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SP drive starts knocking after about five minutes running on the muffs?

K

kimcrwbr1

Banned
I started my AQ131 yesterday and getting ready to do the break in oil change. I noticed a knocking noise sounds like it is coming from the upper gearbox. I have the new U-joints and getting ready to pull the upper gearbox and give it a once over and change any parts if necessary. Could the knocking be the cross pieces or what do I need to focus on when opening up the gearbox. Would one change the dog and piston as a set?
 
Kim, the only thing that comes to mind (without having "hands-on") would be:

  • Bearing Crosses (aka U-joint to some people)
  • PDS bearing
  • Expanded transmission vertical shaft split ring keeper
  • Chip in either the transmission's main drive gear, or in one of the 2 driven gears
  • see below

getting ready to pull the upper gearbox and give it a once over and change any parts if necessary. Could the knocking be the cross pieces or what do I need to focus on when opening up the gearbox. Would one change the dog and piston as a set?
Click to expand...

What are you calling a Dog and Piston.......... the eccentric piston and shift shoe?????

If so, the shift shoes will occassionally break and may produce a rattling sound.
For the cost of one new shift mechanism O-ring, and 2 new O-rings for the drain plug and dip stick, you can remove it and take a look.

If the 30W gear oil is clean.... it can be re-used.


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Hopefully I can tear into it today the PDS bearing is new with engine rebuild. Yes the eccentric piston and shoe I will be replacing the crosses and may as well give the gearset a eyeball while it is out. You wouldnt have a good set of gears looking for a home in my SP-A MT upper gearbox?
 
FIRST... lets try the really easy stuff. What position is the drive in? It should be all the way down a steering set to straight ahead. Is the universals are other than straight (up/down and side to side) they can be noisy.
 
You have a point it is not all the way down I didnt want to drop the front of the boat because of all the rain here in WA. I will have to lower it all the way in order to pull the upper gearbox anyways to change the crosses.
 
Ricardo how do you check for bearing preload my book shows 1.1 ft lbs for used bearings and 2.2 ft lbs for new. Do you just go by feel, I ordered up all the seals and O-rings. Hopeing for a nice day in the near future so I can tilt the front of the boat down to fully lower the drive to pull the upper gearcase. Every time I get a little time the monsoons kick in.
 
Kim.........

kimcrwbr1 said:
Ricardo how do you check for bearing preload my book shows 1.1 ft lbs for used bearings and 2.2 ft lbs for new.
First of all, the thread title implies SP drive. The SP is a later drive using the "A" style transmission.
The "A" transmissions use the all aluminum integral bearing box/clamping collar.
The rolling torque value for this "A" BB is not the same for the Pre- A transmissions.

If you have the steel bearing box (w/ separate aluminum clamping collar), your rolling torque value is set using a "string pull spring scale" arrangement.
The string is wrapped around the BB, and then pulled via a quality spring scale.
The reading gives us our rolling torque value.

Do you just go by feel,
NO.... not without years and years of experience.... and even then... NO! :D

I ordered up all the seals and O-rings. Hopeing for a nice day in the near future so I can tilt the front of the boat down to fully lower the drive to pull the upper gearcase. Every time I get a little time the monsoons kick in.
It will also help if you pull the "set pin".
Click to expand...
 
OK..... apparently the SP-A/MT was available with the AQ131A and AQ131D.
This would be the later "A" transmission with the integral Aluminum BB and Clamping Collar (the one with the bumps on the side).

Make sure that your OEM work shop manual discusses this type of transmission BB rolling torque value.

BTW, these are 30207 and 31307 industry standard bearings.


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Thanks Rick yea all I have is the clymer crap manual and is sparce on the gearbox specs. Would that be the same as the duoprop? Can I use stainless split rings and collar? A guy on ebay says he upgrades the gearboxes he rebuilds to stainless. Do you recommend a good manual as with the cost of parts I want to make damn sure it is right.
 
Rick I finally got around to disassembling the upper gearbox and found two issues. It needs both of the driven gear rollers and the keeper for the upper driveshaft was in poor shape also. Would it be wise to just replace the two driven gear ball bearings while it is apart? In checking there is quit alot of end play on the driveshaft with the new keeper on it and the bearings seem to be in good shape but the book says to replace if there is alot of end play on the verticle shaft. Is there a complete shim kit for a SP-A upper gearbox? The gears are in excellent shape thank god I am having trouble finding the one roller #183668
 
I finally got it back together thanks Rick. New bearings, crosses and reseal and no longer makes any noises and shifts nice and smooth. stoked!
 
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