1981Century
Member
Drive: AQ280 PT
Engine: Volvo Penta AQ290A (GM V8)
Last year when I had the engine out to replace both PDS bearings, I had my upper gear housing off the drive to work on bearing crosses and examine internals.
Two things I noted, some of the shims had corrosion, namely the ones between the clamping ring and upper gear housing. I also had water ingress into the upper gear housing from a cut in the bellows which happened sometime in the 2019 season. Water made it past the sealing ring and around the outside of the double bearing box. Corrosion was present between the double bearing box and the clamping ring making it difficult to pull the double bearing box from the clamping ring. In retrospect, I should have replaced the corroded shims.
I'm going to take off the upper gear housing while its still cold out and bring it inside to further examine. I would like to replace the corroded shims, verify my bearing crosses are still looking good, and that the new bellows held up.
From my understanding, there is a procedure on the double bearing box related to shimming. I assume if I just replace existing shims with new shims of the same thickness, I should be ok but I want to make sure everything is in spec.
1. I see a prestressing procedure for the double bearing box. I never split the bearings apart on the box so I assume I can leave this alone.
2. I see a backlash procedure for the double bearing box set by shims between the double bearing box and gear housing. Not sure the best way to go about that.
3. I assume that once the backlash is set, I should verify the wear pattern on the gear teeth. Some guidance here would be appreciated.
4. I see clearances between the clamping ring and gear housing. I also see clearances that need to be set between the top cover and gear housing. Some guidance here would be appreciated.
5.Anything else I'm missing that can be done with the Upper Gear Housing removed, please let me know!
Obligatory Pic of the engine pulled out from last year!
Thank you
1981Century
Engine: Volvo Penta AQ290A (GM V8)
Last year when I had the engine out to replace both PDS bearings, I had my upper gear housing off the drive to work on bearing crosses and examine internals.
Two things I noted, some of the shims had corrosion, namely the ones between the clamping ring and upper gear housing. I also had water ingress into the upper gear housing from a cut in the bellows which happened sometime in the 2019 season. Water made it past the sealing ring and around the outside of the double bearing box. Corrosion was present between the double bearing box and the clamping ring making it difficult to pull the double bearing box from the clamping ring. In retrospect, I should have replaced the corroded shims.
I'm going to take off the upper gear housing while its still cold out and bring it inside to further examine. I would like to replace the corroded shims, verify my bearing crosses are still looking good, and that the new bellows held up.
From my understanding, there is a procedure on the double bearing box related to shimming. I assume if I just replace existing shims with new shims of the same thickness, I should be ok but I want to make sure everything is in spec.
1. I see a prestressing procedure for the double bearing box. I never split the bearings apart on the box so I assume I can leave this alone.
2. I see a backlash procedure for the double bearing box set by shims between the double bearing box and gear housing. Not sure the best way to go about that.
3. I assume that once the backlash is set, I should verify the wear pattern on the gear teeth. Some guidance here would be appreciated.
4. I see clearances between the clamping ring and gear housing. I also see clearances that need to be set between the top cover and gear housing. Some guidance here would be appreciated.
5.Anything else I'm missing that can be done with the Upper Gear Housing removed, please let me know!
Obligatory Pic of the engine pulled out from last year!
Thank you
1981Century