Gearbox- Help with Inspection

T95 · Jun 21, 2013

Making an effort to get my rebuild underway so I have started with the gearbox. Brief history, I am the second owner, it has something like ten thousand miles on the clock and it sat for over thirty years. Two years ago I dissembled it into components. I don't have Micks Gearbox DVD but I have read and looked at every other resource available.
So, i dissembled the box this week and to my untrained eye it seems to be in decent shape. I would like your expertise and critical eyes to help me determine what needs to be replaced! I have ten photos from photbucket that I will post. Sorry, I am having a bit of trouble reducing the image size.
Looks like the gear oil turned to grease over the decades.
No Cracks, the pawl is showing a little ware Gearbox- Help with Inspection

So the layshaft bearing didnt need to be heated to remove. I was able to wiggle it out. Looks like the outer race is indicating some moving in the bore. JB weld Time??

I did find a SKF roller for the layshaft. So I am not the first one inside this box.

Normal ware?

!st Lay-Normal?

Next two shots are the Sleve 4th. Only two bushing inside and the edge of one is showing some contact.

Both the Main and layshaft look much better in the light than in photos. Neither are blue.

concours · Jun 21, 2013

Do you have access to measuring tools?

Hobot · Jun 21, 2013

Looks almost pristine compared to some still working fine. Looks like only bushes need freshing up and an old bush put in to space the new ones, if not getting the extra long ones now supplied. IF JBW used in bore to stablize the race, wait some days with the thing in sun or low bake oven temps to actually set up the JBW instead of mere clay like waste of time loading it before its time. Oh yeah check shaft tureness.

T95 · Jun 21, 2013

concours said:
Do you have access to measuring tools?

I only have a analog caliper. Not much help for measuring the layshaft bearing bore.

T95 · Jun 21, 2013

hobot said:
Looks almost pristine compared to some still working fine. Looks like only bushes need freshing up and an old bush put in to space the new ones, if not getting the extra long ones now supplied. IF JBW used in bore to stablize the race, wait some days with the thing in sun or low bake oven temps to actually set up the JBW instead of mere clay like waste of time loading it before its time. Oh yeah check shaft tureness.

Do all the gear bushing generally get replaced?
Cure rate on the JB should be no problem. I am not going to have this on the road until next year at the earliest.
Shaft trueness? Am I looking for twist or ware?

pete.v · Jun 21, 2013

As hobot says,, the components look pretty good. Even the bushings look well, having a few score marks but not particularly worn. That is not to say you should not replace them.

As far as the layshaft bearing race is concerned, what sort of fit do you have?

If you have a draw or some resistance to the fit then a Loctite product may be more applicable.

If, however, you have some slop or the bearing will drop in with no effort, then the JBW may be more effective.

All in all though, you are in good shape.

T95 · Jun 21, 2013

pete.v said:
As hobot says,, the components look pretty good. Even the bushings look well, having a few score marks but not particularly worn. That is not to say you should not replace them.

As far as the layshaft bearing race is concerned, what sort of fit do you have?
The bearing will drop in 1/4 of the way./color]
If you have a draw or some resistance to the fit then a Loctite product may be more applicable.
thanks, but I know Steve wont agree with you
If, however, you have some slop or the bearing will drop in with no effort, then the JBW may be more effective.

All in all though, you are in good shape.Music to my ears,

pete.v · Jun 21, 2013

T95 said:
thanks, but I know Steve wont agree with you

ahh, what does he know, he's just Doctor.

To be fair, get more opinions!

Hobot · Jun 21, 2013

A Drrr and brain healed enough not to screw up mixing and matching statements and testimony in public record with my name or handle on it. One, All mc life and times is risky business, so who ya gonna trust... Two the bushes are the weakness elements in AMC so my lazy long term logic says most cost effective eductational and testng to do em all now, which means ordering then getting some of em reamed to fit. Three Nortoneer God Comstock uses JBW in this application. Three-a, if case bore cleavage is still intact then glue in and let next generation marvel at your long term solution to repeat. Three-b, leave note inside shell to heat to oil vaporizing ~500'F-ish to soften hi Temp JBW to melting goo let go. Four shaft wear is rare to be an issue d/t softer bushes going first. Five Shaft candy cane is entirely possible after only one ignorant over tight fully heated triplex chain event and can leave to very frustrating short life times of the poor ole bushes trying to take up the beating of candy cane shafts. Six sell me the lay bearing cheap and get brand new to calm listee's nervous twitches and make a vendor's day better.

FastFred · Jun 21, 2013

Your a lucky barsteward, you should see the gears in mine i just pulled down.... :cry:

T95 · Jun 22, 2013

hobot said:
A Drrr and brain healed enough not to screw up mixing and matching statements and testimony in public record with my name or handle on it. Steve, I have been away from the forum for some time so I am not sure why you brain may need healing. I hope its due to something minor, like one two many cocktails or you just bouncing off the pavement again. One, All mc life and times is risky business, so who ya gonna trust... Two the bushes are the weakness elements in AMC so my lazy long term logic says most cost effective eductational and testng to do em all now, which means ordering then getting some of em reamed to fit. Generally speaking, are you suggesting I replace some or all of the gear bushing? Or, do you suggest that I replace all of the bushings and some of those will need reaming? Three Nortoneer God Comstock uses JBW in this application. Three Nortoneer God Comstock? Oh Wait, I think I got it. Three-a, if case bore cleavage is still intact then glue in and let next generation marvel at your long term solution to repeat. Three-b, leave note inside shell to heat to oil vaporizing ~500'F-ish to soften hi Temp JBW to melting goo let go. Four shaft wear is rare to be an issue d/t softer bushes going first. That makes sense and gives me hope that what I see on the shaft is bushing deposit. Five Shaft candy cane is entirely possible after only one ignorant over tight fully heated triplex chain event and can leave to very frustrating short life times of the poor ole bushes trying to take up the beating of candy cane shafts. I am going to put a straight edge on it to ensure it not a barber pole! Six sell me the lay bearing cheap and get brand new to calm listee's nervous twitches and make a vendor's day better.

Its fate is yet to be detemined, but your on top of the list!.

T95 · Jun 22, 2013

FastFred said:
Your a lucky barsteward, you should see the gears in mine i just pulled down.... :cry:

I saw the photos you posted and do feel luckey!

Hobot · Jun 23, 2013

Well shoot T95, if you are a real mechanic then can assess each item and just order the ones ya most need. In my AMC cases there was no question that everything was worn or bent, so no brainer to just do it all and start clock tickng from there. The brainless part in my case was not checking shafts so their candy cane-ness unraveled my 1st renewal before its time. I was frustrated to find a number of bushes would not fit as sent. The method of reaming seems to matter as far as oil retention surface but I don't remember that detail but assume machinists will. Sorry on leaving the commas out next to spelled numbers.

T95 · Jun 23, 2013

I would never claim to be the real deal. I am just looking for some experienced advice. Inspecting, removing,installing and especially reaming bushings is all new to me. I am really intrested in hearing more on reaming them. I got to say that I expected the bushings to be more substantial. With such thin walls reaming is a more delicat operation than I envisioned.

Gearbox- Help with Inspection

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