A1G2 decisions. Rebuild or replace?

[Swedefj40]

So I took my (1995?) A1G2 off to check my gimbal bearing and noticed that the input shaft (u-joint) bearings were really rough and hard to turn. I took it to the local Merc mechanic and after looking at it said that I should think about buying a new leg. He said the lower half seems good but he figures that there was probably some water intrusion from a bad bellows at some point in the past and it will have probably compromised the lower unit as well. I'm trying to decide if I just get the upper half (which had obvious issues) rebuilt or buy a whole new leg. The mechanic said the cost of a rebuild might justify getting a new leg. If I decide to go the new leg route, do I go with a Merc product or aftermarket (cheaper) like SEI? The mechanic said not to go the cheap route as they're notoriously unreliable and have been known to have issues with only a few (40) hours of use. Opinions please.

 

[Scott Danforth]

I would go SEI if the drive needed rebuilding

However if you have water in the drive, the water is sitting in the lower

 

[rustybronco]

You aren't going to know if its rebuildable or not unless it's taken apart and inspected. At least take the top cover off and look at the innardsthen drain the oil and see if it shows water ingress.

Did the tech open up the drive?

 

[Swedefj40]

I would go SEI if the drive needed rebuilding

However if you have water in the drive, the water is sitting in the lower

I've had the boat for 4 years and never had water in the oil ever. It looks like the previous owner had the issue.

 

[Swedefj40]

You aren't going to know if its rebuildable or not unless it's taken apart and inspected. At least take the top cover off and look at the innardsthen drain the oil and see if it shows water ingress.

Did the tech open up the drive?

 

[Swedefj40]

Yeah he popped the top cover off and also split the case. Like I mentioned there was no evidence of water apart from the bad bearings. The yokes on the u-joint had surface rust on them but the ujoints were like new. The top gears had some very slight rust staining on the outter surface of the tooth face but barely noticeable. The lower half seemed fine to him but he didn't get into it.

 

[rustybronco]

Personally I would replace the bad bearings, check the pre load on the two upper sub assemblies, set the gear depths, reseal it and call it good.

If you have to pay someone it might not be worth it monetarily.

Currently working on replacing gears and bearings on my 95 A1G2. Including special tools ( slide hammer, shop press, shimming tools etc.) Upper gears, bearings, shims, seal kits I'm in at around $900 and I know what I've got. You can't say the same about a used unit.

 

[Scott Danforth]

I've had the boat for 4 years and never had water in the oil ever. It looks like the previous owner had the issue.

Then replace the ujoints and go boating

 

[Grub54891]

If serviced properly every year- or- two, this would not have happened.

 

[Swedefj40]

If serviced properly every year- or- two, this would not have happened.

Yeah you're right. I bought the boat 4 years ago and did my best for routine maintenance. PO had it serviced in the spring of 2018 with new bellows and a few other things. I replaced the impeller the next year and changed the oil as I do every year since but this year I pulled the drive to check the ujoints and gimbal when I found the issues. This is my 1st I/O and I'm learning as I go. Live and learn.

 

[Swedefj40]

Personally I would replace the bad bearings, check the pre load on the two upper sub assemblies, set the gear depths, reseal it and call it good.

If you have to pay someone it might not be worth it monetarily.

Currently working on replacing gears and bearings on my 95 A1G2. Including special tools ( slide hammer, shop press, shimming tools etc.) Upper gears, bearings, shims, seal kits I'm in at around $900 and I know what I've got. You can't say the same about a used unit.

Trust me I've thought about doing it myself. I've done a few Ring and Pinions in the past but those were on vehicles and I had a wealth of information to do it correctly. This is new to me and I haven't done enough research to give it a try. I'm on a bit of a time crunch so for peace of mind, I'll get the shop to do it.

 

[achris]

So I took my (1995?) A1G2 off to check my gimbal bearing and noticed that the input shaft (u-joint) bearings were really rough and hard to turn. I took it to the local Merc mechanic and after looking at it said that I should think about buying a new leg.

