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Repair BP 2j high speed dog clutch teeth and not replace?

StrayAlien

Cast Iron
Joined
Aug 18, 2014
Location
Melbourne, Australia
Hi all,

After a top-end refurb using a H&W kit with bearings and brakes etc on my 1981 (UK) Bridgeport 2j2 I still get some rattle. Not in back gear or neutral so I am figuring it is the dog clutch engagement there having some wear. Though, visually, the engagement teeth looked just fine - no wear evident. I have adjusted the adjustment plate on the hi / lo lever to lift the lever as far as it will go in hi - and even with the plate removed and the lever held by hand as high as it will go some rattle still exists.

Replacement of both parts there is $600+ AUD so not a cheap fix as machine is for home use, not commercial.

I was wondering if anybody has actually repaired them rather than replace them. I understand the sides of the dog teeth are tapered so maybe grinding a little off the face of each to permit them to bed further might do it?

Or am I stupid for even considering it?

All advice appreciated.

Greg.
 
Hi there
I just finished rebuilding my 2j variable speed, I ended up replacing those 2 shafts.
There is a YouTube video of a guy refinishing those 2 shafts, I think it took him a year which is why I decided to just bite the bullitt and replace the two.
 
You can try "floating" the head by loosening the nuts that secure the upper head to the lower part. Then run the head with the splines engaged and tap it lightly around with a plastic or rubber mallet. This is a method for allowing the splines to self-align themselves more accurately. While doing this, you should be able to identify a "sweet spot" where the head runs as quietly as it can. This assumes you also have the engagement lever properly adjusted so that the splines fully mesh (and you may have to readjust it for proper engagement after "floating" the head). Then tighten the nuts back up and secure it in that position.

You can search my posts where this has been discussed before in more detail.
 
RobertoC - sorry I missed you're post. Apologies for late reply. I'll search for it!

Maschine, I think I may have read some of your other posts actually. :-) I read about 'floating' it and so did some practical research at the weekend. That is, I stripped the head down to backgear to have a play.

The pins in the lower head bathtub with have proven a devil to get out. It doesn't really float at all with them in. So, more work needed there.

What I did do that gives me hope that floating may work is this: with no other upper head stuff on at all (stripped to aluminium plate covering bull gear), if I rest the spindle pulley hub on the splined gear hub and engage the dog teeth they mate with no play at all. If I turn spindle by hand from below while holding the pulley hub there is no play.

If I reassemble bathtub and brake etc with spindle pulley hub back in place and re mount it I get play when doing the above test again. The hi/lo lever has them engaged with plenty of adjustment left - so we're good there.

So, that supports the sweet-spot theory. I think with the pulley hub just resting there the axiis might be just a little off and it has better engagement.

So, if I can removed the darn pins I might be able to give the float thing a go and maybe save $700 AUD.

I'll post results here.

Greg.
 
Okay, small correction on 'pins' in above reply. Seemed easier to explain when I was writing the above .. but .. there is actually only one pin. And I be darned if I can figure out how to get it out. Maybe the reason there is only one is that all the others were okay to come out ... but not this one.

The part (#12180107) says it is a taper pin ... but mine has an internal thread on the underside and is a bit mushroomed there, but not like it has been thumped, more like it has been pressed.

How do I get it out? If it is a taper does it come out the top or the bottom?

Many thanks,

Greg.
 
Stray Alien - Are you talking about the pins shown below? (see 16:48)

Bridgeport Head Top Half Teardown - YouTube

They should pop right out. Another thing to consider is that there's some uncertainty in my mind if the head can also be floated using bolts other than the ones that hold the aluminum clamshell and the lower tub part together (which are locked into position with the pins shown in the video). Loosening the castle nuts below them (shown at 19:40) may also facilitate a float...maybe? Not sure about that.
 
Also, I meant to add - if you visually inspected both of your splined engagement teeth and they looked fine? I wouldn't drop $600 (AUD or USD) to replace them. I'd be looking for something else being the noise culprit if that's the case. Also, be aware the Variable Speed Drive (VSD) machines typically don't sound like a Swiss clock operating. Even new there's a bit of "normal noise" to contend with.
 
