Help Removing Rivett 608 Gearbox

I am attempting to repair a Rivett 608, but I cannot figure out how to remove the quick change gear box in one piece. Is it possible to remove it assembled or do I need to disassemble it first?

Yes, it is possible to remove it as a whole unit. I did that on my 1931 model # 608 QC gearbox awhile back as part of the commencement of a general refurb. I had knocked a lot of the lathe down at that time for various reasons.

Reassembly was undertaken only a month ago and proved more difficult however. The problem was the side of the gearbox unit was not going all way to bed of lathe…I was coming up about 1/2" short of mating. At first I thought it was an issue with aligning 2 pins that needed to mate in the blind hole.

The instructions I found in the vintage Rivett materials online suggested the re-attachment would be uneventful (see attached). It was proving to be quite frustrating.

I decided to take it further apart. I wanted to lube the QC gears and see inside there anyway. I broke down the gearbox by my own deduction, pulling the unit apart and exposing the set of QC gears.

When I went to put it back together I encountered the same problem...except I ruled out it being an issue with the alignment pins. It was a press fit and would not go on so I heated it with the heat gun and then using gloves and a deep socket as a drive collar I lined it up with the pins and hammered it into place quickly after it had expanded. Then I reinstalled the gearbox housing back into place.

So it is back on and I have moved on to other aspects of the refurb...it has not been fully tested (but I was)

If you would like to PM me I have more photos and further explanation, etc. of what I've just described..you show me yours and I'll show you mine via email, which is the route I'd prefer.

Well, it came off without too much trouble. A few light taps and I got it off in one piece. However, it seems like one of the two pins has broken off inside mechanism.

I'm trying to figure out what they are for. Is it just alignment or are they for power transmission as well? I had a friend suggest that they may be shear pins as well. Does anyone have any idea what the purpose of these pins are and the best way to fix a broken one?

They are drive pins. Just drill out and make a new one.

This is not the answer to your question, but if you want to remove an reinstall the 2 speed gear box on the bottom side of the table, the best way is to remove the lathe from the table and turn the table over.

Has anyone figured out how to disassembly the stack of gears in the QC box? It was the only part I could not disassembly. Sorry, I don't remember what I had to do to reattach the QC to the bed.

Vince