The Stovebolt Site Forums The Shop Area General Truck Talk King pin Reamer, where to find one?

Did a search but it didn't turn up anything, which supprises me, I'm sure this subject turns up every 50k miles or so.
I'm putting new king pins in my '50' 3/4 ton Chevy. I've been looking for a week but I can't find a used adjustable reamer anywhere, i.e. ebay, here or other forums. McMaster Carr has a new one but it looks to short to grab both bushings at the same time, besides, it's $113, a little stiff for a one time shot. Any ideas, besides using a wheel cylinder hone or taking it to a machine shop?
Also, can't find specks but I've read that the clearance should be .001", that sound correct? That should translate to about .003" at the tread of a 30" tire, (15" radius)that certainly seems tolerable.
I've noticed kits from the vendors for $44 up to $100, is there any difference between these, and do any of the kits contain new thrust bearings?
Thanks,
Denny Graham
Sandwich, IL

Denny,

I have a set of adjustable reamers ordered from Harbor Freight. It's cheap Chinese stuff, but far less than $100 for a set.

I just got my kit for kingpin replacement. I forget which vendor, but the prices were pretty different. I think I got mine for around $50 or so and it looks to be fair quality. The kingpin and bushings are good, as is the thrust bearing and shims... but the lock pins are garbage. Fortunately my old ones are still good, so I'll clean and re-use.

I pressed my bushings in with a bench vice, cheater pipe, 3/4" size 3/8" drive socket, and some big flat washers. They went in clean and straight. Make sure you get the grease hole lined up!

My kingpins just barely slide in my axle right now. PERFECT FIT! A 0.001" clearance between the pin and bushing sounds pretty difficult to do with hand tools. What I'll do is mic the pin and ream the bushings a little over (I'll shoot for 0.001... but will settle for a little more). Once I'm happy with the dimensions, I'll put the kingpins in the deep freeze overnight. Next day I'll put the knuckles in the oven at about 150 and bake them for an hour. Parts should slide together easily then.

I just remembered. I got them from Carters.

Denny Graham,

According to the "Book of Bolts", your 3/4 ton should have floating bushings and pre-fitted pins.

This means the bushings fit into the spindles with a palm press fit, and the king pins fit into those bushings with a palm press, or light 'tap' fit...no reaming required.

Although there are certainly exceptions, this should be how it works. There is a Tech-Tip article that covers this...take a peek.

If oversize king pins are required, the axle eye is the item over bored, or reamed. This should be done in a precise fashion by a machine shop.


Stuart

i got the king pin set from lmc when i replaced them on my 50 3/4 ton. it comes with all the bearings, bushings, etc. and is around $80.00-90.00. i had a local shop press the bushings and ream them for the pins. about $90.00 but that was in 1999.

Only the 1/2 ton trucks had the floating bushings in 1950 http://chevy.tocmp.com/1948_51truckshop/51ctsm0309.htm
I hope this helps. I can't help you find a reamer as I personally would take it to the machine shop.

I did this job about 2 years ago. I found a retired chevy mechanic that had the reemer in his tool box. Spent an entire saturday tring to reem out the hole only to find it was beyond reeming. Took off the front axle and sent it to the machine shop. He trued the hole and oversized to an even bigger outside diameter bushing for about $75.00 (money well spent). I'll send the axle and spendels out next time.

Toyvo,
The king pin bosses in my axle are good, they don’t need re-sizing. The bushings in the knuckle are brass and will yield quite easily to a straight flute adjustable hand reamer, you should only have to remove a few thousands of an inch to line up the axis and bring them out to size. That’s the way it was done in most of the Chevy garages back in the day, I was a parts manager for Chevy for five years back in the late 50’s and 60’s and king pins were a common front end problem.
I’m really surprised that KD or Snap-On don’t still sell king pin reamers.
Denny Graham
Sandwich, IL

I'll second that, I used to work in a machine shop, and I would put a long hone in the honeing machine and get both bushings at the same time. Doing it one bushing at a time will not guarantee that they are lined up, and you may end up with bushings that are not concentric (oblong in relation to) the pin. It will work for awhile, but will greatly reduce the life of your bushings.

