Tapered roller bearing

[1970 Chieftain V]

Pre Alpha "MR". Which way does the tapered roller bearing come off of the drive shaft? Does it come of the pinion gear end or the pre load pin end?

Jason

 

[Don S]

Re: Tapered roller bearing

There are several tapered roller bearings, and not sure what you are calling a drive shaft.
Got a parts breakdown of what you are asking about?

 

[1970 Chieftain V]

Re: Tapered roller bearing

There are several tapered roller bearings, and not sure what you are calling a drive shaft.
Got a parts breakdown of what you are asking about?

It is the bearing on the drive shaft just under the water pump base. The part number is 31-53079A1. I thought it might be obvious which drive shaft I am talking about when I said pinion gear and pre-load pin. Number 22 in this break out

http://www.sterndrive.info/sterndriveparts/lower_gearcase.html

Jason

 

[JCF350]

Re: Tapered roller bearing

Pre Alpha "MR". Which way does the tapered roller bearing come off of the drive shaft? Does it come of the pinion gear end or the pre load pin end?

Jason

It comes off the towards the upper end of the driveshaft.

 

[1970 Chieftain V]

Re: Tapered roller bearing

It comes off the towards the upper end of the driveshaft.

This is wrong. It comes off of the lower end (pinion gear end). If I had done a little more reading in the book before asking this question I would have known.

Jason

 

[Don S]

Re: Tapered roller bearing

This is wrong. It comes off of the lower end (pinion gear end).

No, JCF350 was correct.

 

[1970 Chieftain V]

Re: Tapered roller bearing

No, JCF350 was correct.

But this says it is pressed on from the pinion side:

If it is not viewable it is page 6A-12 in the 1 gig manual. Step 4c and figure 7.

Jason

 

[Don S]

Re: Tapered roller bearing

Well, there is your problem. In your original post, you asked:

Pre Alpha "MR". Which way does the tapered roller bearing come off of the drive shaft?

The "MR" drive is covered in manual #6. That is where I got my picture from.
Not sure which manual you have there, there were several with over 1 gig, but none of them had the MR drive in it.

 

[1970 Chieftain V]

Re: Tapered roller bearing

Well, there is your problem. In your original post, you asked:


The "MR" drive is covered in manual #6. That is where I got my picture from.
Not sure which manual you have there, there were several with over 1 gig, but none of them had the MR drive in it.

Yep that was my mistake. I missed quoted the "MR". When I took the drive apart it looked to me like the "R" drive which is what I meant to type.

Jason

 

[Don S]

Re: Tapered roller bearing

The R is still the same manual as the MR.
What drive do you actually have, Year and engine will also help.
My guess, is you are playing with a "One" drive.

 

[1970 Chieftain V]

Re: Tapered roller bearing

The R is still the same manual as the MR.
What drive do you actually have, Year and engine will also help.
My guess, is you are playing with a "One" drive.

The S/N of the drive is 6346866. I don't know the year of the drive, it was replaced before I got the boat. The engine is an 1970 L6 165. Is it possible to mix and match "one" drive with "R" parts?

Thank you for your help I really appreciate it.

Jason

 

[Don S]

Re: Tapered roller bearing

I don't know exactly what lower unit you have, but it's really old. Will an R drive fit ............... I didn't think so at one time. But who knows what else has been changed on your gimbal housing, bellhousing, upper, lower, etc.

 

[1970 Chieftain V]

Re: Tapered roller bearing

I don't know exactly what lower unit you have, but it's really old. Will an R drive fit ............... I didn't think so at one time. But who knows what else has been changed on your gimbal housing, bellhousing, upper, lower, etc.

It was a backwoods marina that the previous owner had do the work so it is entirely possible they could have cobbled parts together. The reason I thought it was an "R" drive is because of the bearing number. The installed bearing is a Timken 15580. When I looked up that number it came up on the "R" drive. But as CaptJason has in his sig line "just because you found it that way... doesn't mean it's supposed to be that way."

Once again I appreciate the help. I think I have found enough info to finish the job.

Jason

 

[Don S]

Re: Tapered roller bearing

It may still be the same bearing part number, just installed from the opposite end.

Aren't boats fun

 

[JustJason]

Re: Tapered roller bearing

I own a pre alpha drive, I can tell you that there is quite a bit of interchangeablility between the 1A/1B/1C the EZ, R, MR and alpha 1. As far as what part fits what drive is really a crapshoot, and requires a bit of time playing with MIDAS.
Knowing this, your best bet is to start with your serial and ordering parts for the serial#. If worst comes to worst you may have to bring the drive to the dealer to try and have it id'd.

 

[1970 Chieftain V]

Re: Tapered roller bearing

It may still be the same bearing part number, just installed from the opposite end.

Aren't boats fun

This is actually fun stuff. I sit behind a computer all day at work. I really like getting my hands dirty.

Jason

 

[1970 Chieftain V]

Re: Tapered roller bearing

I own a pre alpha drive, I can tell you that there is quite a bit of interchangeablility between the 1A/1B/1C the EZ, R, MR and alpha 1. As far as what part fits what drive is really a crapshoot, and requires a bit of time playing with MIDAS.

That is what I am finding out the further I get into this work. This tapered bearing is the last thing I need. Anything else goes wrong I am going to trash the unit and buy a new one!!

Jason

 

[JustJason]

Re: Tapered roller bearing

for the money your best bet is to pick up an SEI drive and try to get a few bucks for your case on ebay

 

[achris]

Re: Tapered roller bearing

Quite possible you have an 'R' top box (serial number will identify that and I'm at the wrong computer) and you could have any of the following lower box... MC-1, R, MR, Alpha 1. All will bolt straight up. The fact that you have the driveshaft bearing going on from the pinion end means you have either a MC-1 or an R lower unit. Do you have an 'O' ring groove at the top of the driveshaft? If yes, then you have an MC-1 lower box. Do you have plastic inserts in the water intakes? If no, then your lower box is pre-1974. If you don't have an 'O' ring groove, then it could still be an MC-1 because if it's had a new driveshaft at some time in the past it will have had a 'O' ring-free one put in.

Chris.....................

Edit: Now at the right computer and the serial number you gave is for a 1983, 'R' top box.

 

[1970 Chieftain V]

Re: Tapered roller bearing

Do you have an 'O' ring groove at the top of the driveshaft?

Yes

Do you have plastic inserts in the water intakes?

No

Thank you for the info Chris. Like I said to captJason I "should" just pony up the cash and get a new unit. The pinion gear, reverse gear, and forward gear and all bearings really need to be replaced but then that is almost the price of a new unit from SEI. When I took the water pump base off there were 2 rollers missing from the bearing. I didn't find any chunks in the oil. The pinion gear has a few chunks missing from a few teeth. The chunks missing in the pinion gear appear to be an old break. And there isn't any damage to the forward or reverse gear. So I think who ever did work previously might have put them in that way? Anyways, I think I am going to run this until it craps out.

Speaking of new units does anyone know how to convince the Mrs. that I NEED a new outdrive? :redface:

Jason