cast steel materials like knuckles and pitman arms are super easy to ream.
It seems like a lot to spend on something just to use it once, but believe me, you'll use it a lot more than just once. Plus you can always rent it out to your buddies.
 
Years ago when I built mine, we used the reamer. The original hole was bottom up, and we wanted the steering on top, so we reamed top down. That may have been a mistake, or we just did it wrong. but driving about 50 mph just down from the URE Outpost on my way home, it had enough movement that the cotter pin broke, the castle nut came off, the TRE popped out and I suddenly had no steering and nearly hit a minivan coming toward me. My wife and daughter were following me and all I could think was that they were going to watch me die. I barely missed the van and it stopped in the ditch on the opposite side of the road.

Ultimately I had MarsFab drill it out and weld in the tapered insert to fit the 1 ton TRE. No issues since then.
 
If I were you, I'd check to see how much angle you need at the joint before modifying the knuckles. IIRC, the "one ton" es2027 joint maxes out at about 20* from normal.
 
To properly ream it, you will need to use a drill that is about 0.025-0.050" undersize. Reamers are not made to move a lot of material, and the drill will most likely drill oversize. Ideally you want to ream about about 0.005-0.020" off the finished size.

With that said, for your application, you could also just drill it slow and oily with a 5/8" drill bit.

If you don't want to buy tools you'll probably never use again, I have whatever size drills and reamers you might need, so if you want to go that route, shoot me a PM.
 
@Chris_Keziaup @jeepinmatt The upgraded bolts are straight 5/8 bolts. But I think I will just go with the reamer anyway.
Does the steering kit have tie rod ends or heims/spherical rod ends?

Tie rods take a tapered bore and require a tapered reamer.

Heims you just drill it the same size as the bolt. No need to drill it and ream it(with a straight reamer).
 
To properly ream it, you will need to use a drill that is about 0.025-0.050" undersize. Reamers are not made to move a lot of material, and the drill will most likely drill oversize. Ideally you want to ream about about 0.005-0.020" off the finished size.

So, if'n you were going from a smaller TRE taper to larger "1 ton", seems you'd want to open the hole up to *near* the smaller dia. before reaming, correct? Seems like too much meat for the reamer otherwise?
 
So, if'n you were going from a smaller TRE taper to larger "1 ton", seems you'd want to open the hole up to *near* the smaller dia. before reaming, correct? Seems like too much meat for the reamer otherwise?
That is what I did on the pitman arm of my YJ. I bought a flat pitman arm with no hole for the drag link. I can't remember exactly, but I think I drilled the hole to about the small end size of the taper on the drag link, then started with the tapered reamer. Worked great.
 
So, if'n you were going from a smaller TRE taper to larger "1 ton", seems you'd want to open the hole up to *near* the smaller dia. before reaming, correct? Seems like too much meat for the reamer otherwise?
Yes, that would be the best approach. Though a tapered reamer is a little different because it is engaging the periphery, whereas a straight reamer is engaging the leading edge.
 
Last edited:
So I finally got the 1-ton upgrade tie rod and drag link setup for my ZJ. I have to drill the knuckles and pitman arm to 5/8". Is there that big of a difference between the reamer and a drill bit? I am only going to use it for this. Wondering if it's worth it to through the extra cash at a reamer if its only getting used once
This is what I used when I drilled my knuckles and pitman arm for my heim steering. It made drilling them out quick and easy. I did use cutting oil frequently to help with the heat. The 40 bucks was well spent after hearing horror stories of guys using a normal 5/8ths bit taking hours to drill everything out.

Drill America 5/8" Bridge/Construction Reamer with 1/2" Shank, DWR Series

To clarify I did a hiem steering that used a straight 5/8ths bolt instead of a tappered TRE. So the reamer I used was a straight Shank bridge reamer.
 
Last edited:
Does the steering kit have tie rod ends or heims/spherical rod ends?

Tie rods take a tapered bore and require a tapered reamer.

Heims you just drill it the same size as the bolt. No need to drill it and ream it(with a straight reamer).
I still have your other reamer. Thanks for reminding me.
 
if doing TRE's, definitely reamer. If I read correct, you were going to reverse it, bottom up. I did this. Learn from my mistake.
when done, one of the holes was not quite straight. In my case, it didn't hurt/matter. But what I should have done...
Find the diameter of the small end of the hole you need. Drill the hole with a straight drill. Then finish with the reamer.
In essence, going in reverse, the reamer won't guide itself well. Plus, you'll save some life of the reamer (vs cost a drill bit).
And it will be more straight.
(drill press would help if the knuckle is off. but I drilled mine on the vehicle.)
 
Back
Top