A-type overdrive / gearbox trouble shooting

[tdskip]

So either I paid retail for a tonneau cover and got a free O/D gearbox, or I got a cheap O/D gearbox and a free tonneau cover. But, there is a reason the gearbox was so cheap. The shaft won't turn.

I have no idea yet why, but was hoping you guys could help point me it the right direction here. The shaft from the engine to the gearbox will turn slightly. The output shaft coming out of the O/D won't turn at all.

The inside of the main gearbox has gunk in it, but haven't tried to taken the O/D apart.

I've taken the top of the gearbox off and I can't see anything stuck or jammed in the gears.

Ideas?

 

[TR3driver]

Sounds like something locked up or jammed in the OD to me; if it was two gears selected at once or something, then I would expect some play in the output shaft as well. Not much you can do but pull it apart and get the bad news.

Good thing it was free :laugh:

 

[tdskip]

Hi Randall - yep, I think I got what I paid for. LOL.

I just separated the main gearbox housing from the O/D unit, and as expected the gearbox turns fine now but the O/D unit is still locked up tight.

Not looking too nice in there, eh?

What is the next bit to take apart? I like taking things apart...

 

[TR3driver]

From here, I'd remove the 8 springs (should fall out, but apparently they're stuck), then the 4 nuts inside along with their keepers & the two bridge pieces.

Then the 6 nuts (I think it is) that hold the two big OD castings together, and separate the castings. You'll probably need to leave the nuts on the ends of the studs (to protect the threads) & tap them with a brass hammer to get it apart.

PS, lots of rust in there, but if it doesn't get any worse than that, this unit may be salvagable.

 

[tdskip]

OK - got it apart. Output shaft still won't turn. Here is what I'm looking at now;

 

[TR3driver]

So now, tap the black brake ring out of the rear housing and remove the clutch and so on.
Might be worth skimming this article:
https://www.buckeyetriumphs.org/technical/AOD/AOD2/AOD2.htm

 

[tdskip]

Got the brake ring off. The assembly with the rods turns freely now but feels a bit grainy, so not all is well there.

There are three gears just inside the hole in the middle of the assembly with the rods, and those three gears move smoothly as well.

I got the circlip off, but the assembly won't slide out still.

Thanks for the link for the Buckeye A-type guide. Found the J-type but not that one Randall. I'm going to have to read up.

 

[mrv8q]

Cool thread! Like watching a tennis match...

 

[tdskip]

Anyone know how the Clutch Thrust Ring Assembly, the one with the rods sticking out of it, come out?

 

[tdskip]

I also just noticed that the solenoid mounting bracket has been torn off...

Any ideas on replacing that short of "just" ordering a new one? My aluminum welding skills are probably not up to the task.

 

[TR3driver]

Guess I'm confused ... is the clutch assembly still stuck in the rear housing, or are you trying to get the sun (center) gear out of the clutch assembly?

If the clutch assembly is stuck in the rear housing, the direct drive clutch face must be rusted to the annulus. If you can't pry it out, probably the best thing would be to remove the tail flange and speedo drive, then press the annulus out of the rear housing with the clutch still stuck to it. Then you can tap on the edge of the clutch, soak it in PBB, etc. to get the clutch loose.

 

[TR3driver]

A-type OD parts show up on eBay from time to time, usually the bids aren't too terribly high. ISTR I got just the solenoid bracket for about $50 (but that was a few years back and it took several months of trolling to find one).

 

[tdskip]

Hi Randall - sorry if I wasn't clear enough. The clutch assembly is still in the rear housing. Should it just freely pull out?

 

[TR3driver]

Yup, normally it just slides out once the brake ring is out of the way. It's what moves when the OD shifts from direct drive to overdrive & vice versa, so it should move easily. The springs hold the inner clutch face against the cone of the annulus for direct drive; then the hydraulics pull it forward against the spring pressure to bring the outer face against the brake ring for OD.

 

[69tr]

Try Team Triumph for the bracket. He has a large selection of new and used parts.
You might also try John at Quantum Mechanics. I got a solenoid from him. He might have some other stuff.

Good luck, Pete

 

[tdskip]

Yup, normally it just slides out once the brake ring is out of the way. It's what moves when the OD shifts from direct drive to overdrive & vice versa, so it should move easily. The springs hold the inner clutch face against the cone of the annulus for direct drive; then the hydraulics pull it forward against the spring pressure to bring the outer face against the brake ring for OD.

Ah - thanks Randall. That makes sense now, thanks for the explanation. I hit it with PB so let's see if that helps. I have to say it is kind of neat to open one of these up and learn how it works.

Thanks for the heads-up Pete. Will drop them a line.

 

[tdskip]

OK - update as of, well, right now.

Either this thing was run dry, which I don't think so, or some water or wet air got in it and it sat for a long time. The parts themselves look like they'll clean up OK, but the clutch needs to be replaced for sure.

Got the large rear nut off.

Got the speedometer drive out.

Did the clutch assembly loosen up yet? Heck no!

 

[tdskip]

Partial success. Some careful heating of the exterior assembly followed by some immediate spraying of Freeze-Off and here where I am at;

Clutch thrust pins and clutch;

Planet carrier assembly;

The gears in here turn freely;

Good view of the roller assembly;

Lots of crud here;

This also turns, some resistance, but it turns.

 

[startech47]

The one way clutch, roller assembly, should turn with some resistance in one direction and not turn in the other. Overall the over drive does not look too bad. Clean it up, check the bearings, and reassemble.

 

[tdskip]

The one way clutch, roller assembly, should turn with some resistance in one direction and not turn in the other. Overall the over drive does not look too bad. Clean it up, check the bearings, and reassemble.

That is exactly how the roller assembly turned - phew. I removed it and all the roller bearings looked good actually;

Next up was the rear flange, and to disprove pretty much everyone's belief in how I do things (ha!) I actually read the Buckeye guide Randall sent me and used a pulled like they did on the rear flange;

But the pulled wasn't long enough so I had to get creative on how to finish the job. This is what you call an "off-label" use. Can you name the part?

Eventually it came off - including rusty gunk.

Then the thrust washer - which looked pretty good but what do I know;

Leaving me with this;

The gunk on the walls here has metal bits in it...sweet!