Hi Maschine, thanks. Not those bolts in the video - the alignment pins. I don't believe the head can be floated with those three bolts. I assumed that to float it the alignment pins needed to be removed. This is one of them:

View attachment 234520

And from the underside it has an internal thread:

View attachment 234521

The teeth do have wear. The spindle splines seem great. If you look at this pics you can see the 'ears' on each tooth near the outer edge. I have seen pics of worse for sure, I guess when I looked at them initially, they didn't seem worn ... but a closer look showed the ears.

View attachment 234522

It looks like someone has had a go at creating more clearance for the teeth - look at the file marks on the matching dog:

View attachment 234523

So, back to the pins. Is this what i should remove to float it? Still not sure what side it comes out - I assumes it comes out the bottom, but best to be sure!

Greg.
 
Sorry but I cannot see any of the attachments provided. Not sure what the problem is, but I can't see them. The alignment pins I am referring to - not the castle nuts alluded to later - are addressed at 16:48 in the above H&W video. Please see that again or try re-uploading the pics you have.
 
Thanks Maschine,

Apols for late reply - this 16 hours time difference is a killer!

Don't know what happened to those pics but here they are again. Hopefully they work this time.

IMG_20180801_185456.jpgIMG_20180801_185519.jpgIMG_20180801_192453.jpgIMG_20180728_165514.jpg

Yes - it is the pins in the video. But no way that mine just taps like his. But at least it comes out the bottom so I'll try harder. Interesting to note though that mine is not like the taper pin shown as a replacement part - mine has an internal thread underneath. I have seen only one reference to the same thing on these pins. Maybe it is a UK thing? Dunno.

As you can see, the teeth do not look like a car crash as they do in some pics you see about. When I first looked at them I thought they were fine - but I'm somewhat a novice. I'll be back at it this weekend so let's see how we go. I reckon this must be like the 7th time I have had the top end apart in the last two months - you'd think getting the motor back in by onesself would be be getting easier. Nope!

Thanks again for the help.

Greg.
 
I am happy to report that I managed to remove the (rather stubborn) alignment pin and that floating the belt hosing base 'tub' has fixed the rattle. I mean it is completely gone. So strike up one for floating stuff to lose a rattle.

With the hi/lo level in neutral, I placed the tub on the machine with about 1mm or so gap to being fully tightened down and then engaged the teeth and manually spun the spindle. I then tightened things down to just have a smidgeon of play and spun the spindle again a few times. I then tightened it all down.

Thanks for the advice, it is gold. Ever so much appreciated.

If you're ever in Melbourne I owe a beer.

Greg.
 

I had a B'port that had had the clutch teeth built up with hard surfacing braze. I have no idea how they were re-profiled, as they were all worn out again. I considered building them up again, and decided I had better things to do with my time and bought the parts.

I mention this because it appears to me that the teeth in the last photo have been built up with weld, I can see little voids and slag inclusions. The geometry looks OK, but if the overall length of the shaft has been reduced, they may not engage fully. I would try bluing them off; what you want is full contact on both sides of the mating surfaces of the teeth, with NO contact on the flat ends of the shaft.

If you can't get full contact, the two parts will rattle against each other. If that's the case, just bite the bullet and replace the parts.

Dennis
 
Thanks Dennis,

If the 'float' thing didn't work then my last course of action would have been to blue them maybe start filing or something. Btw, I think maybe what looks like flaws in the metal in the second shot is actually little bits of grease but, for sure, you can see filing marks so someone has had a go at it.

As it happens, after the float fix I have to say I am *very* happy with how it is spinning - so my urge (and requirement) to strip it and blue it has kind of evaporated. Thankfully!

Greg.
 
Awesome that it seems to have worked itself out SA! Also, your splines/teeth looks great to me. Looks like nice, sharp edges with minimal wear to me. Glad you didn't need to drop $600 smackers on it. Considering it's running quiet, sounds like you have it dialed in now.

And don't thank me for the advice, I'm just an amateur. I bought my first Bridgeport last year and went through the head using the H&W rebuild kit like you did. Some old timers here told me about the float thing, which definitely helped quiet her down. So I'm happy to share what they told me and very glad to see the "procedure" did the same for you.

And I would love to take you up on the beer offer. Always wanted to visit Aussie land, but haven't yet. Airfare a bit pricey, but someday. Cheers...
 








 
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