Well after three weeks of agony, $150 worth of adjustable reamers and pilots and many hours of trying this and trying that, I finally broke down and took the spindals into the engine re-builder. I was looking all that time for an auto machine shop that had a hone with a long enough mandrel to go through both bushings. Finally found a guy that has a new Sunnen hone and a goodly inventory of tooling for it.
The biggest problem that I ran into at home, was the reamer blades hanging up in the split in the bushing. I still have, an angle blade reamer and pilot on order, but it’s going on the shelf till the next bolt comes along.
Sometimes, that, “please dad, I’d rather do it myself”, attitude really gives me migraines!
Denny Graham
Sandwich, IL

"Split in the bushing"??


Stuart

The key with hand reamers is to, where-ever possible, use a pilot & pilot bush. This both aligns the bush you are reaming to the other one ; and also eliminates 'chatter' - that grabbing effect that occurs. Using the pilot, the reamer will cut smoothly & accurately, even through an oval hole or split bush. Cutting oil is a big help on steel but not any advantage with bronze.

Yah, Stu, the original bushing and the replacement bushings in the 3/4 ton are split virtically. They close up when you press them in.
1/2 ton is full floating and doesnot need to be reamed.
Thought that's what I just said Ken, "adjustable reamers and pilots", I have been known not to make myself understood in the past. That's why I had so much invested in them, the import reamers are cheap but ya can't get them in extended length with the pilots. I also picked up the next size larger reamer so I could do an axle if I run into a bad one.
You can not ream an interupted hole or bushing with a streight blade hand reamer, it will, hang up every time it passes the split and jumps, making the gap even more noticable. You will, end up with a key hole form in the hole. That's what the angle reamers are made for. Again, that is why I said, that I have an angle reamer and PILOT on order.
Moot point now, the honed spindals will be back on the truck tomorrow.
Denny Graham
Denny Graham
Sandwich, IL

I'm a machinist by trade Denny - Only trying to help , sorry to offend.

Ken.

No Offence takin' mate, gotta keep you guys from down under on our side ya know! I've worked in and out of machine shops a good portion of my 65 years also Ken, my brother and I were partners in a shop at one time and I did much of the machine work in our fabrication shop, at the accelerator that I just retired from. It's only common sense that if you run a straight blade into a straight crevasse that its going to hang up. These are different than the solid bushings that are in the ½ ton spindles. We had to take out about .013 mils and the Sunnen hone did the job perfect in about 10min., and for all of twenty bucks, only problem is it took three weeks to find this guy. There would be no problem hand reaming the axle boss or a solid bushing.

I might add as a side note, to anyone buying an adjustable reamer, spend the little bit extra and buy a good one, stay away from the imports. The reamer and pilot I bought from McMaster Carr is from Chadwick & Trefethen Inc., an American company in NH. The surfaces are all ground, deburred and polished, the nuts are machined to a tight tolerance and the adjustment has a very smooth feel to it.
The import that I got from Enco (was real cheap) is very rough to say the least. It’s blackened to cover up the heavy tooling marks, has a rough feel to it, sharp edges, i.e., not deburred and the nuts are a loose fit and hang up in the threads, it’s difficult to adjust accurately. When you mic across the blades after making an adjustment they vary by as much as .010”. also there are no pilots available for them, you will have to make your own if you need extended length and they are an odd metric thread.

Just in case there are any of the guys that are unfamiliar with the extended length reamer, I snapped a picture of the straight and angled pair that I have. The difference between the import and domestic jump right out at you on close inspection.

http://good-times.webshots.com/photo/2185416770098611668XIvwGq
Denny Graham
Sandwich, IL