Output Shaft Coupling Problem

[System_Error_117]

Hey gang!

Just finished changing the output shaft seal on my A4. Now I'm trying to fit the output coupler back in place. Following Mr Moyer's video to the letter I first tried tapping it in, but with no luck, so I fashioned a press like the one Don sells. But the press has made no difference. I can slide the coupler to the point where it's just making contact with the thrust bearing, very smooth and little resistance. Key in the right position, not jammed, etc. Then I need to employ my press, which I crank on until I'm nearly bending the washers on the threaded rod, and it doesn't budge an inch. I can loosen the press and pop the coupler right off like it's made no progress at all. I'm thinking it's failing to align with the inner race of the thrust bearing for some reason. Both are clean and slightly greased. It came appart using the longer bolt method without much force. The other flange bolts are only finger tight, so if any slight play was needed to align the coupling and bearing race, it shoule be able to slip in no problem. Any suggestions? Just don't want to snap something off forcing it tighter and tighter....

[System_Error_117]

Update

After staring at the coupling feeling sorry for myself for a few minutes after posting, I decided to just take it all apart again and see what was going on. I took the thrust bearing plate and output shaft coupling home and started fiddling with them on the bench.

The coupling seems to be far larger then the inner race of the thrust bearing, I probably mushroomed it slightly trying to press it in. I took some sand paper and began slowly and carefully removing any galling. After sanding by hand carefully I can get the coupling to just start bighting into the inner race by tapping it with a hammer. Don't want to go too far and need a puller to remove it again. I'll sand it tonight with some 600 grit wet sand paper to remove any scoring the 180 grit put into the surfaces. Then hopefully when another pair of fresh gaskets arrives from the states it will go a little smoother!

[sastanley]

I don't remember needing a press, but I did mine about 10 years ago now. The hard part for me was getting the old coupling out. I ended up bending the flanges and replaced everything from the seal back.

[System_Error_117]

I don't remember needing a press, but I did mine about 10 years ago now. The hard part for me was getting the old coupling out. I ended up bending the flanges and replaced everything from the seal back.

I was chatting with a marine mechanic friend and he was concerned about the amount of force I was applying to the thrust bearing trying to seat the coupling. I needed to order new gaskets as I had used Permatex on the new ones I had just installed so they tore apart taking it apart again, so I bought a new coupler and bearing. So the new ones better damn fit when they arrive in the next week or two!

[Al Schober]

No idea what the problem is, but something doesn't fit.
T'was me, I'd take my digital caliper and start measuring stuff. Make sure the bearing and the transmission flange are the right size.
Personally had an issue measuring bearing reactions on the first Ohio class submarine. We use a hydraulic jack (with pressure gauge) and dial indicators to lift the shaft. Results were NOT what was expected and pointed to an obstruction inside the thrust bearing. Took apart the thrust bearing and found an oil seal that didn't fit. One surface was as cast - hadn't been machined. GE got the bill for that mistake.

[System_Error_117]

Thrust Bearing Pulled Out

Well after taking it all apart once again I discovered that the thrust bearing had been pulled half way out of the plate its pressed into when I pulled off the output coupling!

I wasn't aware it was supposed to be flush until fully removing the plate and looking at the back where I could clearly see clean fresh steel where the bearing had pulled away from. This wasn't allowing the coupling to seat properly. Bearing was a bit rusty looking, and after giving it a thorough beating with the hammer and press trying to get it seated, I thought it best to just replace entirely.

New bearing and new coupler arrived and everything fit like a glove. Problem solved!