Nice little earner for him!

He said the lower half seems good but he figures that there was probably some water intrusion from a bad bellows at some point in the past

Water in the bellows does not mean water in the drive.

and it will have probably compromised the lower unit as well.

Water in the bellows does not mean water in the drive.

I'm trying to decide if I just get the upper half (which had obvious issues) rebuilt or buy a whole new leg. The mechanic said the cost of a rebuild might justify getting a new leg. If I decide to go the new leg route, do I go with a Merc product or aftermarket (cheaper) like SEI? The mechanic said not to go the cheap route as they're notoriously unreliable and have been known to have issues with only a few (40) hours of use. Opinions please.

Opinion? Find a new (trustworthy) mechanic! Your current one is just towing the Merc sales line. Which is to sell, sell, sell, never repair!

Ok, rough drive gear bearings is such an easy (and cheap) fix. Those bearings are just bog simple Timken bearings, nothing special. Pull the top box to bits and assess. Even if you replace ALL the bearings in the box, there's still less than $150 dollars worth. The tricky bit is setting them up, but here's a tip. I have replaced those bearings in MANY boxes, and apart from the rolling torque set up, when replacing just the bearings, the original shims don't change (bearings are manufactured to a very tight tolerance, less than 1/10 of a thou).. Because I'm me, I do the shim checks every time, and it's only when replacing the box itself that the shims have ever changed. If you're budgeting for a new drive anyway, why not give a bearing replacement a go. The only special tools you'll need are the spanner to remove and refit the cover nut and a torque indicator. And the usual hand tools.

That's my opinion. I have a video on doing the rolling torque set up. Link at the bottom of this post signature.

Chris...

 

[Swedefj40]

Nice little earner for him!

Water in the bellows does not mean water in the drive.

Water in the bellows does not mean water in the drive.

Opinion? Find a new (trustworthy) mechanic! Your current one is just towing the Merc sales line. Which is to sell, sell, sell, never repair!

Ok, rough drive gear bearings is such an easy (and cheap) fix. Those bearings are just bog simple Timken bearings, nothing special. Pull the top box to bits and assess. Even if you replace ALL the bearings in the box, there's still less than $150 dollars worth. The tricky bit is setting them up, but here's a tip. I have replaced those bearings in MANY boxes, and apart from the rolling torque set up, when replacing just the bearings, the original shims don't change (bearings are manufactured to a very tight tolerance, less than 1/10 of a thou).. Because I'm me, I do the shim checks every time, and it's only when replacing the box itself that the shims have ever changed. If you're budgeting for a new drive anyway, why not give a bearing replacement a go. The only special tools you'll need are the spanner to remove and refit the cover nut and a torque indicator. And the usual hand tools.

That's my opinion. I have a video on doing the rolling torque set up. Link at the bottom of this post signature.

Chris...
View attachment 362398

Okay, now you've got me thinking

 

[achris]

Okay, now you've got me thinking

"My work here is complete."

 

[Swedefj40]

Not quite Chris lol, are there any shimming to do on the vertical gear or is the backlash set by the drive gear position?

 

[achris]

Not quite Chris lol, are there any shimming to do on the vertical gear or is the backlash set by the drive gear position?

Yes, shims everywhere. But as I said, when changing JUST the bearings, the shims don't change (or at least I've never seen one change)...

Chris.....

 

[Swedefj40]

Thank you sir

 

[rustybronco]

Water in the bellows does not mean water in the drive.

Opinion? Find a new (trustworthy) mechanic!

There's your best piece of advice.

Since you've done ring and pinions in the past, it should be an easy repair for you. The special tools necessary will add a bit to your costs but still better than replacing a complete drive as suggested.

 

[nola mike]

I thought we were talking about the u-joints being bad?

 

[Swedefj40]

I thought we were talking about the u-joints being bad?

Nope, the ujoints were fine. It's the drive shaft bearings that were bad.